OBJECTIVES: To compare dosing patterns among patients in whom atorvastatin (AS), simvastatin (SS), rosuvastatin (RS), or pravastatin (PS) was newly prescribed. METHODS: Using a large US managed care database, study patients aged ≥18 who were newly prescribed AS, SS, RS, or PS between 10/01/2006-09/30/2007 were identified with a minimum 12 months pre- and 24 months post-index health plan eligibility. A 6-month washout period free of use of any statin was applied to identify patients in whom statin therapy was newly prescribed. The index date was defined as the date of the first prescription fill for statins and 4 cohorts were created based on index statins: AS, SS, RS, or PS. Patients were followed up to 24 months after the index date, and the average daily dose for 12 prescriptions per person, average/median daily dose in each of the first 12 prescriptions, and the average daily statin costs were compared among 4 cohorts. RESULTS: A total of 142,692 patients were identified, comprised of 47,972 AS patients, 21,475 RS patients, 62,954 SS patients, and 10,291 PS patients. The average daily doses of all prescriptions were 21.3mg for AS patients, 10.2mg for RS patients, 29.2mg for SS patients, and 34.6mg for PS patients. The average/median daily dose for the 1st and 12th prescriptions were 20.8mg/20mg and 21.2mg/20mg for AS patients, 10.0mg/10mg and 10.5mg/10mg for RS patients, 28.4mg/20mg and 28.7mg/20mg for SS patients, and 32.8mg/40mg and 35.9mg/40mg for PS patients. The average daily statin costs for the 1st and 12th prescriptions were $2.9 and $3.2 for AS patients, $2.7 and $3.1 for RS patients, $1.5 and $0.8 for SS patients, and $1.4 and $0.9 for PS patients. CONCLUSIONS: Patients initiating AS, RS, SS, and PS experienced little escalation of their statin daily dosing over the 24-month follow-up period.