Changes in Statin Adherence Following an Acute Myocardial Infarction Among Older Adults: Patient Predictors and the Association With Follow‐Up With Primary Care Providers and/or Cardiologists

Abstract

BackgroundHospitalizations for acute myocardial infarctions (AMIs) are associated with changes in statin adherence. It is unclear to what extent adherence changes, which patients are likely to change, and how post‐discharge follow‐up is associated with statin adherence change.Methods and ResultsThis retrospective study used Medicare data for all fee‐for‐service beneficiaries 66 years and older with an AMI hospitalization in 2008–2010 and statin use before their index AMI. Multivariable multinomial logistic regression models (odds ratio [OR] and 99% confidence interval [CI]) were applied to assess associations between both patient characteristics and follow‐up with a primary care provider and/or cardiologist with the outcome of statin adherence change (increase or decrease) from the 6‐month pre‐ to 6‐month post‐AMI periods. Of 113 296 patients, 64.0% had no change in adherence, while 19.7% had increased and 16.3% had decreased adherence after AMI hospitalization. Black and Hispanic patients were more likely to have either increased or decreased adherence than white patients. Patients who required coronary artery bypass graft surgery (OR, 1.34; 99% CI, 1.21–1.49) or percutaneous transluminal coronary angioplasty/stent procedure (OR, 1.25; 99% CI, 1.17–1.32) during their index hospitalization were more likely to have increased adherence. Follow‐up with a primary care provider was only mildly associated with increased adherence (OR, 1.08; 99% CI, 1.00–1.16), while follow‐up with a cardiologist (OR, 1.15; 99% CI, 1.05–1.25) or both provider types (OR, 1.21; 99% CI, 1.12–1.30) had stronger associations with increased adherence.ConclusionsPost‐AMI changes in statin adherence varied by patient characteristics, and improved adherence was associated with post‐discharge follow‐up care, particularly with a cardiologist or both a primary care provider and a cardiologist.

Opening the black box of the group‐based trajectory modeling process to analyze medication adherence patterns: An example using real‐world statin adherence data

“…Our study included 113,296 previously described prevalent statin users . Most were 66‐85 years old (84.5%), female (54.3%), and White (84.3%); 10.1% were “new users”.…”

“…We chose a 6‐month measurement period because our research was investigating how medication adherence directly preceding an AMI may be affected by this event . Our specific trajectory models are not generalizable to other GBTM adherence studies (e.g.…”

“…A 100% sample of US Medicare Chronic Conditions Data Warehouse 2007‐2011 administrative claims data was used . Patients met these eligibility criteria: 2008‐2010 inpatient acute myocardial infarction (AMI) claim in primary/secondary position; ≥66 years old; survived hospitalization; continuously enrolled; statin prescription fill within 12 months pre‐AMI; and no pre‐AMI end‐stage renal disease …”

“…10 Patients met these eligibility criteria: 2008-2010 inpatient acute myocardial infarction (AMI) claim in primary/secondary position; ≥66 years old; survived hospitalization; continuously enrolled; statin prescription fill within 12 months pre-AMI; and no pre-AMI end-stage renal disease. 10 Statin adherence was measured using Part D prescription claims in the 180 days pre-AMI, using proportion of days covered (PDC) and adjusting for hospitalizations and oversupply from previous fills. PDC was calculated in 30-day intervals (Supplemental Figure S1) as days with medication available divided by days in period as a continuous measure (0≤PDC≤1).…”

“…We chose a 6-month measurement period because our research was investigating how medication adherence directly preceding an AMI may be affected by this event. 10 Our specific trajectory models are not generalizable to other GBTM adherence studies (e.g. new users, 12-month adherence, different population); however, our approach could be applied, adding further clarity and standardization to the GBTM medication adherence literature.…”