Propofol sedation does not improve measures of colonoscopy quality but increase cost - findings from a large population-based cohort study

Background

Propofol is often used for sedation during colonoscopy. We assessed the impact of propofol sedation on colonoscopy related quality metrics and cost in a population-based cohort study.

Methods

All colonoscopies performed at 21 hospitals in the province of Ontario, Canada, during an 18-month period, from April 1, 2017 to October 31, 2018, using either propofol or conscious sedation were evaluated. The primary outcome was adenoma detection rate (ADR) and secondary outcomes were sessile serrated polyp detection rate (ssPDR), polyp detection rate (PDR), cecal intubation rate (CIR), and perforation rate. Binary outcomes were assessed using a modified Poisson regression model adjusted for clustering and potential confounders based on patient, procedure, and physician characteristics.

Findings

A total of 46,634 colonoscopies were performed, of which 16,408 (35.2%) received propofol and 30,226 (64.8%) received conscious sedation. Compared to conscious sedation, the use of propofol was associated with a lower ADR (24.6% vs. 27.0%, p < 0.0001) but not ssPDR (5.0% vs. 4.7%, p = 0.26), PDR (40.5% vs 40.4%, p = 0.79), CIR (97.1% vs. 96.8%, p = 0.15) or perforation rate (0.04% vs. 0.06%, p = 0.45). On multi-variable analysis, propofol sedation was not associated with any differences in ADR (RR = 0.90, 95% CI 0.74-1.10, p = 0.30), ssPDR (RR = 1.20, 95% CI 0.90-1.60, p = 0.22), PDR (RR = 1.00, 95% CI 0.90-1.11, p = 0.99), or CIR (RR = 1.00, 95% CI 0.80-1.26, p = 0.99). The additional cost associated with propofol sedation was $12,730,496 for every 100,000 cases.

Interpretation

The use of propofol sedation was not associated with improved colonoscopy related quality metrics but increased costs. The routine use of propofol for colonoscopy should be reevaluated.

Funding

None.

Cost-Effectiveness Analysis of Pharmacogenomics (PGx)-Based Warfarin, Apixaban, and Rivaroxaban Versus Standard Warfarin for the Management of Atrial Fibrillation in Ontario, Canada

OBJECTIVE

To assess the cost-effectiveness of pharmacogenomics (PGx)-based warfarin (i.e., warfarin dosing following genetic testing), apixaban, and rivaroxaban oral anticoagulation versus standard warfarin for the treatment of newly diagnosed patients with nonvalvular atrial fibrillation (AF) aged ≥ 65 years.

METHODS

We developed a Markov decision-analytic model to compare costs [2017 Canadian dollars (C$)] and quality-adjusted life years (QALYs) from the Ontario health care payer perspective over a life-time horizon. The parameters used in the model were derived from the published literature, the Ontario health care administrative database, and expert opinion. To account for the uncertainty of model parameters, we conducted extensive deterministic and probabilistic sensitivity analyses. The results were summarized using incremental cost-effectiveness ratios (ICERs) and cost-effectiveness acceptability curves.

RESULTS

We found that PGx-based warfarin had an ICER of C$17,584/QALY compared with standard warfarin, and apixaban had an ICER of C$64,590/QALY compared with PGx-based warfarin in our base-case analysis. Rivaroxaban was extendedly dominated by PGx-based warfarin and apixaban. The probabilistic sensitivity analysis showed that apixaban, rivaroxaban, PGx-based warfarin, and standard warfarin were cost-effective at some willingness-to-pay (WTP) thresholds. PGx-based warfarin had a higher probability of being cost-effective than apixaban (51.3% versus 14.3%) at a WTP threshold of C$50,000/QALY. At a WTP threshold of C$100,000/QALY, apixaban had a higher probability of being cost-effective than PGx-based warfarin (54.6% versus 22.6%).

CONCLUSION

We found that PGx-based warfarin for patients with AF is cost-effective at a WTP threshold of C$50,000/QALY. Apixaban had a higher probability of being cost-effective (> 50%) at a WTP threshold of C$93,000/QALY.

Risk stratification for treating people at ultra-high risk for psychosis: A cost-effectiveness analysis

People who are at ultra-high risk (UHR) for psychosis receive clinical care with the aim to prevent first-episode psychosis (FEP), regardless of the risk of conversion to psychosis. An economic model from the Canadian health system perspective was developed to evaluate the cost-effectiveness of treating all with UHR compared to risk stratification over a 15-year time horizon, based on conversion probability, expected quality-of-life and costs. The analysis used a decision tree followed by a Markov model. Health states included: Not UHR, UHR with <20 % risk of conversion to FEP (based on the North American Prodrome Longitudinal Study risk calculator), UHR with ≥20 % risk, FEP, Remission, Post-FEP, and Death. The analysis found that: risk stratification (i.e., only treating those with ≥20 % risk) had lower costs ($1398) and quality-adjusted life-years (0.055 QALYs) per person compared to treating all. The incremental cost-effectiveness ratio for 'treat all' was $25,448/QALY, and suggests treating all may be cost-effective. The model was sensitive to changes to the probability of conversion.

Pricing Treatments Cost-Effectively when They Have Multiple Indications: Not Just a Simple Threshold Analysis

BACKGROUND

Economic evaluations of treatments increasingly employ price-threshold analyses. When a treatment has multiple indications, standard price-threshold analyses can be overly simplistic. We examine how rules governing indication-specific prices and reimbursement decisions affect value-based price analyses.

METHODS

We analyze a 2-stage game between 2 players: the therapy's manufacturer and the payer purchasing it for patients. First, the manufacturer selects a price(s) that may be indication specific. Then, the payer decides whether to provide reimbursement at the offered price(s). We assume known indication-specific demand. The manufacturer seeks to maximize profit. The payer seeks to maximize total population incremental net monetary benefit and will not pay more than their willingness-to-pay threshold. We consider game variants defined by constraints on the manufacturer's ability to price and payer's ability to provide reimbursement differentially by indication.

RESULTS

When both the manufacturer and payer can make indication-specific decisions, the problem simplifies to multiple single-indication price-threshold analyses, and the manufacturer captures all the consumer surplus. When the manufacturer is restricted to one price and the payer must make an all-or-nothing reimbursement decision, the selected price is a weighted average of indication-specific threshold prices such that reimbursement of more valuable indications subsidizes reimbursement of less valuable indications. With a single price and indication-specific coverage decisions, the manufacturer may select a high price where fewer patients receive treatment because the payer restricts reimbursement to the set of indications providing value commensurate with the high price. However, the manufacturer may select a low price, resulting in reimbursement for more indications and positive consumer surplus.

CONCLUSIONS

When treatments have multiple indications, economic evaluations including price-threshold analyses should carefully consider jurisdiction-specific rules regarding pricing and reimbursement decisions.

HIGHLIGHTS

With treatment prices rising, economic evaluations increasingly employ price-threshold analyses to identify value-based prices. Standard price-threshold analyses can be overly simplistic when treatments have multiple indications.Jurisdiction-specific rules governing indication-specific prices and reimbursement decisions affect value-based price analyses.When the manufacturer is restricted to one price for all indications and the payer must make an all-or-nothing reimbursement decision, the selected price is a weighted average of indication-specific threshold prices such that reimbursement of the more valuable indications subsidize reimbursement of the less valuable indications.With a single price and indication-specific coverage decisions, the manufacturer may select a high price with fewer patients treated than in the first-best solution. There are also cases in which the manufacturer selects a lower price, resulting in reimbursement for more indications and positive consumer surplus.

Impact of COVID-19-related health care disruptions on pathologic cancer staging during the first pandemic year: a retrospective cohort study from March 2018 to March 2021

BACKGROUND

The COVID-19 pandemic has created major disruptions in cancer care, with reductions in diagnostic tests and treatments. We evaluated the impact of these health care-related changes on cancer staging by comparing cancers staged before and during the pandemic.

METHODS

We performed a retrospective cohort study at London Health Sciences Centre and St. Joseph's Health Care London, London, Ontario, Canada. We evaluated all pathologically staged breast, colorectal, prostate, endometrial and lung cancers (the 5 most common cancers by site, excluding nonmelanoma skin cancer) over a 3-year period (Mar. 15, 2018-Mar. 14, 2021). The pre-COVID-19 group included procedures performed between Mar. 15, 2018, and Mar. 14, 2020, and the COVID-19 group included procedures performed between Mar. 15, 2020, and Mar. 14, 2021. The primary outcome was cancer stage group, based on the pathologic tumour, lymph node, metastasis system. We performed univariate analyses to compare demographic characteristics, pathologic features and cancer stage between the 2 groups. We performed multivariable ordinal regression analyses using the proportional odds model to evaluate the association between stage and timing of staging (before v. during the pandemic).

RESULTS

There were 4055 cases across the 5 cancer sites. The average number of breast cancer staging procedures per 30 days increased during the pandemic compared to the yearly average in the pre-COVID-19 period (41.3 v. 39.6), whereas decreases were observed for endometrial cancer (15.9 v. 16.4), colorectal cancer (21.8 v. 24.3), prostate cancer (13.6 v. 18.5) and lung cancer (11.5 v. 15.9). For all cancer sites, there were no statistically significant differences in demographic characteristics, pathologic features or cancer stage between the 2 groups (p > 0.05). In multivariable regression analysis, for all cancer sites, cases staged during the pandemic were not associated with higher stage (breast: odds ratio [OR] 1.071, 95% confidence interval [CI] 0.826-1.388; colorectal: OR 1.201, 95% CI 0.869-1.661; endometrium: OR 0.792, 95% CI 0.495-1.252; prostate: OR 1.171, 95% CI 0.765-1.794; and lung: OR 0.826, 95% CI 0.535-1.262).

INTERPRETATION

Cancer cases staged during the first year of the COVID-19 pandemic were not associated with higher stage; this likely reflects the prioritization of cancer procedures during times of reduced capacity. The impact of the pandemic period on staging procedures varied between cancer sites, which may reflect differences in clinical presentation, detection and treatment.

White matter hyperintensities and longitudinal cognitive decline in cognitively normal populations and across diagnostic categories: A meta-analysis, systematic review, and recommendations for future study harmonization

INTRODUCTION

The primary aim of this paper is to improve the clinical interpretation of white matter hyperintensities (WMHs) and provide an overarching summary of methodological approaches, allowing researchers to design future studies targeting current knowledge gaps.

METHODS

A meta-analysis and systematic review was performed investigating associations between baseline WMHs and longitudinal cognitive outcomes in cognitively normal populations, and populations with mild cognitive impairment (MCI), Alzheimer's disease (AD), and stroke.

RESULTS

Baseline WMHs increase the risk of cognitive impairment and dementia across diagnostic categories and most consistently in MCI and post-stroke populations. Apolipoprotein E (APOE) genotype and domain-specific cognitive changes relating to strategic anatomical locations, such as frontal WMH and executive decline, represent important considerations. Meta-analysis reliability was assessed using multiple methods of estimation, and results suggest that heterogeneity in study design and reporting remains a significant barrier.

DISCUSSION

Recommendations and future directions for study of WMHs are provided to improve cross-study comparison and translation of research into consistent clinical interpretation.

Impact of non-pharmaceutical interventions and vaccination on COVID-19 outbreaks in Nunavut, Canada: a Canadian Immunization Research Network (CIRN) study

Background

Nunavut, the northernmost Arctic territory of Canada, experienced three community outbreaks of the coronavirus disease 2019 (COVID-19) from early November 2020 to mid-June 2021. We sought to investigate how non-pharmaceutical interventions (NPIs) and vaccination affected the course of these outbreaks.

Methods

We used an agent-based model of disease transmission to simulate COVID-19 outbreaks in Nunavut. The model encapsulated demographics and household structure of the population, the effect of NPIs, and daily number of vaccine doses administered. We fitted the model to inferred, back-calculated infections from incidence data reported from October 2020 to June 2021. We then compared the fit of the scenario based on case count data with several counterfactual scenarios without the effect of NPIs, without vaccination, and with a hypothetical accelerated vaccination program whereby 98% of the vaccine supply was administered to eligible individuals.

Results

We found that, without a territory-wide lockdown during the first COVID-19 outbreak in November 2020, the peak of infections would have been 4.7 times higher with a total of 5,404 (95% CrI: 5,015—5,798) infections before the start of vaccination on January 6, 2021. Without effective NPIs, we estimated a total of 4,290 (95% CrI: 3,880—4,708) infections during the second outbreak under the pace of vaccination administered in Nunavut. In a hypothetical accelerated vaccine rollout, the total infections during the second Nunavut outbreak would have been 58% lower, to 1,812 (95% CrI: 1,593—2,039) infections. Vaccination was estimated to have the largest impact during the outbreak in April 2021, averting 15,196 (95% CrI: 14,798—15,591) infections if the disease had spread through Nunavut communities. Accelerated vaccination would have further reduced the total infections to 243 (95% CrI: 222—265) even in the absence of NPIs.

Conclusions

NPIs have been essential in mitigating pandemic outbreaks in this large, geographically distanced and remote territory. While vaccination has the greatest impact to prevent infection and severe outcomes, public health implementation of NPIs play an essential role in the short term before attaining high levels of immunity in the population.

Supplementary information

The online version contains supplementary material available at 10.1186/s12889-022-13432-1.

Intravenous Thrombolysis After First-Ever Ischemic Stroke and Reduced Incident Dementia Rate

BACKGROUND AND PURPOSE

The use of intravenous thrombolysis is associated with improved clinical outcomes. Whether thrombolysis is associated with reduced incidence of poststroke dementia remains uncertain. We sought to estimate if the use of thrombolysis following first-ever ischemic stroke was associated with a reduced rate of incident dementia using a pragmatic observational design.

METHODS

We included first-ever ischemic stroke patients from the Ontario Stroke Registry who had not previously been diagnosed with dementia. The primary outcome was incident dementia ascertained by a validated diagnostic algorithm. We employed inverse probability of treatment-weighted Cox proportional hazard models to estimate the cause-specific hazard ratio for the association of thrombolysis and incident dementia at 1 and 5 years following stroke.

RESULTS

From July 2003 to March 2013, 7072 patients with ischemic stroke were included, 3276 (46.3%) were female and mean age was 71.0 (SD, 12.8) years. Overall, 38.2% of the cohort (n=2705) received thrombolysis, 77.2% (n=2087) of which was administered within 3 hours of stroke onset. In the first year following stroke, thrombolysis administration was associated with a 24% relative reduction in the rate of developing dementia (cause-specific hazard ratio, 0.76 [95% CI, 0.58-0.97]). This association remained significant at 5 years (cause-specific hazard ratio, 0.79 [95% CI, 0.66-0.91]) and at the end of follow-up (median 6.3 years; cause-specific hazard ratio, 0.79 [95% CI, 0.68-0.89]).

CONCLUSIONS

Thrombolysis administration following first-ever ischemic stroke was independently associated with a reduced rate of dementia. Incident dementia should be considered as a relevant outcome when evaluating risk/benefit of thrombolysis in ischemic stroke patients.

Impact of university re-opening on total community COVID-19 burden

BACKGROUND

University students have higher average number of contacts than the general population. Students returning to university campuses may exacerbate COVID-19 dynamics in the surrounding community.

METHODS

We developed a dynamic transmission model of COVID-19 in a mid-sized city currently experiencing a low infection rate. We evaluated the impact of 20,000 university students arriving on September 1 in terms of cumulative COVID-19 infections, time to peak infections, and the timing and peak level of critical care occupancy. We also considered how these impacts might be mitigated through screening interventions targeted to students.

RESULTS

If arriving students reduce their contacts by 40% compared to pre-COVID levels, the total number of infections in the community increases by 115% (from 3,515 to 7,551), with 70% of the incremental infections occurring in the general population, and an incremental 19 COVID-19 deaths. Screening students every 5 days reduces the number of infections attributable to the student population by 42% and the total COVID-19 deaths by 8. One-time mass screening of students prevents fewer infections than 5-day screening, but is more efficient, requiring 196 tests needed to avert one infection instead of 237.

INTERPRETATION

University students are highly inter-connected with the surrounding off-campus community. Screening targeted at this population provides significant public health benefits to the community through averted infections, critical care admissions, and COVID-19 deaths.

Multifaceted strategies for the control of COVID-19 outbreaks in long-term care facilities in Ontario, Canada

The novel coronavirus disease 2019 (COVID-19) has caused severe outbreaks in Canadian long-term care facilities (LTCFs). In Canada, over 80% of COVID-19 deaths during the first pandemic wave occurred in LTCFs. We sought to evaluate the effect of mitigation measures in LTCFs including frequent testing of staff, and vaccination of staff and residents. We developed an agent-based transmission model and parameterized it with disease-specific estimates, temporal sensitivity of nasopharyngeal and saliva testing, results of vaccine efficacy trials, and data from initial COVID-19 outbreaks in LTCFs in Ontario, Canada. Characteristics of staff and residents, including contact patterns, were integrated into the model with age-dependent risk of hospitalization and death. Estimates of infection and outcomes were obtained and 95% credible intervals were generated using a bias-corrected and accelerated bootstrap method. Weekly routine testing of staff with 2-day turnaround time reduced infections among residents by at least 25.9% (95% CrI: 23.3%-28.3%), compared to baseline measures of mask-wearing, symptom screening, and staff cohorting alone. A similar reduction of hospitalizations and deaths was achieved in residents. Vaccination averted 2-4 times more infections in both staff and residents as compared to routine testing, and markedly reduced hospitalizations and deaths among residents by 95.9% (95% CrI: 95.4%-96.3%) and 95.8% (95% CrI: 95.5%-96.1%), respectively, over 200 days from the start of vaccination. Vaccination could have a substantial impact on mitigating disease burden among residents, but may not eliminate the need for other measures before population-level control of COVID-19 is achieved.

Multifaceted strategies for the control of COVID-19 outbreaks in long-term care facilities in Ontario, Canada

The novel coronavirus disease 2019 (COVID-19) has caused severe outbreaks in Canadian long-term care facilities (LTCFs). In Canada, over 80% of COVID-19 deaths during the first pandemic wave occurred in LTCFs. We sought to evaluate the effect of mitigation measures in LTCFs including frequent testing of staff, and vaccination of staff and residents. We developed an agent-based transmission model and parameterized it with disease-specific estimates, temporal sensitivity of nasopharyngeal and saliva testing, results of vaccine efficacy trials, and data from initial COVID-19 outbreaks in LTCFs in Ontario, Canada. Characteristics of staff and residents, including contact patterns, were integrated into the model with age-dependent risk of hospitalization and death. Estimates of infection and outcomes were obtained and 95% credible intervals were generated using a bias-corrected and accelerated bootstrap method. Weekly routine testing of staff with 2-day turnaround time reduced infections among residents by at least 25.9% (95% CrI: 23.3% - 28.3%), compared to baseline measures of mask-wearing, symptom screening, and staff cohorting alone. A similar reduction of hospitalizations and deaths was achieved in residents. Vaccination averted 2-4 times more infections in both staff and residents as compared to routine testing, and markedly reduced hospitalizations and deaths among residents by 95.9% (95% CrI: 95.4% - 96.3%) and 95.8% (95% CrI: 95.5% - 96.1%), respectively, over 200 days from the start of vaccination. Vaccination could have a substantial impact on mitigating disease burden among residents, but may not eliminate the need for other measures before population-level control of COVID-19 is achieved.

A comparison of COVID-19 epidemiological indicators in Sweden, Norway, Denmark, and Finland

Aims: To compare the early impact of COVID-19 infections and mortality from February to July 2020 across the Nordic nations of Sweden, Norway, Denmark, and Finland through available public data sources and conduct a descriptive analysis of the potential factors that drove different epidemiological outcomes, with a focus on Sweden's response. Methods: COVID-19 cases, deaths, tests, case age distribution, and the difference between 2020 all-cause mortality and the average mortality of the previous 5 years were compared across nations. Patterns in cell phone mobility data, testing strategies, and seniors' care home deaths were also compared. Data for each nation were based on publicly available sources as of July 31, 2020. Results: Compared with its Nordic peers, Sweden had a higher incidence rate across all ages, a higher COVID-19-related death rate only partially explained by population demographics, a higher death rate in seniors' care, and higher all-cause mortality. Sweden had approximately half as much mobility change as its Nordic neighbours until April and followed similar rates as its neighbours from April to July. Denmark led its Nordic peers in testing rates, while Sweden had the highest cumulative test-positivity rate continuously from mid-March. Conclusions: COVID-19 pushed Sweden's health system to its capacity, exposed systemic weaknesses in the seniors' care system, and revealed challenges with implementing effective contact tracing and testing strategies while experiencing a high case burden. Looser government restrictions at the beginning of the outbreak are likely to have played a role in the impact of COVID-19 in Sweden. In an effort to improve epidemic control, Sweden has increased testing rates, implemented more restrictive prevention measures, and increased their intensive care unit bed capacity.

Optimal Allocation of Research Funds under a Budget Constraint

Purpose. Health economic evaluations that include the expected value of sample information support implementation decisions as well as decisions about further research. However, just as decision makers must consider portfolios of implementation spending, they must also identify the optimal portfolio of research investments. Methods. Under a fixed research budget, a decision maker determines which studies to fund; additional budget allocated to one study to increase the study sample size implies less budget available to collect information to reduce decision uncertainty in other implementation decisions. We employ a budget-constrained portfolio optimization framework in which the decisions are whether to invest in a study and at what sample size. The objective is to maximize the sum of the studies' population expected net benefit of sampling (ENBS). We show how to determine the optimal research portfolio and study-specific levels of investment. We demonstrate our framework with a stylized example to illustrate solution features and a real-world application using 6 published cost-effectiveness analyses. Results. Among the studies selected for nonzero investment, the optimal sample size occurs at the point at which the marginal population ENBS divided by the marginal cost of additional sampling is the same for all studies. Compared with standard ENBS optimization without a research budget constraint, optimal budget-constrained sample sizes are typically smaller but allow more studies to be funded. Conclusions. The budget constraint for research studies directly implies that the optimal sample size for additional research is not the point at which the ENBS is maximized for individual studies. A portfolio optimization approach can yield higher total ENBS. Ultimately, there is a maximum willingness to pay for incremental information that determines optimal sample sizes.

Post-mortem 7 Tesla MRI detection of white matter hyperintensities: A multidisciplinary voxel-wise comparison of imaging and histological correlates

White matter hyperintensities (WMH) occur in normal aging and across diagnostic categories of neurodegeneration. Ultra-high field imaging (UHF) MRI machines offer the potential to improve our understanding of WMH. Post-mortem imaging using UHF magnetic resonance imaging (MRI) is a useful way of assessing WMH, however, the responsiveness of UHF-MRI to pathological changes within the white matter has not been characterized. In this study we report post-mortem MRI sequences of white matter hyperintensities in normal aging, Alzheimer's disease, and cerebrovascular disease. Seven Tesla post-mortem MRI reliably detected periventricular WMH using both FLAIR and T2 sequences and reflects underlying pathology of myelin and axon density despite prolonged fixation time. Co-registration of histological images to MRI allowed for direct voxel- wise comparison of imaging findings and pathological changes. Myelin content and cerebrovascular pathology were the most significant predictors of MRI white matter intensity as revealed by linear mixed models. Future work investigating the utility of UHF- MRI in studying cell-specific changes within WMH is required to better understand radio-pathologic correlations.

Dynamics of Drug Resistance: Optimal Control of an Infectious Disease

Antimicrobial resistance is a significant public health threat. In the U.S. alone, 2 million people are infected and 23,000 die each year from antibiotic resistant bacterial infections. In many cases, infections are resistant to all but a few remaining drugs. We examine the case where a single drug remains and solve for the optimal treatment policy for an SIS infectious disease model incorporating the effects of drug resistance. The problem is formulated as an optimal control problem with two continuous state variables, the disease prevalence and drug's "quality" (the fraction of infections that are drug-susceptible). The decision maker's objective is to minimize the discounted cost of the disease to society over an infinite horizon. We provide a new generalizable solution approach that allows us to thoroughly characterize the optimal treatment policy analytically. We prove that the optimal treatment policy is a bang-bang policy with a single switching time. The action/inaction regions can be described by a single boundary that is strictly increasing when viewed as a function of drug quality, indicating that when the disease transmission rate is constant, the policy of withholding treatment to preserve the drug for a potentially more serious future outbreak is not optimal. We show that the optimal value function and/or its derivatives are neither C ¹ nor Lipschitz continuous suggesting that numerical approaches to this family of dynamic infectious disease models may not be computationally stable. Furthermore, we demonstrate that relaxing the standard assumption of constant disease transmission rate can fundamentally change the shape of the action region, add a singular arc to the optimal control, and make preserving the drug for a serious outbreak optimal. In addition, we apply our framework to the case of antibiotic resistant gonorrhea.

Systematic review with meta-analysis: high prevalence and cost of continued aminosalicylate use in patients with ulcerative colitis escalated to immunosuppressive and biological therapies

BACKGROUND

Aminosalicylates are the most frequently prescribed treatment for ulcerative colitis (UC). In the absence of empirical evidence, clinicians are uncertain whether to continue aminosalicylates in patients with UC after escalating therapy.

AIMS

To quantify concomitant aminosalicylate use in UC randomised clinical trials (RCTs), identify factors associated with their use, and estimate treatment costs of concomitant aminosalicylate therapy.

METHODS

MEDLINE, Embase, and CENTRAL were searched from inception to 1 March 2017 for placebo-controlled RCTs of immunosuppressants, biologics, or oral small molecules in adults with UC. The proportion of patients prescribed concomitant aminosalicylates at trial entry was pooled using a random-effects model. Meta-regression was performed to assess trial-level factors associated with aminosalicylate use. Treatment costs were estimated using 2018 formulary data from five Canadian provinces.

RESULTS

Thirty-two trials were included (23 induction only, nine induction, and maintenance trials). The pooled proportion of patients co-prescribed aminosalicylates was 80.7% (95% CI 75.5%-85.1%), with considerable observed heterogeneity (I²  = 95%). In univariable meta-regression, aminosalicylate use was not associated with trial design, setting, year of publication, disease severity, disease duration, or drug class. The estimated direct annual treatment cost of concomitant aminosalicylates is ~$20 million for the Canadian UC population, assuming conservative estimates of UC prevalence, aminosalicylate use and dose, and the lowest cost formulation.

CONCLUSIONS

Approximately 80% of UC patients entering clinical trials of immunosuppressants, biologics, or oral small molecules continue to use aminosalicylates. An RCT is needed to inform the benefits and harms of continuing vs stopping aminosalicylates in patients escalating therapy.

The Effectiveness and Value of Patisiran and Inotersen for Hereditary Transthyretin Amyloidosis

DISCLOSURES

Funding for this summary was contributed by the Laura and John Arnold Foundation, Blue Shield of California, and California Health Care Foundation to the Institute for Clinical and Economic Review (ICER), an independent organization that evaluates the evidence on the value of health care interventions. ICER's annual policy summit is supported by dues from Aetna, AHIP, Anthem, Blue Shield of California, CVS Caremark, Express Scripts, Harvard Pilgrim Health Care, Cambia Health Solutions, United Healthcare, Kaiser Permanente, Premera Blue Cross, AstraZeneca, Genentech, GlaxoSmithKline, Johnson & Johnson, Merck, National Pharmaceutical Council, Prime Therapeutics, Sanofi, Spark Therapeutics, Health Care Service Corporation, Editas, Alnylam, Regeneron, Mallinkrodt, Biogen, HealthPartners, and Novartis. Mickle, Dreitlein, and Pearson are ICER employees. Lasser, Cipriano, and Hoch have nothing to disclose.

Anticoagulation Therapy for Atrial Fibrillation in Patients With Alzheimer's Disease

Background and Purpose- Direct oral anticoagulants (DOACs) are safer, at least equally efficacious, and cost-effective compared to warfarin for stroke prevention in atrial fibrillation (AF) but they remain underused, particularly in demented patients. We estimated the cost-effectiveness of DOACs compared with warfarin in patients with AF and Alzheimer's disease (AD). Methods- We constructed a microsimulation model to estimate the lifetime costs, quality-adjusted life-years (QALYs), and cost-effectiveness of anticoagulation therapy (adjusted-dose warfarin and various DOACs) in 70-year-old patients with AF and AD from a US societal perspective. We stratified patient cohorts based on stage of AD and care setting. Model parameters were estimated from secondary sources. Health benefits were measured in the number of acute health events, life-years, and QALYs gained. We classified alternatives as cost-effective using a willingness-to-pay threshold of $100 000 per QALY gained. Results- For patients with AF and AD, compared with warfarin, DOACs increase costs but also increase QALYs by reducing the risk of stroke. For mild-AD patients living in the community, edoxaban increased lifetime costs by $6603 and increased QALYs by 0.076 compared to warfarin, yielding an incremental cost-effectiveness ratio of $86 882/QALY gained. Even though DOACs increased QALYs compared with warfarin for all patient groups (ranging from 0.019 to 0.085 additional QALYs), no DOAC treatment alternative had an incremental cost-effectiveness ratio <$150 000/QALY gained for patients with moderate to severe AD. For patients living in a long-term care facility with mild AD, the DOAC with the lowest incremental cost-effectiveness ratio (rivaroxaban) costs $150 169 per QALY gained; for patients with more severe AD, the incremental cost-effectiveness ratios were higher. Conclusions- For patients with AF and mild AD living in the community, edoxaban is cost-effective compared with warfarin. Even though patients with moderate and severe AD living in the community and patients with any stage of AD living in a long-term care setting may obtain positive clinical benefits from anticoagulation treatment, DOACs are not cost-effective compared with warfarin for these populations. Compared to aspirin, no oral anticoagulation (warfarin or any DOAC) is cost effective in patients with AF and AD.

Lung cancer costs by treatment strategy and phase of care among patients enrolled in Medicare

Background

We studied trends in lung cancer treatment cost over time by phase of care, treatment strategy, age, stage at diagnosis, and histology.

Methods

Using the Surveillance, Epidemiology, and End Results (SEER)‐Medicare database for years 1998‐2013, we allocated total and patient‐liability costs into the following phases of care for 145 988 lung cancer patients: prediagnosis, staging, surgery, initial, continuing, and terminal. Patients served as self‐controls to determine cancer‐attributable costs based on individual precancer diagnosis healthcare costs. We fit linear regression models to determine cost by age and calendar year for each stage at diagnosis, histology, and treatment strategy and presented all costs in 2017 US dollars.

Results

Monthly healthcare costs prior to lung cancer diagnosis were $861 for a 70 years old in 2017 and rose by an average of $17 per year (P < 0.001). Surgery in 2017 cost $30 096, decreasing by $257 per year (P = 0.007). Chemotherapy and radiation costs remained stable or increased for most stage and histology groups, ranging from $4242 to $8287 per month during the initial six months of care. Costs during the final six months of life decreased for those who died of lung cancer or other causes.

Conclusions

Cost‐effectiveness analyses of lung cancer control interventions in the United States have been using outdated and incomplete treatment cost estimates. Our cost estimates enable updated cost‐effectiveness analyses to determine the benefit of lung cancer control from a health economics point of view.

Cost-effectiveness of naloxone kits in secondary schools

BACKGROUND

We seek to identify conditions under which a plan by the Toronto District School Board (TDSB) to equip high schools with naloxone kits would be cost-effective.

METHODS

We developed a decision-analytic model to evaluate the costs, benefits, and cost-effectiveness of a school-based naloxone program. We estimated model inputs from the medical literature and used Toronto-specific sources whenever available. We present our results varying both the expected total number of opioid overdoses per year across all 112 TDSB high schools and the effectiveness of a school-based naloxone program in reducing mortality.

RESULTS

A school naloxone program likely costs less than CAD$50,000 per quality-adjusted life-year gained if the overdose frequency is at least once each year and it reduces opioid poisoning mortality by at least 40% (from 10% to <6.0%) or if the overdose frequency is at least two per year and the program reduces mortality by at least 20% (from 10% to <8.0%). The results are sensitive to the intensity and cost of staff training, the lifetime costs and life-expectancy of overdose survivors, and the probability of an overdose being fatal in the absence of a school naloxone program.

CONCLUSIONS

School naloxone programs are relatively inexpensive, but that does not ensure that they are a cost-effective use of resources. While potentially cost-effective, if the risk of an overdose in a Toronto high school is low, then other programs aimed at improving the health and wellbeing of students may be better use of limited resources.

Optimal Information Collection Policies in a Markov Decision Process Framework

BACKGROUND

The cost-effectiveness and value of additional information about a health technology or program may change over time because of trends affecting patient cohorts and/or the intervention. Delaying information collection even for parameters that do not change over time may be optimal.

METHODS

We present a stochastic dynamic programming approach to simultaneously identify the optimal intervention and information collection policies. We use our framework to evaluate birth cohort hepatitis C virus (HCV) screening. We focus on how the presence of a time-varying parameter (HCV prevalence) affects the optimal information collection policy for a parameter assumed constant across birth cohorts: liver fibrosis stage distribution for screen-detected diagnosis at age 50.

RESULTS

We prove that it may be optimal to delay information collection until a time when the information more immediately affects decision making. For the example of HCV screening, given initial beliefs, the optimal policy (at 2010) was to continue screening and collect information about the distribution of liver fibrosis at screen-detected diagnosis in 12 years, increasing the expected incremental net monetary benefit (INMB) by $169.5 million compared to current guidelines.

CONCLUSIONS

The option to delay information collection until the information is sufficiently likely to influence decisions can increase efficiency. A dynamic programming framework enables an assessment of the marginal value of information and determines the optimal policy, including when and how much information to collect.

Economically Efficient Hepatitis C Virus Treatment Prioritization Improves Health Outcomes

BACKGROUND

The total cost of treating the 3 million Americans chronically infected with hepatitis C virus (HCV) represents a substantial affordability challenge requiring treatment prioritization. This study compares the health and economic outcomes of alternative treatment prioritization schedules.

METHODS

We developed a multiyear HCV treatment budget allocation model to evaluate the tradeoffs of 7 prioritization strategies. We used optimization to identify the priority schedule that maximizes population net monetary benefit (NMB). We compared prioritization schedules in terms of the number of individuals treated, the number of individuals who progress to end-stage liver disease (ESLD), and population total quality-adjusted life years (QALYs). We applied the model to the population of treatment-naive patients with a total annual HCV treatment budget of US$8.6 billion.

RESULTS

First-come, first-served (FCFS) treats the fewest people with advanced fibrosis, prevents the fewest cases of ESLD, and gains the fewest QALYs. A schedule developed from optimizing population NMB prioritizes treatment in the first year to patients with moderate to severe fibrosis who are younger than 65 years, followed by older individuals with moderate to severe fibrosis. While this strategy yields the greatest population QALYs, prioritization by disease severity alone prevents more cases of ESLD. Sensitivity analysis indicated that the differences between prioritization schedules are greater when the budget is smaller. A 10% annual treatment price reduction enabled treatment 1 year sooner to several patient subgroups, specifically older patients and those with less severe liver fibrosis.

CONCLUSION

In the absence of a sufficient budget to treat all patients, explicit prioritization targeting younger people with more severe disease first provides the greatest health benefits. We provide our spreadsheet model so that decision makers can compare health tradeoffs of different budget levels and various prioritization strategies with inputs tailored to their population.

Systematic review with meta-analysis: prevalence, risk factors and costs of aminosalicylate use in Crohn's disease

BACKGROUND

Aminosalicylates are the most frequently prescribed drugs for patients with Crohn's disease (CD), yet evidence to support their efficacy as induction or maintenance therapy is controversial.

AIMS

To quantify aminosalicylate use in CD clinical trials, identify factors associated with use and estimate direct annual treatment costs of therapy.

METHODS

MEDLINE, Embase and CENTRAL were searched to April 2017 for placebo-controlled trials in adults with CD treated with corticosteroids, immunosuppressants or biologics. The proportion of patients co-prescribed aminosalicylates in placebo arms was pooled using a random-effects model. Meta-regression was used to identify factors associated with aminosalicylate use. Annual treatment costs were estimated using the 2016 Ontario Drug Benefit Program.

RESULTS

Forty-two induction and 10 maintenance trials were included. The pooled proportion of patients co-prescribed aminosalicylates was 44% [95% CI: 39%-49%] in induction trials and 49% [95% CI: 35%-64%] in maintenance trials. There was substantial to considerable heterogeneity (I²  = 86.0%, 91.8% for induction and maintenance trials, respectively). In multivariable meta-regression, aminosalicylate use has decreased over time in induction trials (OR 0.50 [95% CI: 0.34-0.74] per 10-year increment). While a decline has been seen over time, 35% of CD patients were still using aminosalicylates in contemporary trials from the last 5 years. The estimated annual cost for the lowest price mesalazine (mesalamine) formulation is approximately $32 million for the Canadian CD population.

CONCLUSIONS

Over one-third of CD patients entering clinical trials are still co-prescribed aminosalicylates. A definitive trial is needed to inform the conventional practice of using aminosalicylates as CD maintenance therapy.

Population Health and Cost-Effectiveness Implications of a "Treat All" Recommendation for HCV: A Review of the Model-Based Evidence

The World Health Organization HCV Guideline Development Group is considering a "treat all" recommendation for persons infected with hepatitis C virus (HCV). We reviewed the model-based evidence of cost-effectiveness and population health impacts comparing expanded treatment policies to more limited treatment access policies, focusing primarily on evaluations of all-oral directly acting antivirals published after 2012. Searching PubMed, we identified 2,917 unique titles. Sequentially reviewing titles and abstracts identified 226 potentially relevant articles for full-text review. Sixty-nine articles met all inclusion criteria-42 cost-effectiveness analyses and 30 models of population-health impacts, with 3 articles presenting both types of analysis. Cost-effectiveness studies for many countries concluded that expanding treatment to people with mild liver fibrosis, who inject drugs (PWID), or who are incarcerated is generally cost-effective compared to more restrictive treatment access policies at country-specific prices. For certain patient subpopulations in some countries-for example, elderly individuals without fibrosis-treatment is only cost-effective at lower prices. A frequent limitation is the omission of benefits and consequences of HCV transmission (i.e., treatment as prevention; risks of reinfection), which may underestimate or overestimate the cost-effectiveness of a "treat all" policy. Epidemiologic modeling studies project that through a combination of prevention, aggressive screening and diagnosis, and prompt treatment for all fibrosis stages, it may be possible to virtually eliminate HCV in many countries. Studies show that if resources are not available to diagnose and treat all HCV-infected individuals, treatment prioritization may be needed, with alternative prioritization strategies resulting in tradeoffs between reducing mortality or reducing incidence. Notably, because most new HCV infections are among PWID in many settings, HCV elimination requires unrestricted treatment access combined with injection transmission disruption strategies. The model-based evidence suggests that a properly constructed strategy that substantially expands HCV treatment could achieve cost-effective improvements in population health in many countries.

Atrial fibrillation detected after stroke is related to a low risk of ischemic stroke recurrence

Objective

To compare the risk of 1-year ischemic stroke recurrence between atrial fibrillation (AF) diagnosed after stroke (AFDAS) and sinus rhythm (SR) and investigate whether underlying heart disease is as frequent in AFDAS as it is in AF known before stroke (KAF).

Methods

In this retrospective cohort study, we included all ischemic stroke patients admitted to institutions participating in the Ontario Stroke Registry from July 1, 2003, to March 31, 2013. Based on heart rhythm assessed during admission, we classified patients as AFDAS, KAF, or SR. We modeled the relationship between heart rhythm groups and 1-year ischemic stroke recurrence by using Cox regression adjusted for multiple covariates (e.g., oral anticoagulants). We compared the prevalence of coronary artery disease, myocardial infarction, and heart failure among the 3 groups.

Results

Among 23,376 ischemic stroke patients, 15,885 had SR, 587 AFDAS, and 6,904 KAF. At 1 year, 39 (6.6%) patients with AFDAS, 661 (9.6%) with KAF, and 1,269 (8.0%) with SR had recurrent ischemic strokes (p = 0.0001). AFDAS-related ischemic stroke recurrence adjusted risk was not different from that of SR (hazard ratio 0.90 [95% confidence interval 0.63, 1.30]; p = 0.57). Prevalence of coronary artery disease (18.2% vs 34.7%; p < 0.0001), myocardial infarction (11.6% vs 20.5%; p < 0.0001), and heart failure (5.5% vs 16.8%; p < 0.0001) were lower in AFDAS relative to KAF.

Conclusions

The lack of difference in 1-year ischemic stroke recurrence between AFDAS and SR and the lower prevalence of heart disease in AFDAS compared to KAF suggest that the underlying pathophysiology of AFDAS may differ from that of KAF.

Pathophysiology and Risk of Atrial Fibrillation Detected after Ischemic Stroke (PARADISE): A Translational, Integrated, and Transdisciplinary Approach

BACKGROUND

It has been hypothesized that ischemic stroke can cause atrial fibrillation. By elucidating the mechanisms of neurogenically mediated paroxysmal atrial fibrillation, novel therapeutic strategies could be developed to prevent atrial fibrillation occurrence and perpetuation after stroke. This could result in fewer recurrent strokes and deaths, a reduction or delay in dementia onset, and in the lessening of the functional, structural, and metabolic consequences of atrial fibrillation on the heart.

METHODS

The Pathophysiology and Risk of Atrial Fibrillation Detected after Ischemic Stroke (PARADISE) study is an investigator-driven, translational, integrated, and transdisciplinary initiative. It comprises 3 complementary research streams that focus on atrial fibrillation detected after stroke: experimental, clinical, and epidemiological. The experimental stream will assess pre- and poststroke electrocardiographic, autonomic, anatomic (brain and heart pathology), and inflammatory trajectories in an animal model of selective insular cortex ischemic stroke. The clinical stream will prospectively investigate autonomic, inflammatory, and neurocognitive changes among patients diagnosed with atrial fibrillation detected after stroke by employing comprehensive and validated instruments. The epidemiological stream will focus on the demographics, clinical characteristics, and outcomes of atrial fibrillation detected after stroke at the population level by means of the Ontario Stroke Registry, a prospective clinical database that comprises over 23,000 patients with ischemic stroke.

CONCLUSIONS

PARADISE is a translational research initiative comprising experimental, clinical, and epidemiological research aimed at characterizing clinical features, the pathophysiology, and outcomes of neurogenic atrial fibrillation detected after stroke.

Concomitant vascular and neurodegenerative pathologies double the risk of dementia

INTRODUCTION

The relative contributions of vascular and degenerative pathology to dementia are unknown. We aim to quantify the proportion of dementia explained by potentially preventable vascular lesions.

METHODS

We systematically searched for population-based cohorts before February 2017 reporting clinicopathological data for individuals with and without dementia. We calculated the summary proportion and absolute risk of dementia comparing subjects with and without the pathology.

RESULTS

We identified 10 studies comprising 2856 subjects. Vascular-type pathology and mixed pathology are respectively two and three times more likely in demented patients. The summary proportion of dementia is 77%-86% in subjects with mixed degenerative and vascular pathology and 45% in subjects with pure Alzheimer-type pathology.

DISCUSSION

Patients with mixed pathologies have nearly twice the incremental risk of dementia compared with patients with only Alzheimer-type lesions. Consequently, many cases of dementia could be prevented or delayed by targeting the vascular component.

Population-level intervention and information collection in dynamic healthcare policy

We develop a general framework for optimal health policy design in a dynamic setting. We consider a hypothetical medical intervention for a cohort of patients where one parameter varies across cohorts with imperfectly observable linear dynamics. We seek to identify the optimal time to change the current health intervention policy and the optimal time to collect decision-relevant information. We formulate this problem as a discrete-time, infinite-horizon Markov decision process and we establish structural properties in terms of first and second-order monotonicity. We demonstrate that it is generally optimal to delay information acquisition until an effect on decisions is sufficiently likely. We apply this framework to the evaluation of hepatitis C virus (HCV) screening in the general population determining which birth cohorts to screen for HCV and when to collect information about HCV prevalence.

Cost-effectiveness of cerebrospinal biomarkers for the diagnosis of Alzheimer's disease

Background

Accurate and timely diagnosis of Alzheimer’s disease (AD) is important for prompt initiation of treatment in patients with AD and to avoid inappropriate treatment of patients with false-positive diagnoses.

Methods

Using a Markov model, we estimated the lifetime costs and quality-adjusted life-years (QALYs) of cerebrospinal fluid biomarker analysis in a cohort of patients referred to a neurologist or memory clinic with suspected AD who remained without a definitive diagnosis of AD or another condition after neuroimaging. Parametric values were estimated from previous health economic models and the medical literature. Extensive deterministic and probabilistic sensitivity analyses were performed to evaluate the robustness of the results.

Results

At a 12.7% pretest probability of AD, biomarker analysis after normal neuroimaging findings has an incremental cost-effectiveness ratio (ICER) of $11,032 per QALY gained. Results were sensitive to the pretest prevalence of AD, and the ICER increased to over $50,000 per QALY when the prevalence of AD fell below 9%. Results were also sensitive to patient age (biomarkers are less cost-effective in older cohorts), treatment uptake and adherence, biomarker test characteristics, and the degree to which patients with suspected AD who do not have AD benefit from AD treatment when they are falsely diagnosed.

Conclusions

The cost-effectiveness of biomarker analysis depends critically on the prevalence of AD in the tested population. In general practice, where the prevalence of AD after clinical assessment and normal neuroimaging findings may be low, biomarker analysis is unlikely to be cost-effective at a willingness-to-pay threshold of $50,000 per QALY gained. However, when at least 1 in 11 patients has AD after normal neuroimaging findings, biomarker analysis is likely cost-effective. Specifically, for patients referred to memory clinics with memory impairment who do not present neuroimaging evidence of medial temporal lobe atrophy, pretest prevalence of AD may exceed 15%. Biomarker analysis is a potentially cost-saving diagnostic method and should be considered for adoption in high-prevalence centers.

Electronic supplementary material

The online version of this article (doi:10.1186/s13195-017-0243-0) contains supplementary material, which is available to authorized users.

Milder Alzheimer's disease pathology in heart failure and atrial fibrillation

INTRODUCTION

Heart failure (HF) and atrial fibrillation (AF) have been associated with a higher risk of Alzheimer's disease (AD). Whether HF and AF are related to AD by enhancing AD neuropathological changes is unknown.

METHODS

We applied network analyses and multiple logistic regression models to assess the association between HF and AF with severity of AD neuropathology in patients from the National Alzheimer's Coordinating Center database with primary neuropathological diagnosis of AD.

RESULTS

We included 1593 patients, of whom 129 had HF and 250 had AF. HF and AF patients were older and had milder AD pathology. In the network analyses, HF and AF were associated with milder AD neuropathology. In the regression analyses, age (odds ratio [OR] 0.94, 95% confidence interval [CI] 0.93-0.95 per 1-year increase in age, P < .001) and the interaction term HF × AF (OR 0.61, 95% CI 0.40-0.91, P = .014) were inversely related to severe AD pathology, whereas APOE ε4 genotype showed a direct association (OR 1.68, 95% CI 1.31-2.16). Vascular neuropathology was more frequent in patient with HF and AF patients than in those without.

DISCUSSION

HF and AF had milder AD neuropathology. Patients with milder AD lived longer and had more exposure to vascular risk factors. HF and AF patients showed a higher frequency of vascular neuropathology, which could have contributed to lower the threshold for clinically evident dementia.

First-Ever Stroke and Transient Ischemic Attack Incidence and 30-Day Case-Fatality Rates in a Population-Based Study in Argentina

BACKGROUND AND PURPOSE

Epidemiological data about stroke are scarce in low- and middle-income Latin-American countries. We investigated annual incidence of first-ever stroke and transient ischemic attack (TIA) and 30-day case-fatality rates in a population-based setting in Tandil, Argentina.

METHODS

We prospectively identified all first-ever stroke and TIA cases from overlapping sources between January 5, 2013, and April 30, 2015, in Tandil, Argentina. We calculated crude and standardized incidence rates. We estimated 30-day case-fatality rates.

RESULTS

We identified 334 first-ever strokes and 108 TIAs. Age-standardized incidence rate per 100 000 for Segi's World population was 76.5 (95% confidence interval [CI], 67.8-85.9) for first-ever stroke and 25.1 (95% CI, 20.2-30.7) for first-ever TIA, 56.1 (95% CI, 48.8-64.2) for ischemic stroke, 13.5 (95% CI, 9.9-17.9) for intracerebral hemorrhage, and 4.9 (95% CI, 2.7-8.1) for subarachnoid hemorrhage. Stroke incidence was slightly higher for men (87.8; 95% CI, 74.6-102.6) than for women (73.2; 95% CI, 61.7-86.1) when standardized for the Argentinean population. Thirty-day case-fatality rate was 14.7% (95% CI, 10.8-19.5) for ischemic stroke, 24.1% (95% CI, 14.2-36.6) for intracerebral hemorrhage, and 1.9% (95% CI, 0.4-5.8) for TIA.

CONCLUSIONS

This study provides the first prospective population-based stroke and TIA incidence and case-fatality estimate in Argentina. First-ever stroke incidence was lower than that reported in previous Latin-American studies, but first-ever TIA incidence was higher. Thirty-day case-fatality rates were similar to those of other population-based Latin-American studies.

Ischemic Stroke Risk in Patients With Atrial Fibrillation and CHA 2 DS 2 -VASc Score of 1

Background and Purpose—

The CHA 2 DS 2 -VASc score aims to improve risk stratification of ischemic stroke among patients with atrial fibrillation to identify those who can safely forego oral anticoagulation. Oral anticoagulation treatment guidelines remain uncertain for CHA 2 DS 2 -VASc score of 1. We conducted a systematic review and meta-analysis of the risk of ischemic stroke for patients with atrial fibrillation and CHA 2 DS 2 -VASc score of 0, 1, or 2 not treated with oral anticoagulation.

Methods—

We searched MEDLINE, Embase, PubMed, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Web of Science from the start of the database up until April 15, 2015. We included studies that stratified the risk of ischemic stroke by CHA 2 DS 2 -VASc score for patients with nonvalvular atrial fibrillation. We estimated the summary annual rate of ischemic stroke using random effects meta-analyses and compared the estimated stroke rates with published net-benefit thresholds for initiating anticoagulants.

Results—

1162 abstracts were retrieved, of which 10 met all inclusion criteria for the study. There was substantial heterogeneity among studies. The summary estimate for the annual risk of ischemic stroke was 1.61% (95% confidence interval 0%–3.23%) for CHA 2 DS 2 -VASc score of 1, meeting the theoretical threshold for using novel oral anticoagulants (0.9%), but below the threshold for warfarin (1.7%). The summary incident risk of ischemic stroke was 0.68% (95% confidence interval 0.12%–1.23%) for CHA 2 DS 2 -VASc score of 0 and 2.49% (95% confidence interval 1.16%–3.83%) for CHA 2 DS 2 -VASc score of 2.

Conclusions—

Our meta-analysis of ischemic stroke risk in atrial fibrillation patients suggests that those with CHA 2 DS 2 -VASc score of 1 may be considered for a novel oral anticoagulant, but because of high heterogeneity, the decision should be based on individual patient characteristics.

Very Short Paroxysms Account for More Than Half of the Cases of Atrial Fibrillation Detected after Stroke and TIA: A Systematic Review and Meta-Analysis

Background

Guidelines suggest that only poststroke atrial fibrillation episodes lasting 30 s or longer should be considered for anticoagulation. However, little evidence supports this recommendation.

Aims

We performed a systematic review and meta-analysis to investigate the frequency of poststroke atrial fibrillation lasting less than 30 s in stroke and transient ischemic attack patients.

Methods

We searched PubMed, Embase, and Scopus from 1980 to June 30, 2014 for studies reporting the detection of poststroke atrial fibrillation of less than 30 s and of 30 s or longer. The primary endpoint was the proportion of screened patients diagnosed with poststroke atrial fibrillation lasting less than 30 s. The secondary endpoint was the proportion of patients diagnosed with poststroke atrial fibrillation shorter than 30 s among the overall number of patients in whom a poststroke atrial fibrillation was detected after stroke or transient ischemic attack.

Results

From 28 290 titles, we included nine studies in the random-effects meta-analysis. Among stroke and transient ischemic attack patients without a history of atrial fibrillation, 9·0% (95% confidence interval: 4·9–14·3) experienced episodes of poststroke atrial fibrillation shorter than 30 s. An additional 6·5% (95% confidence interval: 3·2–10·9) experienced episodes of poststroke atrial fibrillation longer than 30 s. Among all patients with poststroke atrial fibrillation, 56·3% (95% confidence interval: 37·7–74·0) had poststroke atrial fibrillation episodes shorter than 30 s during diagnostic evaluation. Conclusions The clinical and prognostic significance of poststroke atrial fibrillation episodes shorter than 30 s is unknown. The high frequency of poststroke atrial fibrillation episodes shorter than 30 s justify further investigation into the risk of stroke recurrence and the risk–benefit profile of anticoagulation for this patient population.

Identifying best-fitting inputs in health-economic model calibration: a Pareto frontier approach

BACKGROUND

To identify best-fitting input sets using model calibration, individual calibration target fits are often combined into a single goodness-of-fit (GOF) measure using a set of weights. Decisions in the calibration process, such as which weights to use, influence which sets of model inputs are identified as best-fitting, potentially leading to different health economic conclusions. We present an alternative approach to identifying best-fitting input sets based on the concept of Pareto-optimality. A set of model inputs is on the Pareto frontier if no other input set simultaneously fits all calibration targets as well or better.

METHODS

We demonstrate the Pareto frontier approach in the calibration of 2 models: a simple, illustrative Markov model and a previously published cost-effectiveness model of transcatheter aortic valve replacement (TAVR). For each model, we compare the input sets on the Pareto frontier to an equal number of best-fitting input sets according to 2 possible weighted-sum GOF scoring systems, and we compare the health economic conclusions arising from these different definitions of best-fitting.

RESULTS

For the simple model, outcomes evaluated over the best-fitting input sets according to the 2 weighted-sum GOF schemes were virtually nonoverlapping on the cost-effectiveness plane and resulted in very different incremental cost-effectiveness ratios ($79,300 [95% CI 72,500-87,600] v. $139,700 [95% CI 79,900-182,800] per quality-adjusted life-year [QALY] gained). Input sets on the Pareto frontier spanned both regions ($79,000 [95% CI 64,900-156,200] per QALY gained). The TAVR model yielded similar results.

CONCLUSIONS

Choices in generating a summary GOF score may result in different health economic conclusions. The Pareto frontier approach eliminates the need to make these choices by using an intuitive and transparent notion of optimality as the basis for identifying best-fitting input sets.

Transcatheter aortic valve replacement in nonsurgical candidates with severe, symptomatic aortic stenosis: a cost-effectiveness analysis

BACKGROUND

Transcatheter aortic valve replacement (TAVR) seems to improve the survival and quality of life of patients with aortic stenosis ineligible for surgical aortic valve replacement.

METHODS AND RESULTS

We used a decision analytic Markov model to estimate lifetime costs and benefits in a hypothetical cohort of patients with severe, symptomatic aortic stenosis who were ineligible for surgical aortic valve replacement. The model compared transfemoral TAVR with medical management and was calibrated to the Placement of Aortic Transcatheter Valves (PARTNER) trial. TAVR increased life expectancy from 2.08 to 2.93 years and quality-adjusted life expectancy from 1.19 to 1.93 years. TAVR also reduced subsequent hospitalizations by 1.40 but increased complications, particularly stroke (from 1% to 11% lifetime risk), and also increased lifetime costs from $83,600 to $169,100. The incremental cost-effectiveness of TAVR was $116,500 per quality-adjusted life-year gained ($99,900 per life-year gained). Results were robust to reasonable changes in individual variables but were sensitive to the level of annual healthcare costs caused by noncardiac diseases and to the projected life expectancy of medically treated patients.

CONCLUSIONS

TAVR seems to be an effective but somewhat expensive alternative to medical management among patients with symptomatic aortic stenosis ineligible for surgery. TAVR is more cost-effective for patients with a lower burden of noncardiac disease.

Cost-effectiveness analysis of risk-factor guided and birth-cohort screening for chronic hepatitis C infection in the United States

BACKGROUND

No consensus exists on screening to detect the estimated 2 million Americans unaware of their chronic hepatitis C infections. Advisory groups differ, recommending birth-cohort screening for baby boomers, screening only high-risk individuals, or no screening. We assessed one-time risk assessment and screening to identify previously undiagnosed 40-74 year-olds given newly available hepatitis C treatments.

METHODS AND FINDINGS

A Markov model evaluated alternative risk-factor guided and birth-cohort screening and treatment strategies. Risk factors included drug use history, blood transfusion before 1992, and multiple sexual partners. Analyses of the National Health and Nutrition Examination Survey provided sex-, race-, age-, and risk-factor-specific hepatitis C prevalence and mortality rates. Nine strategies combined screening (no screening, risk-factor guided screening, or birth-cohort screening) and treatment (standard therapy-peginterferon alfa and ribavirin, Interleukin-28B-guided (IL28B) triple-therapy-standard therapy plus a protease inhibitor, or universal triple therapy). Response-guided treatment depended on HCV genotype. Outcomes include discounted lifetime costs (2010 dollars) and quality adjusted life-years (QALYs). Compared to no screening, risk-factor guided and birth-cohort screening for 50 year-olds gained 0.7 to 3.5 quality adjusted life-days and cost $168 to $568 per person. Birth-cohort screening provided more benefit per dollar than risk-factor guided screening and cost $65,749 per QALY if followed by universal triple therapy compared to screening followed by IL28B-guided triple therapy. If only 10% of screen-detected, eligible patients initiate treatment at each opportunity, birth-cohort screening with universal triple therapy costs $241,100 per QALY. Assuming treatment with triple therapy, screening all individuals aged 40-64 years costs less than $100,000 per QALY.

CONCLUSIONS

The cost-effectiveness of one-time birth-cohort hepatitis C screening for 40-64 year olds is comparable to other screening programs, provided that the healthcare system has sufficient capacity to deliver prompt treatment and appropriate follow-on care to many newly screen-detected individuals.

Cost effectiveness of screening strategies for early identification of HIV and HCV infection in injection drug users

OBJECTIVE

To estimate the cost, effectiveness, and cost effectiveness of HIV and HCV screening of injection drug users (IDUs) in opioid replacement therapy (ORT).

DESIGN

Dynamic compartmental model of HIV and HCV in a population of IDUs and non-IDUs for a representative U.S. urban center with 2.5 million adults (age 15-59).

METHODS

We considered strategies of screening individuals in ORT for HIV, HCV, or both infections by antibody or antibody and viral RNA testing. We evaluated one-time and repeat screening at intervals from annually to once every 3 months. We calculated the number of HIV and HCV infections, quality-adjusted life years (QALYs), costs, and incremental cost-effectiveness ratios (ICERs).

RESULTS

Adding HIV and HCV viral RNA testing to antibody testing averts 14.8-30.3 HIV and 3.7-7.7 HCV infections in a screened population of 26,100 IDUs entering ORT over 20 years, depending on screening frequency. Screening for HIV antibodies every 6 months costs $30,700/QALY gained. Screening for HIV antibodies and viral RNA every 6 months has an ICER of $65,900/QALY gained. Strategies including HCV testing have ICERs exceeding $100,000/QALY gained unless awareness of HCV-infection status results in a substantial reduction in needle-sharing behavior.

DISCUSSION

Although annual screening for antibodies to HIV and HCV is modestly cost effective compared to no screening, more frequent screening for HIV provides additional benefit at less cost. Screening individuals in ORT every 3-6 months for HIV infection using both antibody and viral RNA technologies and initiating ART for acute HIV infection appears cost effective.

Cost-effectiveness of imaging strategies to reduce radiation-induced cancer risk in Crohn's disease

BACKGROUND

The aim was to examine the cost-effectiveness of magnetic resonance enterography (MRE) compared with computed tomography enterography (CTE) for routine imaging of small bowel Crohn's disease (CD) patients to reduce patients' life-time radiation-induced cancer risk.

METHODS

We developed a Markov model to compare the lifetime costs, benefits (measured in quality-adjusted life-years [QALYs] of survival and cancers averted) and cost-effectiveness of using MRE rather than CTE for routine disease monitoring in hypothetical cohorts of 100,000 20-year-old patients with CD. We assumed each CT radiation exposure conferred an incremental annual risk of developing cancer using the linear, no-threshold model.

RESULTS

In the base case of 16 mSv per CTE, we estimated that radiation from CTE resulted in 1,206 to 20,146 additional cancers depending on the frequency of patient monitoring. Compared to using CTE only, using MRE until age 30 and CTE thereafter resulted in incremental cost-effectiveness ratios (ICERs) between $37,538 and $41,031 per life-year (LY) gained and between $52,969 and $57,772 per quality-adjusted life-year (QALY) gained. Using MRE until age 50 resulted in ICERs between $58,022 and $62,648 per LY gained and between $84,250 and $90,982 per QALY gained. In a threshold analysis, any use of MRE had an ICER of greater than $100,000 per QALY gained when CT radiation doses are less than 6.0 mSv per CTE exam.

CONCLUSIONS

MRE is likely cost-effective compared to CTE in patients younger than age 50. Low-dose CTE may be an alternative cost-effective choice in the future.

Chapter 9: The MGH-HMS lung cancer policy model: tobacco control versus screening

The natural history model underlying the MGH Lung Cancer Policy Model (LCPM) does not include the two-stage clonal expansion model employed in other CISNET lung models. We used the LCPM to predict numbers of U.S. lung cancer deaths for ages 30-84 between 1975 and 2000 under four scenarios as part of the comparative modeling analysis described in this issue. The LCPM is a comprehensive microsimulation model of lung cancer development, progression, detection, treatment, and survival. Individual-level patient histories are aggregated to estimate cohort or population-level outcomes. Lung cancer states are defined according to underlying disease variables, test results, and clinical events. By simulating detailed clinical procedures, the LCPM can predict benefits and harms attributable to a variety of patient management practices, including annual screening programs. Under the scenario of observed smoking patterns, predicted numbers of deaths from the calibrated LCPM were within 2% of observed over all years (1975-2000). The LCPM estimated that historical tobacco control policies achieved 28.6% (25.2% in men, 30.5% in women) of the potential reduction in U.S. lung cancer deaths had smoking had been eliminated entirely. The hypothetical adoption in 1975 of annual helical CT screening of all persons aged 55-74 with at least 30 pack-years of cigarette exposure to historical tobacco control would have yielded a proportion realized of 39.0% (42.0% in men, 33.3% in women). The adoption of annual screening would have prevented less than half as many lung cancer deaths as the elimination of cigarette smoking.

New protease inhibitors for the treatment of chronic hepatitis C: a cost-effectiveness analysis

BACKGROUND

Chronic hepatitis C virus is difficult to treat and affects approximately 3 million Americans. Protease inhibitors increase the effectiveness of standard therapy, but they are costly. A genetic assay may identify patients most likely to benefit from this treatment advance.

OBJECTIVE

To assess the cost-effectiveness of new protease inhibitors and an interleukin (IL)-28B genotyping assay for treating chronic hepatitis C virus.

DESIGN

Decision-analytic Markov model.

DATA SOURCES

Published literature and expert opinion.

TARGET POPULATION

Treatment-naive patients with chronic, genotype 1 hepatitis C virus monoinfection.

TIME HORIZON

Lifetime.

PERSPECTIVE

Societal.

INTERVENTION

Strategies are defined by the use of IL-28B genotyping and type of treatment (standard therapy [pegylated interferon with ribavirin]; triple therapy [standard therapy and a protease inhibitor]). Interleukin-28B-guided triple therapy stratifies patients with CC genotypes to standard therapy and those with non-CC types to triple therapy.

OUTCOME MEASURES

Discounted costs (in 2010 U.S. dollars) and quality-adjusted life-years (QALYs); incremental cost-effectiveness ratios.

RESULTS OF BASE-CASE ANALYSIS

For patients with mild and advanced fibrosis, universal triple therapy reduced the lifetime risk for hepatocellular carcinoma by 38% and 28%, respectively, and increased quality-adjusted life expectancy by 3% and 8%, respectively, compared with standard therapy. Gains from IL-28B-guided triple therapy were smaller. If the protease inhibitor costs $1100 per week, universal triple therapy costs $102,600 per QALY (mild fibrosis) or $51,500 per QALY (advanced fibrosis) compared with IL-28B-guided triple therapy and $70,100 per QALY (mild fibrosis) and $36,300 per QALY (advanced fibrosis) compared with standard therapy.

RESULTS OF SENSITIVITY ANALYSIS

Results were sensitive to the cost of protease inhibitors and treatment adherence rates.

LIMITATION

Data on the long-term comparative effectiveness of the new protease inhibitors are lacking.

CONCLUSION

Both universal triple therapy and IL-28B-guided triple therapy are cost-effective when the least-expensive protease inhibitor are used for patients with advanced fibrosis.

PRIMARY FUNDING SOURCE

Stanford University.

New protease inhibitors for the treatment of chronic hepatitis C: a cost-effectiveness analysis

BACKGROUND

Chronic hepatitis C virus is difficult to treat and affects approximately 3 million Americans. Protease inhibitors increase the effectiveness of standard therapy, but they are costly. A genetic assay may identify patients most likely to benefit from this treatment advance.

OBJECTIVE

To assess the cost-effectiveness of new protease inhibitors and an interleukin (IL)-28B genotyping assay for treating chronic hepatitis C virus.

DESIGN

Decision-analytic Markov model.

DATA SOURCES

Published literature and expert opinion.

TARGET POPULATION

Treatment-naive patients with chronic, genotype 1 hepatitis C virus monoinfection.

TIME HORIZON

Lifetime.

PERSPECTIVE

Societal.

INTERVENTION

Strategies are defined by the use of IL-28B genotyping and type of treatment (standard therapy [pegylated interferon with ribavirin]; triple therapy [standard therapy and a protease inhibitor]). Interleukin-28B-guided triple therapy stratifies patients with CC genotypes to standard therapy and those with non-CC types to triple therapy.

OUTCOME MEASURES

Discounted costs (in 2010 U.S. dollars) and quality-adjusted life-years (QALYs); incremental cost-effectiveness ratios.

RESULTS OF BASE-CASE ANALYSIS

For patients with mild and advanced fibrosis, universal triple therapy reduced the lifetime risk for hepatocellular carcinoma by 38% and 28%, respectively, and increased quality-adjusted life expectancy by 3% and 8%, respectively, compared with standard therapy. Gains from IL-28B-guided triple therapy were smaller. If the protease inhibitor costs $1100 per week, universal triple therapy costs $102,600 per QALY (mild fibrosis) or $51,500 per QALY (advanced fibrosis) compared with IL-28B-guided triple therapy and $70,100 per QALY (mild fibrosis) and $36,300 per QALY (advanced fibrosis) compared with standard therapy.

RESULTS OF SENSITIVITY ANALYSIS

Results were sensitive to the cost of protease inhibitors and treatment adherence rates.

LIMITATION

Data on the long-term comparative effectiveness of the new protease inhibitors are lacking.

CONCLUSION

Both universal triple therapy and IL-28B-guided triple therapy are cost-effective when the least-expensive protease inhibitor are used for patients with advanced fibrosis.

PRIMARY FUNDING SOURCE

Stanford University.

Cost-effectiveness of computed tomography screening for lung cancer in the United States

INTRODUCTION

A randomized trial has demonstrated that lung cancer screening reduces mortality. Identifying participant and program characteristics that influence the cost-effectiveness of screening will help translate trial results into benefits at the population level.

METHODS

Six U.S. cohorts (men and women aged 50, 60, or 70 years) were simulated in an existing patient-level lung cancer model. Smoking histories reflected observed U.S. patterns. We simulated lifetime histories of 500,000 identical individuals per cohort in each scenario. Costs per quality-adjusted life-year gained ($/QALY) were estimated for each program: computed tomography screening; stand-alone smoking cessation therapies (4-30% 1-year abstinence); and combined programs.

RESULTS

Annual screening of current and former smokers aged 50 to 74 years costs between $126,000 and $169,000/QALY (minimum 20 pack-years of smoking) or $110,000 and $166,000/QALY (40 pack-year minimum), when compared with no screening and assuming background quit rates. Screening was beneficial but had a higher cost per QALY when the model included radiation-induced lung cancers. If screen participation doubled background quit rates, the cost of annual screening (at age 50 years, 20 pack-year minimum) was below $75,000/QALY. If screen participation halved background quit rates, benefits from screening were nearly erased. If screening had no effect on quit rates, annual screening costs more but provided fewer QALYs than annual cessation therapies. Annual combined screening/cessation therapy programs at age 50 years costs $130,500 to $159,700/QALY, when compared with annual stand-alone cessation.

CONCLUSIONS

The cost-effectiveness of computed tomography screening will likely be strongly linked to achievable smoking cessation rates. Trials and further modeling should explore the consequences of relationships between smoking behaviors and screen participation.