Regional Analysis of Diabetes Guideline Adherence Among Migrants in Italy: A Blinder-Oaxaca Decomposition Approach

This retrospective cohort study examines diabetes management adherence among Italian and foreign-born patients in Lombardy and Sicily regions. Using administrative health data, the study focuses on individuals diagnosed with type 1 or type 2 diabetes between January 1 and December 31, 2018, aged 18–100 years. Two process indicators were used to measure adherence over a one-year follow-up: (i) at least one glycated hemoglobin test and two additional screenings (lipid profile, microalbuminuria, or funduscopic examination), and (ii) at least one specialist visit to a diabetes center. Patients were categorized by country of birth, with a focus on migrants from High Migration Pressure Countries (HMPCs). The Blinder-Oaxaca decomposition was applied to assess regional disparities in adherence, separating differences into components explained by variations in observable characteristics and those that may be attributed to structural barriers to healthcare access.