Use of antidepressant drugs and its association with risk of stroke, frequency of hospitalization, and mortality in an elderly population: a descriptive and analytic cohort study

Study type

• Study type:
  Non-interventional study
• Scope of the study:
  Assessment of risk minimisation measure implementation or effectiveness

  Drug utilisation

Non-interventional study

• Non-interventional study design:
  Cohort

Study drug and medical condition

• Anatomical Therapeutic Chemical (ATC) code:
  (N06AA) Non-selective monoamine reuptake inhibitors

  Non-selective monoamine reuptake inhibitors

  (N06AB) Selective serotonin reuptake inhibitors

  Selective serotonin reuptake inhibitors

  (N06AX) Other antidepressants

  Other antidepressants

  (N06CA) Antidepressants in combination with psycholeptics

  Antidepressants in combination with psycholeptics
• Medical condition to be studied:
  Death

  Haemorrhagic stroke

  Ischaemic stroke

  Cerebellar stroke

  Hospitalisation

Population studied

• Age groups:
  Adults (65 to < 75 years)

  Adults (75 to < 85 years)

  Adults (85 years and over)
• Estimated number of subjects:
  417685

Study design details

• Main study objective:
  Drug U: To describe the incident use of antidepressant drugs in a population ≥65 years old during the period of 2009-2015.Risk A: To compare time to occurrence of the composite outcome variable: first episode of nonfatal stroke, fatal stroke, hospitalization due to stroke, or death from any cause among elderly new users and nonusers of SSRI antidepressant drugs
• Outcomes:
  Risk A: Composite variable of fatal or nonfatal stroke, hospitalization due to stroke, or death from any cause, Risk A: Every single event of the composite outcome
• Data analysis plan:
  Drug U: Demographic, diagnostic and pharmacoepidemiologic data will be analysed using descriptive statistics. Prevalence of antidepressant use will be described for all the study period (2009-2015), and for each year stratified by age group, sex, and indication of prescription. Variables will be reported as mean ± standard deviation, median or as frequency and percentage, as appropriate.Risk A: The cohorts will be formed by matching on the propensity score (PS) of their baseline characteristics. PS will be calculated by logistic regression of antidepressant use. Crude incidence rates, rate ratios and adjusted incidence rates and rate ratios will be reported for the composite outcome. For reporting adjusted incidence rates, calculated by Poisson regression will be used. The hazard ratio for the risk of composite outcome will be calculated. An analysis of marginal structural models for co-morbidity and other confounding variables, whose exposure varies over time, will be applied.