Regional variation in ambulatory care-sensitive hospitalizations for people with type 2 diabetes in Germany: insights from a claims data analysis using the PopGrouper

Diabetes-related hospitalizations and amputations serve as indicators of healthcare system performance, revealing regional disparities in diabetes management. This study examines regional variations in diabetes-related and all-cause outcomes among people with type 2 diabetes across Germany, adjusting for morbidity using the novel PopGrouper classification system. The paper aims to test the applicability of the PopGrouper for analyses of regional variations in health care. Based on claims data from the BARMER sickness fund, six outcomes (hospitalizations, emergency hospitalizations, amputations, hospital care costs, inpatient days, and mortality) were analyzed. For each outcome, the ratio of observed to expected outcomes was calculated based on each region’s PopGroup composition and compared to results based on age-sex composition. Finally, the analysis identified top- and bottom-performing regions based on PopGroup-adjusted performance and explored patterns of resource utilization in these regions. The findings reveal the greatest regional variation for amputations and emergency hospitalizations, followed by hospitalizations, for both, age-sex-standardized and PopGroup-standardized ratios. The observed variation was slightly lower with PopGroup standardization than with age-sex standardization, except in the case of mortality. The top-performing regions had lower inpatient resource utilization, but higher outpatient resource utilization and participation in disease management programs in the year prior to the performance outcome measurement. Regional variations in hospitalizations and related outcomes for type 2 diabetes were observed. The PopGrouper enables straightforward risk-adjustment through indirect standardization and can make a significant contribution to controlling for morbidity-related care needs in regional comparative analyses.