Cost-Effectiveness of Different Durations of Dual-Antiplatelet Use After Percutaneous Coronary Intervention.

BACKGROUND: There is uncertainty regarding the optimal duration of dual-antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI). Our goal was to evaluate the cost-effectiveness of different durations of DAPT. METHODS: We created a probabilistic patient-level Markov microsimulation model to assess the discounted lifetime costs and quality-adjusted life years (QALYs) of short duration (3-6 months: short-duration group) vs standard therapy (12 months: standard-duration group) vs prolonged therapy (30-36 months: long-duration group) in patients undergoing PCI. RESULTS: The majority of patients in the model underwent PCI for stable angina (47.1%) with second-generation drug-eluting stents (62%) and were receiving clopidogrel (83.6%). Short-duration DAPT was the most effective strategy (7.163 ± 1.098 QALYs) compared with standard-duration DAPT (7.161 ± 1.097 QALYs) and long-duration DAPT (7.156 ± 1.097 QALYs). However, the magnitude of these differences was very small. Similarly, the average discounted lifetime cost was CAN$24,859 ± $6533 for short duration, $25,045 ± $6533 for standard duration, and $25,046 ± $6548 for long duration. Thus, in the base-case analysis, short duration was dominant, being more effective and less expensive. However, there was a moderate degree of uncertainty, because short duration was the preferred option in only ∼ 55% of simulations at a willingness to pay threshold of $50,000. CONCLUSIONS: Based on a stable angina cohort receiving clopidogrel with second-generation stents, a short duration of DAPT was marginally better. However, the differences are minimal, and decisions about duration of therapy should be driven by clinical data, patient risk of adverse events, including bleeding, and cardiovascular events.

Relation between initial treatment strategy in stable coronary artery disease and 1-year costs in Ontario: a population-based cohort study.

BACKGROUND: Cardiovascular disease is costly, and annual expenditures are projected to increase. Our objective was to examine the variation in patient-level costs and identify drivers of cost in patients with stable coronary artery disease. METHODS: In this retrospective cohort study using administrative databases in Ontario, Canada, we identified all patients with stable coronary artery disease after index angiography between Oct. 1, 2008, and Sept. 30, 2011. We excluded patients with a myocardial infarction within 90 days before the index, with normal coronaries, or with mild coronary disease. We categorized hospitals into low, medium or high revascularization ratio centres. The primary outcome was cumulative 1-year health care costs. A hierarchical generalized linear model identified patient, physician and hospital characteristics associated with patient costs, with 2 main covariates of interest: treatment allocation (medical v. percutaneous coronary intervention v. coronary artery bypass grafting) and hospital revascularization ratio. RESULTS: A total of 183 630 angiography procedures were performed in Ontario during the study period. The final cohort included 39 126 patients with stable coronary artery disease, of which 15 138 received medical treatment and 23 988 received revascularization. The mean 1-year cost was $24 026 (interquartile range $8235-$30 511). The mean costs for medical management and revascularization were $18 069 and $27 786, respectively. The strongest predictor of costs was revascularization (percutaneous coronary intervention: cost ratio 1.27, 95% CI [confidence interval] 1.24-1.31; coronary artery bypass grafting: cost ratio 2.62, 95% CI 2.53-2.71). Hospital revascularization ratio did not significantly affect costs. There was no significant interaction between treatment and revascularization ratio. INTERPRETATION: Most health care costs were due to acute care hospital admissions, and costs were higher for patients undergoing revascularization than medical therapy. This study suggests that treatment decision has a substantial impact on health care resources.

Clinical Impact of Subsequent Depression in Patients With a New Diagnosis of Stable Angina: A Population-Based Study.

BACKGROUND: Depression is prevalent among patients with myocardial infarction and is associated with a worse prognosis. However, little is known about its importance in patients with chronic stable angina. We conducted a retrospective population-based cohort study to determine the occurrence and predictors of developing depression in patients with a new diagnosis of chronic stable angina. In addition, we sought to understand its impact on subsequent clinical outcomes. METHODS AND RESULTS: Our cohort included patients in Ontario, Canada, with stable angina based on obstructive coronary artery disease found on angiogram. Depression was ascertained by physician billing codes and hospital admissions diagnostic codes. We first developed multivariable Cox proportional hazards models to determine predictors of developing depression. Clinical outcomes of interest included all-cause mortality, admission for myocardial infarction, and subsequent revascularization. Using hierarchical multivariable Cox proportional hazards models with occurrence of depression as a time-varying variable to control for potential immortal time bias, we evaluated the impact of depression on clinical outcomes. Our cohort consisted of 22 917 patients. The occurrence of depression after diagnosis of stable chronic angina was 18.8% over a mean follow-up of 1084 days. Predictors of depression included remote history of depression, female sex, and more symptomatic angina based on Canadian Cardiovascular Society class. Patients who developed depression had a higher risk of death (hazard ratio 1.83, 95% confidence interval 1.62-2.07) and admission for myocardial infarction (hazard ratio 1.36, 95% confidence interval 1.10-1.67) compared with nondepressed patients. CONCLUSIONS: Depression is common in patients with chronic stable angina and is associated with increased morbidity and mortality.

Predictors of Initial Revascularization Versus Medical Therapy Alone in Patients With Non-ST-Segment-Elevation Acute Coronary Syndrome Undergoing an Invasive Strategy.

BACKGROUND: Although an invasive strategy is a class I clinical practice guideline for non-ST-segment-elevation acute coronary syndromes, there is wide variation in the proportion of patients who undergo revascularization despite early angiography. We sought to identify the predictors of early revascularization versus medical therapy alone in patients with non-ST-segment-elevation acute coronary syndrome undergoing an invasive strategy and to assess their clinical outcomes. METHODS AND RESULTS: We assessed revascularization status by percutaneous coronary intervention or coronary artery bypass grafting within 7 days of the index angiogram in all patients with non-ST-segment-elevation acute coronary syndrome who underwent an invasive strategy in Ontario, Canada, from October 1, 2008, to October 31, 2013, with follow-up through December 31, 2014. The primary outcome was mortality. Multivariable hierarchical logistic models identified predictors of revascularization, and multivariable Cox models with treatment strategy as a 3-level time-varying covariate assessed the relationship between revascularization status and clinical outcomes. We identified 50 302 patients of whom 34 288 (68.2%) underwent revascularization (percutaneous coronary intervention: 28 011 and coronary artery bypass grafting: 6277). There was a 2-fold variation in revascularization rates across hospitals. A higher risk presentation significantly predicted revascularization (odds ratio, 1.26; 95% confidence interval, 1.18-1.35), as did having the angiogram by an interventional cardiologist (odds ratio, 1.76; 95% confidence interval, 1.57-1.98). Revascularized patients with either percutaneous coronary intervention (hazard ratio, 0.64; 95% confidence interval, 0.60-0.69) or coronary artery bypass grafting (hazard ratio, 0.53; 95% confidence interval, 0.47-0.60) had improved survival compared with medically treated patients. CONCLUSIONS: Although the majority of patients with non-ST-segment-elevation acute coronary syndrome who underwent an early invasive approach received revascularization, there was wide variation. Revascularization was associated with significantly improved survival.

Cost-Effectiveness of Left Atrial Appendage Closure for Stroke Prevention in Atrial Fibrillation Patients With Contraindications to Anticoagulation.

BACKGROUND: Percutaneous left atrial appendage closure (LAAC) is increasingly performed as an alternative to oral anticoagulation (OAC) in patients with nonvalvular atrial fibrillation (AF). We sought to evaluate the cost-effectiveness of treating OAC contraindicated patients with LAAC compared with aspirin alone. METHODS: A probabilistic patient-level Markov microsimulation model with a lifetime horizon was performed to assess the discounted lifetime costs, quality-adjusted life years, and incremental cost-effectiveness ratio of LAAC compared with aspirin for patients with AF with contraindications to OAC. Baseline characteristics were based on a published multicenter Canadian LAAC experience. Clinical events included stroke, bleeding, myocardial infarction, and procedure-related complications. Event rates for stroke and bleeding were based on the CHA2DS2-VASc and HAS-BLED scores. The relative efficacies of LAAC and aspirin, as well as utility scores, were obtained from the published literature. Canadian procedural and long-term costs were obtained from the Ontario Case Costing Initiative and the Ontario Ministry of Health and Long Term Care. RESULTS: Aspirin was less effective than LAAC (4.25 ± 0.53 vs 4.66 ± 0.34 quality-adjusted life years, respectively). The average discounted lifetime cost was CAD$30,748 ± 11,600 for LAAC and $38,974 ± 18,783 for aspirin. Thus, LAAC was dominant, being more effective and less expensive. Our results were robust with a relatively low degree of uncertainty, as LAAC was the preferred option in more than 90% of simulations at a willingness-to-pay threshold of $50,000. CONCLUSIONS: LAAC is a novel stroke preventative therapy for nonvalvular AF and is a cost-effective alternative to aspirin in patients with contraindications to OAC.

Association between publication of appropriate use criteria and the temporal trends in diagnostic angiography in stable coronary artery disease: A population-based study.

BACKGROUND: The appropriate use criteria (AUC) were developed to aid clinicians in making clinical decisions regarding coronary angiography. The aim of the present study was to evaluate the association between the publication of the AUC criteria in diagnostic angiography and rates of angiography in Ontario. METHODS: Our cohort consisted of all patients who underwent coronary angiography in Ontario from 1st October 2008 to 31st October 2013 for the indication of suspected stable coronary artery disease. We determined monthly age- and sex-standardized rates of angiography per 100,000 adults. To determine the association between the publication of the AUC for diagnostic angiograms and the rates of angiography, we conducted a time series analysis using an autoregressive integrated moving average model. As a sensitivity analyses, we evaluated the impact of the AUC on the rates of percutaneous coronary intervention (PCI) per 100 angiograms. RESULTS: We included 114,551 angiograms for stable coronary artery disease. In the period prior to the publication of the AUC, the average monthly age- and sex-standardized rate of angiography was 18.7 per 100,000; post-AUC, the average monthly rate decreased to 17.6 per 100,000 adults (P = .037). In contrast, in the 29,358 PCIs included in the analysis, the monthly PCI rates per 100 angiograms were unchanged (25.2 pre-AUC; 26.8 post-AUC; P = .29). In the sensitivity analysis, the rate of appropriate/inappropriate and uncertain indication did not significantly change over the study period. CONCLUSIONS: The publication of the diagnostic angiography AUC criteria was associated with a decrease in the population rates of diagnostic angiography. This suggests that the AUC potentially was associated with an increased threshold to pursue invasive diagnostic testing.

Predictors and clinical outcomes of inpatient versus ambulatory management after an emergency department visit for atrial fibrillation: A population-based study.

BACKGROUND: There is substantial variation in the management of atrial fibrillation (AF) in the emergency department (ED), particularly whether these patients are admitted to hospital. We sought to identify factors that predict admission and to examine the relationship between AF admission and outcomes. METHODS: We performed a retrospective cohort analysis of patients ≥20 years of age who had an index ED visit with a primary diagnosis of AF from between April 1, 2005, and March 31, 2010, in Ontario, Canada. We excluded patients who died during the index ED visit or hospitalization. A hierarchical logistic regression model was used to determine predictors of hospital admission during the index ED visit. A propensity-matched analysis was used to test for associations between hospital admission and 1-year outcomes. RESULTS: The cohort consisted of 33,699 patients, of whom 16,270 (48.3%) were admitted to hospital. Substantial variation was seen across the 154 hospitals, with admission rates ranging from 3.0% to 91.0%. Admitted patients had higher rates of comorbidities compared to discharged patients. Mortality rates at 1 year were significantly higher in matched admitted versus discharged patients (hazard ratio 1.45, 95% CI 1.33-1.57, P < .001), as were all-cause hospitalizations (hazard ratio 1.18, 95% CI 1.13-1.22, P < .001). CONCLUSIONS: Wide practice variation was observed between hospitals in terms of the proportion of patients admitted. Our data suggest that selected patients when discharged have similar or improved outcomes compared to those who are initially admitted. Future research is needed to better standardize admission/discharge decisions for AF patients in the ED.

Predictors and Outcomes of Routine Versus Optimal Medical Therapy in Stable Coronary Heart Disease.

Although randomized studies have shown optimal medical therapy (OMT) to be as efficacious as revascularization in stable coronary heart disease (CHD), the application of OMT in routine practice is suboptimal. We sought to understand the predictors of receiving OMT in stable CHD and its impact on clinical outcomes. All patients with stable CHD based on coronary angiography from October 2008 to September 2011 were identified in Ontario, Canada. OMT was defined as concurrent use of ß blocker, angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, and statin. Aspirin use was not part of the OMT definition because of database limitations. Multivariable hierarchical logistic models identified predictors of OMT in the 12 months after angiography. Cox proportional hazard models with time-varying covariates for OMT and revascularization status examined differences in death and nonfatal myocardial infarction (MI). In these models, patients transitioned among 4 mutually exclusive treatment groups: no OMT and no revascularization, no OMT and revascularization, OMT and no revascularization, OMT and revascularization. Our cohort had 20,663 patients. Over a mean period of 2.5 years, 8.7% had died. Only 61% received OMT within 12 months. The strongest predictor of receiving OMT at 12 months was OMT before the angiogram (odds ratio 14.40, 95% confidence interval [CI] 13.17 to 15.75, p <0.001). Relative to no OMT and nonrevascularized patients, patients on OMT and revascularized had the greatest reduction in mortality (hazard ratio 0.52, 95% CI 0.45 to 0.60, p <0.001) and nonfatal MI (hazard ratio 0.74, 95% CI 0.64 to 0.84, p <0.001). In conclusion, our study highlights the low rate of OMT in stable CHD. Patients who received both OMT and revascularization achieved the greatest reduction in mortality and nonfatal MI.

An evaluation of southeastern Ontario recreational water quality.

Fecal contamination in recreational waters causes adverse health outcomes in humans; yet, surprisingly, a paucity of literature addresses recreational water quality in North America. The authors addressed this gap by evaluating E. coli contamination of southeastern Ontario, Canada, recreational beach waters between the years 2008-2011. They tested water samples for microbial contamination by the membrane filtration method. They used Friedman's and repeated measures analyses of variance and descriptive statistics to assess annual and monthly E. coli levels as well as noncompliance to the Ontario bathing beach standard. Seven waters showed high noncompliance to the Ontario standard, which could negatively affect the health of local recreational beach users. The authors' study provides much needed baseline information on beach water quality. They call for greater recreational water sampling and reporting standardization across North American jurisdictions.

Determinants of variations in initial treatment strategies for stable ischemic heart disease.

BACKGROUND: The ratio of revascularization to medical therapy (referred to herein as the revascularization ratio) for the initial treatment of stable ischemic heart disease varies considerably across hospitals. We conducted a comprehensive study to identify patient, physician and hospital factors associated with variations in the revascularization ratio across 18 cardiac centres in the province of Ontario. We also explored whether clinical outcomes differed between hospitals with high, medium and low ratios. METHODS: We identified all patients in Ontario who had stable ischemic heart disease documented by index angiography performed between Oct. 1, 2008, and Sept. 30, 2011, at any of the 18 cardiac centres in the province. We classified patients by initial treatment strategy (medical therapy or revascularization). Hospitals were classified into equal tertiles based on their revascularization ratio. The primary outcome was all-cause mortality. Patient follow-up was until Dec. 31, 2012. Hierarchical logistic regression models identified predictors of revascularization. Multivariable Cox proportional hazards models, with a time-varying covariate for actual treatment received, were used to evaluate the impact of the revascularization ratio on clinical outcomes. RESULTS: Variation in revascularization ratios was twofold across the hospitals. Patient factors accounted for 67.4% of the variation in revascularization ratios. Physician and hospital factors were not significantly associated with the variation. Significant patient-level predictors of revascularization were history of smoking, multivessel disease, high-risk findings on noninvasive stress testing and more severe symptoms of angina (v. no symptoms). Treatment at hospitals with a high revascularization ratio was associated with increased mortality compared with treatment at hospitals with a low ratio (hazard ratio 1.12, 95% confidence interval 1.03-1.21). INTERPRETATION: Most of the variation in revascularization ratios across hospitals was warranted, in that it was driven by patient factors. Nonetheless, the variation was associated with potentially important differences in mortality.

Identifying predictors of cumulative healthcare costs in incident atrial fibrillation: a population-based study.

BACKGROUND: Atrial fibrillation (AF) has substantial impacts on healthcare resource utilization. Our objective was to understand the pattern and predictors of cumulative healthcare costs in AF patients after incident diagnosis in an emergency department (ED). METHODS AND RESULTS: Patients discharged after a first presentation of AF to an ED in Ontario, Canada, were identified from April 1, 2005, through March 31, 2010. Per-patient cumulative healthcare costs were determined until death or March 31, 2012. Join-point analyses identified clinically relevant cost phases. Hierarchical generalized linear models with a logarithmic link and gamma distribution determined predictors of cost per phase. Our cohort was 17 980 patients. During a mean follow-up of 3.9 years, 17.1% of patients died. Three distinct cost phases were identified: 2-month post-index ED visit phase, 12-month predeath phase, and a stable/chronic phase. The mean cost per patient in the first month post-index ED visit was $1876 (95% CI $1822 to $1931), $8050 (95% CI $7666 to $8434) in the month before death, and $640 (95% CI $624 to $655) per month for the stable/chronic phase. The main cost component in the post-index phase was physician services (32% of all costs) and hospitalizations for the predeath phase (72% of all costs). The CHA2DS2-VASc clinical risk score was a strong predictor of costs (rate ratio 1.91 and 5.08 for score of 7 versus score of 0 in predeath phase and postindex phase, respectively). CONCLUSIONS: There are distinct phases of resource utilization in AF, with highest costs in the predeath phase.

Association between appropriateness of coronary revascularization and quality of life in patients with stable ischemic heart disease.

BACKGROUND: The relationship between appropriateness score, treatment strategy and quality of life (QOL) among patients with stable ischemic heart disease (SIHD) is not known. In this prospective cohort study, we evaluated changes in generic and cardiac-specific quality of life in patients with documented SIHD, comparing patients with revascularization versus those with medical therapy alone, stratified by their appropriateness scores. METHODS: Consecutive patients with SIHD undergoing elective coronary angiogram from November 1st 2008 to December 1st 2009 completed the Seattle Angina Questionnaire (SAQ) and EQ-5D at the time of procedure and at 1 year. The appropriateness for coronary revascularization was determined at the time of coronary angiography. RESULTS: Our final cohort consisted of 425 patients, 69.4% of whom underwent revascularization. In the overall cohort, 272 (64.0%) had appropriate indications for revascularization, while 57 (13.4%) had inappropriate indications and 96 (22.6%) had uncertain indications. On average, patients improved in most QOL domains, regardless of treatment strategy and appropriateness score. In patients with appropriate indications, revascularized patients had greater improvements in both generic (0.073; 95% CI 0.003-0.144; p-value 0.04) and disease-specific indices, including angina stability (14.6; 95% CI 0.85-28.3; p-value 0.04), physical limitation (9.3; 95% CI 0.71-17.8; p-value 0.03) and disease perception (12.7; 95% CI4.3-21.1; p-value 0.003) compared to medically treated patients. However, patients with uncertain and inappropriate indications also had improvements in physical limitation and disease perception with revascularization compared to medical therapy. CONCLUSIONS: Patients who had appropriate revascularization derived the greatest improvement in QOL compared with medical therapy.

Identifying future research priorities using value of information analyses: left atrial appendage occlusion devices in atrial fibrillation.

BACKGROUND: Left atrial appendage occlusion devices are cost effective for stroke prophylaxis in atrial fibrillation when compared with dabigatran or warfarin. We illustrate the use of value-of-information analyses to quantify the degree and consequences of decisional uncertainty and to identify future research priorities. METHODS AND RESULTS: A microsimulation decision-analytic model compared left atrial appendage occlusion devices to dabigatran or warfarin in atrial fibrillation. Probabilistic sensitivity analysis quantified the degree of parameter uncertainty. Expected value of perfect information analyses showed the consequences of this uncertainty. Expected value of partial perfect information analyses were done on sets of input parameters (cost, utilities, and probabilities) to identify the source of the greatest uncertainty. One-way sensitivity analyses identified individual parameters for expected value of partial perfect information analyses. Population expected value of perfect information and expected value of partial perfect information provided an upper bound on the cost of future research. Substantial uncertainty was identified, with left atrial appendage occlusion devices being preferred in only 47% of simulations. The expected value of perfect information was $8542 per patient and $227.3 million at a population level. The expected value of partial perfect information for the set of probability parameters represented the most important source of uncertainty, at $6875. Identified in 1-way sensitivity analyses, the expected value of partial perfect information for the odds ratio for stroke with left atrial appendage occlusion compared with warfarin was calculated at $7312 per patient or $194.5 million at a population level. CONCLUSION: The relative efficacy of stroke reduction with left atrial appendage occlusion devices in relation to warfarin is an important source of uncertainty. Improving estimates of this parameter should be the priority for future research in this area.

Impact of system and physician factors on the detection of obstructive coronary disease with diagnostic angiography in stable ischemic heart disease.

BACKGROUND: Wide variation exists in the detection rate of obstructive coronary artery disease (CAD) with elective coronary angiography for suspected stable ischemic heart disease. We sought to understand the incremental impact of nonclinical factors on this variation. METHODS AND RESULTS: We included all patients who underwent coronary angiography for possible suspected stable ischemic heart disease, from October 1, 2008, to September 30, 2011, in Ontario, Canada. Nonclinical factors of interest included physician self-referral for angiography, the physician type (invasive or interventional), and hospital type. Hospitals were categorized into diagnostic angiogram only centers, stand-alone percutaneous coronary intervention centers, or full service centers with coronary artery bypass surgery available. Multivariable hierarchical logistic models were developed to identify system and physician-level predictors of obstructive CAD, after adjustment for patient factors. Our cohort consisted of 60 986 patients, of whom 31 726 had obstructive CAD (52.0%), with significant range across hospitals from 37.3% to 69.2%. Fewer self-referral patients (49.8%) had obstructive CAD compared with nonself-referral patients (53.5%), with an odds ratio of 0.89 (95% confidence interval, 0.86-0.93; P<0.001). Angiograms performed by invasive physicians had a lower likelihood of obstructive CAD compared with those by interventional physicians (48.2% versus 56.9%; odds ratio, 0.85; 95% confidence interval, 0.81-0.90; P<0.001). Fewer angiograms at diagnostic only centers showed obstructive CAD (42.0%) compared with full service centers (55.1%; odds ratio, 0.62; 95% confidence interval, 0.39-0.98; P=0.04). Nonclinical factors accounted for 23.8% of the variation between hospitals. CONCLUSIONS: Physician and system factors are important predictors of obstructive CAD with coronary angiography.

Impact of wait times on the effectiveness of transcatheter aortic valve replacement in severe aortic valve disease: a discrete event simulation model.

BACKGROUND: There is increasing demand for transcatheter aortic valve replacement (TAVR) as the primary treatment option for patients with severe aortic stenosis who are high-risk surgical candidates or inoperable. We used mathematical simulation models to estimate the hypothetical effectiveness of TAVR with increasing wait times. METHODS: We applied discrete event modelling, using data from the Placement of Aortic Transcatheter Valves (PARTNER) trials. We compared TAVR with medical therapy in the inoperable cohort, and compared TAVR to conventional aortic valve surgery in the high-risk cohort. One-year mortality and wait-time deaths were calculated in different scenarios by varying TAVR wait times from 10 days to 180 days, while maintaining a constant wait time for surgery at a mean of 15.6 days. RESULTS: In the inoperable cohort, the 1-year mortality for medical therapy was 50%. When the TAVR wait time was 10 days, the TAVR wait-time mortality was 1.9% with a 1-year mortality of 31.5%. TAVR wait-time deaths increased to 28.9% with a 180-day wait, with a 1-year mortality of 41.4%. In the high-risk cohort, the wait-time deaths and 1-year mortality for the surgical patients were 2.5% and 27%, respectively. The TAVR wait-time deaths increased from 2.2% with a 10-day wait to 22.4% with a 180-day wait, and a corresponding increase in 1-year mortality from 24.5% to 32.6%. Mortality with TAVR exceeded surgery when TAVR wait times exceeded 60 days. CONCLUSIONS: Modest increases in TAVR wait times have a substantial effect on the effectiveness of TAVR in inoperable patients and high-risk surgical candidates.

Conversion of the Seattle Angina Questionnaire into EQ-5D utilities for ischemic heart disease: a systematic review and catalog of the literature.

BACKGROUND: There is a paucity of preference-based (utility) measures of health-related quality of life for patients with ischemic heart disease (IHD); in contrast, the Seattle Angina Questionnaire (SAQ) is a widely used descriptive measure. Our objective was to perform a systematic review of the literature to identify IHD studies reporting SAQ scores in order to apply a mapping algorithm to convert these to preference-based scores for secondary use in economic evaluations. METHODS: Relevant articles were identified in MEDLINE (Ovid), EMBASE (Ovid), Cochrane Library (Wiley), HealthStar (Ovid), and PubMed from inception to 2012. We previously developed and validated a mapping algorithm that converts SAQ descriptive scores to European Quality of Life-5 Dimensions (EQ-5D) utility scores. In the current study, this mapping algorithm was used to estimate EQ-5D utility scores from SAQ scores. RESULTS: Thirty-six studies met the inclusion criteria. The studies were categorized into three groups, ie, general IHD (n=13), acute coronary syndromes (n=4), and revascularization (n=19). EQ-5D scores for patients with general IHD were in the range of 0.605-0.843 at baseline, and increased to 0.649-0.877 post follow-up. EQ-5D scores for studies of patients with recent acute coronary syndromes increased from 0.706-0.796 at baseline to 0.795-0.942 post follow-up. The revascularization studies had EQ-5D scores in the range of 0.616-0.790 at baseline, and increased to 0.653-0.928 after treatment; studies that focused only on coronary artery bypass grafting increased from 0.643-0.788 at baseline to 0.653-0.928 after grafting, and studies that focused only on percutaneous coronary intervention increased in score from 0.616-0.790 at baseline to 0.668-0.897 after treatment. CONCLUSION: In this review, we provide a catalog of estimated health utility scores across a wide range of disease severity and following various interventions in patients with IHD. Our catalog of EQ-5D scores can be used in IHD-related economic evaluations.

Comparative-effectiveness of revascularization versus routine medical therapy for stable ischemic heart disease: a population-based study.

BACKGROUND: Randomized studies have shown optimal medical therapy to be as efficacious as revascularization in stable ischemic heart disease (IHD). It is not known if these efficacy results are reflected by real-world effectiveness. OBJECTIVE: To evaluate the comparative effectiveness of routine medical therapy versus revascularization with percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) in stable IHD. DESIGN: Observational cohort study. PATIENTS: Stable IHD patients from 1 October 2008 to 30 September 2011, identified using a Registry of all angiography patients in Ontario, Canada. INTERVENTION: Revascularization, defined as PCI/CABG within 90 days after index angiography. MAIN MEASURES: Death, myocardial infarction (MI) or repeat PCI/CABG. Revascularization was compared to medical therapy using a) multivariable Cox-proportional hazard models with therapy strategy treated as a time-varying covariate; and b) a propensity score matched analysis. Post-angiography medication use was determined. KEY RESULTS: We identified 39,131 stable IHD patients, of whom 15,139 were treated medically, and 23,992 were revascularized (PCI = 15,604; CABG = 8,388). Mean follow-up was 2.5 years. Revascularization was associated with fewer deaths (HR 0.76; 95 % CI 0.68-0.84; p < 0.001) ,MIs (HR 0.78; 95 % CI 0.72-0.85; p < 0.001) and repeat PCI/CABG (HR 0.59; 95 % CI 0.50-0.70; p < 0.001) than medical therapy. In the propensity-matched analysis of 12,362 well-matched pairs of revascularized and medical therapy patients, fewer deaths (8.6 % vs 12.7 %; HR 0.75; 95 % CI 0.69-0.81; p < 0.001) , MIs (11.7 % vs 14.4 %; HR 0.84; 95 % CI 0.77-0.93 p < 0.001) and repeat PCI/CABG ( 17.4 % vs 24.1 %;HR 0.67; 95 % 0.63-0.71; p < 0.001) occurred in revascularized patients, over the 4.1 years of follow-up. The revascularization patients had higher uptake of clopidogrel (70.3 % vs 27.2 %; p < 0.001), ß-blockers (78.2 % vs 76.7 %; p = 0.010), and statins (94.7 % vs 91.5 %, p < 0.001) in the 1-year post-angiogram. CONCLUSIONS: Stable IHD patients treated with revascularization had improved risk-adjusted outcomes in clinical practice, potentially due to under-treatment of medical therapy patients.

The effect of multidisciplinary heart failure clinic characteristics on 1-year postdischarge health care costs: a population-based study.

BACKGROUND: Although multidisciplinary heart failure (HF) clinics are efficacious, it is not known how patient factors or HF clinic structural indicators and process measures have an impact on the cumulative health care costs. RESEARCH DESIGN: In this retrospective cohort study using administrative databases in Ontario, Canada, we identified 1216 HF patients discharged alive after an acute care hospitalization in 2006 and treated at a HF clinic. The primary outcome was the cumulative 1-year health care costs. A hierarchical generalized linear model with a logarithmic link and gamma distribution was developed to determine patient-level and clinic-level predictors of cost. RESULTS: The mean 1-year cost was $27,809 (range, $69 to $343,743). There was a 7-fold variation in the mean costs by clinic, from $14,670 to $96,524. Delays in being seen at a HF clinic were a significant patient-level predictor of costs (rate ratio 1.0015 per day; P<0.001). Being treated at a clinic with >3 physicians was associated with lower costs (rate ratio 0.78; P=0.035). Unmeasured patient-level differences accounted for 97.4% of the between-patient variations in cost. The between-clinic variation in costs decreased by 16.3% when patient-level factors were accounted for; it decreased by a further 49.8% when clinic-level factors were added. CONCLUSIONS: From a policy perspective, the wide spectrum of HF clinic structure translates to inefficient care. Greater guidance as to the type of patient seen at a HF clinic, the timeliness of the initial visit, and the most appropriate structure of the HF clinics may potentially result in more cost-effective care.

Rate and predictors of the conversion of abstracts presented at the Canadian Cardiovascular Congress scientific meetings to full peer-reviewed publications.

The rate of conversion of abstracts presented at scientific meetings into peer-reviewed published manuscripts is an important metric for medical societies, because it facilitates translation of scientific knowledge into practice. We determined the rate and predictors of conversion of scientific abstracts presented at the Canadian Cardiovascular Congress (CCC) from 2006 to 2010 into peer-reviewed article publications within 2 years of their initial presentation. Using a previously validated computer algorithm, we searched the International Statistical Institute Web of Science to identify peer-reviewed full manuscript publications of these abstracts. A multivariable logistic regression was used to identify independent factors associated with successful publication. From 2006 to 2010, 3565 abstracts were presented at the CCC. Overall 24.1% of presented abstracts were published within 2 years of the conference. Mean impact factor for publications was 5.2 (range, 0.4-53.2). The type of presentation (for poster vs oral; odds ratio, 0.71; 95% confidence interval, 0.60-0.83; P < 0.001) and category of presentation (P < 0.001) were significantly associated with successful publication. Late breaking abstracts and those related to cancer and clinical sciences were more likely to be published, compared with prevention, vascular biology, and pediatrics. In conclusion, the publication rate at the CCC is only marginally lower than that reported for large international North American and European cardiology conferences (30.6%). Efforts should focus on several identified barriers to improve conversion of abstracts to full report publication.