Presentation (CTI)

OBJECTIVES: Mood, anxiety, and related disorders affect approximately 10% of the Canadian population. Antidepressants have been found to be effective for the treatment of moderate to severe forms of these disorders and practice guidelines recommend antidepressant treatment to be continued for at least 6 to 12 months after symptom remission to reduce the risk of relapse. In our study, we assessed the real-world persistence of antidepressants among Manitobans diagnosed with mood, anxiety, and related disorders.
METHODS: This retrospective cohort study used outpatient prescription dispensation data from the Population Health Research Data Repository housed at the Manitoba Centre for Health Policy to identify individuals who initiated an antidepressant between 2016 and 2022. Persistence was defined as a continuous days-supply of a prescription with no gap greater than 60 days between the last day of the days-supply provided and the first day of the subsequent prescription refill. The proportion of individuals who persisted on their first antidepressant prescription was determined at 3, 6, 9, and 12 months. Logistic regression was used to estimate the odds ratio (OR) for persistence.
RESULTS: Among 76,200 individuals, 63.27% were female, 63.11% resided in urban Manitoba, and 62.32% were between 25 and 65 years old. About 30.21% of individuals filled their first antidepressant prescription only once, and 75.36% of users discontinued therapy before 1 year. The proportion of individuals who persisted with their initial antidepressant therapy declined over 3, 6, 9, and 12 months (56.09%, 40.63%, 32.98%, and 24.67%, respectively). Younger age, female sex, and urban residence were associated with increased persistence (p<0.05).
CONCLUSIONS: Our study showed almost half of the individuals did not persist with antidepressant therapy at 3 months and there was a declining trend in antidepressant persistence from the initial prescription over time. Further investigation into the factors associated with low persistence is warranted.