Knowledge of the different usage patterns that emerge during a long-term statin therapy is limited. The aim of this study was to characterize statin use, including the rates of reinitiation after extended periods of non-use, transitions between good and poor adherence, and the effect of the length of a drug-free period on the identification of new users.
The study cohort comprised individuals aged 45-84 years who were identified in the Finnish prescription register as having purchased statins between 1997 and 2007. New users in 1997, including those with no statin purchases during the preceding 3 years, were followed-up until institutionalization, death, or 31 December 2007. Reinitiation rates after =180 days with no refill for statins were analyzed using survival analysis. Annual adherence levels and the prevalences of good (proportion of days covered =0.80) and poor (