Objectives: To assess the performance of the adapted Diabetes Complications Severity Index (aDCSI) translated to International Classification of Diseases, Tenth Revision (ICD-10) in predicting hospitalizations, mortality, and healthcare-associated costs.
Study design: Retrospective closed cohort study based on secondary data analysis.
Methods: We translated the aDCSI to ICD-10 and calculated aDCSI scores based on health insurance claims data. To assess predictive performance, we used multivariate regression models to calculate risk ratios (RRs) of hospitalizations and mortality and linear predictors of cost.
Results: We analyzed a sample of 157,115 patients with diabetes mellitus. RRs of hospitalizations (total and cause specific) rose with increasing aDCSI scores. Predicting total hospitalizations over a 4-year period, unadjusted RRs were 1.22 for an aDCSI score of 1 (compared with a score of 0), 1.55 for a score of 2, 1.77 for a score of 3, 2.11 for a score of 4, and 2.72 for scores of 5 and higher. Cause-specific hospitalizations and mortality showed similar results. Costs clearly increased in each successive score category.
Conclusions: Our study supports the validity of the aDCSI as a severity measure for complications of diabetes, as it correlates to and predicts total and cause-specific hospitalizations, mortality, and costs. The aDCSI's performance in ICD-10-coded data is comparable with that in International Classification of Diseases, Ninth Revision-coded data.