Cost-effectiveness of statins for primary cardiovascular prevention in chronic kidney disease

Abstract

Objectives: The authors sought to evaluate the cost-effectiveness of statins for primary prevention of myocardial infarction (MI) and stroke in patients with chronic kidney disease (CKD).

Background: Patients with CKD have an elevated risk of MI and stroke. Although HMG Co-A reductase inhibitors (“statins”) may prevent cardiovascular events in patients with non–dialysis-requiring CKD, adverse drug effects and competing risks could materially influence net effects and clinical decision-making.

Methods: We developed a decision-analytic model of CKD and cardiovascular disease (CVD) to determine the cost-effectiveness of low-cost generic statins for primary CVD prevention in men and women with hypertension and mild-to-moderate CKD. Outcomes included MI and stroke rates, discounted quality-adjusted life years (QALYs) and lifetime costs (2010 USD), and incremental cost-effectiveness ratios.

Results: For 65-year-old men with moderate hypertension and mild-to-moderate CKD, statins reduced the combined rate of MI and stroke, yielded 0.10 QALYs, and increased costs by $1,800 ($18,000 per QALY gained). For patients with lower baseline cardiovascular risks, health and economic benefits were smaller; for 65-year-old women, statins yielded 0.06 QALYs and increased costs by $1,900 ($33,400 per QALY gained). Results were sensitive to rates of rhabdomyolysis and drug costs. Statins are less cost-effective when obtained at average retail prices, particularly in patients at lower CVD risk.

Conclusions: Although statins reduce absolute CVD risk in patients with CKD, the increased risk of rhabdomyolysis, and competing risks associated with progressive CKD, partly offset these gains. Low-cost generic statins appear cost-effective for primary prevention of CVD in patients with mild-to-moderate CKD and hypertension.

Figure 1. Statin Cost-effectiveness – Differing Cardiovascular Risk Groups

Figure 1a Lower Cardiovascular Risk (women) Figure 1b Higher Cardiovascular Risk (men) Moderate HTN: SBP 130-140 on treatment; Mild HTN: SBP 120–130 on treatment; No HTN: SBP 120–130 without treatment. *Indicates patients for whom statins are currently recommended according to ATP III guidelines due to 10-year probability of myocardial infarction (based on traditional cardiovascular risk factors) ≥ 20%.

Figure 1. Statin Cost-effectiveness – Differing Cardiovascular Risk Groups

Figure 1a Lower Cardiovascular Risk (women) Figure 1b Higher Cardiovascular Risk (men) Moderate HTN: SBP 130-140 on treatment; Mild HTN: SBP 120–130 on treatment; No HTN: SBP 120–130 without treatment. *Indicates patients for whom statins are currently recommended according to ATP III guidelines due to 10-year probability of myocardial infarction (based on traditional cardiovascular risk factors) ≥ 20%.

Figure 2. Price Sensitivity Analysis – Cost-effectiveness at Different Statin Prices

Treatment effect for Pravastatin (RR 0.8) obtained from a meta-analysis of statin trials in patients with CKD, weighted heavily by the Pravastatin Pooling Project.(11) Treatment effect for Rosuvastatin obtained from an analysis of the CKD population from the Jupiter Trial in patients with high CRP(7). $4 per month prices obtained from Wal-Mart Retail Prescription Drug Program List (24) are comparable to those paid by Veterans Affairs facilities (25) while remaining prices are average retail prices obtained from consumer reports(37).

Figure 3. Sensitivity Analysis

Cost-effectiveness of statins was most sensitive to the risk of rhabdomyolysis in patients at lower baseline cardiovascular risk; an increase in the rate of rhabdomyolysis in 50 year-old women with moderate hypertension makes statins considerably less cost-effective.

Figure 4. Exploratory Analysis – Cost-effectiveness if Statins Cause Diabetes in 65 year-old men and women

*estimate of statin-induced diabetes incidence from a meta-analysis Cost-effectiveness is not sensitive to the long-term risk of diabetes at rates that have been described. If the long-term risk of diabetes from statins is more than 2-fold higher in women and 6-fold higher in men than described, no statins becomes the preferred strategy as it yields longer quality-adjusted life expectancy at a lower cost