Patterns and factors associated with SSRI medication adherence: a retrospective study using pharmacy claims data

Objectives: To assess the patterns and risk factors associated with selective serotonin reuptake inhibitor (SSRI) medication adherence among enrollees of a multiple employer welfare beneficiary association operating in Florida.Methods: This study used a pharmacy claims database for beneficiaries of the Independent Colleges and Universities Benefits Association. The sample of 2541 patients were enrollees who filled two or more consecutive SSRI prescriptions during the analysis period 2015-20. Adherence was measured as the proportion of days covered by a medication. Multiple logistic regression analysis was used to explore the relationship between sociodemographic, healthcare access, and clinical and medication-related factors and adherence.Key findings: Adherence was associated with higher odds of being female [odds ratio (OR): 1.2, 95% confidence interval (CI): 0.995-1.464, P < .10] and higher pill burden (OR: 1.3, CI: 1.021-1.642, P< 0.05). Patients using only retail pharmacies (OR: 0.356, CI: 0.196-0.645, P < .01), having any out-of-pocket costs (OR: 0.552, CI: 0.348-0.875, P < .50), changing the prescriber over the duration of the treatment (OR: 0.708, CI: 0.589-0.851, P < .01), taking antihypertensive (OR: 0.708, CI: 0.5077-0.988, P < 0.50), and asthma (OR: 0.609, CI: 0.450-0.826, P < .01) medications were less likely to be adherent. Prescriber specialty was not found to be associated with adherence.Conclusion: These findings can inform policymakers and healthcare insurance companies on barriers to medication access and recommend strategies to eliminate these barriers and design interventions to improve the adherence of groups at risk for nonadherence. Healthcare providers can identify patients who are less likely to be adherent and customize counseling interventions for these patients.