Gastric Volume and Antral Area in the Fasting State: A Meta-analysis of Individual Patient Data

BACKGROUND

Pulmonary aspiration of gastric content is a serious anesthetic complication. Gastric point-of-care ultrasound can determine the type and volume of gastric content when clinical information is equivocal. However, a cutoff value of either antral cross-sectional area or volume that may be considered as the upper limit of normal in fasting subjects is still controversial. The aim of this study is to characterize the distribution of baseline antral area and volume in fasting adult subjects and to identify an upper limit (95th percentile) of these distributions.

METHODS

The authors conducted a meta-analysis of individual participant data of primary studies from an academic research network of investigators collaborating in gastric ultrasound. Studies between January 2009 and December 2020 were included.

RESULTS

Twelve primary studies met inclusion criteria and were included in the analysis with a sample size of 1,203 subjects. The 95th percentile of area values (measured in the right lateral decubitus) was 9.9 cm2 (95% CI, 9.4 to 10.4), and of volume, 2.3 ml/kg (95% CI, 2.3 to 2.4). In addition, an antrum grade 0 or 1 indicates a 98% probability of an antral area below the 95th percentile.

CONCLUSIONS

An area of 10 cm2 measured in the right lateral decubitus could be a simple, data-driven upper limit of antral area that could serve as a surrogate of upper limit of normal gastric volume values in fasting adults. These results are limited by the highly selected sampling of the studies included.

EDITOR’S PERSPECTIVE

Factors associated with the use of psychedelics, ketamine and MDMA among sexual and gender minority youths in Canada: a machine learning analysis

BACKGROUND

Substance use is increasing among sexual and gender minority youth (SGMY). This increase may be due to changes in social norms and socialisation, or due to SGMY exploring the potential therapeutic value of drugs such as psychedelics. We identified predictors of psychedelics, MDMA and ketamine use.

METHODS

Data were obtained from 1414 SGMY participants who completed the ongoing longitudinal 2SLGBTQ+ Tobacco Project in Canada between November 2020 to January 2021. We examined the association between 80 potential features (including sociodemographic factors, mental health-related factors and substance use-related factors) with the use of psychedelics, MDMA and ketamine in the past year. Random forest classifier was used to identify the predictors most associated with reported use of these drugs.

RESULTS

18.1% of participants have used psychedelics in the past year; 21.9% used at least one of the three drugs. Cannabis and cocaine use were the predictors most strongly associated with any of these drugs, while cannabis, but not cocaine use, was the one most associated with psychedelic use. Other mental health and 2SLGBTQ+ stigma-related factors were also associated with the use of these drugs.

CONCLUSION

The use of psychedelics, MDMA and ketamine among 2SLGBTQ+ individuals appeared to be largely driven by those who used them together with other drugs. Depression scores also appeared in the top 10 factors associated with these illicit drugs, suggesting that there were individuals who may benefit from the potential therapeutic value of these drugs. These characteristics should be further investigated in future studies.

A Randomized Three-Arm Double-Blind Placebo-Controlled Study of Homeopathic Treatment of Children and Youth with Attention-Deficit/Hyperactivity Disorder

Objectives: Approximately 30% of children diagnosed with attention-deficit/hyperactivity disorder (ADHD), the most prevalent mental health disorder in children worldwide, do not respond to conventional pharmaceutical treatments. Previous studies of homeopathic treatment for ADHD have been inconclusive. The objectives of this study were to determine if there (a) is an overall effect of homeopathic treatment (homeopathic medicines plus consultation) in the treatment of ADHD; (b) are any specific effects the homeopathic consultation alone in the treatment of ADHD; and (c) are any specific effects of homeopathic medicines in the treatment of ADHD. Design: The design was a randomized double-blind placebo-controlled clinical trial. Setting/Location: Toronto, Canada. Subjects: Children aged 6-16 years diagnosed with ADHD. Interventions: Participants were randomized to one of three arms: Arm 1 (Remedy and Consultation); Arm 2 (Placebo and Consultation); or Arm 3 (Usual Care). Outcome Measures: Primary Outcome was the change of CGI-P T score between baseline and 28 weeks. Results: There was an improvement in ADHD symptoms as measured by the Conner 3 Global Index-Parent T-score in the two groups (Arms 1 and 2) that received consultations with a homeopathic practitioner when compared with the usual care control group (Arm 3). Parents of the children in the study who received homeopathic consultations (Arms 1 and 2) also reported greater coping efficacy compared with those receiving usual care (Arm 3). There was no difference in adverse events among the three study arms. Conclusions: In this study, homeopathic consultations provided over 8 months with the use of homeopathic remedy was associated with a decrease in ADHD symptoms in children aging 6-16 years when compared with usual treatment alone. Children treated with homeopathic consultations and placebo experienced a similar decrease in ADHD symptoms; however, this finding did not reach statistical significance when correcting for multiple comparisons. Homeopathic remedies in and of themselves were not associated with any change in ADHD symptoms. Clinical Trial Registration: This trial was registered on ClinicalTrials.gov; NCT02086864.

Association of delayed adequate antimicrobial treatment and organ dysfunction in pediatric bloodstream infections

BACKGROUND

Bloodstream infections (BSIs) are associated with significant mortality and morbidity, including multiple organ dysfunction. We explored if delayed adequate antimicrobial treatment for children with BSIs is associated with change in organ dysfunction as measured by PELOD-2 scores.

METHODS

We conducted a multicenter, retrospective cohort study of critically ill children <18 years old with BSIs. The primary outcome was change in PELOD-2 score between days 1 (index blood culture) and 5. The exposure variable was delayed administration of adequate antimicrobial therapy by ≥3 h from blood culture collection. We compared PELOD-2 score changes between those who received early and delayed treatment.

RESULTS

Among 202 children, the median (interquartile range) time to adequate antimicrobial therapy was 7 (0.8-20.1) hours; 124 (61%) received delayed antimicrobial therapy. Patients who received early and delayed treatment had similar baseline characteristics. There was no significant difference in PELOD-2 score changes from days 1 and 5 between groups (PELOD-2 score difference -0.07, 95% CI -0.92 to 0.79, p = 0.88).

CONCLUSIONS

We did not find an association between delayed adequate antimicrobial therapy and PELOD-2 score changes between days 1 and 5 from detection of BSI. PELOD-2 score was not sensitive for clinical effects of delayed antimicrobial treatment.

IMPACT

In critically ill children with bloodstream infections, there was no significant change in organ dysfunction as measured by PELOD-2 scores between patients who received adequate antimicrobial therapy within 3 h of their initial positive blood culture and those who started after 3 h. Higher PELOD-2 scores on day 1 were associated with larger differences in PELOD-2 scores between days 1 and 5 from index positive blood cultures. Further study is required to determine if PELOD-2 or alternative measures of organ dysfunction could be used as primary outcome measures in trials of antimicrobial interventions in pediatric critical care research.

Rates of pediatric emergency department visits vary according to neighborhood marginalization in Ottawa, Canada

OBJECTIVES

To determine the association between neighborhood marginalization and rates of pediatric ED visits in Ottawa, Ontario. Secondary objectives investigated if the association between neighborhood marginalization and rates varied by year, acuity, and distance to hospital.

METHODS

We calculated rates of pediatric ED visits per 1000 person-years for census dissemination areas within 100 km of the Children's Hospital of Eastern Ontario for patients < 18 years old from January 2018 through December 2020. The 2016 Ontario Marginalization Index categorized neighborhoods along quintiles of residential instability, material deprivation, ethnic concentration, and dependency. Generalized mixed-effects models determined the incidence rate ratios of pediatric ED visits for each quintile of marginalization; multivariate models were used to control for year of presentation and distance to hospital. Analysis was repeated for low versus high acuity ED visits.

RESULTS

There were 154,146 ED visits from patients in 2055 census dissemination areas within 100 km of CHEO from 2018 to 2020. After controlling for year and distance from hospital in multivariate analyses, there were higher rates of pediatric ED visits for dissemination areas with high residential instability, high material deprivation, and low ethnic concentration. These findings did not change according to visit acuity.

CONCLUSIONS

Neighborhood residential instability and material deprivation should be considered when locating alternatives to emergency care.

Machine learning models for predicting seizure outcome after MR-guided laser interstitial thermal therapy in children

OBJECTIVE

MR-guided laser interstitial thermal therapy (MRgLITT) is associated with lower seizure-free outcome but better safety profile compared to open surgery. However, the predictors of seizure freedom following MRgLITT remain uncertain. This study aimed to use machine learning to predict seizure-free outcome following MRgLITT and to identify important predictors of seizure freedom in children with drug-resistant epilepsy.

METHODS

This multicenter study included children treated with MRgLITT for drug-resistant epilepsy at 13 epilepsy centers. The authors used clinical data, diagnostic investigations, and ablation features to predict seizure-free outcome at 1 year post-MRgLITT. Patients from 12 centers formed the training cohort, and patients in the remaining center formed the testing cohort. Five machine learning algorithms were developed on the training data by using 10-fold cross-validation, and model performance was measured on the testing cohort. The models were developed and tested on the complete feature set. Subsequently, 3 feature selection methods were used to identify important predictors. The authors then assessed performance of the parsimonious models based on these important variables.

RESULTS

This study included 268 patients who underwent MRgLITT, of whom 44.4% had achieved seizure freedom at 1 year post-MRgLITT. A gradient-boosting machine algorithm using the complete feature set yielded the highest area under the curve (AUC) on the testing set (AUC 0.67 [95% CI 0.50-0.82], sensitivity 0.71 [95% CI 0.47-0.88], and specificity 0.66 [95% CI 0.50-0.81]). Logistic regression, random forest, support vector machine, and neural network yielded lower AUCs (0.58-0.63) compared to the gradient-boosting machine but the findings were not statistically significant (all p > 0.05). The 3 feature selection methods identified video-EEG concordance, lesion size, preoperative seizure frequency, and number of antiseizure medications as good prognostic features for predicting seizure freedom. The parsimonious models based on important features identified by univariate feature selection slightly improved model performance compared to the complete feature set.

CONCLUSIONS

Understanding the predictors of seizure freedom after MRgLITT will assist with prognostication.

Evaluating the Utility and Privacy of Synthetic Breast Cancer Clinical Trial Data Sets

PURPOSE

There is strong interest from patients, researchers, the pharmaceutical industry, medical journal editors, funders of research, and regulators in sharing clinical trial data for secondary analysis. However, data access remains a challenge because of concerns about patient privacy. It has been argued that synthetic data generation (SDG) is an effective way to address these privacy concerns. There is a dearth of evidence supporting this on oncology clinical trial data sets, and on the utility of privacy-preserving synthetic data. The objective of the proposed study is to validate the utility and privacy risks of synthetic clinical trial data sets across multiple SDG techniques.

METHODS

We synthesized data sets from eight breast cancer clinical trial data sets using three types of generative models: sequential synthesis, conditional generative adversarial network, and variational autoencoder. Synthetic data utility was evaluated by replicating the published analyses on the synthetic data and assessing concordance of effect estimates and CIs between real and synthetic data. Privacy was evaluated by measuring attribution disclosure risk and membership disclosure risk.

RESULTS

Utility was highest using the sequential synthesis method where all results were replicable and the CI overlap most similar or higher for seven of eight data sets. Both types of privacy risks were low across all three types of generative models.

DISCUSSION

Synthetic data using sequential synthesis methods can act as a proxy for real clinical trial data sets, and simultaneously have low privacy risks. This type of generative model can be one way to enable broader sharing of clinical trial data.

A Machine Learning Approach Reveals Distinct Predictors of Vaping Dependence for Adolescent Daily and Non-Daily Vapers in the COVID-19 Era

Since 2016, there has been a substantial rise in e-cigarette (vaping) dependence among young people. In this prospective cohort study, we aimed to identify the different predictors of vaping dependence over 3 months among adolescents who were baseline daily and non-daily vapers. We recruited ever-vaping Canadian residents aged 16-25 years on social media platforms and asked them to complete a baseline survey in November 2020. A validated vaping dependence score (0-23) summing up their responses to nine questions was calculated at the 3-month follow-up survey. Separate lasso regression models were developed to identify predictors of higher 3-month vaping dependence score among baseline daily and non-daily vapers. Of the 1172 participants, 643 (54.9%) were daily vapers with a mean age of 19.6 ± 2.6 years and 76.4% (n = 895) of them being female. The two models achieved adequate predictive performance. Place of last vape purchase, number of days a pod lasts, and the frequency of nicotine-containing vaping were the most important predictors for dependence among daily vapers, while race, sexual orientation and reporting treatment for heart disease were the most important predictors in non-daily vapers. These findings have implications for vaping control policies that target adolescents at different stages of vape use.

Number of epilepsy surgeries has decreased despite an increase in pre-surgical evaluations at a tertiary pediatric epilepsy center in Ontario

OBJECTIVE

A recent U.S. study reported that the number of epilepsy surgeries has remained stable or declined in recent years despite an increase in pre-surgical evaluation. This study aimed to evaluate trends in pre-surgical evaluation and epilepsy surgery from 2001 to 2019 and to determine whether these trends have changed in the later period (2014-2019) compared to earlier period (2001-2013).

METHODS

This study evaluated trends in pre-surgical evaluation and epilepsy surgery at a tertiary pediatric epilepsy center. Children with drug resistant epilepsy who were evaluated for surgery were included. Clinical data, reasons for not undergoing surgery, and surgical characteristics of surgery patients were collected. Overall trends and trends in later period compared to earlier period for pre-surgical evaluation and epilepsy surgery were assessed.

RESULTS

There were 1151 children who were evaluated for epilepsy surgery and 546 underwent surgery. There was an upward trend in pre-surgical evaluation in the earlier period (rate ratio [RR]=1.04 (95%CI:1.02-1.07), p<0.001) and the trajectory of presurgical evaluation in the later period was not significantly different to the earlier period (RR=1.00 [95%CI:0.95-1.06], p = 0.88). Among the reasons for not undergoing surgery, failure to localize the seizures occurred more frequently in later period than earlier period (22.6% vs. 17.1% respectively, p = 0.024). For number of surgeries, there was an upward trend between 2001 and 2013 (RR=1.08 [95%CI:1.05-1.11], p<0.001), and a decreasing trend in the later period compared to earlier period (RR=0.91 [95%CI:0.84-0.99], p = 0.029).

CONCLUSION

Despite an increasing trend in pre-surgical evaluation, there was a decreasing trend in the number of epilepsy surgery in the later period as there was a larger proportion of patients in whom the seizures could not be localized. Trends in presurgical evaluation and epilepsy surgery will continue to evolve with introduction of technologies such as stereo-EEG and minimally invasive laser therapy.

Abstract P6-05-43: Validity of EQ-5D-5L for women with breast cancer

Background: The EuroQol- 5 Dimension (EQ-5D) is a generic patient-reported outcome measure widely used to capture meaningful change in health-related quality of life between treatments to inform drug and health technology reimbursement decision making. We investigated the construct validity of EQ-5D-5L in women with breast cancer.

Methods: This study included adult women diagnosed with stage I to IV breast cancer, who completed the EQ-5D-5L and the Edmonton Symptom Assessment System (ESAS) during outpatient clinic visits at two academic cancer centres in Toronto. We evaluated construct validity through assessing known-group validity and convergent/divergent validity. For known-group validity, the primary analysis tested the hypothesis that EQ-5D-5L could adequately discriminate between patients with metastatic disease and early-stage disease; secondary analyses addressed utility values between women in breast-cancer associated health states. A suggested minimally important difference (MID) for the Canadian scoring of the EQ-5D-5L is 0.037; we evaluated whether the lower bound of the 95% confidence interval (95%CI) exceeded this value. In terms of convergent/divergent validity, the primary analysis tested the hypothesis that EQ-5D-5L mean utility values for each health state (HS) would be at least moderately correlated with ESAS total symptom distress score (SDS) (|r|&gt;0.30) using Wilcoxon rank-sum tests and Spearman’s correlation tests. Construct validity was considered as acceptable if the hypotheses of the primary analysis are satisfied.

Results: We recruited 549 women, 406 (74%) with early-stage disease and 143 (26%) with metastatic disease (HS5), with a mean age of 57 (SD 12); 412 (75%) had been diagnosed with breast cancer in the 7 years prior to recruitment and were receiving active treatment for their cancer. The mean utility value for early-stage breast cancer was 0.84 (95% CI 0.83-0.86) and for metastatic breast cancer (0.78, 95% CI 0.76-0.81). This difference was 0.060 (95% CI 0.036 to 0.085, p&lt; 0.001) with the lower bound of the confidence interval slightly less than the prespecified MID (0.037). There was no significant difference between the mean utility value for women in the first year after primary breast cancer diagnosis (HS1), and women in their second to fifth year after a primary breast cancer treated with curative intent (HS3) or between women in HS1 and women in their sixth and following years after a primary breast cancer treated with curative intent (HS4). EQ-5D-5L also did not discriminate between women in HS3 and HS4. For convergent/divergent validity, there was a negative correlation between utility values and ESAS physical, emotional and total SDSs. EQ-5D-5L and ESAS total SDSs correlation coefficients were higher than 0.30 for all health states.

Conclusion: EQ-5D-5L met criteria for convergent/divergent validity in women with breast cancer. The tests for discriminant validity were equivocal, suggesting more research is needed for assessing construct validity with a larger sample size.

Table 1. EQ-5D-5L Utility Values. N= number; Std Dev= standard deviation; IQR= interquartile range; CI= confidence interval

Citation Format: Sofia Torres, Maureen Trudeau, Geoffrey Liu, Nicholas Mitsakakis, Ahmed Bayoumi. Validity of EQ-5D-5L for women with breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-05-43.

Predicting the outcome of liver transplantation in patients with non-alcoholic steatohepatitis cirrhosis: The NASH LT risk-benefit calculator

BACKGROUND

Non-alcoholic Steatohepatitis (NASH) cirrhosis is the second most common indication for liver transplantation (LT) in the US and often is associated with significant co-morbidities. We validated a model and risk prediction score that reflects the benefit derived from LT for NASH cirrhosis by predicting 5-year survival post-LT.

METHODS

We developed a prediction score utilizing 6515 NASH deceased donor LT (DDLT) recipients from 2002 to 2019 from the Scientific Registry of Transplant Recipients (SRTR) database to identify a parsimonious set of independent predictors of survival. Coefficients of relevant recipient factors were converted to weighted points to construct a risk scoring system that was then externally validated.

RESULTS

The final risk score includes the following independent recipient predictors and corresponding points: recipient age (5 points for age ≥70 years), functional status (3 points for total assistance), presence of TIPSS (2 points), hepatic encephalopathy (1 point), serum creatinine (5 points if >1.45 mg/dl), need for mechanical ventilation (3 points), and dialysis within 1 week prior to LT (7 points). Diabetes is a stratifying variable for baseline risk. Scores range from 0 to 20 with scores above 13 having an overall survival of <65% at 5 years post-LT. Internal and external validation indicated good predictive ability.

CONCLUSION

Our practically useable and validated risk score helps to identify and stratify candidates who will derive the most long-term benefit from LT for NASH cirrhosis.

Disparities in health utilities among hepatitis C patients receiving care in different settings

BACKGROUND: Although chronic hepatitis C (CHC) disproportionately affects marginalized individuals, most health utility studies are conducted in hospital settings which are difficult for marginalized patients to access. We compared health utilities in CHC patients receiving care at hospital-based clinics and socio-economically marginalized CHC patients receiving care through a community-based program. METHODS: We recruited CHC patients from hospital-based clinics at the University Health Network and community-based sites of the Toronto Community Hep C Program, which provides treatment, support, and education to patients who have difficulty accessing mainstream health care. We elicited utilities using six standardized instruments (EuroQol-5D-3L [EQ-5D], Health Utilities Index Mark 2/Mark 3 [HUI2/HUI3], Short Form-6D [SF-6D], time trade-off [TTO], and Visual Analogue Scale [VAS]). Multivariable regression analysis was performed to examine factors associated with differences in health utility. RESULTS: Compared with patients recruited from the hospital setting (n = 190), patients recruited from the community setting (n = 101) had higher unemployment (87% versus 67%), history of injection drug use (88% versus 42%), and history of mental health issue(s) (79% versus 46%). Unadjusted health utilities were lower in community than hospital patients (e.g., EQ-5D: 0.722 [SD 0.209] versus 0.806 [SD 0.195]). Unemployment and a history of mental health issue(s) were significant predictors of low health utility. CONCLUSIONS: Socio-economically marginalized CHC patients have lower health utilities than patients typically represented in the CHC utility literature. Their utilities should be incorporated into future cost-utility analyses to better represent the population living with CHC in health policy decisions.

Severe iron deficiency anemia in the paediatric emergency department: A retrospective study

Background

Transfusion is discouraged in hemodynamically stable children with severe iron deficiency anemia (IDA). Intravenous (IV) iron sucrose (IS) could be an alternative for some patients; however, there is a paucity of data on its use in the paediatric emergency department (ED).

Methods

We analyzed patients presenting with severe IDA at the Children's Hospital of Eastern Ontario (CHEO) ED between September 1, 2017, and June 1, 2021. We defined severe IDA as microcytic anemia <70 g/L and either a ferritin <12 ng/mL or a documented clinical diagnosis.

Results

Of 57 patients, 34 (59%) presented with nutritional IDA and 16 (28%) presented with IDA secondary to menstrual bleeding. Fifty-five (95%) patients received oral iron. Thirteen (23%) patients additionally received IS and after 2 weeks, the average Hgb was similar to transfused patients. The median time for patients receiving IS without PRBC transfusion to increase their Hgb by at least 20 g/L was 7 days (95%CI 0.7 to 10.5 days). Of 16 (28%) children who were transfused with PRBC, there were three mild reactions, and one patient who developed transfusion associated circulatory overload (TACO). There were two mild and no severe reactions to IV iron. There were no return visits to the ED due to anemia in the following 30 days.

Conclusions

Management of severe IDA with IS was associated with a rapid rise in Hgb without severe reactions or returns to ED. This study highlights a strategy for management of severe IDA in hemodynamically stable children that spares them the risks associated with PRBC transfusion. Paediatric specific guidelines and prospective studies are needed to guide the use of IV iron in this population.

Seizure outcome of pediatric magnetic resonance-guided laser interstitial thermal therapy versus open surgery: A matched noninferiority cohort study

OBJECTIVE

Minimally invasive magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) has been proposed as an alternative to open epilepsy surgery, to address concerns regarding the risk of open surgery. Our primary hypothesis was that seizure freedom at 1 year after MRgLITT is noninferior to open surgery in children with drug-resistant epilepsy (DRE). The secondary hypothesis was that MRgLITT has fewer complications and shorter hospitalization than surgery. The primary objective was to compare seizure outcome of MRgLITT to open surgery in children with DRE. The secondary objective was to compare complications and length of hospitalization of the two treatments.

METHODS

This retrospective multicenter cohort study included children with DRE treated with MRgLITT or open surgery with 1-year follow-up. Exclusion criteria were corpus callosotomy, neurostimulation, multilobar or hemispheric surgery, and lesion with maximal dimension > 60 mm. MRgLITT patients were propensity matched to open surgery patients. The primary outcome was seizure freedom at 1 year posttreatment. The difference in seizure freedom was compared using noninferiority test, with noninferiority margin of -10%. The secondary outcomes were complications and length of hospitalization.

RESULTS

One hundred eighty-five MRgLITT patients were matched to 185 open surgery patients. Seizure freedom at 1 year follow-up was observed in 89 of 185 (48.1%) MRgLITT and 114 of 185 (61.6%) open surgery patients (difference = -13.5%, one-sided 97.5% confidence interval = -23.8% to ∞, p_{Noninferiority}  = .79). The lower confidence interval boundary of -23.8% was below the prespecified noninferiority margin of -10%. Overall complications were lower in MRgLITT compared to open surgery (10.8% vs. 29.2%, respectively, p < .001). Hospitalization was shorter for MRgLITT than open surgery (3.1 ± 2.9 vs. 7.2 ± 6.1 days, p < .001).

SIGNIFICANCE

Seizure outcome of MRgLITT at 1 year posttreatment was inferior to open surgery. However, MRgLITT has the advantage of better safety profile and shorter hospitalization. The findings will help counsel children and parents on the benefits and risks of MRgLITT and contribute to informed decision-making on treatment options.

Machine learning applications in tobacco research: a scoping review

OBJECTIVE

Identify and review the body of tobacco research literature that self-identified as using machine learning (ML) in the analysis.

DATA SOURCES

MEDLINE, EMABSE, PubMed, CINAHL Plus, APA PsycINFO and IEEE Xplore databases were searched up to September 2020. Studies were restricted to peer-reviewed, English-language journal articles, dissertations and conference papers comprising an empirical analysis where ML was identified to be the method used to examine human experience of tobacco. Studies of genomics and diagnostic imaging were excluded.

STUDY SELECTION

Two reviewers independently screened the titles and abstracts. The reference list of articles was also searched. In an iterative process, eligible studies were classified into domains based on their objectives and types of data used in the analysis.

DATA EXTRACTION

Using data charting forms, two reviewers independently extracted data from all studies. A narrative synthesis method was used to describe findings from each domain such as study design, objective, ML classes/algorithms, knowledge users and the presence of a data sharing statement. Trends of publication were visually depicted.

DATA SYNTHESIS

74 studies were grouped into four domains: ML-powered technology to assist smoking cessation (n=22); content analysis of tobacco on social media (n=32); smoker status classification from narrative clinical texts (n=6) and tobacco-related outcome prediction using administrative, survey or clinical trial data (n=14). Implications of these studies and future directions for ML researchers in tobacco control were discussed.

CONCLUSIONS

ML represents a powerful tool that could advance the research and policy decision-making of tobacco control. Further opportunities should be explored.

Correlates of wanting to seek help for mental health and substance use concerns by sexual and gender minority young adults during the COVID-19 pandemic: A machine learning analysis

The COVID-19 pandemic has worsened the mental health and substance use challenges among many people who are Two Spirit, lesbian, gay, bisexual, transgender, queer, questioning, and intersex (2SLGBTQI+). We aimed to identify the important correlates and their effects on the predicted likelihood of wanting to seek help among 2SLGBTQI+ young adults for mental health or substance use concerns during the pandemic. A cross-sectional survey was conducted in 2020-2021 among 2SLGBTQI+ young adults aged 16-29 living in two Canadian provinces (Ontario and Quebec). Among 1414 participants, 77% (n = 1089) wanted to seek help for their mental health or substance use concerns during the pandemic, out of these, 69.8% (n = 760) reported delay in accessing care. We built a random forest (RF) model to predict the status of wanting to seek help, which achieved moderately high performance with an area under the receiver operating characteristic curve (AUC) of 0.85. The top 10 correlates of wanting to seek help were worsening mental health, age, stigma and discrimination, and adverse childhood experiences. The interactions of adequate housing with certain sexual orientations, gender identities and mental health challenges were found to increase the likelihood of wanting to seek help. We built another RF model for predicting risk of delay in accessing care among participants who wanted to seek help (n = 1089). The model identified a similar set of top 10 correlates of delay in accessing care but lacked adequate performance (AUC 0.61). These findings can direct future research and targeted prevention measures to reduce health disparities for 2SLGBTQI+ young adults.

Salivary testing for SARS-CoV-2 in the pediatric population: a diagnostic accuracy study

BACKGROUND

Accurate and timely testing for SARS-CoV-2 in the pediatric population is crucial to control the COVID-19 pandemic; saliva testing has been proposed as a less invasive alternative to nasopharyngeal swabs. We sought to compare the detection of SARS-CoV-2 using saliva versus nasopharyngeal swab in the pediatric population, and to determine the optimum time of testing for SARS-CoV-2 using saliva.

METHODS

We conducted a longitudinal diagnostic study in Ottawa, Canada, from Jan. 19 to Mar. 26, 2021. Children aged 3-17 years were eligible if they exhibited symptoms of COVID-19, had been identified as a high-risk or close contact to someone confirmed positive for SARS-CoV-2 or had travelled outside Canada in the previous 14 days. Participants provided both nasopharyngeal swab and saliva samples. Saliva was collected using a self-collection kit (DNA Genotek, OM-505) or a sponge-based kit (DNA Genotek, ORE-100) if they could not provide a saliva sample into a tube.

RESULTS

Among 1580 paired nasopharyngeal and saliva tests, 60 paired samples were positive for SARS-CoV-2. Forty-four (73.3%) were concordant-positive results and 16 (26.6%) were discordant, among which 8 were positive only on nasopharyngeal swab and 8 were positive only on saliva testing. The sensitivity of saliva was 84.6% (95% confidence interval 71.9%-93.1%).

INTERPRETATION

Salivary testing for SARS-CoV-2 in the pediatric population is less invasive and shows similar detection of SARS-CoV-2 to nasopharyngeal swabs. It may therefore provide a feasible alternative for diagnosis of SARS-CoV-2 infection in children.

Correlates of past year suicidal thoughts among sexual and gender minority young adults: A machine learning analysis

Sexual and gender minority populations are at elevated risk of experiencing suicidal thoughts and attempting suicide. The COVID-19 pandemic exacerbated mental health and substance use challenges among this population. We aimed to examine the relative importance and effects of intersectional factors and strong interactions associated with the risk of suicidal thoughts among Canadian lesbian, gay, bisexual, transgender, queer, questioning, intersex and Two Spirit (LGBTQI2S+) young adults. A cross-sectional online survey was conducted among LGBTQI2S + participants aged 16-29 years living in two Canadian provinces (Ontario, Quebec). Among 1414 participants (mean age 21.90 years), 61% (n = 857) participants reported suicidal thoughts in last 12 months. We built a random forest model to predict the risk of having past year suicidal thoughts, which achieved high performance with an area under the receiver operating characteristic curve (AUC) of 0.84. The top 10 correlates identified were: seeking help from health professionals for mental health or substance use issues since the start of the pandemic, current self-rated mental health status, insulted by parents or adults in childhood, ever heard that being identifying as LGBTQI2S+ is not normal, age in years, past week feeling depressed, lifetime diagnosis of mental illness, lifetime diagnosis of depressive disorder, past week feeling sad, ever pretended to be straight or cisgender to be accepted. The increase in the risk of suicidal thoughts for those having mental health challenges or facing minority stressors is more pronounced in those living in urban areas or being unemployed than those living in rural areas or being employed.

Factors associated with hypothermia within the first 6 hours of life in infants born at ≥340 weeks' gestation: a multivariable analysis

BACKGROUND

Lack of appropriate temperature management has been associated with significant adverse outcomes in preterm and low birthweight neonates. There is a lack of similar investigations in the late preterm (34⁰-36⁶) and term (≥37⁰) neonate population. Our aim was to identify key risk factors as well as clinical outcomes associated with hypothermia in this population.

METHODS

A retrospective chart review was conducted at the Ottawa Hospital including all eligible infants ≥34⁰ weeks' gestation over a one-month period in November 2020. Infant, maternal, and delivery room variables were collected, including prematurity, maternal temperature, delivery mode, birthweight, and premature rupture of membranes, as well as clinical outcomes such as NICU/SCN admission and length of stay. Regression models were generated, adjusted for covariates, and stepwise regression was performed.

RESULTS

Four hundred forty infants were included in the analysis; 26.8% (118/440) were hypothermic within 6 hours of delivery. In the multivariable analysis, prematurity, low 5 minute Apgar score (< 7) or need for resuscitation, maternal hypertension, and absence of premature rupture of membranes > 18 hours or suspected maternal infection were significantly associated with hypothermia within 6 hours of delivery (p < 0.05). Multivariable analysis of clinical outcomes demonstrated a significant association between hypothermia within 6 hours of delivery and NICU/SCN admission (OR = 2.87; 95% CI 1.36, 6.04), need for respiratory support or diagnosis of respiratory distress syndrome (OR = 3.94; 95% CI 1.55, 10.50), and length of stay (exp(β) = 1.20; 95% bootstrap CI 1.04, 1.37).

CONCLUSIONS

Our results suggest there are similar factors associated with hypothermia in our study population of infants born at ≥34⁰ weeks' gestation compared to prior studies in preterm and low-birthweight infants. Furthermore, hypothermia is associated with higher risk of adverse outcomes, which highlights the need to prevent hypothermia in all newborns.

Developing the Breast Utility Instrument to Measure Health-Related Quality-of-Life Preferences in Patients with Breast Cancer: Selecting the Item for Each Dimension

Introduction. Generic preference-based instruments inadequately measure breast cancer (BrC) health-related quality-of-life preferences given advances in therapy. Our overall purpose is to develop the Breast Utility Instrument (BUI), a BrC-specific preference-based instrument. This study describes the selection of the BUI items. Methods. A total of 408 patients from diverse BrC health states completed the EORTC QLQ-C30 and BR45 (breast module). For each of 10 dimensions previously assessed with confirmatory factor analysis, we evaluated data fit to the Rasch model based on global model and item fit, including threshold ordering, item residuals, infit and outfit, differential item functioning (age), and unidimensionality. Misfitting items were removed iteratively, and the model fit was reassessed. From items fitting the Rasch model, we selected 1 item per dimension based on high patient- and clinician-rated item importance, breadth of item thresholds, and clinical relevance. Results. Global model fit was good in 7 and borderline in 3 dimensions. Separation index was acceptable in 4 dimensions. Item selection criteria were maximized for the following items: 1) physical functioning (trouble taking a long walk), 2) emotional functioning (worry), 3) social functioning (interfering with social activities), 4) pain (having pain), 5) fatigue (tired), 6) body image (dissatisfied with your body), 7) systemic therapy side effects (hair loss), 8) sexual functioning (interest in sex), 9) breast symptoms (oversensitive breast), and 10) endocrine therapy symptoms (problems with your joints). Conclusions. We propose 10 items for the BUI. Our next steps include assessing the measurement properties prior to eliciting preference weights of the BUI.

Highlights

A previous confirmatory factor analysis established 10 dimensions of the European Organisation for Research and Treatment of Cancer (EORTC) core quality of life questionnaire (QLQ-C30) and its breast module (BR45). In this study, we selected 1 item per dimension based on fit to the Rasch model, patient- and clinician-rated item importance, breadth of item thresholds, and clinical relevance. These items form the core of the future Breast Utility Instrument (BUI). The future BUI will be a novel breast cancer–specific preference-based instrument that potentially will better reflect women’s preferences in clinical decision making and cost utility analyses.

A longitudinal analysis of early lung function trajectory in survivors of childhood Hodgkin lymphoma

BACKGROUND

Childhood Hodgkin lymphoma survivors suffer from long-term effects decades after treatment completion with a prevalence of pulmonary dysfunction of up to 65.2%.

AIMS

This study explored the early trajectory of pulmonary function in pediatric cancer patients with Hodgkin lymphoma who received pulmonary toxic therapy.

METHODS AND RESULTS

In this single-center, 20-year retrospective cohort study, we included patients who were <18 years old at diagnosis of Hodgkin lymphoma between January 1994 and December 2014, and received bleomycin or thoracic radiation. We measured pulmonary function and reported on percent predicted values for forced expiratory volume in 1 s, total lung capacity, and diffusing capacity of the lungs. We used linear mixed models to identify the association of clinical factors with longitudinal changes in lung function at time points before and after treatment completion. Of 80 children who met inclusion criteria, all were treated with bleomycin, and 83.8% received thoracic radiation. More than half (51.2%) of patients had any abnormalities in lung function measures during the study observation period which averaged 24.2 months (±31.1SD). Females, younger age at diagnosis and treatment with radiation were associated with lower lung function measurements at various time points. While the majority of children experienced a recovery of their lung function within 1-2 years after treatment completion, some children with these risk factors did not.

CONCLUSION

Pulmonary function abnormalities begin early in children treated for Hodgkin lymphoma. While the majority of children demonstrate a slow and continuous improvement in lung function back to baseline over time, we recommend routine asymptomatic screening of pulmonary function in certain childhood cancer survivors, particularly females, those diagnosed young and patients who received radiation therapy.

Development and validation of machine learning models for prediction of seizure outcome after pediatric epilepsy surgery

OBJECTIVE

There is substantial variability in reported seizure outcome following pediatric epilepsy surgery, and lack of individualized predictive tools that could evaluate the probability of seizure freedom postsurgery. The aim of this study was to develop and validate a supervised machine learning (ML) model for predicting seizure freedom after pediatric epilepsy surgery.

METHODS

This is a multicenter retrospective study of children who underwent epilepsy surgery at five pediatric epilepsy centers in North America. Clinical information, diagnostic investigations, and surgical characteristics were collected, and used as features to predict seizure-free outcome 1 year after surgery. The dataset was split randomly into 80% training and 20% testing data. Thirty-five combinations of five feature sets with seven ML classifiers were assessed on the training cohort using 10-fold cross-validation for model development. The performance of the optimal combination of ML classifier and feature set was evaluated in the testing cohort, and compared with logistic regression, a classical statistical approach.

RESULTS

Of the 801 patients included, 61.3% were seizure-free 1 year postsurgery. During model development, the best combination was XGBoost ML algorithm with five features from the univariate feature set, including number of antiseizure medications, magnetic resonance imaging lesion, age at seizure onset, video-electroencephalography concordance, and surgery type, with a mean area under the curve (AUC) of .73 (95% confidence interval [CI] = .69-.77). The combination of XGBoost and univariate feature set was then evaluated on the testing cohort and achieved an AUC of .74 (95% CI = .66-.82; sensitivity = .87, 95% CI = .81-.94; specificity = .58, 95% CI = .47-.71). The XGBoost model outperformed the logistic regression model (AUC = .72, 95% CI = .63-.80; sensitivity = .72, 95% CI = .63-.82; specificity = .66, 95% CI = .53-.77) in the testing cohort (p = .005).

SIGNIFICANCE

This study identified important features and validated an ML algorithm, XGBoost, for predicting the probability of seizure freedom after pediatric epilepsy surgery. Improved prognostication of epilepsy surgery is critical for presurgical counseling and will inform treatment decisions.

Noninferiority Margin Size and Acceptance of Trial Results: Contingent Valuation Survey of Clinician Preferences for Noninferior Mortality

Objectives

We used modified contingent valuation methodology to determine how noninferiority margin sizes influence clinicians’ willingness to accept clinical trial results that compare mortality in critically ill children.

Methods

We surveyed pediatric infectious diseases and critical care clinicians in Canada, Australia, and New Zealand and randomized respondents to review 1 of 9 mock abstracts describing a noninferiority trial of bacteremic critically ill children assigned to 7 or 14 d of antibiotics. Each scenario showed higher mortality in the 7-d group but met noninferiority criterion. We explored how noninferiority margins and baseline mortality rates influenced respondent acceptance of results.

Results

There were 106 survey respondents: 65 (61%) critical care clinicians, 28 (26%) infectious diseases physicians, and 13 (12%) pharmacists. When noninferiority margins were 5% and 10%, 73% (24/33) and 79% (27/33) respondents would accept shorter treatment, compared with 44% (17/39) when the margin was 20% (P = 0.003). Logistic regression adjusted for baseline mortality showed 5% and 10% noninferiority margins were more likely to be associated with acceptance of shorter treatment compared with 20% margins (odds ratio [OR] 3.5, 95% confidence interval [CI]: 1.3–9.6, P = 0.013; OR 5.1, 95% CI: 1.8–14.6, P = 0.002). Baseline mortality was not a significant predictor of acceptance of shorter treatment.

Conclusions

Clinicians are more likely to accept shorter treatment when noninferiority margins are ≤10%. However, nearly half of respondents who reviewed abstracts with 20% margins were still willing to accept shorter treatment. This is a novel application of contingent valuation methodology to elicit acceptance of research results among end users of the medical literature.

Highlights

Antimicrobial treatment duration for uncomplicated bloodstream infections in critically ill children: a multicentre observational study

Background

Bloodstream infections (BSIs) cause significant morbidity and mortality in critically ill children but treatment duration is understudied. We describe the durations of antimicrobial treatment that critically ill children receive and explore factors associated with treatment duration.

Methods

We conducted a retrospective observational cohort study in six pediatric intensive care units (PICUs) across Canada. Associations between treatment duration and patient-, infection- and pathogen-related characteristics were explored using multivariable regression analyses.

Results

Among 187 critically ill children with BSIs, the median duration of antimicrobial treatment was 15 (IQR 11–25) days. Median treatment durations were longer than two weeks for all subjects with known sources of infection: catheter-related 16 (IQR 11–24), respiratory 15 (IQR 11–26), intra-abdominal 20 (IQR 14–26), skin/soft tissue 17 (IQR 15–33), urinary 17 (IQR 15–35), central nervous system 33 (IQR 15–46) and other sources 29.5 (IQR 15–55) days. When sources of infection were unclear, the median duration was 13 (IQR 10–16) days. Treatment durations varied widely within and across PICUs. In multivariable linear regression, longer treatment durations were associated with severity of illness (+ 0.4 days longer [95% confidence interval (CI), 0.1 to 0.7, p = 0.007] per unit increase in PRISM-IV) and central nervous system infection (+ 17 days [95% CI, 6.7 to 27.4], p = 0.001). Age and pathogen type were not associated with treatment duration.

Conclusions

Most critically ill children with BSIs received at least two weeks of antimicrobial treatment. Further study is needed to determine whether shorter duration therapy would be effective for selected critically ill children.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03219-z.

Predicting Long-term Survival After Liver Transplantation in Patients With NASH Cirrhosis

Nonalcoholic steatohepatitis (NASH) cirrhosis is the second most common indication for liver transplantation (LT) in the United States.¹ Patients are increasingly older at presentation, with higher rates of metabolic syndrome, obesity, hyperlipidemia, diabetes mellitus, and renal failure.² They are also at higher risk of cardiovascular events and mortality while on the waiting list¹ and in the post-transplant period.^3,4 We sought to identify predictors of long-term benefit based on 5-year survival post-LT in NASH cirrhosis, thereby delineating those patients that derive a clear benefit from LT versus those in whom LT may be futile.

Developing the Breast Utility Instrument, a preference-based instrument to measure health-related quality of life in women with breast cancer: Confirmatory factor analysis of the EORTC QLQ-C30 and BR45 to establish dimensions

OBJECTIVES

Breast cancer (BrC) and its treatments impair health-related quality of life (HRQoL). Utility is a measure of HRQoL that includes preferences for health outcomes, used in treatment decision-making. Generic preference-based instruments lack BrC-specific concerns, indicating the need for a BrC-specific preference-based instrument. Our objective was to determine dimensions of the European Organisation for Research and Treatment of Cancer (EORTC) general cancer (QLQ-C30) and breast module (BR45) instruments, the first step in our development of the novel Breast Utility Instrument (BUI).

METHODS

Patients (n = 408) attending outpatient BrC clinics at an urban cancer centre, and representing a spectrum of BrC health states, completed the QLQ-C30 and BR45. We performed confirmatory factor analysis of the combined QLQ-C30 and BR45 using mean-and variance-adjusted unweighted least squares estimation. The hypothesized factor model was based on clinical relevance, item distributions, missing data, item-importance, and internal reliability of dimensions. Models were evaluated based on global and item fit, local areas of strain, and likelihood ratio tests of nested models.

RESULTS

Our final model had 10 dimensions: physical and role functioning, emotional functioning, social functioning, body image, pain, fatigue, systemic therapy side effects, sexual functioning and enjoyment, arm and breast symptoms, and endocrine therapy symptoms. Good overall model fit was achieved: χ2/df: 1.45, Tucker-Lewis index: 0.946, comparative fit index: 0.951, standardized root-mean-square residual: 0.069, root-mean-square error of approximation: 0.033 (0.030-0.037). All items had salient factor loadings (λ>0.4, p<0.001).

CONCLUSIONS

We identified important BrC HRQoL dimensions to develop the BUI, a BrC-specific preference-based instrument.

Abstract P4-10-22: Patient reported symptoms and functional status in breast cancer

Background: To improve symptom management in cancer patients, the province of Ontario (Canada) implemented the collection of the Edmonton Symptom Assessment System (ESAS) and Patient-Reported Functional Status (PRFS) tool at cancer centre outpatient visits. ESAS measures 9 symptoms on a scale from 0 (no symptoms) to 10 (worst possible symptom); scores &gt; 4 (moderate to severe) require intervention. The PRFS tool is a version of the Eastern Cooperative Oncology Group performance status tool designed to be completed by the patient; scores range from 0 (“normal with no limitation”) to 4 (“pretty much bedridden, rarely out of bed”). Our main objective was to describe the symptom burden and functional status of breast cancer (BC) patients.Methods: This cross-sectional study included women with stage I-IV BC who completed the ESAS and the PRFS tool during outpatient clinic visits at 2 Toronto academic centres. ESAS and PRFS scores were described for 3 participant groups: women diagnosed with early-stage BC (ESBC= stages I-III) in the year prior to enrolment; women with ESBC diagnosed &gt; 1 year prior to enrolment; and women with metastatic BC. Multivariable logistic regression models were used to identify factors associated with ESAS scores &gt; 4 for each ESAS symptom. Covariates included age, comorbidity, BC subtype, disease group, previous surgery, and current systemic therapy. Results: Of 381 women, 107 (28%) were diagnosed with ESBC ≤ 1 year prior to enrolment; 171 (45%) were diagnosed with ESBC &gt; 1 year prior to enrolment; 103 (27%) had metastatic BC. Mean age was 57 (SD17) years. For ESBC, tiredness had the highest incidence of moderate to severe scores, followed by impaired well-being and anxiety (Table 1). For metastatic BC, impaired well-being had the highest incidence of moderate to severe symptoms, followed by tiredness and anxiety. More than 20% of metastatic BC patients had scores &gt; 4 for pain, drowsiness, shortness of breath and depression. Most reported PRFS scores of 0 (“Normal with no limitations”) or 1 (“Not my normal self, but able to be up and about with fairly normal activities”), but 17% of metastatic BC patients reported a PRFS of 2 (“Not feeling up to most things, but in bed or chair less than half the day”). A comorbidity score ≥1 was associated with moderate to severe depression (OR 2.0; 95%CI 1.1-3.7), lack of appetite (OR 3.1; 95%CI 1.4-6.6), shortness of breath (OR 2.6; 95%CI 1.3-5.2), tiredness (OR 2.0; 95%CI 1.2-3.3) and impaired well-being (OR 2.0; 95%CI 1.2-3.4). Metastatic BC was associated with moderate to severe scores for anxiety (OR 2.3; 95%CI 1.2-4.5), pain (OR 3.0; 95%CI 1.4-6.4) and impaired well-being (OR 2.1; 95%CI 1.1-4.0). Conclusion: A high prevalence of symptom scores &gt; 4 was found both in ESBC and metastatic BC, highlighting the need of symptom screening for all BC patients. Particular attention should be paid to patients with comorbidity scores ≥ 1, who have increased odds of presenting higher symptom scores.

Table 1.- Prevalence of ESAS scores ≥ 4 and PRFS scores for each disease group.ESAS SymptomsPercent with ESAS scores ≥ 4 (moderate to severe)Early-Stage Breast Cancer – 1st year (N=107)Early-Stage Breast Cancer – &gt; 1st year (N=171)Metastatic Breast Cancer (N=103)Total (N=381)Pain12.1%14.7%30.1%18.2%Tiredness25.2%30.1%39.8%31.3%Drowsiness1.8%12.9%25.2%16.6%Nausea9.4%3.5%7.8%4.2%Lack of Appetite10.3%7.1%13.6%9.5%Shortness of Breath14%7.6%22.3%12.4%Depression17.7%14.6%22.6%16.5%Anxiety24.3%17.2%35.3%21.3%Well-being1.8%25.7%44.1%30.3%PRFS scoresPercent with PRFS ScoreNormal with no limitations (0)30.8%49.7%28.2%38.6%Not my normal self, but able to be up and about with fairly normal activities (1)52.3%42.1%50.5%47.2%Not feeling up to most things, but in bed or chair less than half the day (2)12.2%4.7%16.5%10%Able to do little activity and spend most of the day in bed or chair (3)3.7%2.3%4.9%3.4%Pretty much bedridden, rarely out of bed (4)----

Citation Format: Sofia Torres, Ahmed Bayoumi, Geoffrey Liu, Ana Beatriz Kinupe Abrahao, Nicholas Mitsakakis, Murray Krahn, Maureen Trudeau. Patient reported symptoms and functional status in breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-10-22.

Abstract P4-12-11: Eq-5d-5l utility scores for patients with breast cancer

Background: The EuroQol- 5 Dimension (EQ-5D) is a generic patient-reported outcome measure widely used to capture meaningful change in health-related quality of life between treatments to inform drug and health technology reimbursement decision making. The EQ-5D-5L (5 level) consists of 5 dimensions (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression) and a visual analogue scale (VAS). Each dimension has 5 levels, ranging from 1 “no problems” to 5 “extreme problems”, generating 3125 distinct health states (HS). The VAS score ranges from 0 (worst health imaginable) to 100 (best health imaginable). We used Canadian Index values to calculate community-weighted utility scores for 5 pre-defined breast cancer (BC) disease states.Methods: This cross-sectional study included adult women diagnosed with stage I to IV BC, who completed EQ-5D-5L, during outpatient clinic visits at two academic cancer centres in Toronto. Participants were classified into 5 disease states, considered relevant both to clinical practice and economic modeling, ranging from primary breast cancer to metastatic disease. EQ-5D-5L scores were described for each disease state, and mean utility scores and VAS scores were calculated.Results: 549 women were included; the mean age was 57 (SD 12) years; 72% had a Charlson Comorbidity Index of 0. A majority reported “Slight” to “Moderate” problems for the “Pain/Discomfort” (60%) and “Anxiety/Depression” (55%) dimensions of EQ-5D-5L; in all other dimensions, most patients reported “No problems”. As expected, patients with metastatic BC had the highest proportion of reported problems. The mean EQ-5D-5L index score was 0.83 (SD 0.13; range 0.36 to 0.95), with a distribution skewed towards full health and a ceiling effect of 20% (n=110; Table 1). Only 126 different self-reported health states were observed in our patient population. Mean VAS was 75 (SD 17.5; range 10 to 100). For early BC, mean index scores were: 0.87 (n=49; SD 0.07) for patients on chemotherapy (+/-targeted therapy); 0.85 (n=212; SD 0.12) for patients on endocrine treatment (+/-targeted therapy); 0.79 (n=16; SD 16) for patients on targeted therapy; and 0.84 (n=129; SD 0.14) for patients not receiving systemic therapy. For metastatic BC, mean index scores were: 0.79 (n=36, SD 14) for patients on chemotherapy (+/-targeted therapy); 0.80 (n=79, SD 0.14) for patients on endocrine treatment (+/-targeted therapy); 0.69 (n=8; SD 0.19) for patients on targeted therapy; and 0.77 (n=20; SD 0.14) for patients not receiving systemic therapy.Conclusions: BC had an impact mainly in the “Pain/Discomfort” and “Anxiety/Depression” dimensions of EQ-5D-5L. A high ceiling effect was observed in this patient population, despite using the 5L version of EQ-5D. EQ-5D-5L health utilities were significantly lower for metastatic BC, but no significant differences were found among various early-stage BC states.

Table 1.- Mean EQ-5D-5L Index and VAS scoresEQ-5D-5LIndex ScoresVASDisease StateN (%)Mean (SD)Min-MaxMean (SD)Min-Max1st year after primary BC146 (27)0.85 (0.12)*0.23-0.9576.5(16.6)10-1001st year after recurrence or primary BC13 (2)0.78 (0.21)0.13-0.9568.9(23.3)20-1002nd-5th year after a primary BC or recurrence treated with curative intent185 (34)0.84 (0.11)*0.21-0.9578.3(14.7)36-1006th and following years after a primary BC or recurrence treated with curative intent62 (11)0.86 (0.14)*0.36-0.9581.0(15.6)20-100Metastatic BC143 (26)0.78 (0.14)0.29-0.9567.3(19.2)21-100Total549 (100)0.83 (0.13)0.13-0.9575.0(17.5)10-100*significant difference was found between these disease states and metastatic diseases (P &lt; 0.05).

Citation Format: Sofia Torres, Ahmed Bayoumi, Maureen Trudeau, Ana Beatriz Kinupe Abrahao, Nicholas Mitsakakis, Murray Krahn, Geoffrey Liu. Eq-5d-5l utility scores for patients with breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-12-11.

Time Costs and Out-of-Pocket Costs in Patients With Chronic Hepatitis C in a Publicly Funded Health System

OBJECTIVES

Chronic hepatitis C (CHC) infection affects more than 70 million people worldwide and imposes considerable health and economic burdens on patients and society. This study estimated 2 understudied components of the economic burden, patient out-of-pocket (OOP) costs and time costs, in patients with CHC in a tertiary hospital clinic setting and a community clinic setting.

METHODS

This was a multicenter, cross-sectional study with hospital-based (n = 174) and community-based (n = 101) cohorts. We used a standardized instrument to collect healthcare resource use, time, and OOP costs. OOP costs included patient-borne costs for medical services, nonprescription drugs, and nonmedical expenses related to healthcare visits. Patient and caregiver time costs were estimated using an hourly wage value derived from patient-reported employment income and, where missing, derived from the Canadian census. Sensitivity analysis explored alternative methods of valuing time. Costs were reported in 2020 Canadian dollars.

RESULTS

The mean 3-month OOP cost was $55 (95% confidence interval [CI] $21-$89) and $299 (95% CI $170-$427) for the community and hospital cohorts, respectively. The mean 3-month patient time cost was $743 (95% CI $485-$1002) (community) and $465 (95% CI $248-$682) (hospital). The mean 3-month caregiver time cost was $31 (95% CI $0-$63) (community) and $277 (95% CI $174-$380) (hospital). Patients with decompensated cirrhosis bore the highest costs.

CONCLUSIONS

OOP costs and patient and caregiver time costs represent a considerable economic burden to patient with CHC, equivalent to 14% and 21% of the reported total 3-month income for the hospital-based and community-based cohorts, respectively.

Predictors of perceived success in quitting smoking by vaping: A machine learning approach

Prior research has suggested that a set of unique characteristics may be associated with adult cigarette smokers who are able to quit smoking using e-cigarettes (vaping). In this cross-sectional study, we aimed to identify and rank the importance of these characteristics using machine learning. During July and August 2019, an online survey was administered to a convenience sample of 889 adult smokers (age ≥ 20) in Ontario, Canada who tried vaping to quit smoking in the past 12 months. Fifty-one person-level characteristics, including a Vaping Experiences Score, were assessed in a gradient boosting machine model to classify the status of perceived success in vaping-assisted smoking cessation. This model was trained using cross-validation and tested using the receiver operating characteristic (ROC) curve. The top five most important predictors were identified using a score between 0% and 100% that represented the relative importance of each variable in model training. About 20% of participants (N = 174, 19.6%) reported success in vaping-assisted smoking cessation. The model achieved relatively high performance with an area under the ROC curve of 0.865 and classification accuracy of 0.831 (95% CI [confidence interval] 0.780 to 0.874). The top five most important predictors of perceived success in vaping-assisted smoking cessation were more positive experiences measured by the Vaping Experiences Score (100%), less previously failed quit attempts by vaping (39.0%), younger age (21.9%), having vaped 100 times (16.8%), and vaping shortly after waking up (15.8%). Our findings provide strong statistical evidence that shows better vaping experiences are associated with greater perceived success in smoking cessation by vaping. Furthermore, our study confirmed the strength of machine learning techniques in vaping-related outcomes research based on observational data.

Is Oral Contrast Beneficial for Visualization of the Appendix in Low-Weight Children?

Purpose: It has been shown that oral contrast does not improve the diagnostic accuracy of Computed Tomography (CT) for appendicitis in pediatric patients; however, the cohorts in these studies were not stratified by weight or body mass index. The purpose of this study is to assess the benefit of oral contrast administration for identifying the appendix in younger children in the lower weight quartile. Materials and Methods: This retrospective study comprised 100 patients (2-10 years) in lower weight quartile who had intravenous contrast-enhanced CT of the abdomen and pelvis, 37 of which with oral contrast, and 63 without. A pediatric radiologist and a pediatric radiology fellow independently assessed whether the appendix was visualized or not. In case of discrepancy, an additional pediatric radiologist was the "tie-breaker." Chi-squared test was used to compare the proportion of visualized appendix between the groups (with and without oral contrast). Inter-rater reliability was determined using Cohen's Kappa coefficient. Results: There was no significant difference in the visualization of the appendix between the group with oral contrast and without (P = 1). The Cohen Kappa coefficients were .33 (.05, .62) and .91 (.73, 1.00) for the "no oral" and "oral" groups, respectively, yielding evidence of a difference (P = .007). Conclusions: There was no significant difference in the visualization of the appendix using CT with or without oral contrast in low-weight pediatric patients. The inter-rater reliability, however, was significantly higher in the group given oral contrast. Additional studies assessing the value of oral contrast for the sole indication of appendicitis may provide clearer results.

Evaluation of Fertility Preservation Counseling and Treatments for Female Oncology Patients in an Urban Pediatric Canadian Center

Purpose: Several international organizations and guidelines have recommended implementation of structured fertility preservation (FP) discussions with patients and their families before initiation of chemotherapy and radiation treatments in children. This study aimed to identify current trends and rates in FP counseling and treatments at a Canadian pediatric tertiary care center. Objectives were to measure guideline adherence for FP counseling at our institution by determining (1) the frequency of FP counseling in pediatric female oncological patients at our institution, (2) the frequency of FP treatment in this study population, and (3) the factors associated with FP pre-treatment counseling. Methods: A retrospective chart review was performed, including all pediatric and adolescent female patients (age <18) seen in consultation by the oncology team. Demographic data, as well as documentation of FP counseling and referral to a reproductive endocrinology and infertility (REI) specialist and subsequent FP treatment were collected. Results: A total of 89 female pediatric patients were included in our study. Forty-two patients received fertility counseling (47.2%; 95% confidence interval [CI] 37.2-57.5). Only 29/42 (69.0%; 95% CI: 54-80.9) received counseling before onset of treatment. A 12/42 (41.4%; 95% CI: 25-59.3) of the patients who received FP counseling were referred to an REI specialist and 11/12 proceeded with FP treatment (37.9%, 95% CI: 22.7-56). Conclusion: This study presents contemporary data on the rates of FP counseling in Canadian pediatric female oncological patients and demonstrates low rates of FP counseling in our patient population.

Machine Learning Applications in Mental Health and Substance Use Research Among the LGBTQ2S+ Population: Scoping Review

BACKGROUND

A high risk of mental health or substance addiction issues among sexual and gender minority populations may have more nuanced characteristics that may not be easily discovered by traditional statistical methods.

OBJECTIVE

This review aims to identify literature studies that used machine learning (ML) to investigate mental health or substance use concerns among the lesbian, gay, bisexual, transgender, queer or questioning, and two-spirit (LGBTQ2S+) population and direct future research in this field.

METHODS

The MEDLINE, Embase, PubMed, CINAHL Plus, PsycINFO, IEEE Xplore, and Summon databases were searched from November to December 2020. We included original studies that used ML to explore mental health or substance use among the LGBTQ2S+ population and excluded studies of genomics and pharmacokinetics. Two independent reviewers reviewed all papers and extracted data on general study findings, model development, and discussion of the study findings.

RESULTS

We included 11 studies in this review, of which 81% (9/11) were on mental health and 18% (2/11) were on substance use concerns. All studies were published within the last 2 years, and most were conducted in the United States. Among mutually nonexclusive population categories, sexual minority men were the most commonly studied subgroup (5/11, 45%), whereas sexual minority women were studied the least (2/11, 18%). Studies were categorized into 3 major domains: web content analysis (6/11, 54%), prediction modeling (4/11, 36%), and imaging studies (1/11, 9%).

CONCLUSIONS

ML is a promising tool for capturing and analyzing hidden data on mental health and substance use concerns among the LGBTQ2S+ population. In addition to conducting more research on sexual minority women, different mental health and substance use problems, as well as outcomes and future research should explore newer environments, data sources, and intersections with various social determinants of health.

Impact of a peer comparison intervention on seasonal influenza vaccine uptake in community pharmacy: A national cluster randomized study

BACKGROUND

Seasonal influenza vaccine (SIV) uptake in the United States remains suboptimal, requiring new and innovative strategies.

OBJECTIVE

To evaluate the impact of a behavioral peer comparison (PC) intervention on SIV uptake in community pharmacies across the United States.

METHODS

A cluster randomized study was conducted across a national network of Walmart community pharmacies (> 4500 sites) during the 2019-2020 influenza season. The clusters consisted of 416 markets, each containing an average of 11 pharmacies. All pharmacies in a market were randomly assigned to either no intervention or the PC intervention, a software-delivered communication informing on-site staff, including pharmacists and pharmacy technicians, of their pharmacy's weekly performance, measured as SIV doses administered, compared with that of peer pharmacies within their market. The outcome was the pharmacy-level cumulative SIV doses administered during the intervention period (September 1, 2019,-February 29, 2020). Linear regression models were used to estimate the PC impact, with multiway cluster-robust SEs estimated by market and state.

RESULTS

A total of 4589 pharmacies were enrolled in the study, with 2297 (50.1%) randomized to the control group and 2292 (49.9%) randomized to the PC intervention group. Overall, compared with the control pharmacies, the PC pharmacies administered 3.7% (95% CI -0.3% to 7.9%) additional SIV doses. Among large-format pharmacies, the PC pharmacies administered 4.1% (95% CI 0.1%-8.3%) additional SIV doses compared with the controls. Historically low-performing large-format PC pharmacies administered 6.1% (95% CI 0.5%-11.9%) additional SIV doses compared with the controls. No statistically significant treatment effects were observed among small-format pharmacies.

CONCLUSION

Our findings demonstrate that PCs can improve SIV uptake among large-format community pharmacies, with historically low-performing pharmacies potentially exhibiting the greatest relative impact. Wide-scale implementation of PCs in community pharmacies may help to further improve SIV uptake in these settings.

Testing for non-inferior mortality: a systematic review of non-inferiority margin sizes and trial characteristics

OBJECTIVE

To describe the size and variability of non-inferiority margins used in non-inferiority trials of medications with primary outcomes involving mortality, and to examine the association between trial characteristics and non-inferiority margin size.

DESIGN

Systematic review.

DATA SOURCES

Medline, Medline In Process, Medline Epub Ahead of Print and Embase Classic+Embase databases from January 1989 to December 2019.

ELIGIBILITY CRITERIA

Prospective non-inferiority randomised controlled trials comparing pharmacological therapies, with primary analyses for non-inferiority and primary outcomes involving mortality alone or as part of a composite outcome. Trials had to prespecify non-inferiority margins as absolute risk differences or relative to risks of outcome and provide a baseline risk of primary outcome in the control intervention.

RESULTS

3992 records were screened, 195 articles were selected for full text review and 111 articles were included for analyses. 82% of trials were conducted in thrombosis, infectious diseases or oncology. Mortality was the sole primary outcome in 23 (21%) trials, and part of a composite primary outcome in 88 (79%) trials. The overall median non-inferiority margin was an absolute risk difference of 9% (IQR 4.2%-10%). When non-inferiority margins were expressed relative to the baseline risk of primary outcome in control groups, the median relative non-inferiority margin was 1.5 (IQR 1.3-1.7). In multivariable regression analyses examining the association between trial characteristics (medical specialty, inclusion of paediatric patients, mortality as a sole or part of a composite primary outcome, presence of industry funding) and non-inferiority margin size, only medical specialty was significantly associated with non-inferiority margin size.

CONCLUSION

Absolute and relative non-inferiority margins used in published trials comparing medications are large, allowing conclusions of non-inferiority in the context of large differences in mortality. Accepting the potential for large increases in outcomes involving mortality while declaring non-inferiority is a challenging methodological issue in the conduct of non-inferiority trials.

Identifying Subjects at Risk for Diaphragm Atrophy During Mechanical Ventilation Using Routinely Available Clinical Data

BACKGROUND

Diaphragmatic respiratory effort during mechanical ventilation is an important determinant of patient outcome, but direct measurement of diaphragmatic contractility requires specialized instrumentation and technical expertise. We sought to determine whether routinely collected clinical variables can predict diaphragmatic contractility and stratify the risk of diaphragm atrophy.

METHODS

We conducted a secondary analysis of a prospective cohort study on diaphragm ultrasound in mechanically ventilated subjects. Clinical variables, such as breathing frequency, ventilator settings, and blood gases, were recorded longitudinally. Machine learning techniques were used to identify variables predicting diaphragm contractility and stratifying the risk of diaphragm atrophy (> 10% decrease in thickness from baseline). Performance of the variables was evaluated in mixed-effects logistic regression and random-effects tree models using the area under the receiver operating characteristic curve.

RESULTS

Measurements were available for 761 study days in 191 subjects, of whom 73 (38%) developed diaphragm atrophy. No routinely collected clinical variable, alone or in combination, could accurately predict either diaphragm contractility or the development of diaphragm atrophy (model area under the receiver operating characteristic curve 0.63-0.75). The risk of diaphragm atrophy was not significantly different according to the presence or absence of patient-triggered breaths (38.3% vs 38.6%; odds ratio 1.01, 95% CI 0.05-2.03). Diaphragm thickening fraction < 15% during either of the first 2 d of the study was associated with a higher risk of atrophy (44.6% vs 26.1%; odds ratio 2.28, 95% CI 1.05-4.95).

CONCLUSIONS

Diaphragmatic contractility and the risk of diaphragm atrophy could not be reliably determined from routinely collected clinical variables and ventilator settings. A single measurement of diaphragm thickening fraction measured within 48 h of initiating mechanical ventilation can be used to stratify the risk of diaphragm atrophy during mechanical ventilation.

A machine learning approach to identify correlates of current e-cigarette use in Canada

Aim: Popularity of electronic cigarettes (i.e. e-cigarettes) is soaring in Canada. Understanding person-level correlates of current e-cigarette use (vaping) is crucial to guide tobacco policy, but prior studies have not fully identified these correlates due to model overfitting caused by multicollinearity. This study addressed this issue by using classification tree, a machine learning algorithm. Methods: This population-based cross-sectional study used the Canadian Tobacco, Alcohol, and Drugs Survey (CTADS) from 2017 that targeted residents aged 15 or older. Forty-six person-level characteristics were first screened in a logistic mixed-effects regression procedure for their strength in predicting vaper type (current vs. former vaper) among people who reported to have ever vaped. A 9:1 ratio was used to randomly split the data into a training set and a validation set. A classification tree model was developed using the cross-validation method on the training set using the selected predictors and assessed on the validation set using sensitivity, specificity and accuracy. Results: Of the 3,059 people with an experience of vaping, the average age was 24.4 years (standard deviation = 11.0), with 41.9% of them being female and 8.5% of them being aboriginal. There were 556 (18.2%) current vapers. The classification tree model performed relatively well and suggested attraction to e-cigarette flavors was the most important correlate of current vaping, followed by young age (< 18) and believing vaping to be less harmful to oneself than cigarette smoking. Conclusions: People who vape due to flavors are associated with very high risk of becoming current vapers. The findings of this study provide evidence that supports the ongoing ban on flavored vaping products in the US and suggests a similar regulatory intervention may be effective in Canada.

Does biomarker use in oncology improve clinical trial failure risk? A large-scale analysis

Purpose

To date there has not been an extensive analysis of the outcomes of biomarker use in oncology.

Methods

Data were pooled across four indications in oncology drawing upon trial outcomes from www.clinicaltrials.gov: breast cancer, non‐small cell lung cancer (NSCLC), melanoma and colorectal cancer from 1998 to 2017. We compared the likelihood drugs would progress through the stages of clinical trial testing to approval based on biomarker status. This was done with multi‐state Markov models, tools that describe the stochastic process in which subjects move among a finite number of states.

Results

Over 10000 trials were screened, which yielded 745 drugs. The inclusion of biomarker status as a covariate significantly improved the fit of the Markov model in describing the drug trajectories through clinical trial testing stages. Hazard ratios based on the Markov models revealed the likelihood of drug approval with biomarkers having nearly a fivefold increase for all indications combined. A 12, 8 and 7‐fold hazard ratio was observed for breast cancer, melanoma and NSCLC, respectively. Markov models with exploratory biomarkers outperformed Markov models with no biomarkers.

Conclusion

This is the first systematic statistical evidence that biomarkers clearly increase clinical trial success rates in three different indications in oncology. Also, exploratory biomarkers, long before they are properly validated, appear to improve success rates in oncology. This supports early and aggressive adoption of biomarkers in oncology clinical trials.

The association between immune checkpoint or BRAF/MEK inhibitor therapy and uveitis in patients with advanced cutaneous melanoma

BACKGROUND

Treatment with immune checkpoint and BRAF/MEK inhibitors has significantly improved the survival of patients with advanced cutaneous melanoma and other metastatic malignancies. Therapy-related uveitis is a rare ocular adverse event, which may potentially lead to legal blindness. The epidemiology of treatment-related uveitis is currently insufficiently known.

PATIENTS AND METHODS

In this cohort study, we asked whether exposure to either immune checkpoint or BRAF/MEK inhibitors was associated with a higher risk of developing uveitis compared with the general population. Based on a Bayesian framework, we estimated the probability of developing uveitis with a right-censored, exponential survival model using data from the Zurich Melanoma Registry. The registry included all adult patients treated for advanced cutaneous melanoma between January 2008 and December 2018 at the University Hospital of Zurich, Switzerland.

RESULTS

In total, 304 patients (64%) were treated with immune checkpoint and 186 patients (38%) with BRAF/MEK inhibitors. Median follow-up time was 74 days (interquartile range: 57-233 days). Eleven patients developed uveitis and 30 patients died. We estimated the probability of developing uveitis per year in the general population as 0.05% (95% credibility interval [CrI]: 0.02%-0.1%). Corresponding posterior probabilities of treatment-related uveitis were 3.48% (95% CrI: 0.93%-7.49%) and 5.04% (95% CrI: 2.07%-9.19%) for immune checkpoint or BRAF/MEK inhibitors (posterior probability for difference: 76%).

CONCLUSIONS

Immune checkpoint and particularly BRAF/MEK inhibitor therapies are associated with an increase in the risk of developing uveitis. Treatment-related uveitis is not associated with systemic adverse events of immune checkpoint or BRAF/MEK inhibitors.

Health care costs associated with chronic hepatitis C virus infection in Ontario, Canada: a retrospective cohort study

BACKGROUND

High-quality estimates of health care costs are required to understand the burden of illness and to inform economic models. We estimated the costs associated with hepatitis C virus (HCV) infection from the public payer perspective in Ontario, Canada.

METHODS

In this population-based retrospective cohort study, we identified patients aged 18-105 years diagnosed with chronic HCV infection in Ontario from 2003 to 2014 using linked administrative data. We allocated the time from diagnosis until death or the end of follow-up (Dec. 31, 2016) to 9 mutually exclusive health states using validated algorithms: no cirrhosis, no cirrhosis (RNA negative) (i.e., cured HCV infection), compensated cirrhosis, decompensated cirrhosis, hepatocellular carcinoma, both decompensated cirrhosis and hepatocellular carcinoma, liver transplantation, terminal (liver-related) and terminal (non-liver-related). We estimated direct medical costs (in 2018 Canadian dollars) per 30 days per health state and used regression models to identify predictors of the costs.

RESULTS

We identified 48 239 patients with chronic hepatitis C, of whom 30 763 (63.8%) were men and 35 891 (74.4%) were aged 30-59 years at diagnosis. The mean 30-day costs were $798 (95% confidence interval [CI] $780-$816) (n = 43 568) for no cirrhosis, $661 (95% CI $630-$692) (n = 6422) for no cirrhosis (RNA negative), $1487 (95% CI $1375-$1599) (n = 4970) for compensated cirrhosis, $3659 (95% CI $3279-$4039) (n = 3151) for decompensated cirrhosis, $4238 (95% CI $3480-$4996) (n = 550) for hepatocellular carcinoma, $8753 (95% CI $7130-$10 377) (n = 485) for both decompensated cirrhosis and hepatocellular carcinoma, $4539 (95% CI $3746-$5333) (n = 372) for liver transplantation, $11 202 (95% CI $10 645-$11 760) (n = 3201) for terminal (liver-related) and $8801 (95% CI $8331-$9271) (n = 5278) for terminal (non-liver-related) health states. Comorbidity was the most significant predictor of total costs for all health states.

INTERPRETATION

Our findings suggest that the financial burden of HCV infection is substantially higher than previously estimated in Canada. Our comprehensive, up-to-date cost estimates for clinically defined health states of HCV infection should be useful for future economic evaluations related to this disorder.

Universal Drug Coverage and Socioeconomic Disparities in Health Care Costs Among Persons With Diabetes

OBJECTIVE

To examine whether neighborhood socioeconomic status (SES) is a predictor of non-drug-related health care costs among Canadian adults with diabetes and, if so, whether SES disparities in costs are reduced after age 65 years, when universal drug coverage commences as an insurable benefit.

RESEARCH DESIGN AND METHODS

Administrative health databases were used to examine publicly funded health care expenditures among 698,113 younger (20-64 years) and older (≥65 years) adults with diabetes in Ontario from April 2004 to March 2014. Generalized linear models were constructed to examine relative and absolute differences in health care costs (total and non-drug-related costs) across neighborhood SES quintiles, by age, with adjustment for differences in age, sex, diabetes duration, and comorbidity.

RESULTS

Unadjusted costs per person-year in the lowest SES quintile (Q1) versus the highest (Q5) were 39% higher among younger adults ($5,954 vs. $4,270 [Canadian dollars]) but only 9% higher among older adults ($10,917 vs. $9,993). Adjusted non-drug costs (primarily for hospitalizations and physician visits) were $1,569 per person-year higher among younger adults in Q1 vs. Q5 (modeled relative cost difference: 35.7% higher) and $139.3 million per year among all individuals in Q1. Scenarios in which these excess costs per person-year were decreased by ≥10% or matched the relative difference among seniors suggested a potential for savings in the range of $26.0-$128.2 million per year among all lower-SES adults under age 65 years (Q1-Q4).

CONCLUSIONS

SES is a predictor of diabetes-related health care costs in our setting, more so among adults under age 65 years, a group that lacks universal drug coverage under Ontario's health care system. Non-drug-related health care costs were more than one-third higher in younger, lower-SES adults, translating to >$1 billion more in health care expenditures over 10 years.

Understanding resource utilization and mortality in COPD to support policy making: A microsimulation study

Chronic obstructive pulmonary disease (COPD) poses a significant but heterogeneous burden to individuals and healthcare systems. Policymakers develop targeted policies to minimize this burden but need personalized tools to evaluate novel interventions and target them to subpopulations most likely to benefit. We developed a platform to identify subgroups that are at increased risk of emergency department visits, hospitalizations and mortality and to provide stratified patient input in economic evaluations of COPD interventions. We relied on administrative and survey data from Ontario, Canada and applied a combination of microsimulation and multi-state modeling methods. We illustrated the functionality of the platform by quantifying outcomes across smoking status (current, former, never smokers) and by estimating the effect of smoking cessation on resource use and survival, by comparing outcomes of hypothetical cohorts of smokers who quit at diagnosis and smokers that continued to smoke post diagnosis. The cumulative incidence of all-cause mortality was 37.9% (95% CI: 34.9, 41.4) for never smokers, 34.7% (95% CI: 32.1, 36.9) for current smokers, and 46.4% (95% CI: 43.6, 49.0) for former smokers, at 14 years. Over 14 years, smokers who did not quit at diagnosis had 16.3% (95% CI: 9.6, 38.4%) more COPD-related emergency department visits than smokers who quit at diagnosis. In summary, we combined methods from clinical and economic modeling to create a novel tool that policymakers and health economists can use to inform future COPD policy decisions and quantify the effect of modifying COPD risk factors on resource utilization and morality.

Development and Validation of a Clinical Prediction Tool for Seasonal Influenza Vaccination in England

IMPORTANCE

Timely identification of patients likely to miss seasonal influenza vaccination (SIV) could help health care practitioners tailor services and gain efficiency.

OBJECTIVE

To develop and validate a predictive model of SIV uptake among at-risk adults.

DESIGN, SETTING, AND PARTICIPANTS

This prognostic study constructed a prediction model for vaccine uptake by adults at increased risk of influenza-associated complications. Drawing from the Clinical Practice Research Datalink database's records of primary care data of 324 284 adults routinely collected at general practices across England from January 2011 to December 2016, logistic regression models were trained on data from patients registered from January 2012 to December 2013 and validated with out-of-sample data from patients registered from January 2015 to December 2016. Data were extracted from the database December 2018 and analyzed between September 2019 and December 2019.

EXPOSURES

Covariates included sex, age, race/ethnicity, smoking status, socioeconomic status, previous pneumococcal vaccination, prior season SIV uptake, and clinical risk conditions.

MAIN OUTCOMES AND MEASURES

The main outcome was patient-level SIV uptake. Model performance was measured via misclassification rate, Brier score, sensitivity, specificity, and area under the curve.

RESULTS

The training data sets consisted of 324 284 (aged 18 to 64 years) and 186 426 (aged 65 years or older) patients. The mean (SD) age in the training data among patients aged 18 to 64 years was 45 (13) years; 161 487 (49.8%) were women, and 102 133 (31.5%) were categorized as white. Among patients aged 65 years or older, the mean (SD) age was 77 (8) years; 96 169 (51.6%) were women, and 64 996 (34.9%) were categorized as white. The validation data sets consisted of 35 210 patients aged 18 to 64 years and 25 497 aged 65 years or older. The mean (SD) age in the validation data set among patients aged 18 to 64 years was 42 (14) years; 17 296 (49.1%) were women, and 13 346 (37.9%) were categorized as white. Among patients aged 65 years or older, the mean (SD) age was 73 (8) years; 13 135 (51.5%) were women, and 9641 (37.8) were categorized as white. Among patients aged 18 to 64 years, SIV uptake was 35.9% (95% CI, 35.7%-36.0%) and 32.6% (95% CI, 32.1%-33.1%) for the training and validation data sets, respectively. Among patients aged 65 years or older, SIV uptake was 83.1% (95% CI, 82.9%-83.2%) and 76.1% (95% CI, 75.5%-76.6%) for the training and validation data sets, respectively. Prior season SIV uptake and pneumococcal vaccination status were the best predictors of SIV uptake. Predicted SIV uptake probabilities for patients aged 18 to 64 years were reliable, but biased toward underpredicting, whereas, among patients aged 65 years or older, they were variable and biased toward overpredicting. Briefly, in out-of-sample validation among patients aged 18 to 64 years, misclassification rates were 0.163 to 0.164, Brier scores were 0.124 to 0.125, area under the receiver operating characteristic curve values ranged from 0.876 to 0.877, sensitivity ranged from 0.705 to 0.720, and specificity ranged from 0.896 to 0.902. In patients aged 65 years or older, misclassification rates were 0.120 to 0.125, Brier scores were 0.0953 to 0.0959, area under the receiver operating characteristic curve was 0.877, sensitivity ranged from 0.919 to 0.936, and specificity ranged from 0.680 to 0.753.

CONCLUSIONS AND RELEVANCE

This study suggests that data obtained from primary care records could accurately predict SIV uptake among at-risk adults. Further research is needed to assess the feasibility and efficacy of implementing this model in clinical settings.

Exploring the Benefits of Transformations in Health Utility Mapping

Background. Quality-of-life research and cost-effectiveness analyses frequently require data on health utility, a global measure of health-related quality of life. When utilities are unavailable, researchers have "mapped" descriptive instruments to utility instruments, using samples of responses to both instruments. Health utilities have an idiosyncratic distribution, with upper bound and probability mass at 1, left skewness, and kurtosis. Estimation of mean utility values conditional on covariates is of interest, particularly in health utility mapping applications. Traditional linear regression may be unsuitable because fundamental assumptions are violated. Complex statistical methods come with deficiencies that may outweigh their benefits. Aim. To investigate the benefits of transforming the health utility response variable before fitting a linear regression model. Methods. We compared log, logit, arcsin, and Box-Cox transformations with an untransformed model, using several measures of model accuracy. We made our evaluation by designing and conducting a simulation study and reanalyzing data from 2 published studies, which "mapped" a psychometric descriptive instrument to a utility instrument. Results. In the simulation study, log transformation with smearing estimator had in most cases the lowest bias but one of the highest variances, especially for estimating low utility values under small sample size. The untransformed model was outperformed by the transformed models. Findings were inconclusive for the analysis of real data, where arcsin gave the lowest error for one of the data sets, while the untransformed model had the best performance for the other. Conclusions. We identified the benefits of transformations and offered suggestions for future modeling of health utilities. However, the benefits were moderate and no single transformation appeared to be universally optimal, suggesting that selection requires examination on a case-by-case basis.

Patient and practice level factors associated with seasonal influenza vaccine uptake among at-risk adults in England, 2011 to 2016: An age-stratified retrospective cohort study

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Disparities in uptake by ethnicity, varying by age, were evident.

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Older adults with higher socioeconomic deprivation were less likely to be vaccinated.

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Patients with morbid obesity had the lowest odds of being vaccinated.

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Patients who had more annual GP consultations were more likely to be vaccinated.

We sought to gain insights into the determinants of seasonal influenza vaccine (SIV) uptake by conducting an age-stratified analysis (18–64 and 65+) of factors associated with SIV uptake among at-risk adults registered to English practices. Records for at-risk English adults between 2011 and 2016 were identified using the Clinical Practice Research Datalink database. SIV uptake was assessed annually. The associations of patient, practice, and seasonal characteristics with SIV uptake were assessed via cross-sectional and longitudinal analyses, using mixed-effects and general estimating equation logistic regression models. Overall SIV uptake was 35.3% and 74.0% for adults 18–64 and 65+, respectively. Relative to white patients, black patients were least likely to be vaccinated (OR_18-64: 0.82 (95% CI: 0.80, 0.85); OR₆₅₊: 0.59 (95% CI: 0.56, 0.62)), while Asian patients among 18–64 year olds were most likely to be vaccinated (OR_18-64: 1.10 (95% CI: 1.07, 1.13)). Females were more likely than males to be vaccinated among 18–64 year olds (OR_18-64: 1.19 (95% CI: 1.18, 1.20)). Greater socioeconomic deprivation was associated with decreased odds of uptake among older patients (OR₆₅₊: 0.74 (95% CI: 0.71, 0.77)). For each additional at-risk condition, odds of uptake increased (OR_18-64: 2.33 (95% CI: 2.31, 2.36); OR₆₅₊: 1.39 (95% CI: 1.38, 1.39)). Odds of uptake were highest among younger patients with diabetes (OR_18-64: 4.25 (95% CI: 4.18, 4.32)) and older patients with chronic respiratory disease (OR₆₅₊: 1.60 (95% CI: 1.58, 1.63)), whereas they were lowest among morbidly obese patients of all ages (OR_18-64: 0.68 (95% CI: 0.67, 0.70); OR₆₅₊: 0.97 (95% CI: 0.94, 0.99)). Prior influenza season severity and vaccine effectiveness were marginally predictive of uptake. Our age-stratified analysis uncovered SIV uptake disparities by ethnicity, sex, age, socioeconomic deprivation, and co-morbidities, warranting further attention by GPs and policymakers alike.

A Systematic Review and Meta-Analysis of Health Utilities in Patients With Chronic Hepatitis C

BACKGROUND

Chronic hepatitis C (CHC) is among the most burdensome infectious diseases in the world. Health utilities are a valuable tool for quantifying this burden and conducting cost-utility analysis.

OBJECTIVE

Our study summarizes the available data on utilities in CHC patients. This will facilitate analyses of CHC treatment and elimination strategies.

METHODS

We searched MEDLINE, Embase, and the Cochrane Library for studies measuring utilities in CHC patients. Utilities were pooled by health state and utility instrument using meta-analysis. A further analysis used meta-regression to adjust for the effects of clinical status and methodological variation.

RESULTS

Fifty-one clinical studies comprising 15 053 patients were included. Based on the meta-regression, patients' utilities were lower for more severe health states (predicted mean EuroQol-5D-3L utility for mild/moderate CHC: 0.751; compensated cirrhosis: 0.671; hepatocellular carcinoma: 0.662; decompensated cirrhosis: 0.602). Patients receiving interferon-based treatment had lower utilities than those on interferon-free treatment (0.647 vs 0.733). Patients who achieved sustained virologic response (0.786) had higher utilities than those with mild to moderate CHC. Utilities were substantially higher for patients in experimental studies compared to observational studies (coefficient: +0.074, P < .05). The time tradeoff instrument was associated with the highest utilities, and the Health Utilities Index 3 was associated with the lowest utilities.

CONCLUSION

Chronic hepatitis C is associated with a significant impairment in global health status, as measured by health utility instruments. Impairment is greater in advanced disease. Experimental study designs yield higher utilities-an effect not previously documented. Curative therapy can alleviate the burden of CHC, although further research is needed in certain areas, such as the long-term impacts of treatment on utilities.

New Insights into the Epidemiology of Prostate Cancer in Ontario

The epidemiology of prostate cancer (PC) continues to change. We evaluated the changes in incidence, in average age at diagnosis, and in survival from 1992 to 2015 in Ontario. We compared the cumulative incidence of PC-specific and non PC-specific mortality using two algorithms for cause of death: Method 1 assigned deaths from "other cancers" to non PC-specific causes, and Method 2 assigned these cases to PC-specific mortality. There were 188,714 cases diagnosed with PC between 1992 and 2015 in Ontario. The average age at diagnosis declined from 1992 to 2008 by 0.26 year (3.1 months) annually (p < 0.001) and increased by 0.15 year (1.8 months) thereafter (p > 0.05). Between 2010 and 2015, the proportion of patients diagnosed at stage IV increased, and the proportion diagnosed at stage I decreased (p-values for trends <0.001). Overall survival significantly improved over the years. The cumulative incidence of PC-specific mortality at 5 and 10 years was 6.8 and 9.8% using Method 1, and 10.2 and 16.8% using Method 2. We observed trends toward older age and more advanced stage at PC diagnosis in Ontario. Further studies are needed to validate algorithms for estimating PC-specific mortality from administrative databases.