Use of a tiered review for evaluation of appropriate use of hydroxymethylglutaryl coenzyme A reductase-inhibitor therapy

Abstract

Despite abundant evidence of the benefits of lipid lowering in reducing mortality from all causes in high-risk patients with or without coronary artery disease (CAD) and the wide availability of guidelines for targeting such patients more aggressively, there are indications that this population is still being treated suboptimally. Our study sought to ascertain the appropriateness of prescribing practices of the hydroxymethylglutaryl coenzyme A-reductase (HMG-CoA) inhibitor pravastatin that was used at our facility at the time. We conducted a drug utilization review of a randomly chosen sample of patients receiving prescriptions for pravastatin at the outpatient clinics of a tertiary care, academically affiliated Veterans Affairs medical center. The algorithm we used was based on National Cholesterol Education Program Adult Treatment Panel-2 guidelines. Patient charts were reviewed for the presence of CAD and standard cardiac risk factors and for lipid determinations performed since 1986, when laboratory test results began to be compiled electronically. The initial review was performed by a pharmacist; cases the pharmacist identified as involving possible suboptimal prescribing practices were subsequently reviewed and classified by a cardiologist. From the pharmacy database, we derived a random sample of 118 patients who were receiving doses >20 mg (high-dose cases) and 100 patients receiving doses of < or =20 mg (standard-dose cases). The pharmacist's review found 57 (48%) high-dose cases and 47 (47%) standard-dose cases that were questionable; the cardiologist's review of these cases determined that 43 (36%) high-dose cases and 38 (38%) standard-dose cases involved suboptimal prescribing practices. The deficiencies noted in patients receiving standard-dose pravastatin were generally minor; however, 23% of the deficiencies noted in patients receiving high-dose therapy were serious ones that may have exposed the patients to unnecessary therapy or caused a delay in their receiving appropriate therapy. In conclusion, slightly more than one third of a randomly selected sample of patients treated with an HMG-CoA reductase inhibitor at a tertiary care medical center were receiving suboptimal therapy. Suboptimal prescribing practices have both clinical and economic implications, and a tiered, multidisciplinary review process allows convenient monitoring of prescribing practices.