Postdischarge Class-Complete Secondary Prevention Medication Nonadherence After Ischemic Stroke: Overall and Comorbidity-Specific Patterns

Objective: This study aimed to evaluate postdischarge class-complete secondary prevention medication nonadherence after ischemic stroke and identify overall and comorbidity-specific factors associated with 180-day nonadherence. Methods: We conducted a retrospective cohort study using prospectively collected follow-up data from a stroke registry, including consecutive patients hospitalized with acute ischemic stroke. Medication use was assessed at discharge, 90 days, and 180 days after discharge. Class-complete discontinuation—that is, discontinuation of at least one of the secondary prevention medication classes prescribed at discharge, including antiplatelet agents, anticoagulants, lipid-lowering medications, antihypertensive medications, and glucose-lowering medications—was the primary outcome. Any-use adherence, defined as continued use of at least one secondary prevention medication class, was used for comparison. Multivariable logistic regression was performed to identify factors associated with 180-day class-complete nonadherence, with subgroup analyses among patients with hypertension and diabetes mellitus. Results: A total of 2549 patients with ischemic stroke were included. At 180 days, 1408 patients (55.2%) had discontinued at least one prescribed secondary prevention medication class, whereas only 738 (29.0%) had discontinued all prescribed classes; 1141 (44.8%) continued every class prescribed at discharge. Class-complete adherence declined from 59.4% at 90 days to 44.8% at 180 days, whereas any-use adherence was 85.9% and 71.0%, respectively. Each additional discharge medication class was associated with higher odds of 180-day class-complete nonadherence in a prespecified multivariable model (adjusted odds ratio [OR], 1.50; 95% CI, 1.27– 1.79). Cardioembolism (OR, 2.11; 95% CI, 1.37– 3.26), dyslipidemia (OR, 1.50; 95% CI, 1.09– 2.07), and large-artery atherosclerosis (OR, 1.24; 95% CI, 1.03– 1.49) were also associated with nonadherence; hypertension was of borderline significance (OR, 1.23; 95% CI, 0.99– 1.54; P = 0.067). In subgroup analyses, the association with number of discharge medication classes was similar across the hypertension and diabetes mellitus subgroups, with no evidence of effect modification (P for interaction = 0.32 and 0.67), whereas the association with large-artery atherosclerosis was stronger among patients with hypertension (OR, 1.37; 95% CI, 1.08– 1.73) or diabetes mellitus (OR, 1.43; 95% CI, 1.10– 1.87) than among those without (P for interaction = 0.036 and 0.009, respectively). Conclusion: Class-complete medication nonadherence was common within 180 days after ischemic stroke discharge and often reflected partial discontinuation rather than complete cessation of secondary prevention therapy. Medication-class–specific follow-up may help identify incomplete regimen continuation and guide targeted support for patients with greater treatment complexity, atherosclerotic stroke mechanisms, or chronic vascular comorbidities.