Adherence to Psychotropic Medication Before and During COVID-19: A Population-Wide Retrospective Observational Study

Abstract

Background: The coronavirus disease 2019 (COVID-19) pandemic and associated public health measures have shifted the way people access health care. We aimed to study the effects of the COVID-19 pandemic on psychotropic medication adherence.

Methods: A retrospective cohort study using administrative data from the Manitoba Centre for Health Policy Manitoba Population Research Data Repository was conducted. Outpatients who received at least 1 prescription for an antidepressant, antipsychotic, anxiolytic/sedative-hypnotic, cannabinoid, lithium, or stimulants from 2015 to 2020 in Manitoba, Canada, were included. Adherence was measured using the proportion of individuals with a mean possession ratio of ≥0.8 over each quarter. Each quarter of 2020 after COVID-19-related health measures were implemented was compared with the expected trend using autoregression models for time series data plus indicator variables. Odds ratio of drug discontinuation among those previously adherent in 2020 was compared with each respective quarter of 2019.

Results: There were 1,394,885 individuals in the study population in the first quarter of 2020 (mean [SD] age, 38.9 [23.4] years; 50.3% female), with 36.1% having a psychiatric diagnosis in the preceding 5 years. Compared with the expected trend, increases in the proportions of individuals adherent to antidepressants and stimulants were observed in the fourth quarter (October-December) of 2020 (both P < 0.001). Increases in the proportions of individuals with anxiolytic and cannabinoid adherence were observed in the third quarter (July-September) of 2020 (both P < 0.05), whereas a decrease was seen with stimulants in the same quarter ( P < 0.0001). No significant changes were observed for antipsychotics. All drug classes except lithium had decreases in drug discontinuation in previously adherent patients during the pandemic compared with 2019.

Conclusions: Improved adherence to most psychotropic medications in the 9 months after public health restrictions were enacted was observed. Patients who were already adherent to their psychotropic medications were less likely to discontinue them during the pandemic.