Impact of pooled procurement of medicines on patient adherence and economic burden: evidence from China.

Background: Pooled procurement is widely adopted to improve medicine affordability, yet its impact on patients' medicine adherence and economic burden remains underexplored. This study addresses these gaps under China's National Volume-Based Procurement (NVBP) policy.

Methods: Using claims data from Tianjin, China (2017-2020), we conducted a retrospective cohort study of new-users of NVBP antihypertensive medicines before and after policy implementation. During one-year follow-up since medicine initiation, medicine adherence (measured by proportional days covered), medicine persistence (measured by discontinuation rate), and direct medical costs (broken down by components) were compared between cohorts. Linear regressions, Cox proportional hazard models and generalised linear models were used to analyse outcome differences, adjusting for patients' demographics, medical history, and prior health care utilisation.

Results: We identified 14 560 and 18 858 patients in pre- and post-policy cohorts, respectively (mean age = 57.1; 52.8% men). Compared to the pre-policy cohort, the post-policy cohort presented a slight increase in adherence to NVBP medicines (proportional days cover = 0.31 vs. 0.28; adjusted difference = 0.021; P < 0.0001), but no significant change in discontinuation rate. Hypertension-related costs decreased by 19.5% (1509.2 vs. 1804.8 Chinese Yuan; P < 0.0001) for the post-policy cohort, entirely attributed to saving in costs of NVBP medicines (480.6 vs. 772.6 Chinese Yuan; adjusted difference = -47.5%; P < 0.0001). No significant difference was observed in costs for other medicines and services. The cost saving was equally borne by patients and health plans.

Conclusions: China's NVBP modestly improved adherence and significantly reduced the economic burden for patients. To fully deliver patient-centred benefits of pooled procurement for chronic disease medicines beyond price cuts, it should be paired with supply- and demand-side auxiliary measures. China's experience, including financial incentives, regulatory oversight, favourable reimbursement policies and public campaigns, may offer lessons for other settings. Longer-term studies in broader populations are needed to further research.