Statin prescribing in the elderly in the Netherlands: a pharmacy database time trend study

Abstract

Introduction: There is some evidence that the beneficial effects of HMG-CoA reductase inhibitors (statins) in the elderly are at least comparable to the effects in middle-aged people. However, several studies have shown prescription rates of statins to be significantly lower in the elderly than in younger populations.

Objective: The aim of the present study was to monitor statin prescribing trends in the elderly in the Netherlands over time in terms of prevalence, incidence, type of statin, dose prescribed and adherence to clinical guidelines.

Methods: The database of a community pharmacy in Utrecht, which includes prescription data for approximately 11,000 people, was analysed to investigate trends in statin prescriptions from January 1999 to December 2008. The 1-year prevalence and incidence of statin use stratified by age were determined for each calendar year. Rate ratios (RRs) and 95% confidence intervals were calculated with 1999 as the reference year. Furthermore, the following trends of interest were calculated for each calendar year: the percentage of statin users prescribed simvastatin or atorvastatin, the median dose of simvastatin and atorvastatin prescribed, and the percentage of simvastatin users prescribed a dosage of 40 mg/day (which is recommended by the Dutch multidisciplinary guideline).

Results: The 1-year prevalence of statin use in medication users aged >or=50 years increased from 13.9% in 1999 to 22.8% in 2008 (RR 1.6; 95% CI 1.4, 1.9; p < 0.001). Overall, the lowest prevalence (5.1% in 1999 and 15.2% in 2008) and incidence rates (3.2% in 2000 and 4.2% in 2008) were found in patients aged >or=80 years. Before 2006, simvastatin was the most commonly prescribed statin, but the number of users declined as the percentage of patients with new simvastatin prescriptions decreased (from 43.4% in 2000 to 36.5% in 2005) and the percentage of patients treated with new atorvastatin prescriptions increased (from 37.7% in 2000 to 47.3% in 2005). As from 2006, when the Dutch multidisciplinary guideline for Cardiovascular Risk Management was introduced, recommending treatment with a daily simvastatin dose of 40 mg, the number of simvastatin users increased again and most treatment-naive patients were started on simvastatin (62.3% in 2006, increasing to 66.7% in 2008). The median simvastatin dose increased from 10 mg in 1999 to 20 mg in 2001, remaining at the same dose until 2008, and appeared to be related to the patient's age. From 2006, patients aged >or=80 years were the least likely group to receive the recommended dose of 40 mg simvastatin daily (10.0-20.0% of simvastatin users aged >or=80 years compared with 32.5-36.9% of simvastatin users aged 60-69 years).

Conclusion: Despite the benefits of statin treatment previously reported in older patients, the prevalence and incidence of statin use were lower in elderly patients compared with younger patients. In addition, lower dosages of statins were prescribed. These findings suggest the beneficial effects of statins in the elderly observed in clinical trials may not be achieved in everyday practice.