DOI: 10.1136/bmjopen-2024-094824 ISSN: 2044-6055

Incidence of type 2 diabetes by socioeconomic deprivation in Germany between 2014 and 2019: an ecological study

Katharina Piedboeuf-Potyka, Ramona Hering, Mandy Schulz, Malwina Mackowiak, Ralph Brinks, Oliver Kuß, Annika Hoyer, Thaddäus Tönnies

Objective

To estimate type 2 diabetes incidence trends by sex and socioeconomic position (SEP) and evaluate trends in SEP-related inequalities in incidence.

Design

Ecological study using ambulatory claims data and regression-based modelling.

Setting

All 401 counties in Germany, covering the entire country.

Participants

All individuals with statutory health insurance (~85% of the population). Incident cases of type 2 diabetes were identified annually from 2014 to 2019 using the International Statistical Classification of Diseases and Related Health Problems, 10th revision codes.

Primary and secondary outcome measures

Incident type 2 diabetes at the county level, adjusted for age and modelled using a mixed negative binomial regression. SEP was measured using the German Index of Socioeconomic Deprivation, and a random intercept accounted for county-level heterogeneity.

Results

The incidence of type 2 diabetes decreased between 2014 and 2017 and plateaued thereafter. Trends were similar between sexes and deprivation levels. The greatest difference was observed between high and low deprivation, with an incidence rate ratio of 1.20 (95% CI: 1.14 to 1.27) among men and 1.21 (95% CI: 1.14 to 1.27) among women in 2014.

Conclusions

There was a positive trend in the decline in age-adjusted type 2 diabetes incidence between 2014 and 2019. However, social inequality persisted with deprived groups at higher risk of type 2 diabetes. The level of inequality was comparable between men and women. Continued monitoring is essential to assess whether these short-term trends persist over time.