Impact of China's National Volume-Based Drug Procurement: A Multilevel Interrupted Time Series Analysis on Medical Expenditures in Hypertensive Patients.

Background: The National Volume-Based Procurement (NVBP), implemented in China in 2019, aims to reduce patients' economic burden by lowering drug prices and promoting the use of NVBP drugs in public hospitals. We evaluated the impact of NVBP on medical expenditures among hypertensive patients, analyzing both the overall impact and variations in policy effects across individual hospitals.

Methods: Using medical records from 1.17 million hypertensive patients across 82 hospitals in Tianjin (2017-2021), we conducted an interrupted time series analysis to assess expenditure changes among hypertensive patients for the treatment of hypertension, dyslipidaemia, type 2 diabetes, and chronic ischemic heart disease (IHD). Multilevel model was employed to estimate the overall impact and hospital-specific variations in policy effects.

Results: NVBP implementation significantly reduced per-visit outpatient expenditures among hypertensive patients for the treatment of hypertension (-15.61%), dyslipidaemia (-25.77%), and diabetes (-17.59%) by lowering drug expenditures. Although drug expenditures for chronic IHD decreased, non-drug expenditures increased, leading to no significant change in total expenditures for chronic IHD (-8.97%). For inpatient expenditures, no significant changes in total per-admission expenditures were observed for chronic IHD or diabetes hospitalizations. Drug expenditures for diabetes decreased significantly, but diagnostic expenditures increased, while no significant change was found in chronic IHD drug expenditures. At the individual hospital level, significant variations in policy effects were observed. Despite the overall decrease in outpatient expenditures for the treatment of hypertension, dyslipidaemia, and diabetes, only 45.6%, 67.2%, and 46.3% of hospitals, respectively, showed significant decreases, while the remainder exhibited either non-significant changes or increases.

Conclusion: NVBP effectively reduced outpatient expenditures among hypertensive patients for the treatment of hypertension, dyslipidaemia, and diabetes, suggesting its potential to alleviate patients' economic burdens. However, the increases in non-drug expenditures and substantial variations in policy effects across hospitals highlight a room for further improvement in policy implementation and overall effectiveness.