Impact of regulatory interventions to restrict the combined use of renin-angiotensin system-acting agents in Denmark: interrupted time series analysis

Study type

• Study topic:
  Other
• Study topic, other:
  Disease/Epidemiology study
• Study type:
  Non-interventional study
• Scope of the study:
  Drug utilisation

  Effectiveness study (incl. comparative)
• Data collection methods:
  Secondary use of data

Non-interventional study

• Non-interventional study design:
  Other
• Non-interventional study design, other:
  Descriptive analysis of the whole Danish population

Population studied

• Short description of the study population:
  The source population was derived from the population of Denmark (~5.8 million): those who picked up a prescription for an ARB or ACEi from a community pharmacy between 1 January 2008 and 31 December 2018 and were ≥18 years old.
• Age groups:
  • Adult and elderly population (≥18 years)

    • Adults (18 to < 65 years)

      • Adults (18 to < 46 years)
      • Adults (46 to < 65 years)
    • Elderly (≥ 65 years)

      • Adults (65 to < 75 years)
      • Adults (75 to < 85 years)
      • Adults (85 years and over)
• Estimated number of subjects:
  400

Study design details

• Main study objective:
  The primary objective of this study was to assess the impact of the EMA referral procedure on the co-prescribing of RAS-acting agents by examining the trends in co-dispensing of angiotensin-converting enzyme inhibitor (ACEis) and angiotensin II receptor blocker (ARBs) in Denmark.
• Outcomes:
  Monthly prevalence of patients co-dispensed an angiotensin-converting enzyme inhibitor (ACEis) and angiotensin II receptor blocker (ARBs) on the same day per 1,000,000 population, A secondary objective of this study was to describe the population in terms of demographics (age and sex) co-prescribed an angiotensin-converting enzyme inhibitor and an angiotensin II receptor blocker over time.
• Data analysis plan:
  We used autoregressive integrated moving average (ARIMA) interrupted time series regression model as outlined by the Cochrane Effective Practice and Organisation of Care (EPOC) to evaluate the change in dispensing trends from pre-intervention to post-intervention. A linear regression model of the monthly prevalence of co-medication of ACEis and ARBs was used. We used 24 data points before and 24 data points after the intervention and aimed for a minimum of 100 observations at each data point.