Temporal trends and regional disparities in costs and affordability of non-insulin antidiabetic drugs in China, 2015–2022: a retrospective observational study
Xingchen Liu, Fengping Lei, Sundus Shukar, Xingyu Liu, Haoqi Wei, Chen Chen, Yu Fang, Caijun YangObjectives
To assess temporal trends and regional disparities in the costs and affordability of non-insulin antidiabetic drugs in China between 2015 and 2022.
Design
A retrospective observational study using monthly provincial procurement data.
Setting
27 provincial-level administrative regions in mainland China from 2015 to 2022.
Participants
No individual participants were included. The units of analysis were aggregated monthly procurement records for 29 non-insulin antidiabetic drugs classified into nine therapeutic categories.
Primary and secondary outcome measures
The primary outcomes were the 30-day treatment cost and affordability ratio of non-insulin antidiabetic drugs at the national and regional levels. The 30-day treatment cost was calculated using defined daily doses and affordability was assessed as the ratio of the 30-day treatment cost to the corresponding minimum daily wage. Secondary outcomes included temporal changes in costs and affordability by therapeutic category, active ingredient and region.
Results
National average monthly costs fluctuated before 2019, reaching a peak of US$18.53 in 2019 and subsequently declined to US$11.34 in 2022. Costs declined across all therapeutic categories from 2019 to 2022, although the magnitude of reduction varied considerably. Affordability also improved over the study period, but substantial differences remained across therapeutic categories. By 2022, only biguanides and sulfonylureas had achieved good affordability at the category level, while several other categories remained above the affordability threshold. Regional disparities persisted throughout the study period; in 2022, affordability was relatively more favourable in the central region and poorer in the northwest, and no region achieved overall good affordability.
Conclusions
Between 2015 and 2022, the cost and affordability of non-insulin antidiabetic drugs in China improved overall, but disparities persisted across therapeutic categories and regions. These findings highlight the continuing challenge of ensuring equitable access to higher-cost therapies and provide a historical benchmark for evaluating subsequent changes in drug costs and affordability.