Managed care trends in statin usage

HMG-CoA reductase inhibitors ("statins") have become the drug class of choice for the treatment of hyperlipidemia. Six product brands encompassing 20 dosage strengths have been available during the past two years. The objective of this review is to describe dosing trends for the six statin brands and to determine if and how these trends vary among managed care plans as a function of product market share.

Utilization of HMG-CoA reductase inhibitors was examined using the NDC Health Information Services (Phoenix, Ariz.) database for the two-year period ending December 2000. This database contains unit dispensing data at the dosage-strength level for 1,079 managed care plans. Trends in market share, mean daily dose, and dosage distribution of the six current statin brands were examined. The relationship of market share to mean dose was also examined for each brand.

Market share decreased for all statin brands during the two-year period, except for the two newest entries, atorvastatin (up 9.7 share points) and cerivastatin (up 4.6 share points). The mean dose of all statins increased during the two-year period. A statistically significant negative correlation between market share and mean dose was found for atorvastatin and a positive correlation was found for fluvastatin (P < 0.01). Furthermore, atorvastatin share was significantly correlated to lower mean doses of all other statin brands. That is, higher use of atorvastatin was associated with lower doses of all statin products.

In developing a cost-management strategy, managed care organizations should take historical and anticipated market-share changes and dose-mix changes into account along with the product's clinical efficacy and total cost of care.