Comparison of prescription drug costs in the United States and the United Kingdom, part 2: proton pump inhibitors.

STUDY OBJECTIVE: To compare the annual cost of proton pump inhibitors (PPIs) in the United States and in the United Kingdom.

DESIGN: Matched-cohort cost analysis.

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

STUDY POPULATION: We initially identified more than 1 million people in the GPRD who were younger than 65 years of age and who were prescribed at least one prescription drug in 2005. Each of these people was then matched by year of birth and sex to one person in the U.S. database. From the matched pool, we estimated that 280,000 people were aged 55-64 years from each country. Of these, an estimated 27,230 (9.7%) in the U.S. were prescribed a PPI compared with 22,560 (8.1%) in the U.K. After excluding patients who did not receive the PPI continuously or who switched PPIs during the year, there remained 11,292 people in the U.S. and 9923 in the U.K. who were prescribed a single PPI preparation continuously during 2005 (annual PPI users).

MEASUREMENTS AND MAIN RESULTS: Annual drug costs were determined by random sampling. The estimated annual cost/patient in the U.S. ranged from $901 for generic omeprazole to $1485 for lansoprazole. In the U.K., the annual costs were similar, approximately $400 for each PPI, irrespective of whether the agents were available in generic formulation. The total estimated annual cost of PPIs for 2005 in this study group was $14 million in the U.S. compared with $4.1 million in the U.K.

CONCLUSION: The cost of continuous use of PPIs covered by private insurance companies in the U.S. in 2005 was more than 3 times the cost covered by the U.K. government. This result is consistent with the findings of an earlier study on relative costs of statins between the countries.