AIMS: To investigate the ‘real world’ effectiveness of robust statin therapy, focusing on the effect of dose and early treatment discontinuation on the risk of hospitalization for acute myocardial infarction (AMI). METHODS AND RESULTS: In the PHARMdatabase, including among others drug-dispensing and hospital discharge records for more than two million subjects in the Netherlands, 59 094 new users of statins in the period 1 January 1991 until 31 December 2004, >/= 18 years of age were identified.In these patients, exposure to statins, both in terms of persistence and dose, was determined over the first two treatment years. To determine the risk for AMI, patients were followed from this 2-year time point until the first hospital admission for AMI, death, or end of the study period. A total of 31 557 patients (53%) discontinued statin use within 2 years; 20 883 patients (35%) were persistent users with an average equipotent dose >/= 4. A 30% reduction in risk of hospitalization for AMI with persistent statin use was observed. The protective effect increased with a higher dose (20 and 40% risk reduction with an equipotent dose = 3 and >/= 4, respectively). CONCLUSION: These results show that statins are suboptimally used in real life for havingthe maximum benefit in terms of preventing AMI.