Spatial and temporal disparities in general practitioner provision: a 21-year longitudinal analysis from Lower Saxony, Germany

Abstract Background Equitable access to general practitioner services remains a persistent challenge for health systems and is critical for reducing health inequalities, particularly between urban and rural regions. Understanding the spatial and temporal dynamics of primary care provision is vital for informed healthcare planning and policy. Methods Spatial and temporal disparities in the supply of general practitioners across Lower Saxony, Germany, were assessed over a 21-year period (2000–2021). Data from the Association of Statutory Health Insurance Physicians and municipal population statistics were used to develop the General Practitioner Regional Index - a composite measure incorporating both the availability and accessibility of general practitioners. Non-parametric statistical tests were applied to identify significant trends at the municipal level. Results Pronounced geographic inequities in general practitioner supply were identified. More than 40% of the population resides in areas with declining supply, while only 5% experience improvements. Urban centres and their peripheries consistently exhibited higher and mostly stable levels of general practitioner supply. In contrast, rural small towns and villages demonstrated both lower baseline accessibility and more frequent negative trends. The primary driver of supply losses in affected areas was physician retirement, while relocation played a secondary role and typically occurred within similar regional types, thereby limiting redistribution effects. Conclusions The results underscore the persistence of urban–rural disparities in general practitioner availability and highlight physician retirements as the principal factor behind declining supply, with limited offsetting effects from physician migration. The findings indicate a need for spatially sensitive, succession-focused workforce strategies and innovative primary care models to mitigate rural undersupply and promote health equity. Trial registration Not applicable. This study does not report the results of a health care intervention on human participants.