OBJECTIVES: To document dose titration, persistence, and adherence among patients with high-risk vascular disease (HRVD) receiving statin therapy in an employed Japanese population. METHODS: A retrospective analysis was conducted using the Japan Medical Data Center (JMDC) database, which contained inpatient, outpatient, and pharmacy claims of 800,000 lives from 2006–2011. HRVD was identified based on diagnoses for cerebrovascular disease, peripheral artery disease, coronary artery disease with diabetes, and history of acute coronary syndrome (ACS) (with an ACS claim >30–≤365 days after ACS-related hospitalization) between 1/1/2008–12/31/2009. Patients were required to have insurance coverage for ≥12 months before and ≥24 months after first HRVD claim. Patients receiving statin therapy were selected to assess dose titration, persistence, and adherence. Persistence (therapy duration) was defined as number of days between the first and last available medication. Adherence was assessed using the medication possession ratio (MPR), defined as the number of days with statin therapy on hand divided by duration of statin therapy. RESULTS: A total of 3,417 patients met the inclusion criteria. The most common statins received were atorvastatin (32.43%), rosuvastatin (22.21%), and pravastatin (20.00%). At initiation, mean(SD) dose (mg/day) was 9.00(3.66) for atorvastatin, 2.97(1.50) for rosuvastatin, and 9.12(3.09) for pravastatin. The percentage of patients with dose titration was low (range: 1.02% for simvastatin to 5.01% for rosuvastatin). Mean(SD) persistence ranged from 460.77(270.26) days for fluvastatin to 540.08(247.51) days for atorvastatin. Mean(SD) MPR ranged from 0.90(0.16) for rosuvastatin to 0.95(0.11) for fluvastatin. When MPR was alternatively measured over the entire 24 month follow-up period, mean(SD) MPR ranged from 0.75(0.29) for rosuvastatin to 0.80(0.26) for fluvastatin. CONCLUSIONS: Statin titration among Japanese patients with HRVD was rare, and most patients remained on the lowest dosage available during follow-up. Although statin adherence was good, these findings raise potential concerns about under-treatment/under-management of HRVD in Japan.