OBJECTIVES: Dyslipidemia is a common disease that may lead to undesired cardiovascular outcomes. We evaluated the LDL-c lowering drug use for patients at three levels of risk defined by ATP III guidelines. METHODS: Three cohorts were identified according to ATP III risk classification: high risk=CHD or CHD equivalent (HR); moderate risk=2+ risk factors (MR); low risk=0-1 risk factor (LRIt’s recommended that patient with these risk levels should receive the treatment if LDL was greater than 130, 160 and 190 mg/dL, respectively. All patients were required to have 6-month continuous health insurance coverage as ascertainment period and LDL lowering drug use was evaluated in the subsequent two years using the US Impact insurance claims database. RESULTS: We identified 9,866 HR, 17,539 MR and 14,975 LR patients from 2006 to 2008. Compared with LR patients during 6-month baseline, HR and MR patients were older (mean age of 59, 59 versus 49 years), visited a cardiologist more often (46.9%, 12.2% vs 4.5%), had more hypertension (80.0%, 90.8% vs 10.8%) and diabetes (19.3%, 14.6% vs 4.6%), and incurred higher mean healthcare expenditures ($8,803, $3,419 vs $1,966). For all three cohorts, the majority of patients did not have lipid lowering medications dispensed within 2 years (57.1%, 54.4% and 58.2%, respectively). For patients who did, lower dose statins was the most commonly dispensed (52.0%, 52.6% and 51.4%, respectively). Overall, the medication possession rate is low (~0.6) and a relatively low percentage of patients changed their medications. CONCLUSIONS: Despite ATP recommendations for treatment, the majority of the patients at all risk levels were not using lipid lowering medications two years after ascertainment of excess LDL level. Among patients who obtained the medications, lower dose statins were most commonly used. Furthermore, medication adherence in the treated patients was suboptimal, suggesting remaining unmet therapeutic needs in this patient population.