Statin treatment is a safe and effective method of reducing cardiovascular events in both primary and secondary prevention.^1,2 Persistence with statin use in trials is generally high. Analysis of the WOSCOPS (west of Scotland coronary prevention study) showed that the efficacy of pravastatin depends on compliance. Although long term persistence with statin treatment in elderly patients has been studied,^3,4 little is known about long term persistence in the general population including all age categories and both primary and secondary prevention. The aim of this study was to assess long term persistence with statin use in the general Dutch population and to identify the determinants of failure to persist with these drugs.

METHODS

We used data from the PHARMO medical record linkage system including drug dispensing records from community pharmacies and hospital discharge records of 865 000 subjects in the Netherlands. Clustering pharmacies within PHARMO areas results in drug dispensing histories containing > 95% of all prescriptions dispensed to a particular patient.

Persistence was assessed for all new users of statins (not receiving any statin for at least two years before being prescribed the first statin) during 1998–2002. Cerivastatin was withdrawn from the market and so patients receiving cerivastatin were excluded. Episodes of statin use were constructed for each patient. In cases of interruptions of < 45 days between …