Hospital Variation in Adherence Rates to Secondary Prevention Medications and the Implications on Quality
Background—Medication adherence is important to improve long-term outcomes after acute myocardial infarction (MI). We hypothesized that there is significant variation among United States (U.S.) hospitals in terms of post-MI medication adherence, and that patients treated at hospitals with higher post-MI medication adherence will have better long-term cardiovascular outcomes.
Methods—We identified 19,704 Medicare patients discharged after acute MI from 347 U.S. hospitals participating in the Acute Coronary Treatment and Intervention Outcomes Network Registry-Get With The Guidelines (ACTION Registry-GWTG) from 1/2/2007 to 10/1/2010. Using linked Medicare Part D prescription filling data, medication adherence was defined as proportion of days covered (PDC) >80% within 90 days post-discharge. Cox proportional hazards modeling was used to compare 2-year major adverse cardiovascular events (MACE) among hospitals with high, moderate, and low 90-day medication adherence.
Results—By 90 days post-MI, overall rates of adherence to medications prescribed at discharge were 68% for beta-blockers, 63% for statins, 64% for angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs), and 72% for thienopyridines. Adherence to these medications up to 90 days varied significantly among hospitals: beta-blockers (PDC >80%; 59-75%), statins (55-69%), thienopyridines (64-77%), and ACEIs/ARBs (57-69%). Compared with hospitals in the lowest quartile of 90-day composite medication adherence, hospitals with the highest adherence had lower unadjusted and adjusted 2-year MACE risk (27.5% vs. 35.3%, adjusted hazard ratio [HR] 0.88, 95% confidence interval [CI] 0.80-0.96). High adherence hospitals also had lower adjusted rates of death or readmission (HR 0.90, 95% CI 0.85-0.96), while there was no difference in mortality after adjustment.
Conclusions—Post-discharge use of secondary prevention medications vary significantly among U.S. hospitals and are inversely associated with two-year outcomes. Hospitals may improve post-discharge medication adherence and patient outcomes through better coordination of care between inpatient and outpatient settings.
- Received April 26, 2017.
- Revision received November 30, 2017.
- Accepted January 4, 2018.