Publications by Year: 2018

2018
Pottegård A, Hallas J, Wang SV, Gagne JJ. Identifying signals of interest when screening for drug-outcome associations in health care data. Br J Clin Pharmacol. 2018;84 (9) :1865-1867.
Bykov K, Gagne JJ, Wang B, Choudhry NK. Impact of a Metoprolol Extended Release Shortage on Post-Myocardial Infarction β-Blocker Utilization, Adherence, and Rehospitalization. Circ Cardiovasc Qual Outcomes. 2018;11 (10) :e004096.Abstract
BACKGROUND: Shortages of chronic medications are an increasingly common problem, yet little is known about their impact on drug utilization and clinical outcomes. We evaluated the population-level impact of metoprolol extended release shortage that occurred in the United States in 2009 to 2010. METHODS AND RESULTS: We conducted a population-based, time series analysis of 38 914 patients (mean age, 60 years; 69% men) discharged after hospitalization for myocardial infarction (MI) between January 2006 and November 2012 in a large commercial insurance database. The shortage period was defined as February 2009 to June 2010. Data before September 2008 was defined as preshortage period and data after June 2010 as postshortage period. Outcomes were proportion of patients who filled any long- or short-acting β-blocker within 30 days of discharge, adherence to β-blockers within the first year of therapy among patients who initiated β-blockers, and rates of 1-year rehospitalization for MI or unstable angina. Post-MI statin utilization and adherence were evaluated as control outcomes. During the preshortage period, 70% of patient filled a β-blocker, mean monthly adherence was 76%, and the average monthly rate of rehospitalization was 6.5 events per 100 person-years, as compared with β-blocker use of 62%, average adherence of 70%, and rehospitalization rate of 5.6 events per 100 person-years during the shortage. After accounting for the baseline (preshortage) trends, the shortage was associated with significant monthly reductions in postdischarge β-blocker use (-0.57% of patients [95% CI, -0.90 to -0.24] per month) and an immediate decrease in adherence (-4.58% days covered [95% CI, -6.12 to -3.04]). No negative impact on rates of rehospitalization, post-MI statin utilization, or statin adherence was observed. β-Blocker utilization began to increase after the resolution of the shortage. CONCLUSIONS: The nationwide metoprolol extended release shortage in the United States was associated with fewer patients receiving any long- or short-acting β-blocker post-MI and lower adherence to β-blocker therapy for those who did receive it, but did not appear to appreciably affect clinical outcomes at the population level.
Lewey J, Gagne JJ, Franklin J, Lauffenburger JC, Brill G, Choudhry NK. Impact of High Deductible Health Plans on Cardiovascular Medication Adherence and Health Disparities. Circ Cardiovasc Qual Outcomes. 2018;11 (11) :e004632.Abstract
BACKGROUND: High deductible health plans (HDHP) are associated with high levels of patient cost-sharing and are becoming increasingly used in the United Status as a means of reducing healthcare utilization and spending. Our objective is to determine whether HDHP enrollment is associated with a change in adherence to evidence-based medications to treat cardiovascular risk factors and whether such changes vary based on race/ethnicity or socioeconomic status. METHODS AND RESULTS: We conducted a retrospective cohort study using an interrupted time series with concurrent control group design among beneficiaries of Aetna-a national commercial insurer. We included 14 866 patients who filled prescriptions for medications to treat hypertension, high cholesterol, or diabetes mellitus between 2009 and 2014 and who switched from a traditional plan into an HDHP and 14 866 controls who did not switch to an HDHP matched based on calendar time, medication class, race/ethnicity, socioeconomic status, and propensity score. We were specifically interested in evaluating 4 prespecified subgroups based on race/ethnicity (white versus nonwhite) and socioeconomic status (higher versus lower). The main outcome was medication adherence as measured by proportion of days covered. The overall cohort had an average age of 53 years, and 44% were women. Baseline adherence was the lowest in the nonwhite patient group. Switching to an HDHP was associated with a decrease in the level of adherence of 5 percentage points across all 4 subgroups (change in level, -5.0%; 95% CI, -5.9% to -4.0%; P<0.0001). CONCLUSIONS: HDHP enrollment was associated with a reduction in adherence to medications to treat cardiovascular risk factors. The magnitude of this effect did not vary based on race/ethnicity or socioeconomic status. Because racial/ethnic minorities have lower rates of medication adherence, future studies should evaluate whether HDHP-associated changes in adherence have greater clinical consequences for these patients.
Krumme AA, Glynn RJ, Schneeweiss S, Gagne JJ, Dougherty SJ, Brill G, Choudhry NK. Medication Synchronization Programs Improve Adherence To Cardiovascular Medications And Health Care Use. Health Aff (Millwood). 2018;37 (1) :125-133.Abstract
Medication synchronization programs based in pharmacies simplify the refill process by enabling patients to pick up all of their medications on a single visit. This can be especially important for improving medication adherence in patients with complex chronic diseases. We evaluated the impact of two synchronization programs on adherence, cardiovascular events, and resource use among Medicare beneficiaries treated between 2011 and 2014 for two or more chronic conditions-at least one of which was hypertension, hyperlipidemia, or diabetes. Among nearly 23,000 patients matched by propensity score, the mean proportion of days covered (a measure of medication adherence) for the control group of patients without a synchronization program was 0.84 compared to 0.87 for synchronized patients-a gain of 3 percentage points. Adherence improvement in synchronized versus control patients was three times greater in patients with low baseline adherence, compared to those with higher baseline adherence. Rates of hospitalization and emergency department visits and rates of outpatient visits were 9 percent and 3 percent lower in the synchronized group compared to the control group, respectively, while cardiovascular event rates were similar. Synchronization programs were associated with improved adherence for patients with cardiovascular disease, especially those with low baseline adherence.
Pickard SS, Gauvreau K, Gurvitz M, Gagne JJ, Opotowsky AR, Jenkins KJ, Prakash A. A National Population-based Study of Adults With Coronary Artery Disease and Coarctation of the Aorta. Am J Cardiol. 2018;122 (12) :2120-2124.Abstract
Adults with repaired coarctation of the aorta (CoA) suffer reduced long-term survival compared with the general population, in part due to coronary artery disease (CAD). There is conflicting evidence as to whether or not CoA is an independent risk factor for CAD. The primary aim was to determine if CoA is independently associated with premature myocardial infarction (MI) in the contemporary era. The secondary aim was to determine if CoA is independently associated with early coronary intervention. In a cross-sectional study using the National Inpatient Sample database from 2005 to 2014, we compared the age at MI and the age at coronary intervention (coronary artery bypass grafting or percutaneous coronary intervention, in the absence of MI diagnosis) in patients with and without CoA using weighted linear regression. Among 5,472,416 observations with a primary diagnosis of MI, 174 had a diagnosis of CoA. Patients with CoA had MI 7.2 years younger than those without CoA, after adjusting for potential confounders (95% CI -11.3, -3.1, p = 0.001). Among 3,631,718 patients without a diagnosis of MI who underwent coronary artery bypass grafting or percutaneous coronary intervention, 279 had a diagnosis of CoA. Patients with CoA who underwent coronary intervention were 15.6 years younger than those without CoA, after adjusting for potential confounders (95% CI -18.3, -12.9, p < 0.001). In conclusion, patients with CoA have MI at a slightly younger age and undergo coronary intervention at a significantly younger age than those without CoA in the contemporary era. Our findings support continued close surveillance for and treatment of modifiable risk factors for CAD.
Ladha KS, Gagne JJ, Patorno E, Huybrechts KF, Rathmell JP, Wang SV, Bateman BT. Opioid Overdose After Surgical Discharge. JAMA. 2018;320 (5) :502-504.
Mundkur ML, Rough K, Huybrechts KF, Levin R, Gagne JJ, Desai RJ, Patorno E, Choudhry NK, Bateman BT. Patterns of opioid initiation at first visits for pain in United States primary care settings. Pharmacoepidemiol Drug Saf. 2018;27 (5) :495-503.Abstract
PURPOSE: The primary objective of this study was to characterize variation in patterns of opioid prescribing within primary care settings at first visits for pain, and to describe variation by condition, geography, and patient characteristics. METHODS: 2014 healthcare utilization data from Optum's Clinformatics™ DataMart were used to evaluate individuals 18 years or older with an initial presentation to primary care for 1 of 10 common pain conditions. The main outcomes assessed were (1) the proportion of first visits for pain associated with an opioid prescription fill and (2) the proportion of opioid prescriptions with >7 days' supply. RESULTS: We identified 205 560 individuals who met inclusion criteria; 9.1% of all visits were associated with an opioid fill, ranging from 4.1% (headache) to 28.2% (dental pain). Approximately half (46%) of all opioid prescriptions supplied more than 7 days, and 10% of prescriptions supplied ≥30 days. We observed a 4-fold variation in rates of opioid initiation by state, with highest rates of prescribing in Alabama (16.6%) and lowest rates in New York (3.7%). CONCLUSIONS: In 2014, nearly half of all patients filling opioid prescriptions received more than 7 days' of opioids in an initial prescription. Policies limiting initial supplies have the potential to substantially impact opioid prescribing in the primary care setting.
Chrischilles EA, Gagne JJ, Fireman B, Nelson J, Toh S, Shoaibi A, Reichman ME, Wang S, Nguyen M, Zhang R, et al. Prospective surveillance pilot of rivaroxaban safety within the US Food and Drug Administration Sentinel System. Pharmacoepidemiol Drug Saf. 2018;27 (3) :263-271.Abstract
PURPOSE: The US Food and Drug Administration's Sentinel system developed tools for sequential surveillance. METHODS: In patients with non-valvular atrial fibrillation, we sequentially compared outcomes for new users of rivaroxaban versus warfarin, employing propensity score matching and Cox regression. A total of 36 173 rivaroxaban and 79 520 warfarin initiators were variable-ratio matched within 2 monitoring periods. RESULTS: Statistically significant signals were observed for ischemic stroke (IS) (first period) and intracranial hemorrhage (ICH) (second period) favoring rivaroxaban, and gastrointestinal bleeding (GIB) (second period) favoring warfarin. In follow-up analyses using primary position diagnoses from inpatient encounters for increased definition specificity, the hazard ratios (HR) for rivaroxaban vs warfarin new users were 0.61 (0.47, 0.79) for IS, 1.47 (1.29, 1.67) for GIB, and 0.71 (0.50, 1.01) for ICH. For GIB, the HR varied by age: <66 HR = 0.88 (0.60, 1.30) and 66+ HR = 1.49 (1.30, 1.71). CONCLUSIONS: This study demonstrates the capability of Sentinel to conduct prospective safety monitoring and raises no new concerns about rivaroxaban safety.
Wang SV, Jin Y, Fireman B, Gruber S, He M, Wyss R, Shin HJ, Ma Y, Keeton S, Karami S, et al. Relative Performance of Propensity Score Matching Strategies for Subgroup Analyses. Am J Epidemiol. 2018;187 (8) :1799-1807.Abstract
Postapproval drug safety studies often use propensity scores (PSs) to adjust for a large number of baseline confounders. These studies may involve examining whether treatment safety varies across subgroups. There are many ways a PS could be used to adjust for confounding in subgroup analyses. These methods have trade-offs that are not well understood. We conducted a plasmode simulation to compare relative performance of 5 methods involving PS matching for subgroup analysis, including methods frequently used in applied literature whose performance has not been previously directly compared. These methods varied as to whether the overall PS, subgroup-specific PS, or no rematching was used in subgroup analysis as well as whether subgroups were fully nested within the main analytical cohort. The evaluated PS subgroup matching methods performed similarly in terms of balance, bias, and precision in 12 simulated scenarios varying size of the cohort, prevalence of exposure and outcome, strength of relationships between baseline covariates and exposure, the true effect within subgroups, and the degree of confounding within subgroups. Each had strengths and limitations with respect to other performance metrics that could inform choice of method.
Wang SV, Kulldorff M, Glynn RJ, Gagne JJ, Pottegård A, Rothman KJ, Schneeweiss S, Walker AM. Reuse of data sources to evaluate drug safety signals: When is it appropriate?. Pharmacoepidemiol Drug Saf. 2018;27 (6) :567-569.
Gagne JJ, Houstoun M, Reichman ME, Hampp C, Marshall JH, Toh S. Safety assessment of niacin in the US Food and Drug Administration's mini-sentinel system. Pharmacoepidemiol Drug Saf. 2018;27 (1) :30-37.Abstract
PURPOSE: The Heart Protection Study 2-Treatment of HDL to Reduce the Incidence of Vascular Events (HPS2-THRIVE) trial found higher incidence rates of adverse reactions, including bleeding, in patients receiving the combination of extended-release niacin and laropiprant versus placebo. It is not known whether these adverse events are attributable to laropiprant, not approved in the USA, or to extended-release niacin. We compared rates of major gastrointestinal bleeding and intracranial hemorrhage among initiators of extended-release niacin and initiators of fenofibrate. METHODS: We used Mini-Sentinel (now Sentinel) to conduct an observational, new user cohort analysis. We included data from 5 Data Partners covering the period from January 1, 2007 to August 31, 2013. Individuals who initiated extended-release niacin were propensity score-matched to individuals who initiated fenofibrate. Within the matched cohorts, we used Cox proportional hazards models to compare rates of hospitalization for major gastrointestinal bleeding events and intracranial hemorrhage assessed using validated claims-based algorithms. RESULTS: A total of 234 242 eligible extended-release niacin initiators were identified, of whom 210 389 (90%) were 1:1 propensity score-matched to eligible fenofibrate initiators. In propensity score-matched analyses, no differences were observed between exposure groups in rates of major gastrointestinal bleeding (hazard ratio [HR], 0.98; 95% confidence interval [CI], 0.82 to 1.18) or intracranial hemorrhage (HR, 1.21; 95% CI, 0.66 to 2.22). Results were similar in pre-specified sensitivity and subgroup analyses. CONCLUSIONS: We did not observe evidence for an association between extended-release niacin versus fenofibrate and rates of major gastrointestinal bleeding or intracranial hemorrhage.
Martin D, Gagne JJ, Gruber S, Izem R, Nelson JC, Nguyen MD, Ouellet-Hellstrom R, Schneeweiss S, Toh S, Walker AM. Sequential surveillance for drug safety in a regulatory environment. Pharmacoepidemiol Drug Saf. 2018;27 (7) :707-712.
Najafzadeh M, Schneeweiss S, Choudhry NK, Wang SV, Gagne JJ. Simulation for Predicting Effectiveness and Safety of New Cardiovascular Drugs in Routine Care Populations. Clin Pharmacol Ther. 2018;104 (5) :1008-1015.Abstract
In the presence of heterogeneity of treatment effect (HTE), the average treatment effect from a randomized controlled trial (RCT) may not be applicable to different patients, such as those in observational settings. Our objective was to develop a novel approach that uses individual-level simulation to expand RCT results to target patient populations in the presence of HTE. For this purpose, we compared the results of the Randomized Evaluation of Long-Term Anticoagulation Therapy (RE-LY) trial, and two observational studies that compared benefits and risks of dabigatran to warfarin in patients with atrial fibrillation. We developed a simulation model that replicates the rates of ischemic stroke and major bleeding observed in RE-LY using published outcome risk models and participants' baseline characteristics. We used our validated simulation model to predict what the results of the RCT would have been had it been conducted in populations similar to those in the observational studies.
Pickard SS, Gauvreau K, Gurvitz M, Gagne JJ, Opotowsky AR, Jenkins KJ, Prakash A. Stroke in Adults With Coarctation of the Aorta: A National Population-Based Study. J Am Heart Assoc. 2018;7 (11).Abstract
BACKGROUND: Adults with repaired coarctation of the aorta (CoA) have reduced long-term survival compared with the general population. This study aimed to determine whether CoA is independently associated with premature ischemic and hemorrhagic stroke in the contemporary era. METHODS AND RESULTS: This was a cross-sectional study utilizing the National Inpatient Sample database from 2005 to 2014. We hypothesized that patients with CoA are hospitalized with ischemic and hemorrhagic stroke at a younger age compared with the general population. To test this hypothesis, we compared the age at stroke in patients with and without a diagnosis of CoA using simple and multivariable weighted linear regression. Among 4 894 582 stroke discharges, 207 had a diagnosis of CoA. Patients with CoA had strokes at significantly younger age compared with patients without CoA: 18.9 years younger for all-cause stroke (<0.001), 15.9 years younger for ischemic stroke (<0.001), and 28.5 years younger for hemorrhagic stroke (<0.001), after adjusting for potential confounders. There was no significant difference in the proportion of ischemic strokes between those with and without CoA (79.2% versus 83.0%, =0.50). However, CoA patients had a higher proportion of subarachnoid hemorrhage (11.8% versus 4.8%, =0.039) than those without CoA. Among patients who had a hemorrhagic stroke, the prevalence of unruptured intracranial aneurysms was higher in patients with CoA compared with those without CoA (23.3% versus 2.5%, =0.002). CONCLUSIONS: Patients with CoA have both ischemic and hemorrhagic strokes at significantly younger ages compared with the general population.
Krumme AA, Pawar A, Schneeweiss S, Glynn RJ, Choudhry NK, Kulldorff M, Ortiz AS, Avorn J, Gagne JJ. Study protocol for the dabigatran, apixaban, rivaroxaban, edoxaban, warfarin comparative effectiveness research study. J Comp Eff Res. 2018;7 (1) :57-66.Abstract
Since 2010, four oral anticoagulants have been approved for marketing in addition to warfarin for treatment of thromboembolic disease. Limited head-to-head data exist comparing these treatments, leaving patients and clinicians with little guidance for selecting a strategy that balances recurrence reduction with bleeding risk. In the dabigatran, apixaban, rivaroxban, edoxaban and warfarin comparative effectiveness research study, we compare all five currently available oral anticoagulant agents for the extended treatment of deep venous thrombosis and pulmonary embolism, as well as no extended treatment, and evaluate whether results differ in specific sub-populations. As our population includes Medicare novel anticoagulant users and large numbers of commercially insured and Medicaid patients, our results will likely be transportable to the majority of US patients experiencing a DVT or pulmonary embolism. CLINICAL TRIALS REGISTRATION: NCT03271450.
Donneyong MM, Kulik A, Gagne JJ. Trends and Patterns of Corticosteroid Use During Coronary Artery Bypass Grafting Surgery in the United States. J Cardiovasc Pharmacol Ther. 2018;23 (3) :226-236.Abstract
BACKGROUND: Several clinical trials have documented clinical benefits associated with prophylactic corticosteroid administration at the time of coronary artery bypass graft (CABG) surgery, including a reduction in the risk of atrial fibrillation and hospital length of stay. Despite the published data, the extent to which providers have adopted the perioperative use of corticosteroids remains unknown. OBJECTIVES: To assess temporal trends, between-hospital variation, and determinants of perioperative intravenous corticosteroid use during CABG surgery. METHODS: We identified all patients admitted for CABG surgery in the Premier Healthcare Database (2003-2014), a large US-based inpatient database. We determined the proportion of patients administered prophylactic corticosteroids on the day of CABG surgery. Linear time-series models were used to estimate the rate and trend of corticosteroid use over time. Separate multivariable generalized estimating equation models were used to quantify the variation in and determinants of perioperative corticosteroid use. RESULTS: Of 401 788 eligible patients who underwent a CABG surgery between 2003 and 2014, 20% (n = 80 681) were administered intravenous prophylactic perioperative corticosteroids (methylprednisolone, dexamethasone, or hydrocortisone). Corticosteroid use increased from 17.5% in 2003 to 22.6% in 2014 (annual rate = 0.42%; P < .001). Individual hospitals accounted for >50% of variation in corticosteroid use. High between-hospital variation was also observed, and the probability of utilization was ≥32.4% in the upper versus ≤3.4% in the bottom quartiles of hospitals. CONCLUSION: Prophylactic corticosteroid administration during CABG has increased gradually since 2003. To further evaluate the risk-benefit trade-off associated with their use, we believe a large-scale outcomes study is warranted to assess this highly variable practice.
Dong Y-H, Jin Y, Tsacogianis TN, He M, Hsieh P-H, Gagne JJ. Use of olmesartan and enteropathy outcomes: a multi-database study. Aliment Pharmacol Ther. 2018;47 (6) :792-800.Abstract
BACKGROUND: Multiple case reports suggest that olmesartan may be linked to sprue-like enteropathy; however, few epidemiological studies have examined this association and results have been mixed. AIM: To assess whether olmesartan is associated with a higher rate of enteropathy vs other angiotensin II receptor blockers (ARBs). METHODS: We conducted a cohort study among ARB initiators in 5 US claims databases representing different health insurance programmes. Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for enteropathy-related outcomes, including coeliac disease, malabsorption, concomitant diagnoses of diarrhoea and weight loss, and non-infectious enteropathy, comparing olmesartan initiators to initiators of other ARBs after propensity score (PS) matching. RESULTS: We identified 1 928 469 eligible patients. The unadjusted incidence rates were 0.82, 1.41, 1.66 and 29.20 per 1000 person-years for coeliac disease, malabsorption, concomitant diagnoses of diarrhoea and weight loss, and non-infectious enteropathy respectively. HRs after PS matching comparing olmesartan to other ARBs were 1.21 (95% CI, 1.05-1.40), 1.00 (95% CI, 0.88-1.13), 1.22 (95% CI, 1.10-1.36) and 1.04 (95% CI, 1.01-1.07) for each outcome. HRs were larger for patients aged 65 years and older (eg for coeliac disease, 1.57 [95% CI, 1.20-2.05]), for patients receiving treatment for more than 1 year (1.62 [95% CI, 1.24-2.12]), and for patients receiving higher cumulative olmesartan doses (1.78 [95% CI, 1.33-2.37]). CONCLUSIONS: This large-scale, multi-database study found a higher rate of enteropathy in olmesartan initiators as compared to initiators of other ARBs, although the absolute incidence rate was low in both groups.
Wohlfahrt A, Campos A, Iversen MD, Gagne JJ, Massarotti E, Solomon DH, Feldman CH. Use of rheumatology-specific patient navigators to understand and reduce barriers to medication adherence: Analysis of qualitative findings. PLoS One. 2018;13 (7) :e0200886.Abstract
OBJECTIVE: Adherence to medications among patients with rheumatic diseases is often suboptimal. Patient navigators, individuals trained in care coordination, motivational interviewing and basic rheumatology and pharmacology, have not been employed to explore and address this issue. We piloted a single-site, single arm intervention to determine the feasibility and acceptability of using rheumatology-specific navigators to understand and reduce barriers to adherence to oral disease modifying anti-rheumatic drugs (DMARDs). We analyzed our qualitative findings from navigator-patient interactions as well as patient satisfaction with the intervention. METHODS: We recruited patients ≥18 years with a systemic rheumatic disease who initiated an oral DMARD within the prior 6 months. Navigators conducted baseline needs assessments and 2-4 week follow-up calls to understand and address issues related to medication adherence. We analyzed patient-navigator encounters qualitatively using content analysis to identify key themes related to barriers to adherence and navigator actions performed in response to the barriers described. We also categorized intentional and unintentional nonadherent behavior and assessed satisfaction with the navigator experience (range 0-5, 5 = most satisfied). RESULTS: 107 rheumatology patients were followed for up to 6 months. Mean patient age was 55 years (+17) and 93% were female; 36% described one or more episode of intentional or unintentional nonadherence. The three most common themes identified as barriers to adherence were fear of adverse events (raised by 54%), concerns about medication effectiveness (43%), and challenges with medication acquisition (32%). 86% of participants described at least one adherence-related barrier. Frequent navigator actions included facilitation of patient-doctor communication (38%), medication and diagnosis education (27%), and development of individualized strategies to improve adherence (16%). Patients were satisfied with the navigator experience (mean 4.4 + 0.9). CONCLUSION: Navigators uncovered and addressed a number of medication adherence-related concerns and patients were satisfied with the services provided.
Kumamaru H, Lee MP, Choudhry NK, Dong Y-H, Krumme AA, Khan N, Brill G, Kohsaka S, Miyata H, Schneeweiss S, et al. Using Previous Medication Adherence to Predict Future Adherence. J Manag Care Spec Pharm. 2018;24 (11) :1146-1155.Abstract
BACKGROUND: Medication nonadherence is a major public health problem. Identification of patients who are likely to be and not be adherent can guide targeted interventions and improve the design of comparative-effectiveness studies. OBJECTIVE: To evaluate multiple measures of patient previous medication adherence in light of predicting future statin adherence in a large U.S. administrative claims database. METHODS: We identified a cohort of patients newly initiating statins and measured their previous adherence to other chronic preventive medications during a 365-day baseline period, using metrics such as proportion of days covered (PDC), lack of second fills, and number of dispensations. We measured adherence to statins during the year after initiation, defining high adherence as PDC ≥ 80%. We built logistic regression models from different combinations of baseline variables and previous adherence measures to predict high adherence in a random 50% sample and tested their discrimination using concordance statistics (c-statistics) in the other 50%. We also assessed the association between previous adherence and subsequent statin high adherence by fitting a modified Poisson model from all relevant covariates plus previous mean PDC categorized as < 25%, 25%-79%, and ≥ 80%. RESULTS: Among 89,490 statin initiators identified, a prediction model including only demographic variables had a c-statistic of 0.578 (95% CI = 0.573-0.584). A model combining information on patient comorbidities, health care services utilization, and medication use resulted in a c-statistic of 0.665 (95% CI = 0.659-0.670). Models with each of the previous medication adherence measures as the only explanatory variable yielded c-statistics ranging between 0.533 (95% CI = 0.529-0.537) for lack of second fill and 0.666 (95% CI = 0.661-0.671) for maximum PDC. Adding mean PDC to the combined model yielded a c-statistic of 0.695 (95% CI = 0.690-0.700). Given a sensitivity of 75%, the predictor improved the specificity from 47.7% to 53.6%. Patients with previous mean PDC < 25% were half as likely to show high adherence to statins compared with those with previous mean PDC ≥ 80% (risk ratio = 0.49, 95% CI = 0.46-0.50). CONCLUSIONS: Including measures of previous medication adherence yields better prediction of future statin adherence than usual baseline clinical measures that are typically used in claims-based studies. DISCLOSURES: This study was funded by the Patient-Centered Outcomes Research Institute (ME-1309-06274). Kumamaru, Kohsaka, and Miyata are affiliated with the Department of Healthcare Quality Assessment at the University of Tokyo, which is a social collaboration department supported by National Clinical Database. The department was formerly supported by endowments from Johnson & Johnson K.K., Nipro, Teijin Pharma, Kaketsuken K.K., St. Jude Medical Japan, Novartis Pharma K.K., Taiho Pharmaceutical, W. L. Gore & Associates, Olympus Corporation, and Chugai Pharmaceutical. Gagne has received grants from Novartis Pharmaceuticals and Eli Lilly and Company to the Brigham and Women's Hospital for unrelated work. He is a consultant to Aetion, a software company, and to Optum. Choudhry has received grants from the National Heart, Lung, and Blood Institute, PhRMA Foundation, Merck, Sanofi, AstraZeneca, CVS, and MediSafe. Schneeweiss is consultant to WHISCON and Aetion, a software manufacturer of which he also owns equity. He is principal investigator of investigator-initiated grants to the Brigham and Women's Hospital from Bayer, Genentech, and Boehringer Ingelheim unrelated to the topic of this study. He does not receive personal fees from biopharmaceutical companies. No potential conflict of interest was reported by the other authors.
Sun JW, Rogers JR, Her Q, Welch EC, Panozzo CA, Toh S, Gagne JJ. Validation of the Combined Comorbidity Index of Charlson and Elixhauser to Predict 30-Day Mortality Across ICD-9 and ICD-10. Med Care. 2018;56 (9) :812.

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