Supplementary file 2_Geographical and temporal variations in availability of national price negotiated novel anticancer drugs: a spatial statistical study based on two cross-sectional datasets in China.xlsx

ObjectiveThe National Drug Price Negotiation (NDPN) has significantly reduced the prices and improved the nationwide availability of novel anticancer drugs (NADs) in China. However, geographical disparities in their availability remain concerning. This study aims to assess these spatial variations and temporal changes, and the determinants using geographic information system (GIS) and spatial statistical methods.
MethodsTwo cross-sectional datasets were used corresponding the implementation date of the 2023 NDPN list (1 January 2024) and 9 months after (1 October 2024). Data on drug-providing institutions were extracted from National Healthcare Security Administration (NHSA) platform. Drug availability was measured by the weighted supply number of drug-providing institutions per 1,000 cancer patients, analyzed separately for hospitals and retail pharmacies. Kernel density estimation (KDE) was used to visualize spatial distribution. The Theil index assessed inequality, and Moran’s index measured spatial clustering. Multiple linear regression (OLS) and geographically weighted regression (GWR) were employed to examine the influence of economic development and healthcare infrastructure on drug availability.
ResultsA total of 71 NADs in the 2023 NDPN list were analyzed. By October, drug-providing institutions had become more concentrated in the eastern coastal provinces compared to January. Availability improved in both hospitals and retail pharmacies, with higher levels observed in eastern and central provinces, with lower in the western provinces, especially in the Southwest. Inequality declined and spatial clustering increased for both hospital-based and overall availability across provinces (Theil index, hospital: 0.074–0.062, overall: 0.045–0.044; Moran’s I, hospital: 0.315–0.362, overall: 0.452–0.453). Both OLS and GWR models showed a significant and strengthening association between availability (in hospitals and overall) and GDP per capita [e.g., hospital: OLS coef, 0.787–0.833, p < 0.001; GWR mean coef (SD), 0.795 (0.047)−0.834 (0.044); overall: OLS coef, 0.744–0.794, p < 0.01; GWR mean coef (SD), 0.726 (0.119)−0.763 (0.161)]. Retail pharmacy-based availability was positively associated with the number of local chain pharmacies [OLS coef, 0.098–0.122, p < 0.05; GWR mean coef (SD), 0.084 (0.006)−0.107 (0.010)].
ConclusionThe availability of price-negotiated NADs increasingly concentrated in economically developed and medically advanced eastern provinces, while remaining lower in southwest. Efforts should target economically underdeveloped areas.

研究目的：国家药品价格谈判（National Drug Price Negotiation, NDPN）已显著降低中国新型抗肿瘤药物（novel anticancer drugs, NADs）的价格并提升其全国可及性，但此类药物可及性的地域差异仍令人担忧。本研究旨在借助地理信息系统（geographic information system, GIS）与空间统计方法，评估其空间分布差异与时序变化，并探究其影响因素。
研究方法：本研究采用两份横断面数据集，分别对应2023年国家药品价格谈判药品清单的实施日（2024年1月1日）及实施后9个月（2024年10月1日）。药品供应机构数据从国家医保局（National Healthcare Security Administration, NHSA）平台提取。药物可及性以每千名癌症患者对应的加权供应机构数量进行衡量，并分别针对医院与零售药店开展分析。采用核密度估计（Kernel Density Estimation, KDE）可视化空间分布；利用泰尔指数（Theil index）评估不平等程度，莫兰指数（Moran’s index）衡量空间集聚性；通过多元线性回归（普通最小二乘回归, ordinary least squares, OLS）与地理加权回归（geographically weighted regression, GWR），探究经济发展水平与医疗基础设施对药物可及性的影响。
研究结果：本研究共分析2023年国家药品价格谈判药品清单中的71种新型抗肿瘤药物。至2024年10月，药品供应机构较1月时更集中于东部沿海省份。医院与零售药店的药物可及性均有所提升，东部与中部省份可及性水平更高，西部省份尤其是西南地区可及性较低。各省医院渠道及整体药物可及性的不平等程度有所下降，空间集聚性则有所提升（泰尔指数：医院渠道0.074→0.062，整体0.045→0.044；莫兰指数：医院渠道0.315→0.362，整体0.452→0.453）。普通最小二乘回归与地理加权回归模型均显示，医院渠道及整体药物可及性与人均GDP呈显著正相关且关联强度增强[例如：医院渠道：普通最小二乘回归系数0.787~0.833，p<0.001；地理加权回归平均系数（标准差）0.795(0.047)~0.834(0.044)；整体：普通最小二乘回归系数0.744~0.794，p<0.01；地理加权回归平均系数（标准差）0.726(0.119)~0.763(0.161)]。零售药店渠道的药物可及性与本地连锁药店数量呈正相关[普通最小二乘回归系数0.098~0.122，p<0.05；地理加权回归平均系数（标准差）0.084(0.006)~0.107(0.010)]。
研究结论：价格谈判后的新型抗肿瘤药物可及性愈发集中于经济发达、医疗资源先进的东部省份，而西南地区可及性仍处于较低水平。未来应重点关注经济欠发达地区的药物可及性提升工作。