Identifying patients with physician-diagnosed asthma in health administrative databases

The impact of a history of asthma on long-term outcomes of people with newly diagnosed chronic obstructive pulmonary disease: A population study

BACKGROUND

Little is known about the natural history of chronic obstructive pulmonary disease (COPD) that has developed from airway remodeling due to asthma, as compared with other COPD phenotypes.

OBJECTIVE

We compared long-term health outcomes of individuals with COPD with and without a history of asthma in a population-based cohort study.

METHODS

All individuals with physician-diagnosed COPD between the ages 40 and 55 years from 2009 and 2011 were identified and followed until March 2013 through provincial health administrative data (Ontario, Canada). The exposure was a history of asthma at least 2 years before the diagnosis of COPD to ensure it preceded COPD. The hazards of COPD-, respiratory-, and cardiovascular (CV)-related hospitalizations and all-cause mortality were compared between groups using a Cox regression model controlling for demographic characteristics, comorbidities, and level of health care.

RESULTS

Among 9053 patients with COPD, 2717 (30%) had a history of asthma. Over a median of 2.9 years, 712 (8%) individuals had a first COPD hospitalization, 964 (11%) a first respiratory-related and 342 (4%) a first CV-related hospitalization, and 556 (6%) died. Controlling for confounding, a history of asthma was significantly associated with COPD and respiratory-related hospitalizations (hazard ratio, 1.53 [95% CI, 1.29-1.82] and hazard ratio, 1.63 [95% CI, 1.14-1.88], respectively), but not with CV-related hospitalizations or all-cause mortality. Additional analyses confirmed that these findings were not likely a result of unmeasured confounding or misclassification.

CONCLUSIONS

Middle-aged individuals with physician-diagnosed COPD and a history of asthma had a higher hazard of hospitalizations due to COPD and other respiratory diseases than did those without.

Evaluating the Validity of a Two-stage Sample in a Birth Cohort Established from Administrative Databases

BACKGROUND

When using administrative databases for epidemiologic research, a subsample of subjects can be interviewed, eliciting information on undocumented confounders. This article presents a thorough investigation of the validity of a two-stage sample encompassing an assessment of nonparticipation and quantification of the extent of bias.

METHODS

Established through record linkage of administrative databases, the Québec Birth Cohort on Immunity and Health (n = 81,496) aims to study the association between Bacillus Calmette-Guérin vaccination and asthma. Among 76,623 subjects classified in four Bacillus Calmette-Guérin-asthma strata, a two-stage sampling strategy with a balanced design was used to randomly select individuals for interviews. We compared stratum-specific sociodemographic characteristics and healthcare utilization of stage 2 participants (n = 1,643) with those of eligible nonparticipants (n = 74,980) and nonrespondents (n = 3,157). We used logistic regression to determine whether participation varied across strata according to these characteristics. The effect of nonparticipation was described by the relative odds ratio (ROR = ORparticipants/ORsource population) for the association between sociodemographic characteristics and asthma.

RESULTS

Parental age at childbirth, area of residence, family income, and healthcare utilization were comparable between groups. Participants were slightly more likely to be women and have a mother born in Québec. Participation did not vary across strata by sex, parental birthplace, or material and social deprivation. Estimates were not biased by nonparticipation; most RORs were below one and bias never exceeded 20%.

CONCLUSIONS

Our analyses evaluate and provide a detailed demonstration of the validity of a two-stage sample for researchers assembling similar research infrastructures.

Substance-related and addictive disorders among adults with intellectual and developmental disabilities (IDD): an Ontario population cohort study

OBJECTIVES

Describe the prevalence of substance-related and addictive disorders (SRAD) in adults with intellectual and developmental disabilities (IDD) and compare the sociodemographic and clinical characteristics of adults with IDD and SRAD to those with IDD or SRAD only.

DESIGN

Population-based cohort study (the Health Care Access Research and Development Disabilities (H-CARDD) cohort).

SETTING

All legal residents of Ontario, Canada.

PARTICIPANTS

66 484 adults, aged 18-64, with IDD identified through linked provincial health and disability income benefits administrative data from fiscal year 2009. 96 589 adults, aged 18-64, with SRAD but without IDD drawn from the provincial health administrative data.

MAIN OUTCOME MEASURES

Sociodemographic (age group, sex, neighbourhood income quintile, rurality) and clinical (psychiatric and chronic disease diagnoses, morbidity) characteristics.

RESULTS

The prevalence of SRAD among adults with IDD was 6.4%, considerably higher than many previous reports and also higher than found for adults without IDD in Ontario (3.5%). Among those with both IDD and SRAD, the rate of psychiatric comorbidity was 78.8%, and the proportion with high or very high overall morbidity was 59.5%. The most common psychiatric comorbidities were anxiety disorders (67.6%), followed by affective (44.6%), psychotic (35.8%) and personality disorders (23.5%). These adults also tended to be younger and more likely to live in the poorest neighbourhoods compared with adults with IDD but no SRAD and adults with SRAD but no IDD.

CONCLUSIONS

SRAD is a significant concern for adults with IDD. It is associated with high rates of psychiatric and other comorbidities, indicating that care coordination and system navigation may be important concerns. Attention should be paid to increasing the recognition of SRAD among individuals with IDD by both healthcare and social service providers and to improving staff skills in successfully engaging those with both IDD and SRAD.

Childhood Exposure to Ambient Air Pollutants and the Onset of Asthma: An Administrative Cohort Study in Québec

BACKGROUND

Although it is well established that air pollutants can exacerbate asthma, the link with new asthma onset in children is less clear.

OBJECTIVE

We assessed the association between the onset of childhood asthma with both time of birth and time-varying exposures to outdoor air pollutants.

METHOD

An open cohort of children born in the province of Québec, Canada, was created using linked medical-administrative databases. New cases of asthma were defined as one hospital discharge with a diagnosis of asthma or two physician claims for asthma within a 2 year period. Annual ozone (O3) levels were estimated at the child's residence for all births 1999-2010, and nitrogen dioxide (NO2) levels during 1996-2006 were estimated for births on the Montreal Island. Satellite based concentrations of fine particles (PM2.5) were estimated at a 10 km × 10 km resolution and assigned to residential postal codes throughout the province (1996-2011). Hazard ratios (HRs) were assessed with Cox models for the exposure at the birth address and for the time-dependent exposure. We performed an indirect adjustment for secondhand smoke (SHS).

RESULTS

We followed 1,183,865 children (7,752,083 person-years), of whom 162,752 became asthmatic. After controlling for sex and material and social deprivation, HRs for an interquartile range increase in exposure at the birth address to NO2 (5.45 ppb), O3 (3.22 ppb), and PM2.5 (6.50 μg/m3) were 1.04 (95% CI: 1.02, 1.05), 1.11 (95% CI: 1.10, 1.12), and 1.31 (95% CI: 1.28, 1.33), respectively. Effects of O3 and PM2.5 estimated with time-varying Cox models were similar to those estimated using exposure at birth, whereas the effect of NO2 was slightly stronger (HR = 1.07; 95% CI: 1.05, 1.09).

CONCLUSIONS

Asthma onset in children appears to be associated with residential exposure to PM2.5, O3 and NO2.

CITATION

Tétreault LF, Doucet M, Gamache P, Fournier M, Brand A, Kosatsky T, Smargiassi A. 2016. Childhood exposure to ambient air pollutants and the onset of asthma: an administrative cohort study in Québec. Environ Health Perspect 124:1276-1282; http://dx.doi.org/10.1289/ehp.1509838.

Preoperative Laboratory Investigations: Rates and Variability Prior to Low-risk Surgical Procedures

BACKGROUND

Increasing attention has been focused on low-value healthcare services. Through Choosing Wisely campaigns, routine laboratory testing before low-risk surgery has been discouraged in the absence of clinical indications. The authors investigated rates, determinants, and institutional variation in laboratory testing before low-risk procedures.

METHODS

Patients who underwent ophthalmologic surgeries or predefined low-risk surgeries in Ontario, Canada, between April 1, 2008, and March 31, 2013, were identified from population-based administrative databases. Preoperative blood work was defined as a complete blood count, prothrombin time, partial thromboplastin, or basic metabolic panel within 60 days before an index procedure. Adjusted associations between patient and institutional factors and preoperative testing were assessed with hierarchical multivariable logistic regression. Institutional variation was characterized using the median odds ratio.

RESULTS

The cohort included 906,902 patients who underwent 1,330,466 procedures (57.1% ophthalmologic and 42.9% low-risk surgery) at 119 institutions. Preoperative blood work preceded 400,058 (30.1%) procedures. The unadjusted institutional rate of preoperative blood work varied widely (0.0 to 98.1%). In regression modeling, significant predictors of preoperative testing included atrial fibrillation (adjusted odds ratio [AOR], 2.58; 95% CI, 2.51 to 2.66), preoperative medical consultation (AOR, 1.68; 95% CI, 1.65 to 1.71), previous mitral valve replacement (AOR, 2.33; 95% CI, 2.10 to 2.58), and liver disease (AOR, 1.69; 95% CI, 1.55 to 1.84). The median odds ratio for interinstitutional variation was 2.43.

CONCLUSIONS

Results of this study suggest that testing is associated with a range of clinical covariates. However, an association was similarly identified with preoperative consultation, and significant variation between institutions exists across the jurisdiction.

Using physician billing claims from the Ontario Health Insurance Plan to determine individual influenza vaccination status: an updated validation study

BACKGROUND

Owing to the absence of a vaccination registry in Ontario, administrative data are currently the best available source to determine population-based individual-level influenza vaccination status. Our objective was to validate physician billing claims for influenza vaccination in the Ontario Health Insurance Plan database against the Canadian Community Health Survey.

METHODS

We used self-reported seasonal influenza vaccination status of Ontario residents surveyed between 2007 and 2009 as the reference standard. The survey responses were linked to physician claims database records to validate billing codes for influenza vaccination. We calculated sensitivity, specificity, positive predictive value and negative predictive value with 95% confidence intervals (CIs). We stratified the data by several covariates and comorbidities to determine stratum-specific performance characteristics. We used these estimates to adjust an estimate of influenza vaccine effectiveness for the 2010/11 influenza season.

RESULTS

For the 47 301 patients included in the analysis, the sensitivity for the billing codes was 49.8% (95% CI 49.0%-50.5%), specificity was 95.7% (95% CI 95.5%-96.0%), positive predictive value was 88.4% (95% CI 87.8%-89.0%) and negative predictive value was 74.5% (95% CI 74.0%-74.9%). Performance measures were optimized in patients aged 65 years and older, particularly those with comorbidities.

INTERPRETATION

Although administrative data have limitations for determining influenza vaccination status, owing to the high positive predictive value, they are well suited for self-controlled study designs that are often used to assess vaccine safety. For studies of coverage and effectiveness, restricting the cohort to patients aged 65 years and older will minimize misclassification bias. Performance characteristics from this study can be used to mitigate misclassification bias.

Ambient air pollution and adverse birth outcomes: Differences by maternal comorbidities

BACKGROUND

Prenatal exposure to ambient air pollution has been associated with adverse birth outcomes, but the potential modifying effect of maternal comorbidities remains understudied. Our objective was to investigate whether associations between prenatal air pollution exposures and birth outcomes differ by maternal comorbidities.

METHODS

A total of 818,400 singleton live births were identified in the province of Ontario, Canada from 2005 to 2012. We assigned exposures to fine particulate matter (PM2.5), nitrogen dioxide (NO2) and ozone (O3) to maternal residences during pregnancy. We evaluated potential effect modification by maternal comorbidities (i.e. asthma, hypertension, pre-existing diabetes mellitus, heart disease, gestational diabetes and preeclampsia) on the associations between prenatal air pollution and preterm birth, term low birth weight and small for gestational age.

RESULTS

Interquartile range (IQR) increases in PM2.5 (2μg/m(3)), NO2 (9ppb) and O3 (5ppb) over the entire pregnancy were associated with a 4% (95% CI: 2.4-5.6%), 8.4% (95% CI: 5.5-10.3%) and 2% (95% CI: 0.5-4.1%) increase in the odds of preterm birth, respectively. Increases of 10.6% (95% CI: 0.2-2.1%) and 23.8% (95% CI: 5.5-44.8%) in the odds of preterm birth were observed among women with pre-existing diabetes while the increases were of 3.8% (95% CI: 2.2-5.4%) and 6.5% (95% CI: 3.7-8.4%) among women without this condition for pregnancy exposure to PM2.5 and NO2, respectively (Pint<0.01). The increase in the odds of preterm birth for exposure to PM2.5 during pregnancy was higher among women with preeclampsia (8.3%, 95% CI: 0.8-16.4%) than among women without (3.6%, 95% CI: 1.8-5.3%) (Pint=0.04). A stronger increase in the odds of preterm birth was found for exposure to O3 during pregnancy among asthmatic women (12.0%, 95% CI: 3.5-21.1%) compared to non-asthmatic women (2.0%, 95% CI: 0.1-3.5%) (Pint<0.01). We did not find statistically significant effect modification for the other outcomes investigated.

CONCLUSIONS

Findings of this study suggest that associations of ambient air pollution with preterm birth are stronger among women with pre-existing diabetes, asthma, and preeclampsia.

Transcranial Doppler Screening Among Children and Adolescents With Sickle Cell Anemia

IMPORTANCE

With transcranial Doppler (TCD) screening, we can identify children and adolescents with sickle cell anemia who are at the highest risk of stroke. An accurate claims-based method for identifying children and adolescents with sickle cell anemia was recently developed and validated that establishes the necessary groundwork to enable large population-based assessments of health services utilization among children and adolescents with sickle cell anemia using administrative claims data.

OBJECTIVE

To assess the feasibility of using administrative claims data to identify and describe the receipt of TCD screening among children and adolescents with sickle cell anemia and to characterize opportunities for intervention.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cross-sectional study using Medicaid claims data from 2005 to 2010. Medicaid claims data were obtained from the following states: Florida, Illinois, Louisiana, Michigan, South Carolina, and Texas. Children and adolescents 2 to 16 years of age with sickle cell anemia were identified by the presence of 3 or more Medicaid claims with a diagnosis of sickle cell anemia within a calendar year (2005-2010). A total of 4775 children and adolescents contributed 10 787 person-years throughout the study period. Data were analyzed in 2015. A subset of children and adolescents enrolled for 2 or more consecutive years was identified to examine potential predictors of TCD screening, which included age, sex, previous receipt of TCD screening, state of residence, and health services utilization (well-child visits, outpatient visits, emergency department visits, and inpatient visits).

MAIN OUTCOMES AND MEASURES

Receipt of TCD screening was assessed by year and state. Using logistic regression with generalized estimating equations, we included associated predictors in a multivariable model to estimate odds of TCD screening.

RESULTS

For a total of 4775 children and adolescents 2 to 16 years of age, TCD screening rates increased over the 6-year study period from 22% to 44% (P < .001); rates varied substantially across states. A subset of 2388 children and adolescents with sickle cell anemia (50%) was enrolled for 2 or more consecutive years. Each year of increasing age was associated with 3% lower odds of TCD screening (odds ratio, 0.97 [95% CI, 0.95-0.98]; P = .002). Previous receipt of TCD screening (odds ratio, 2.44 [95% CI, 2.11-2.81]; P < .001) and well-child visits (odds ratio, 1.10 [95% CI, 1.03-1.18]; P = .007) were associated with higher odds of receiving a TCD screening.

CONCLUSIONS AND RELEVANCE

Despite national recommendations, TCD screening rates remain low. Successful strategies to improve TCD screening rates may capitalize on the numerous health care interactions among children and adolescents with sickle cell anemia.

The impact of frailty on outcomes and healthcare resource usage after total joint arthroplasty

Aims

Total joint arthroplasty (TJA) is commonly performed in elderly patients. Frailty, an aggregate expression of vulnerability, becomes increasingly common with advanced age, and independently predicts adverse outcomes and the use of resources after a variety of non-cardiac surgical procedures. Our aim was to assess the impact of frailty on outcomes after TJA.

Patients and Methods

We analysed the impact of pre-operative frailty on death and the use of resources after elective TJA in a population-based cohort study using linked administrative data from Ontario, Canada.

Results

Of 125 163 patients aged > 65 years having elective TJA, 3023 (2.4%) were frail according to the Johns Hopkins ACG frailty-defining diagnoses indicator. One year follow-up was complete for all patients. Frail patients had a higher adjusted one year risk of mortality (hazard ratio 3.03, 95% confidence interval (CI) 2.62 to 3.51), a higher rate of admission to intensive care (odds ratio (OR) 2.52, 95% CI 2.21 to 2.89), increased length of stay (incidence rate ratio 1.62, 95% CI 1.59 to 1.65), a higher rate of discharge to institutional care (OR 2.09, 95% CI 1.93 to 2.25), a higher rate of re-admission (OR 1.33, 95% CI 1.07 to 1.66) and increased costs at 30, 90 and 365 days post-operatively. Frailty affected outcomes after total hip arthroplasty more than after total knee arthroplasty. Take home message: Frailty is an important risk factor for death after elective TJA, and increases post-operative resource utilisation across many metrics. Processes to optimise the outcomes and efficiency of TJA in frail patients are needed. Cite this article: Bone Joint J 2016;98-B:799–805.

The relative impact of chronic conditions and multimorbidity on health-related quality of life in Ontario long-stay home care clients

PURPOSE

To examine the relative impact of 16 common chronic conditions and increasing morbidity on health-related quality of life (HRQL) in a population-based sample of home care clients in Ontario, Canada.

METHODS

Participants were adult clients assessed with the Resident Assessment Instrument for Home Care (RAI-HC) between January and June 2009 and diagnosed with one (or more) of 16 common chronic conditions. HRQL was evaluated using the Minimum Data Set-Health Status Index (MDS-HSI), a preference-based measure derived from items captured in the RAI-HC. Multivariable linear regression models assessed the relative impact of each condition, and increasing number of diagnoses, on MDS-HSI scores.

RESULTS

Mean (SD) MDS-HSI score in the study population (n = 106,159) was 0.524 (0.213). Multivariable analysis revealed a statistically significant (p < 0.05) and clinically important (difference ≥ 0.03) decrease in MDS-HSI scores associated with stroke (-0.056), osteoarthritis (-0.036), rheumatoid arthritis (-0.033) and congestive heart failure (CHF, -0.030). Differences by age and sex were observed; most notably, the negative impact associated with dementia was greater among men (-0.043) than among women (-0.019). Further, HRQL decreased incrementally with additional diagnoses. In all models, chronic conditions and number of diagnoses accounted for a relatively small proportion of the variance observed in MDS-HSI.

CONCLUSION

Clinically important negative effects on HRQL were observed for clients with a previous diagnosis of stroke, osteo- and rheumatoid arthritis, or CHF, as well as with increasing levels of multimorbidity. Findings provide baseline preference-based HRQL scores for home care clients with different diagnoses and may be useful for identifying, targeting and evaluating care strategies toward populations with significant HRQL impairments.

Emergency department use by people with HIV in Ontario: a population-based cohort study

BACKGROUND

Emergency department use may reflect poor access to primary care. Our objective was to compare rates and causes of emergency department use between adults living with and without HIV.

METHODS

We conducted a population-based study involving Ontario residents living with and without HIV between Apr. 1, 2011, and Mar. 31, 2012. We frequency matched adults with HIV to 4 HIV-negative people by age, sex and census division, and used random-effects negative binomial regression to compare rates of emergency department use. We classified visits as low urgency or high urgency, and also examined visits for ambulatory care sensitive conditions. Hospital admission following an emergency department visit was a secondary outcome.

RESULTS

We identified 14 534 people with HIV and 58 136 HIV-negative individuals. Rates of emergency department use were higher among people with HIV (67.3 v. 31.2 visits per 100 person-years; adjusted rate ratio 1.58, 95% confidence interval [CI] 1.51-1.65). Similar results were observed for low-urgency visits. With the exception of hypertension, visit rates for ambulatory care sensitive conditions were higher among people with HIV. People with HIV were also more likely than HIV-negative individuals to be admitted to hospital following an emergency department visit (adjusted odds ratio 1.55, 95% CI 1.43-1.69).

INTERPRETATION

Compared with HIV-negative individuals, people with HIV had high rates of emergency department use, including potentially avoidable visits. These findings strongly support the need for comprehensive care for people with HIV.

Bacillus Calmette-Guérin (BCG) Vaccination in Infancy and Risk of Childhood Diabetes

BACKGROUND

A narrow time window in infancy may be relevant for the aetiology of immune-mediated type 1 diabetes. We investigated whether a non-specific immune stimulation in the first year of life, as resulting from Bacillus Calmette-Guérin (BCG) vaccination, was associated with childhood diabetes.

METHODS

Using data from a birth cohort assembled through linkage of administrative databases, 78,492 subjects born in 1974 were the object of the present analysis. Information was extracted from the birth, death, and BCG vaccination registries. Diabetes-related health services were obtained from administrative health databases (physician billing claims and hospitalisation data) until 1994. Subjects were classified as having diabetes according to two validated definitions: (1) ≥2 diabetes-related medical visits within 2 years or ≥1 hospitalisation for diabetes; and 2) ≥4 diabetes-related medical visits within 2 years. Cox proportional hazards regression was used to estimate adjusted hazard ratios (HR) and 95% confidence interval (CI), adjusted for potential confounders.

RESULTS

Forty-four per cent of subjects were BCG vaccinated in the first year of life. According to the first and second definition, respectively, 293 (0.37%) and 230 (0.29%) subjects were classified as having diabetes. There was no association between BCG vaccination in the first year of life and risk of diabetes with either definition (HR(def1)  = 0.92, 95% CI 0.73, 1.17; HR(def2)  = 1.04, 95% CI 0.80, 1.37), and results did not differ by sex.

CONCLUSIONS

Given the potentially critical importance of the exposure window and paucity of studies addressing BCG vaccination timing in relation to diabetes risk, this question deserves further investigation.

Glucocorticoid-induced osteoporosis management among seniors, by year, sex, and indication, 1996-2012

We identified that glucocorticoid-induced osteoporosis management (bone mineral density testing or osteoporosis treatment) among seniors improved among men (2 to 23 %) and women (10 to 48 %) between 1996 and 2007, and then remained relatively stable through to 2012. Differences were also noted by indication (from a low of 21 % for respiratory conditions to a high of 41 % for rheumatic conditions).

PURPOSE

The aim of our study was to describe the proportion of chronic oral glucocorticoid (GC) users that receive osteoporosis management (bone mineral density test or osteoporosis treatment) by sex and over time.

METHODS

We identified community-dwelling older adults initiating chronic oral GC therapy in Ontario using pharmacy data from 1996 to 2012. Chronic GC use was defined as greater than or equal to two oral GC prescriptions dispensed and ≥450 mg prednisone equivalent over a 6-month period. Osteoporosis management within 6 months of starting chronic GC therapy was examined by sex, year, indication for therapy, and osteoporosis management history. Results were summarized using descriptive statistics.

RESULTS

We identified 72,099 men and 95,975 women starting chronic oral GC therapy (mean age = 74.9 years, SD = 6.5). Approximately two thirds of patients (65 %) received ≥900 mg within the 6-month chronic use window. GC-induced osteoporosis management increased from 2 to 23 % (men) and 10 to 48 % (women) between 1996 and 2007, and then remained relatively stable through to 2012. A higher proportion of patients with prior osteoporosis management were managed within 6 months (56 % men, 67 % women) of chronic GC use, compared to patients without prior management (12 % men, 23 % women). Patients with rheumatic disease were managed most commonly (41 %), and patients with respiratory conditions were managed least commonly (21 %).

CONCLUSIONS

GC-induced osteoporosis management improved significantly over time for both sexes yet remains low. Significant care gaps by sex and between clinical areas represent a missed opportunity for fracture prevention among patients requiring chronic GC therapy.

Identifying patients with asthma in primary care electronic medical record systems Chart analysis-based electronic algorithm validation study

OBJECTIVE

To develop and test a variety of electronic medical record (EMR) search algorithms to allow clinicians to accurately identify their patients with asthma in order to enable improved care.

DESIGN

A retrospective chart analysis identified 5 relevant unique EMR information fields (electronic disease registry, cumulative patient profile, billing diagnostic code, medications, and chart notes); asthma-related search terms were designated for each field. The accuracy of each term was tested for its ability to identify the asthma patients among all patients whose charts were reviewed. Increasingly sophisticated search algorithms were then designed and evaluated by serially combining individual searches with Boolean operators.

SETTING

Two large academic primary care clinics in Hamilton, Ont.

PARTICIPANTS

Charts for 600 randomly selected patients aged 16 years and older identified in an initial EMR search as likely having asthma (n = 150), chronic obstructive pulmonary disease (n = 150), other respiratory conditions (n = 150), or nonrespiratory conditions (n = 150) were reviewed until 100 patients per category were identified (or until all available names were exhausted). A total of 398 charts were reviewed in full and included.

MAIN OUTCOME MEASURES

Sensitivity and specificity of each search for asthma diagnosis (against the reference standard of a physician chart review-based diagnosis).

RESULTS

Two physicians reviewed the charts identified in the initial EMR search using a standardized data collection form and ascribed the following diagnoses in 398 patients: 112 (28.1%) had asthma, 81 (20.4%) had chronic obstructive pulmonary disease, 104 (26.1%) had other respiratory conditions, and 101 (25.4%) had nonrespiratory conditions. Concordance between reviewers in chart abstraction diagnosis was high (κ = 0.89, 95% CI 0.80 to 0.97). Overall, the algorithm searching for patients who had asthma in their cumulative patient profiles or for whom an asthma billing code had been used was the most accurate (sensitivity of 90.2%, 95% CI 87.3% to 93.1%; specificity of 83.9%, 95% CI 80.3% to 87.5%).

CONCLUSION

Usable, practical search algorithms that accurately identify patients with asthma in existing EMRs are presented. Clinicians can apply 1 of these algorithms to generate asthma registries for targeted quality improvement initiatives and outcome measurements. This methodology can be emulated for other diseases.

Are family physicians comprehensively using electronic medical records such that the data can be used for secondary purposes? A Canadian perspective

Background

With the introduction and implementation of a variety of government programs and policies to encourage adoption of electronic medical records (EMRs), EMRs are being increasingly adopted in North America. We sought to evaluate the completeness of a variety of EMR fields to determine if family physicians were comprehensively using their EMRs and the suitability of use of the data for secondary purposes in Ontario, Canada.

Methods

We examined EMR data from a convenience sample of family physicians distributed throughout Ontario within the Electronic Medical Record Administrative data Linked Database (EMRALD) as extracted in the summer of 2012. We identified all physicians with at least one year of EMR use. Measures were developed and rates of physician documentation of clinical encounters, electronic prescriptions, laboratory tests, blood pressure and weight, referrals, consultation letters, and all fields in the cumulative patient profile were calculated as a function of physician and patient time since starting on the EMR.

Results

Of the 167 physicians with at least one year of EMR use, we identified 186,237 patients. Overall, the fields with the highest level of completeness were for visit documentations and prescriptions (>70 %). Improvements were observed with increasing trends of completeness overtime for almost all EMR fields according to increasing physician time on EMR. Assessment of the influence of patient time on EMR demonstrated an increasing likelihood of the population of EMR fields overtime, with the largest improvements occurring between the first and second years.

Conclusions

All of the data fields examined appear to be reasonably complete within the first year of adoption with the biggest increase occurring the first to second year. Using all of the basic functions of the EMR appears to be occurring in the current environment of EMR adoption in Ontario. Thus the data appears to be suitable for secondary use.

Identifying Obstructive Sleep Apnea in Administrative Data

Background:

Health administrative (HA) databases are increasingly used to identify surgical patients with obstructive sleep apnea (OSA) for research purposes, primarily using diagnostic codes. Such means to identify patients with OSA are not validated. The authors determined the accuracy of case-ascertainment algorithms for identifying patients with OSA with the use of HA data.

Methods:

Clinical data derived from an academic health sciences network within a universal health insurance plan were used as the reference standard. The authors linked patients to HA data and retrieved all claims in the 2 yr before surgery to determine the presence of any diagnostic codes, diagnostic procedures, or therapeutic interventions consistent with OSA.

Results:

The authors identified 4,965 patients (2003 to 2012) who underwent preoperative polysomnogram. Of these, 4,353 patients were linked to HA data; 2,427 of these (56%) had OSA based on diagnosis by a sleep physician or the apnea hypopnea index. A claim for a polysomnogram and receipt of a positive airway pressure device had a sensitivity, specificity, and positive likelihood ratio (+LR) for OSA of 19, 98, and 10.9%, respectively. An International Classification of Diseases, Tenth Revision, code for sleep apnea in hospitalization abstracts was 9% sensitive and 98% specific (+LR, 4.5). A physician billing claim for OSA (International Classification of Diseases, Ninth Revision, 780.5) was 58% sensitive and 38% specific (+LR, 0.9). A polysomnogram and a positive airway pressure device or any code for OSA was 70% sensitive and 36% specific (+LR, 1.1).

Conclusions:

No code or combination of codes provided a +LR high enough to adequately identify patients with OSA. Existing studies using administrative codes to identify OSA should be interpreted with caution.

Asthma deaths in a large provincial health system. A 10-year population-based study

RATIONALE

Individuals with asthma are more likely to die from chronic conditions than the general population. Measuring only mortality with asthma listed as the primary cause of death may lead to an underestimation of total asthma mortality.

OBJECTIVES

To examine mortality patterns in the asthma population over 10 years, including asthma as the primary cause of death (asthma-specific mortality) and asthma as a secondary, contributing cause of death (asthma-contributing mortality).

METHODS

Health administrative data from Ontario, Canada were used to identify mortality rates and cause of death in subjects 0 to 99 years of age. Mortality rates were calculated in the asthma and general population from 1999 to 2008. Total asthma mortality was estimated by adding rates of asthma-specific and asthma-contributing mortality for years 2003 to 2008.

MEASUREMENTS AND MAIN RESULTS

Asthma-specific mortality rates per 100,000 asthma population decreased by 54.4% from 13.6 in 1999 to 6.2 in 2008. In 2008, the asthma population had higher all-cause mortality compared with the general population (rate ratio, 1.3), asthma-specific mortality rates were 60% higher among those in the lowest compared with highest socioeconomic status, and total asthma mortality was fourfold higher than asthma-specific mortality alone (21.6 vs. 5.4 per 100,000).

CONCLUSIONS

All-cause mortality rates have decreased substantially over the past decade. Compared with the general population, the asthma population has higher all-cause mortality and is more likely to die from comorbid conditions. Total asthma mortality was fourfold higher than asthma-specific mortality, highlighting the importance of comprehensive measurement approaches that include asthma-specific and asthma-contributing mortality.

Preoperative testing before low-risk surgical procedures

BACKGROUND

There is concern about increasing utilization of low-value health care services, including preoperative testing for low-risk surgical procedures. We investigated temporal trends, explanatory factors, and institutional and regional variation in the utilization of testing before low-risk procedures.

METHODS

For this retrospective cohort study, we accessed linked population-based administrative databases from Ontario, Canada. A cohort of 1 546 223 patients 18 years or older underwent a total of 2 224 070 low-risk procedures, including endoscopy and ophthalmologic surgery, from Apr. 1, 2008, to Mar. 31, 2013, at 137 institutions in 14 health regions. We used hierarchical logistic regression models to assess patient- and institution-level factors associated with electrocardiography (ECG), transthoracic echocardiography, cardiac stress test or chest radiography within 60 days before the procedure.

RESULTS

Endoscopy, ophthalmologic surgery and other low-risk procedures accounted for 40.1%, 34.2% and 25.7% of procedures, respectively. ECG and chest radiography were conducted before 31.0% (95% confidence interval [CI] 30.9%-31.1%) and 10.8% (95% CI 10.8%-10.8%) of procedures, respectively, whereas the rates of preoperative echocardiography and stress testing were 2.9% (95% CI 2.9%-2.9%) and 2.1% (95% CI 2.1%-2.1%), respectively. Significant variation was present across institutions, with the frequency of preoperative ECG ranging from 3.4% to 88.8%. Receipt of preoperative ECG and radiography were associated with older age (among patients 66-75 years of age, for ECG, adjusted odds ratio [OR] 18.3, 95% CI 17.6-19.0; for radiography, adjusted OR 2.9, 95% CI 2.8-3.0), preoperative anesthesia consultation (for ECG, adjusted OR 8.7, 95% CI 8.5-8.8; for radiography, adjusted OR 2.2, 95% CI 2.1-2.2) and preoperative medical consultation (for ECG, adjusted OR 6.8, 95% CI 6.7-6.9; for radiography, adjusted OR 3.6, 95% CI 3.5-3.6). The median ORs for receipt of preoperative ECG and radiography were 2.3 and 1.6, respectively.

INTERPRETATION

Despite guideline recommendations to limit testing before low-risk surgical procedures, preoperative ECG and chest radiography were performed frequently. Significant variation across institutions remained after adjustment for patient- and institution-level factors.

The Accuracy of an Electronic Pulmonary Embolism Severity Index Auto-Populated from the Electronic Health Record: Setting the stage for computerized clinical decision support

BACKGROUND

The Pulmonary Embolism (PE) Severity Index identifies emergency department (ED) patients with acute PE that can be safely managed without hospitalization. However, the Index comprises 11 weighted variables, complexity that can impede its integration into contextual workflow.

OBJECTIVE

We designed a computerized version of the PE Severity Index (e-Index) to automatically extract the required variables from discrete fields in the electronic health record (EHR). We tested the e-Index on the study population to determine its accuracy compared with a gold standard generated by physician abstraction of the EHR on manual chart review.

METHODS

This retrospective cohort study included adults with objectively-confirmed acute PE in four community EDs from 2010-2012. Outcomes included performance characteristics of the e-Index for individual values, the number of cases requiring physician editing, and the accuracy of the e-Index risk category (low vs. higher).

RESULTS

For the 593 eligible patients, there were 6,523 values automatically extracted. Fifty one of these needed physician editing, yielding an accuracy at the value-level of 99.2% (95% confidence interval [CI], 99.0%-99.4%). Sensitivity was 96.9% (95% CI, 96.0%-97.9%) and specificity was 99.8% (95% CI, 99.7%-99.9%). The 51 corrected values were distributed among 47 cases: 43 cases required the correction of one variable and four cases required the correction of two. At the risk-category level, the e-Index had an accuracy of 96.8% (95% CI, 95.0%-98.0%), under-classifying 16 higher-risk cases (2.7%) and over-classifying 3 low-risk cases (0.5%).

CONCLUSION

Our automated extraction of variables from the EHR for the e-Index demonstrates substantial accuracy, requiring a minimum of physician editing. This should increase user acceptability and implementation success of a computerized clinical decision support system built around the e-Index, and may serve as a model to automate other complex risk stratification instruments.

Increased risk of mycobacterial infections associated with anti-rheumatic medications

RATIONALE

Anti-tumour necrosis factor (TNF) agents and other anti-rheumatic medications increase the risk of TB in rheumatoid arthritis (RA). Whether they increase the risk of infections with nontuberculous mycobacteria (NTM) is uncertain.

OBJECTIVES

To determine the effect of anti-TNF therapy and other anti-rheumatic drugs on the risk of NTM disease and TB in older patients with RA.

METHODS

Population-based nested case-control study among Ontario seniors aged ≥67 years with RA who were prescribed at least one anti-rheumatic medication between 2001 and 2011. We identified cases of TB and NTM disease microbiologically and identified drug exposures using linked prescription drug claims. We estimated ORs using conditional logistic regression, controlling for several potential confounders.

MEASUREMENTS AND MAIN RESULTS

Among 56 269 older adults with RA, we identified 37 cases of TB and 211 cases of NTM disease; each case was matched to up to 10 controls. Individuals with TB or NTM disease were both more likely to be using anti-TNF therapy (compared with non-use); adjusted ORs (95% CIs) were 5.04 (1.27 to 20.0) and 2.19 (1.10 to 4.37), respectively. Exposure to leflunomide and other anti-rheumatic drugs with high immunosuppressing potential also were associated with both TB and NTM disease, while oral corticosteroids and hydroxychloroquine were associated with NTM disease.

CONCLUSIONS

Anti-TNF use is associated with increased risk of both TB and NTM disease, but appears to be a relatively greater risk for TB. Several other anti-rheumatic drugs were also associated with mycobacterial infections.

The increasing burden and complexity of multimorbidity

BACKGROUND

Multimorbidity, the co-occurrence of two or more chronic conditions, is common among older adults and is known to be associated with high costs and gaps in quality of care. Population-based estimates of multimorbidity are not readily available, which makes future planning a challenge. We aimed to estimate the population-based prevalence and trends of multimorbidity in Ontario, Canada and to examine patterns in the co-occurrence of chronic conditions.

METHODS

This retrospective cohort study includes all Ontarians (aged 0 to 105 years) with at least one of 16 common chronic conditions. Descriptive statistics were used to examine and compare the prevalence of multimorbidity by age and number of conditions in 2003 and 2009. The co-occurrence of chronic conditions among individuals with multimorbidity was also explored.

RESULTS

The prevalence of multimorbidity among Ontarians rose from 17.4% in 2003 to 24.3% in 2009, a 40% increase. This increase over time was evident across all age groups. Within individual chronic conditions, multimorbidity rates ranged from 44% to 99%. Remarkably, there were no dominant patterns of co-occurring conditions.

CONCLUSION

The high prevalence of multimorbidity and numerous combinations of conditions suggests that single, disease-oriented management programs may be less effective or efficient tools for high quality care compared to person-centered approaches.

The increasing burden and complexity of multimorbidity

BACKGROUND

Multimorbidity, the co-occurrence of two or more chronic conditions, is common among older adults and is known to be associated with high costs and gaps in quality of care. Population-based estimates of multimorbidity are not readily available, which makes future planning a challenge. We aimed to estimate the population-based prevalence and trends of multimorbidity in Ontario, Canada and to examine patterns in the co-occurrence of chronic conditions.

METHODS

This retrospective cohort study includes all Ontarians (aged 0 to 105 years) with at least one of 16 common chronic conditions. Descriptive statistics were used to examine and compare the prevalence of multimorbidity by age and number of conditions in 2003 and 2009. The co-occurrence of chronic conditions among individuals with multimorbidity was also explored.

RESULTS

The prevalence of multimorbidity among Ontarians rose from 17.4% in 2003 to 24.3% in 2009, a 40% increase. This increase over time was evident across all age groups. Within individual chronic conditions, multimorbidity rates ranged from 44% to 99%. Remarkably, there were no dominant patterns of co-occurring conditions.

CONCLUSION

The high prevalence of multimorbidity and numerous combinations of conditions suggests that single, disease-oriented management programs may be less effective or efficient tools for high quality care compared to person-centered approaches.

Asthma exacerbations during the first trimester of pregnancy and congenital malformations: revisiting the association in a large representative cohort

BACKGROUND

We previously reported an increased prevalence of any congenital malformation among women experiencing moderate-to-severe asthma exacerbations during the first trimester of pregnancy, based on a study in which 90.1% of the cohort of women were social welfare recipients. This study re-examined the association between asthma exacerbations and congenital malformations in a new large representative cohort of asthmatic pregnant women.

METHODS

A cohort of 36 587 pregnancies in asthmatic women was reconstructed from Québec Province administrative databases (1998-2009). Occurrences of asthma exacerbations during the first trimester of pregnancy were assessed and categorised into severe, moderate and no such exacerbations. For comparison, we also considered moderate and severe asthma exacerbations combined. Congenital malformations were identified using diagnoses recorded in the hospitalisation database. Generalised estimation equations were used to estimate adjusted ORs of congenital malformations.

RESULTS

The prevalence of any congenital malformation was 19.1%, 11.7% and 12.0% among women with severe, moderate and no such exacerbations during the first trimester, respectively. The adjusted OR for all malformations was 1.64 (95% CI 1.02 to 2.64) when women with severe exacerbations were compared with those in the reference group, while no association was seen for moderate exacerbations. Also, no association was observed between cases of moderate and severe asthma exacerbations combined and any congenital malformation.

CONCLUSIONS

Only severe asthma exacerbations were found to significantly increase the risk of congenital malformations in this representative study. Previous studies possibly overestimated the risk because they were based mainly on women at a lower socioeconomic status.

Methods for identifying 30 chronic conditions: application to administrative data

BACKGROUND

Multimorbidity is common and associated with poor clinical outcomes and high health care costs. Administrative data are a promising tool for studying the epidemiology of multimorbidity. Our goal was to derive and apply a new scheme for using administrative data to identify the presence of chronic conditions and multimorbidity.

METHODS

We identified validated algorithms that use ICD-9 CM/ICD-10 data to ascertain the presence or absence of 40 morbidities. Algorithms with both positive predictive value and sensitivity ≥70% were graded as "high validity"; those with positive predictive value ≥70% and sensitivity <70% were graded as "moderate validity". To show proof of concept, we applied identified algorithms with high to moderate validity to inpatient and outpatient claims and utilization data from 574,409 people residing in Edmonton, Canada during the 2008/2009 fiscal year.

RESULTS

Of the 40 morbidities, we identified 30 that could be identified with high to moderate validity. Approximately one quarter of participants had identified multimorbidity (2 or more conditions), one quarter had a single identified morbidity and the remaining participants were not identified as having any of the 30 morbidities.

CONCLUSIONS

We identified a panel of 30 chronic conditions that can be identified from administrative data using validated algorithms, facilitating the study and surveillance of multimorbidity. We encourage other groups to use this scheme, to facilitate comparisons between settings and jurisdictions.

Methods for identifying 30 chronic conditions: application to administrative data

BACKGROUND

Multimorbidity is common and associated with poor clinical outcomes and high health care costs. Administrative data are a promising tool for studying the epidemiology of multimorbidity. Our goal was to derive and apply a new scheme for using administrative data to identify the presence of chronic conditions and multimorbidity.

METHODS

We identified validated algorithms that use ICD-9 CM/ICD-10 data to ascertain the presence or absence of 40 morbidities. Algorithms with both positive predictive value and sensitivity ≥70% were graded as "high validity"; those with positive predictive value ≥70% and sensitivity <70% were graded as "moderate validity". To show proof of concept, we applied identified algorithms with high to moderate validity to inpatient and outpatient claims and utilization data from 574,409 people residing in Edmonton, Canada during the 2008/2009 fiscal year.

RESULTS

Of the 40 morbidities, we identified 30 that could be identified with high to moderate validity. Approximately one quarter of participants had identified multimorbidity (2 or more conditions), one quarter had a single identified morbidity and the remaining participants were not identified as having any of the 30 morbidities.

CONCLUSIONS

We identified a panel of 30 chronic conditions that can be identified from administrative data using validated algorithms, facilitating the study and surveillance of multimorbidity. We encourage other groups to use this scheme, to facilitate comparisons between settings and jurisdictions.

Asthma, type 1 and type 2 diabetes mellitus, and inflammatory bowel disease amongst South Asian immigrants to Canada and their children: a population-based cohort study

BACKGROUND

There is a high and rising rate of immune-mediated diseases in the Western world. Immigrants from South Asia have been reported to be at higher risk upon arrival to the West. We determined the risk of immune-mediated diseases in South Asian and other immigrants to Ontario, Canada, and their Ontario-born children.

METHODS

Population-based cohorts of patients with asthma, type 1 diabetes (T1DM), type 2 diabetes (T2DM), and inflammatory bowel disease (IBD) were derived from health administrative data. We determined the standardized incidence, and the adjusted risk of these diseases in immigrants from South Asia, immigrants from other regions, compared with non-immigrant residents of Ontario. The risk of these diseases in the Ontario-born children of immigrants were compared to the children of non-immigrants.

RESULTS

Compared to non-immigrants, adults from South Asia had higher risk of asthma (IRR 1.56, 95%CI 1.51-1.61) and T2DM (IRR 2.59, 95%CI 2.53-2.65). Adults from South Asia had lower incidence of IBD than non-immigrants (IRR 0.32, 95%CI 0.22-0.49), as did immigrants from other regions (IRR 0.29, 95%CI 0.20-0.42). Compared to non-immigrant children, the incidence of asthma (IRR 0.66, 95%CI 0.62-0.71) and IBD (IRR 0.47, 95%CI 0.33-0.67) was low amongst immigrant children from South Asia. However, the risk in Ontario-born children of South Asian immigrants relative to the children of non-immigrants was higher for asthma (IRR 1.75, 95%CI 1.69-1.81) and less attenuated for IBD (IRR 0.90, 95%CI 0.65-1.22).

CONCLUSION

Early-life environmental exposures may trigger a genetic predisposition to the development of asthma and IBD in South Asian immigrants and their Canada-born children.

Is drug insurance status an effect modifier in epidemiologic database studies? The case of maternal asthma and major congenital malformations

BACKGROUND

Our previous work on the association between maternal asthma and congenital malformations was based on cohorts formed by women with public drug insurance, i.e., over-represented by women with lower socioeconomic status, questioning the generalizability of our findings. This study aimed to evaluate whether or not drug insurance status, as a proxy of socioeconomic status, is an effect modifier for the association between maternal asthma and major congenital malformations.

METHODS

A cohort of 36,587 pregnancies from asthmatic women and 198,935 pregnancies from nonasthmatic women selected independently of their drug insurance status was reconstructed with Québec administrative databases (1998-2009). Asthmatic women were identified using a validated case definition of asthma. Cases of major congenital malformations were identified using diagnostic codes recorded in the hospitalization database. Drug insurance status at the beginning of pregnancy was classified into three groups: publicly insured with social welfare, publicly insured without social welfare, and privately insured. Adjusted odds ratios were estimated with generalized estimation equations, including an interaction term between maternal asthma and drug insurance status.

RESULTS

The prevalence of congenital malformations was 6.8% among asthmatic women and 5.8% among nonasthmatics. The impact of asthma on the prevalence of congenital malformations was significantly greater in women publicly insured with social welfare (odds ratio = 1.42; 95% confidence interval, 1.25-1.61) than in the other two groups ([odds ratio = 1.10; 1.00-1.21] in the publicly insured without social welfare and [odds ratio = 1.13; 1.07-1.20] in the privately insured group).

CONCLUSION

The increased risk of major congenital malformation associated with asthma was significantly higher among pregnant women publicly insured with social welfare than among those privately insured. As a result of this effect modification by drug insurance status, findings from Québec observational studies using databases mainly formed of patients publicly insured with social welfare may not be generalized to the entire population.

Health administrative data can be used to define a shared care typology for people with HIV

OBJECTIVES

Building on an existing theoretical shared primary care/specialist care framework to (1) develop a unique typology of care for people living with human immunodeficiency virus (HIV) in Ontario, (2) assess sensitivity of the typology by varying typology definitions, and (3) describe characteristics of typology categories.

STUDY DESIGN AND SETTING

Retrospective population-based observational study from April 1, 2009, to March 31, 2012. A total of 13,480 eligible patients with HIV and receiving publicly funded health care in Ontario. We derived a typology of care by linking patients to usual family physicians and to HIV specialists with five possible patterns of care. Patient and physician characteristics and outpatient visits for HIV-related and non-HIV-related care were used to assess the robustness and characteristics of the typology.

RESULTS

Five possible patterns of care were described as low engagement (8.6%), exclusively primary care (52.7%), family physician-dominated comanagement (10.0%), specialist-dominated comanagement (30.5%), and exclusively specialist care (5.2%). Sensitivity analyses demonstrated robustness of typology assignments. Visit patterns varied in ways that conform to typology assignments.

CONCLUSION

We anticipate this typology can be used to assess the impact of care patterns on the quality of primary care for people living with HIV.

Quality of asthma care under different primary care models in Canada: a population-based study

Background

Previous research has shown variations in quality of care and patient outcomes under different primary care models. The objective of this study was to use previously validated, evidence-based performance indicators to measure quality of asthma care over time and to compare quality of care between different primary care models.

Methods

Data were obtained for years 2006 to 2010 from the Ontario Asthma Surveillance Information System, which uses health administrative databases to track individuals with asthma living in the province of Ontario, Canada. Individuals with asthma (n=1,813,922) were divided into groups based on the practice model of their primary care provider (i.e., fee-for-service, blended fee-for-service, blended capitation). Quality of asthma care was measured using six validated, evidence-based asthma care performance indicators.

Results

All of the asthma performance indicators improved over time within each of the primary care models. Compared to the traditional fee-for-service model, the blended fee-for-service and blended capitation models had higher use of spirometry for asthma diagnosis and monitoring, higher rates of inhaled corticosteroid prescription, and lower outpatient claims. Emergency department visits were lowest in the blended fee-for-service group.

Conclusions

Quality of asthma care improved over time within each of the primary care models. However, the amount by which they improved differed between the models. The newer primary care models (i.e., blended fee-for-service, blended capitation) appear to provide better quality of asthma care compared to the traditional fee-for-service model.

Electronic supplementary material

The online version of this article (doi:10.1186/s12875-015-0232-y) contains supplementary material, which is available to authorized users.

Receipt of glucocorticoid monotherapy among Medicare beneficiaries with rheumatoid arthritis

OBJECTIVE

Using disease-modifying antirheumatic drugs (DMARDs) improves outcomes in rheumatoid arthritis (RA) and is a nationally endorsed quality measure. We investigated the prevalence and predictors of receiving glucocorticoids alone for the treatment of RA in a nationwide sample of Medicare beneficiaries.

METHODS

Among individuals ages ≥65 years with RA enrolled in the Part D prescription drug benefit in 2009, we compared those with ≥1 DMARD claim to those receiving glucocorticoid monotherapy, defined as no DMARD claim and an annual glucocorticoid supply of ≥180 days or an annual dose of ≥900 mg of prednisone or equivalent. We fit multivariable models to determine the sociodemographic and clinical factors associated with glucocorticoid monotherapy.

RESULTS

Of 8,125 beneficiaries treated for RA, 10.2% (n = 825) received glucocorticoids alone. Beneficiaries with low incomes were more likely to receive glucocorticoids alone (12.3%; 95% confidence interval [95% CI] 10.9-13.8% versus 9.4%; 95% CI 8.6-10.1%), as were those living in certain US regions. More physician office visits and hospitalizations were associated with glucocorticoid monotherapy. Individuals who had no contact with a rheumatologist were significantly more likely to receive glucocorticoids alone (17.5%; 95% CI 16.0-19.0% versus 8.5%; 95% CI 7.4-9.5% for those with no rheumatology visits versus 1-4 visits).

CONCLUSION

Approximately 1 in 10 Medicare beneficiaries treated for RA received glucocorticoids without DMARDs in 2009. Compared to DMARD users, glucocorticoid users were older, had lower incomes, were more likely to live in certain US regions, and were less likely to have seen a rheumatologist, suggesting persistent gaps in quality of care despite expanded drug coverage under Part D.

Safety of valproic acid in patients with chronic obstructive pulmonary disease: a population-based cohort study

PURPOSE

Valproic acid is an anticonvulsant that also inhibits histone deacetylase (HDAC), a property that could worsen pulmonary function in patients with chronic obstructive pulmonary disease (COPD). The clinical significance of this property is unknown. We therefore compared the risk of COPD exacerbation in older patients with COPD commencing treatment with either valproic acid or phenytoin, an anticonvulsant that does not affect HDAC.

METHODS

We conducted a population-based retrospective cohort study of Ontario residents with COPD aged 66 years or older who started treatment with valproic acid or phenytoin between 1 April 1993 and 30 November 2012. The primary outcome was a hospital admission or emergency department visit for a COPD exacerbation within 240 days of drug initiation. A secondary outcome examined initiation of oral corticosteroids in the outpatient setting.

RESULTS

During the study period, we identified 4596 COPD patients who commenced valproic acid and 8478 who commenced phenytoin. Following multivariable adjustment, valproic acid did not increase the risk of the primary outcome (adjusted hazard ratio 1.00, 95% confidence interval 0.79 to 1.26). Although valproic acid was associated with a lower risk of initiating oral corticosteroids in the first thirty days following commencement of anticonvulsant therapy (adjusted hazard ratio 0.32; 95% confidence interval 0.21 to 0.49), no difference was observed during subsequent follow-up.

CONCLUSION

Among older patients with COPD, treatment with valproic acid does not increase the risk of adverse pulmonary outcomes relative to phenytoin. These findings suggest that valproate-induced HDAC inhibition is of little clinical relevance in this context.

The Cardiovascular Health in Ambulatory Care Research Team (CANHEART): using big data to measure and improve cardiovascular health and healthcare services

BACKGROUND

The CArdiovascular HEalth in Ambulatory care Research Team (CANHEART) is conducting a unique, population-based observational research initiative aimed at measuring and improving cardiovascular health and the quality of ambulatory cardiovascular care provided in Ontario, Canada. A particular focus will be on identifying opportunities to improve the primary and secondary prevention of cardiovascular events in Ontario's diverse multiethnic population.

METHODS AND RESULTS

A population-based cohort comprising 9.8 million Ontario adults ≥20 years in 2008 was assembled by linking multiple electronic survey, health administrative, clinical, laboratory, drug, and electronic medical record databases using encoded personal identifiers. The cohort includes ≈9.4 million primary prevention patients and ≈400,000 secondary prevention patients. Follow-up on clinical events is achieved through record linkage to comprehensive hospitalization, emergency department, and vital statistics administrative databases. Profiles of cardiovascular health and preventive care will be developed at the health region level, and the cohort will be used to study the causes of regional variation in the incidence of major cardiovascular events and other important research questions.

CONCLUSIONS

Linkage of multiple databases will enable the CANHEART study cohort to serve as a powerful big data resource for scientific research aimed at improving cardiovascular health and health services delivery. Study findings will be shared with clinicians, policy makers, and the public to facilitate population health interventions and quality improvement initiatives.

Sparse modeling of spatial environmental variables associated with asthma

Geographically distributed environmental factors influence the burden of diseases such as asthma. Our objective was to identify sparse environmental variables associated with asthma diagnosis gathered from a large electronic health record (EHR) dataset while controlling for spatial variation. An EHR dataset from the University of Wisconsin's Family Medicine, Internal Medicine and Pediatrics Departments was obtained for 199,220 patients aged 5-50years over a three-year period. Each patient's home address was geocoded to one of 3456 geographic census block groups. Over one thousand block group variables were obtained from a commercial database. We developed a Sparse Spatial Environmental Analysis (SASEA). Using this method, the environmental variables were first dimensionally reduced with sparse principal component analysis. Logistic thin plate regression spline modeling was then used to identify block group variables associated with asthma from sparse principal components. The addresses of patients from the EHR dataset were distributed throughout the majority of Wisconsin's geography. Logistic thin plate regression spline modeling captured spatial variation of asthma. Four sparse principal components identified via model selection consisted of food at home, dog ownership, household size, and disposable income variables. In rural areas, dog ownership and renter occupied housing units from significant sparse principal components were associated with asthma. Our main contribution is the incorporation of sparsity in spatial modeling. SASEA sequentially added sparse principal components to Logistic thin plate regression spline modeling. This method allowed association of geographically distributed environmental factors with asthma using EHR and environmental datasets. SASEA can be applied to other diseases with environmental risk factors.

Risk of mycobacterial infections associated with rheumatoid arthritis in Ontario, Canada

OBJECTIVE

Patients with rheumatoid arthritis (RA) are at increased risk of TB. Little is known about the risk of nontuberculous mycobacteria (NTM) disease in these patients. We sought to ascertain the rate of NTM infection and TB in all residents of Ontario, Canada, with and without RA.

METHODS

In a cohort study, all Ontarians aged ≥ 15 years in January 2001 were followed until December 2010. Individuals with RA were identified using a validated algorithm to search hospitalization and physician billing claims. We linked Public Health Ontario Laboratory data to identify all cases of laboratory-confirmed TB and NTM disease. Analysis was performed using Cox proportional hazards regression.

RESULTS

We identified 113,558 Ontarians with RA and 9,760,075 Ontarians without RA. Relative to the non-RA group, adjusted hazard ratios (HRs) and 95% CIs for TB (1.92, [1.50-2.47]) and NTM disease (2.07, [1.84-2.32]) demonstrated increased risks in the RA group. Among those with RA, per 100,000 person-years, NTM disease (HR, 41.6; 95% CI, 37.1-46.5) was more common than TB (HR, 8.5; 95% CI, 6.5-10.8). After full adjustment, people with RA who developed NTM disease were 1.81 times as likely to die than uninfected people with RA.

CONCLUSIONS

Mycobacterial infections are more common in Ontarians with RA, with NTM disease more likely than TB. NTM disease is associated with an increased risk of death in patients with RA. Given the rising rates of NTM disease worldwide, determining whether this risk is due to the use of immunosuppressive medications vs RA itself is an important objective for future research.

The association of asthma education centre characteristics on hospitalizations and emergency department visits in Ontario: a population-based study

BACKGROUND

International guidelines recommend patient education as an essential component of optimal asthma management. Since 1990 hospital-based asthma education centres (AECs) have been established in Ontario, Canada. It is unknown whether patient outcomes are related to the level of services provided.

METHODS

Using linked, population-based health administrative and hospital survey data we analyzed a population of patients aged 2 to 55 years with a hospitalization for asthma (N = 12 029) or a high acuity asthma emergency department (ED) visit (N = 63 025) between April 2004 and March 2007 and followed for three years. Administrative data documenting individuals' attendance at AECs were not available. Poisson models were used to test the association of potential access to various AEC service models (outpatient service availability and in-hospital services) with asthma readmissions, ED visits or death within 6 to 36 months following the index admission or ED visit.

RESULTS

Fifty three of 163 acute care hospitals had an AEC (N = 36) or had access by referral (N = 17). All AECs documented use with guideline-based recommendations for AE programs. ED patients having access to an AEC that offered full-time, extended hours had reduced rates of adverse outcomes (adjusted relative rate [aRR] 0.78, 95% confidence interval [CI] 0.69, 0.90) compared to those with no AEC access. Hospitalized patients with access to asthma education during hospitalization had reduced rates of adverse events (aRR 0.87, 95% CI 0.75, 1.00) compared to those with no inhospital AEC access.

CONCLUSION

Although compliant with asthma guideline-based program elements, on a population basis access to asthma education centres is associated only with a modest benefit for some admitted and ED patients and depends on the level of access to services provided. Review of both services provided and strategies to address potential barriers to care are necessary.

The burden of asthma among the South Asian and Chinese population residing in Ontario

BACKGROUND

The South Asian and Chinese populations represent a significant portion of the population of Ontario; however, little is known about the burden of respiratory OBJECTIVE: To investigate the prevalence of asthma and the associated health care burden among South Asian and Chinese populations living in Ontario.

METHODS

Using administrative health data for Ontario, the authors identified individuals of South Asian and Chinese descent using a validated surname algorithm and compared the prevalence of asthma in these groups with the general population using an established asthma case definition for the period 2002 to 2010. Also compared were the rates of asthma-specific emergency department visits and hospitalizations among the ethnic groups.

RESULTS

In 2010, the prevalence of asthma in South Asians residing in Ontario was similar to that of the general population (12.1% versus 12.4%), and was increasing at a faster rate than in the general population (0.51%⁄year versus 0.34%⁄year). Compared with the general population, the South Asian population had fewer emergency department visits for asthma, whereas the asthma-related hospitalization rate was greatest among the South Asian population (0.45 per 100 person-years). The Chinese population had the lowest asthma prevalence and associated health care use.

CONCLUSION

The burden of asthma among South Asians in Ontario is increasing and warrants further investigation to determine the reasons for this rise.

Quantifying comorbidity in individuals with COPD: a population study

Chronic obstructive pulmonary disease (COPD) has been associated with many types of comorbidity. We aimed to quantify the real world impact of COPD on lower respiratory tract infection, cardiovascular disease, diabetes, psychiatric disease, musculoskeletal disease and cancer, and their impact on COPD through health services.

A population study using health administrative data from Ontario, Canada, in 2008–2012 was conducted. Absolute and adjusted relative rates of ambulatory care visits, emergency department visits and hospitalisations for the comorbidities of interest in people with and without COPD were determined and compared.

Among 7 241 591 adults, 909 948 (12.6%) had COPD. Over half of all lung cancer, a third of all lower respiratory tract infection and cardiovascular disease, a quarter of all low trauma fracture, and a fifth of all psychiatric, musculoskeletal, non-lung cancer and diabetes ambulatory care visits, emergency department visits and hospitalisations in Ontario were used by people with COPD. Individuals with COPD used about five times more health services for lung cancer, and two times more health services for lower respiratory tract infections and cardiovascular disease than people without COPD.

Individuals with COPD use a disproportionate amount of health services for comorbid disease, placing significant burden on the healthcare system.

[Development and validation of an algorithm to identify cancer recurrences from hospital data bases]

OBJECTIVES

Hospital cancer registries and hospital databases are valuable and efficient sources of information for research into cancer recurrences. The aim of this study was to develop and validate algorithms for the detection of breast cancer recurrence.

METHODS

A retrospective observational study was conducted on breast cancer cases from the cancer registry of a third level university hospital diagnosed between 2003 and 2009. Different probable cancer recurrence algorithms were obtained by linking the hospital databases and the construction of several operational definitions, with their corresponding sensitivity, specificity, positive predictive value and negative predictive value.

RESULTS

A total of 1,523 patients were diagnosed of breast cancer between 2003 and 2009. A request for bone gammagraphy after 6 months from the first oncological treatment showed the highest sensitivity (53.8%) and negative predictive value (93.8%), and a pathology test after 6 months after the diagnosis showed the highest specificity (93.8%) and negative predictive value (92.6%). The combination of different definitions increased the specificity and the positive predictive value, but decreased the sensitivity.

CONCLUSIONS

Several diagnostic algorithms were obtained, and the different definitions could be useful depending on the interest and resources of the researcher. A higher positive predictive value could be interesting for a quick estimation of the number of cases, and a higher negative predictive value for a more exact estimation if more resources are available. It is a versatile and adaptable tool for other types of tumors, as well as for the needs of the researcher.

Physical health and gender as risk factors for usage of services for mental illness

Background

People with comorbid mental and physical illness (PI) experience worse health, inadequate care and increased mortality relative to those without mental illness (MI). The role of gender in this relationship is not fully understood. This study examined gender differences in onset of mental health service usage among people with physical illness (COPD, asthma, hypertension and type II diabetes) compared with a control cohort.

Methods

We used a unique linked dataset consisting of the 2000–2001 Canadian Community Health Survey and medical records (n=17 050) to examine risk of onset of MI among those with and without PI among Ontario residents (18–74 years old) over a 10-year period (2002–2011). Adjusted COX proportional survival analysis was conducted.

Results

Unadjusted use of MI medical services in the PI cohort was 55.6% among women and 44.7% (p=0.0001) among men; among controls 48.1% of the women and 36.7% of the men used MI medical services (p=0.0001). The relative risk of usage among women in the PI group relative to controls was 1.16. Among men, the relative risk was 1.22. Women were 1.45 times more likely to use MI medical services relative to men (HR=1.45, CI 1.35 to 1.55). Respondents in the PI cohort were 1.32 times more likely to use MI medical services (HR=1.32, CI 1.23 to 1.42) relative to controls. Women in the PI cohort used MI medical services 6.4 months earlier than PI males (p=0.0059). In the adjusted model, women with PI were most likely to use MI medical services, followed by women controls, men with PI and men controls. There was no significant interaction between gender and PI cohort.

Conclusions

Further, gender-based research focusing on onset of usage of MI services among those with and without chronic health problems will enable better understanding of gender-based health disparities to improve healthcare quality, delivery and public health policy.

Asthma and chronic obstructive pulmonary disease (COPD) prevalence and health services use in Ontario Métis: a population-based cohort study

INTRODUCTION

Chronic respiratory diseases cause a significant health and economic burden around the world. In Canada, Aboriginal populations are at increased risk of asthma and chronic obstructive pulmonary disease (COPD). There is little known, however, about these diseases in the Canadian Métis population, who have mixed Aboriginal and European ancestry. A population-based study was conducted to quantify asthma and COPD prevalence and health services use in the Métis population of Ontario, Canada's largest province.

METHODS

The Métis Nation of Ontario Citizenship Registry was linked to provincial health administrative databases to measure and compare burden of asthma and COPD between the Métis and non-Métis populations of Ontario between 2009 and 2012. Asthma and COPD prevalence, health services use (general physician and specialist visits, emergency department visits, hospitalizations), and mortality were measured.

RESULTS

Prevalences of asthma and COPD were 30% and 70% higher, respectively, in the Métis compared to the general Ontario population (p<0.001). General physician and specialist visits were significantly lower in Métis with asthma, while general physician visits for COPD were significantly higher. Emergency department visits and hospitalizations were generally higher for Métis compared to non-Métis with either disease. All-cause mortality in Métis with COPD was 1.3 times higher compared to non-Métis with COPD (p = 0.01).

CONCLUSION

There is a high burden of asthma and COPD in Ontario Métis, with significant prevalence and acute health services use related to these diseases. Lower rates of physician visits suggest barriers in access to primary care services.

A cross-sectional, population-based study measuring comorbidity among people living with HIV in Ontario

BACKGROUND

As people diagnosed with HIV and receiving combination antiretroviral therapy are now living longer, they are likely to acquire chronic conditions related to normal ageing and the effects of HIV and its treatment. Comordidities for people with HIV have not previously been described from a representative population perspective.

METHODS

We used linked health administrative data from Ontario, Canada. We applied a validated algorithm to identify people with HIV among all residents aged 18 years or older between April 1, 1992 and March 31, 2009. We randomly selected 5 Ontario adults who were not identified with HIV for each person with HIV for comparison. Previously validated case definitions were used to identify persons with mental health disorders and any of the following physical chronic diseases: diabetes, congestive heart failure, acute myocardial infarction, stroke, hypertension, asthma, chronic obstructive lung disease, peripheral vascular disease and end-stage renal failure. We examined multimorbidity prevalence as the presence of at least two physical chronic conditions, or as combined physical-mental health multimorbidity. Direct age-sex standardized rates were calculated for both cohorts for comparison.

RESULTS

34.4% (95% confidence interval (CI) 33.6% to 35.2%) of people with HIV had at least one other physical condition. Prevalence was especially high for mental health conditions (38.6%), hypertension (14.9%) and asthma (12.7%). After accounting for age and sex differences, people with HIV had significantly higher prevalence of all chronic conditions except myocardial infarction and hypertension, as well as substantially higher multimorbidity (prevalence ratio 1.30, 95% CI 1.18 to 1.44) and combined physical-mental health multimorbidity (1.79, 95% CI 1.65 to 1.94). Prevalence of multimorbidity among people with HIV increased with age. The difference in prevalence of multimorbidity between the two cohorts was more pronounced among women.

CONCLUSION

People living with HIV in Ontario, especially women, had higher prevalence of comorbidity and multimorbidity than the general population. Quantifying this morbidity at the population level can help inform healthcare delivery requirements for this complex population.

Trends in HIV prevalence, new HIV diagnoses, and mortality among adults with HIV who entered care in Ontario, 1996/1997 to 2009/2010: a population-based study

BACKGROUND

Population-based estimates of HIV prevalence, rates of new HIV diagnoses, and mortality rates among persons with HIV who have entered care are needed to optimize health service delivery and to improve the health outcomes of these individuals. However, these data have been lacking for Ontario.

METHODS

Using a validated case-finding algorithm and linked administrative health care databases, we conducted a population-based study to determine the prevalence of HIV and rates of new HIV diagnoses among adults aged 18 years or older in Ontario between fiscal year 1996/1997 and fiscal year 2009/2010, as well as all-cause mortality rates among persons with HIV over the same period.

RESULTS

Between 1996/1997 and 2009/2010, the number of adults living with HIV increased by 98.6% (from 7608 to 15,107), and the age- and sex-standardized prevalence of HIV increased by 52.8% (from 92.8 to 141.8 per 100,000 population; p < 0.001). Women and individuals 50 years of age or older accounted for increasing proportions of persons with HIV, rising from 12.8% to 19.7% (p < 0.001) and from 10.4% to 29.9% (p < 0.001), respectively, over the study period. During the study period, age- and sex-standardized rates of new HIV diagnoses decreased by 32.5% (from 12.3 to 8.3 per 100,000 population; p < 0.001) and mortality rates among adults with HIV decreased by 71.9% (from 5.7 to 1.6 per 100 adults with HIV; p < 0.001).

INTERPRETATION

The prevalence of HIV infection in Ontario increased considerably between 1996/1997 and 2009/2010, with a greater relative burden falling on women and individuals aged 50 years of age or older. These trends may be due to the decreased rate of new diagnoses among younger men. All-cause mortality rates declined among persons with HIV who entered care.