Impact of Hospitalization for Acute Myocardial Infarction on Adherence to Statins Among Older Adults

Abstract

Background Little is known about the impact of hospitalization for an acute myocardial infarction (AMI) on subsequent adherence to statins. Methods and Results Using administrative claims from a 5% random sample of Medicare beneficiaries, we identified a cohort of Medicare patients ≥65 years, hospitalized from 2007–2011, taking statins in the year before AMI hospitalization (n=6,618). We then determined the proportion of patients nonadherent to statins (proportion of days covered [PDC] <80%) in the year before AMI hospitalization who became statin adherent (PDC ≥80%) in the year after AMI hospitalization. The proportion of statin adherent patients who became nonadherent was also studied. These proportions were compared with patients hospitalized for pneumonia (n=11,471) and patients not hospitalized (n=158,099) in 2010 and 2011. Among patients nonadherent to statins before AMI hospitalization, 37.7% became adherent after discharge. Patients hospitalized for AMI were more likely to become adherent than patients hospitalized for pneumonia (aRR 1.70, 95%CI 1.57–1.84) or patients not hospitalized (aRR 1.79, 95%CI 1.68–1.90). Among patients adherent to statins before AMI hospitalization, 32.6% became nonadherent after discharge. Those hospitalized for AMI were less likely to become nonadherent than those hospitalized for pneumonia (aRR 0.93, 95%CI 0.88–0.98) but more likely to become nonadherent than patients without hospitalizations (aRR 1.41, 95%CI 1.35–1.48). Conclusions Among nonadherent patients, hospitalization for AMI was associated with increased likelihood of becoming adherent to statins compared to hospitalization for pneumonia or no hospitalizations. Among adherent patients, hospitalization for AMI was associated with increased likelihood of becoming nonadherent to statins compared to no hospitalizations.

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

“…Similar to previous findings, patients with greater comorbidity burden at baseline were more likely to have decreased adherence and less likely to have increased adherence after AMI hospital discharge. It is also possible that clinicians stopped preventative medications in patients with a short life expectancy.…”

“…However, research has shown that this does not often happen for Medicare beneficiaries, and even when it does, these claims are often adjudicated into Part D records Medicare patients are also less likely to use medication samples than those in the privately insured population . Third, we did not have a control group in this study, but previous research using two control groups––patients without a hospitalization and patients hospitalized for pneumonia––found that AMI hospitalizations were associated with changes in statin adherence …”

“…It is the first to employ a nationally representative sample of all Medicare fee‐for‐service beneficiaries who had an AMI in the period 2008–2010, enabling us to investigate more risk factors with improved generalizability. We also investigated the impact of post‐AMI follow‐up with a clinician, which was noted as an important factor in previous research on this topic . Further, our several definitions of adherence change allowed assessment of varying magnitudes of adherence change and the inclusion of all study patients in a single statistical model.…”

“…However, discontinuity during transitions in care––including both lack of follow‐up and breakdown of communication among multiple providers––may also negatively impact adherence . It is unclear how post‐AMI follow‐up with either a primary care provider (PCP) and/or a cardiologist may affect changes in adherence among patients who are already using statins …”

“…In order to effectively develop clinical and policy interventions to improve adherence to secondary prevention therapies, it is important to understand how medication adherence may change in response to an AMI, which patients are more likely to have increased or decreased adherence, and how follow‐up with healthcare providers may affect this change. The evidence available from prior studies is insufficient to address these questions . Therefore, the aims of this study were (1) to determine to what extent older patients’ adherence to statins may change after an AMI, (2) to identify patient characteristics associated with change in statin adherence after an AMI, and (3) to assess whether post‐discharge follow‐up with PCPs and/or cardiologists is associated with change in statin adherence after an AMI.…”