Spatial inequalities and contextual correlates of methylphenidate dispensing in Jiangsu Province, China

Understanding geographic inequalities in psychotropic medication dispensing is important for improving health equity and informing place-based pharmaceutical management. This study characterized the spatiotemporal distribution of methylphenidate hydrochloride extended-release tablet dispensing in Jiangsu Province, China, from 2019 to 2023 and examined its socioeconomic and education-related correlates.

Annual county-level dispensed tablet volumes were analyzed using Getis-Ord Gi* hot-spot analysis, standard deviational ellipses, and weighted-centroid analysis. Prefecture-level contextual correlates were examined using annual Lasso models interpreted with SHAP.

The proportion of county-level units with zero recorded dispensing decreased from approximately 52%-36%, while the proportion with annual volumes exceeding 20,000 tablets increased from 7% to 20%. Southern Jiangsu consistently exhibited higher dispensing volumes than Northern Jiangsu, with Central Jiangsu generally occupying an intermediate position. Getis-Ord Gi* identified localized high-value concentrations mainly in Southern and parts of Central Jiangsu. The standard deviational ellipse area increased by 23.1%, while the weighted centroid remained in south-central Jiangsu. Within the annual Lasso models, predictive importance was allocated mainly to economic-demographic indicators in 2019-2020 and more strongly to education-related indicators in 2021-2023.

The findings support geographically differentiated monitoring of medication access, dispensing patterns, and prescribing quality.