Comparison of prescription drug costs in the United States and the United Kingdom, part 3: methylphenidate.

STUDY OBJECTIVE: To compare the annual cost of methylphenidate in the United States and the United Kingdom.

DESIGN: Matched-cohort cost analysis.

DATA SOURCES: The U.K. General Practice Research Database (GPRD) and MarketScan Commercial Claims and Encounters Database, a large, U.S. self-insured medical claims database.

STUDY POPULATION: We initially identified 1.6 million people in the GPRD who were younger than 65 years of age in 2005. These people were then matched by year of birth and sex with 1.6 million people in the U.S. database. From this matched pool, we estimated that 98,000 boys aged 5-14 years from each country in 2005 were prescribed at least one drug. Of these, 6485 (6.6%) in the U.S. were prescribed methylphenidate compared with 1405 (1.4%) in the U.K. After excluding those who did not receive methylphenidate continuously, there remained 2298 boys in the U.S. and 939 in the U.K. who were prescribed methylphenidate continuously during 2005 (annual methylphenidate users). We estimated and compared drug costs (presented in 2005 U.S. dollars) for continuous users separately in the two countries.

MEASUREMENTS AND MAIN RESULTS: Estimated drug costs were determined by random sampling. Estimated annual costs/patient in the U.S. ranged from $402 for doses of 5-10 mg to $821 for doses greater than 20 mg. In the U.K., costs ranged from $146 for doses of 5-10 mg to $661 for doses greater than 20 mg. The total annual cost of the continuous receipt of methylphenidate in the U.S. was $170,199 compared with $39,393 in the U.K.

CONCLUSION: The cost of methylphenidate for boys aged 5-14 years paid by private insurance companies in the U.S. was more than 4 times higher than comparable costs paid by the government in the U.K.