Cholesterol Level Goal Attainment with Statins: Clinical Management Guideline Recommendations versus Management in Actual Clinical Practice

Abstract

To compare the cholesterol level goal attainment rates in patients receiving simvastatin doses recommended in clinical practice guidelines and simvastatin doses most frequently prescribed in clinical practice versus other statins at various dose levels, and to assess statin adherence rates in patients receiving all statins. Retrospective cohort study. PHARMO database, which contains linked prescription drug information, hospitalization records, and laboratory test results of over 1 million patients in the Netherlands. A total of 7355 new statin users with available cholesterol level measurements before and 12 months after starting statin treatment between 1999 and 2006. Simvastatin was chosen as the reference drug because policy makers in the Netherlands have promoted the use of generically available statins to reduce costs. Cholesterol level goal attainment rates were compared in patients receiving simvastatin 40 mg/day, which was the statin dose promoted in the 2006 Dutch cardiovascular risk management guidelines, or simvastatin 20 mg/day, which was the most frequently prescribed dose up to 2006, versus other statins at various dose levels. Relative risks (RRs) were adjusted for age, sex, year of therapy initiation, cardiovascular disease, type 2 diabetes mellitus, hypertension, baseline low-density lipoprotein cholesterol level, and adherence during the 3 months before the 12-month follow-up cholesterol measurement. Compared with simvastatin 40 mg/day, cholesterol goal attainment rates were significantly higher with atorvastatin 40 mg/day (RR 1.15, 95% confidence interval [CI] 1.04-1.28) and rosuvastatin 10 mg/day (RR 1.13, 95% CI 1.04-1.23), were similar with atorvastatin 20 mg/day (RR 1.06, 95% CI 0.97-1.16) and rosuvastatin 20 mg/day (RR 1.14, 95% CI 0.93-1.39), and were significantly lower with all other frequently used statin dose levels. Compared with simvastatin 20 mg/day, cholesterol goal attainment was significantly higher with any dose of atorvastatin and rosuvastatin, but were lower with any dose of pravastatin. Goal attainment rates were similar among patients with lower and higher cardiovascular risk. Among the 13-18% of patients who had follow-up cholesterol level measurements at 12 months in all statin groups, the proportion of adherent patients was approximately 75%; this was higher than the proportion of adherent patients in the total population (48-55%), which included patients without follow-up cholesterol levels. A larger proportion of patients reached cholesterol lipid goals with simvastatin 40 mg/day. Cholesterol level goals were achieved by many patients using the recommended simvastatin 40 mg/day, but by fewer patients among those using the more commonly prescribed simvastatin 20 mg/day. Therefore, especially in high-risk patients, the choice of statin should be based on baseline cholesterol levels and expected reductions in these levels, and treatment should be adapted if targets are not met. Improved cholesterol level monitoring may increase adherence and cholesterol management.