Benefit Plan Design and Prescription Drug Utilization Among Asthmatics: Do Patient Copayments Matter?

William H. Crown, Ernst R. Berndt, Onur Baser, Stan N. Finkelstein, Whitney P. Witt

NBER Working Paper No. 10062
Issued in November 2003
NBER Program(s):Aging, Health Economics, Public Economics

Objective: The ratio of controller to reliever medication use has been proposed as a measure of treatment quality for asthma patients. In this study we examine the effects of plan level mean out-of-pocket asthma medication patient copayments and other features of benefit plan design on the use of controller medications alone, controller and reliever medications (combination therapy), and reliever medications alone. Methods: 1995-2000 MarketScan claims data were used to construct plan-level out-of-pocket copayment and physician/practice prescriber preference variables for asthma medications. Separate multinomial logit models were estimated for patients in fee-for-service (FFS) and non-FFS plans relating benefit plan design features, physician/practice prescribing preferences, patient demographics, patient comorbidities and county-level income variables to patient-level asthma treatment patterns. Results: We find that the controller reliever ratio rose steadily over 1995-2000, along with out-of-pocket payments for asthma medications, which rose more for controllers than for relievers. However, after controlling for other variables, plan level mean out-of-pocket copayments were not found to have a statistically significant influence upon patient-level asthma treatment patterns. On the other hand, physician practice prescribing patterns strongly influenced patient level treatment patterns. Conclusions: There is no strong statistical evidence that higher levels of out-of-pocket copayments for prescription drugs influence asthma treatment patterns. However, physician/practice prescribing preferences influence patient treatment.

download in pdf format
   (888 K)

email paper

The NBER Bulletin on Aging and Health provides summaries of publications like this.  You can sign up to receive the NBER Bulletin on Aging and Health by email.

Machine-readable bibliographic record - MARC, RIS, BibTeX

Document Object Identifier (DOI): 10.3386/w10062


Users who downloaded this paper also downloaded* these:
Crown, Berndt, Baser, Witt, Witt, Maguire, and Haver Benefit Plan Design and Prescription Drug Utilization Among Asthmatics: Do Patient Copayments Matter?
Gaynor, Li, and Vogt w12758 Is Drug Coverage a Free Lunch? Cross-Price Elasticities and the Design of Prescription Drug Benefits
Chandra, Gruber, and McKnight w12972 Patient Cost-Sharing, Hospitalization Offsets, and the Design of Optimal Health Insurance for the Elderly
Dor and Encinosa w10738 How Does Cost-Sharing Affect Drug Purchases? Insurance Regimes in the Private Market for Prescription Drugs
Dor, Grossman, and Koroukian w10377 Transaction Prices and Managed Care Discounting for Selected Medical Technologies: A Bargaining Approach
NBER Videos

National Bureau of Economic Research, 1050 Massachusetts Ave., Cambridge, MA 02138; 617-868-3900; email:

Contact Us