Does a cardiovascular event change adherence to statin treatment in patients with type 2 diabetes? A matched cohort design

Dianna De Vries, Petra Denig, Stefan Vegter, H.J. Bos, Maarten J. Postma, Eelko Hak

Research output: Contribution to journalMeeting AbstractAcademic


Background: Statin treatment is associated with a reduction in the risk of cardiovascular events. To be effective, adherence is essential but this may be influenced by the occurrence of a cardiovascular event while being on treatment. Objectives: To assess the effect of an apparent first event on statin adherence rates in type 2 diabetes patients. Methods: A matched cohort study was conducted among type 2 diabetes patients initiating statin treatment for primary prevention in the Groningen University pharmacy database. Index patients who had a drug-treated cardiovascular event (index date) after statin initiation were matched to a reference patient without such an event with similar gender, age at statin initiation, initiation date, follow-up period and adherence level before the event. Medication proxies were used to identify apparent events. Adherence rates were measured as percentages of days covered (PDC), relative risks with 95% confidence intervals (95%CI) were calculated for shifts in adherence levels (nonadherent, partial-adherent, full-adherent) around the index date. Adherence rates around the index date were evaluated using Wilcoxon signed ranks tests and Mann-Whitney U Tests. Results: We could match 375 of the 855 eligible index patients. Index patients had on average a PDC of 81% after the index date; reference patients had a PDC of 71% (P
Original languageEnglish
Pages (from-to)319-320
Number of pages2
JournalPharmacoepidemiology and Drug Safety
Issue numberS1
Publication statusPublished - 1-Oct-2014


  • statin (protein)
  • human
  • patient
  • non insulin dependent diabetes mellitus
  • pharmacoepidemiology
  • risk management
  • diabetic patient
  • primary prevention
  • cohort analysis
  • drug therapy
  • confidence interval
  • Wilcoxon signed ranks test
  • university
  • follow up
  • gender
  • data base
  • risk factor
  • rank sum test
  • pharmacy
  • risk

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