TY - JOUR AU - Crown, William H AU - Berndt, Ernst R AU - Baser, Onur AU - Finkelstein, Stan N AU - Witt, Whitney P TI - Benefit Plan Design and Prescription Drug Utilization Among Asthmatics: Do Patient Copayments Matter? JF - National Bureau of Economic Research Working Paper Series VL - No. 10062 PY - 2003 Y2 - November 2003 DO - 10.3386/w10062 UR - http://www.nber.org/papers/w10062 L1 - http://www.nber.org/papers/w10062.pdf N1 - Author contact info: Ernst R. Berndt MIT Sloan School of Management 100 Main Street, E62-533 Cambridge, MA 02142 E-Mail: eberndt@mit.edu Whitney Witt University of Wisconsin, Madison School of Medicine and Public Health Department of Population Health Sciences 707 WARF Building 610 Walnut Street, Office 503 Madison, WI 53726 Tel: (608) 265 - 6290 Fax: (608) 263 - 2820 E-Mail: wwitt@wisc.edu M1 - published as William H. Crown, Ernst R. Berndt, Onur Baser, Stan N. Finkelstein, Whitney P. Witt, Jonathan Maguire, Kenan E. Haver. "Benefit Plan Design and Prescription Drug Utilization Among Asthmatics: Do Patient Copayments Matter?," in David M. Cutler and Alan M. Garber, editors, "Frontiers in Health Policy Research, Volume 7" MIT Press (2004) AB - 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. ER -