Low adherence to antidepressants is associated with increased mortality following stroke: A large nationally representative cohort study

Abstract

Post stroke depression is common and pervasive. In the general population, there has been some controversy that antidepressant (AD) medication is associated with premature mortality. Data is still lacking regarding the association between adherence to antidepressants (AD) and all-cause mortality. In this retrospective analysis of a population-based cohort of patients, 32,361 post-stroke patients who purchased at least one AD were followed for all-cause mortality over 4-years. Adherence to AD was measured as a ratio between dispensed and prescribed durations and was modeled as: non-adherence (<20%, n=8619), poor (20–50%, n=5108), moderate (50–80%, n=5656), and good (>80%, n=12,978) adherence. Multivariable survival analyses, adjusted for demographic and clinical variables including physical comorbidities known to influence mortality, were conducted. Unadjusted mortality rates were 16.5%, 20.2%, 22.2% and 23.7% in those classified as non-adherent, poor, moderate and good adherence respectively (χ2=174.6, p<0.0001). In the adjusted model, the non-adherent and poor adherence groups had significantly increased mortality Hazard Ratios (HR) of 1.25 (95% CI: 1.17–1.33) and 1.17 (95% CI: 1.09–1.26) respectively compared to the good adherence group. This nationally representative data suggests that poor adherence to AD is associated with increased all-cause mortality among people who had a stroke. Given our findings and the high prevalence of anxiety and depression along with AD effectiveness, efforts to promote AD adherence in this population may be warranted in clinical practice.