OBJECTIVES: Comprehensively assess the patterns and the risk factors associated with selective serotonin reuptake inhibitor (SSRIs) non-adherence in a pharmacy claims dataset for beneficiaries of the Independent Colleges and Universities Benefits Association (ICUBA).

METHODS: This retrospective study uses a pharmacy claims database to assess the prescription refill records for SSRI for beneficiaries who filled their prescriptions during the period 2015-2020. Factors associated with antidepressant non-adherence are grouped into three categories: sociodemographic, healthcare access, and clinical and medication factors. The association between adherence and these factors is explored using multiple logistic regression analysis. Adherence is measured as the proportion of days covered (PDC) by a medication.

RESULTS: The study includes 2,541 patients with an average level of adherence of 83.6%. 70.2% of the sample are considered adherent. Being adherent is significantly associated with age as patients in age category of 18-44 are 21.0% less likely to adherent than those age 45-64. Females are 21.2% more likely to be adherent than males. Patient receiving their medication from retail pharmacies are 64.4% less likely to be adherent that patients who also used both mail and retail pharmacies. Compared to patients without a copayment, patients paying copayments are 44.8% less likely to be adherent. Number of pills patients take per day increased the likelihood of adherence by 28.7%. Patients who change their prescriber during their treatment are 29.5% less likely to be adherent than those who did not. Patients who have their prescriber in-state (Florida) are 29.1% less likely to be adherent than the rest. Finally, patients taking antihypertensive medication and patients take asthma medication are 28.5% and 38.5% less likely to be adherent than the rest.

CONCLUSIONS: This study provides insight into how to better address the issue of non-adherence, hence leading to improved therapeutic and economic outcomes for patients, their families, and society as a whole.