Impact of China's National Volume-Based Procurement on Drug Procurement Price, Volume, and Expenditure: An Interrupted Time Series Analysis in Tianjin.

Abstract

National Volume-Based Procurement (NVBP) program has been carried out in China to lower drug prices and reduce patients' medication burden. This study aims to evaluate its impact on drug purchasing in Tianjin city, one of the first 11 cities piloting NVBP in China. Using monthly drug procurement data from Tianjin Medical Purchasing Center between 2018 and 2020, this study identified bid-winning drugs and their alternative drugs in the pilot NVBP, and evaluated the policy impacts on their procurement price (cost of defined daily dose, DDDc), volume (the number of defined daily dose, DDDs), and expenditure, during the first (initiated at April 1, 2019) and second (initiated at April 25, 2020) procurement cycles of pilot NVBP, applying interrupted time series (ITS) analysis. Included drugs were classified into 12 pharmacological subgroups for further analysis. Decrease in DDDc of NVBP-covered drugs (bid-winning and non-winning drugs) were observed in the first (level change: -CNY 3.878/DDD, P<.001; trend change: -CNY 0.068/DDD, P=.001; relative change: -61.55%) and second (level change: -CNY 0.356/DDD, P=.049) procurement cycles of pilot NVBP, while no significant change was observed for the DDDc of alternative drugs, except for the increase in antidiarrheic and anti-inflammatory/antirheumatic subgroups as more expensive drugs were purchased from new suppliers in the second procurement cycle. The DDDs of bid-winning drugs significantly increased, while decreased for the non-winning original and generic drugs. Procurement expenditure was saved for NVBP-covered drugs (level change: -CNY 7.29×107, P<.001; trend change: -CNY 5.62×106, P<.001; relative change: -62.60%). However, during the second procurement cycle, procurement volume and expenditure of alternative drugs increased significantly in 7 out of 12 subgroups. The pilot NVBP policy in China reduced procurement price, promoted generic substitution, and saved procurement expenditure. However, the increase in procurement price, volume and expenditure of alternative drugs may reveal the significance of regulating healthcare institutions' drug purchasing behavior.