Comorbidity Type and Health Care Costs in Type 2 Diabetes: A Retrospective Claims Database Analysis

Pei-Jung Lin, Elle Pope, Fang Liz Zhou

Previous studies suggest that the type and combination of comorbidities may impact diabetes care, but their cost implications are less clear. This study characterized how diabetes patients' health care utilization and costs may vary according to comorbidity type classified on the basis of the Piette and Kerr framework. We conducted a retrospective observational study of privately insured US adults newly diagnosed with type 2 diabetes (n = 138,466) using the 2014-2016 Optum Clinformatics® Data Mart. Diabetes patients were classified into five mutually exclusive comorbidity groups: concordant only, discordant only, both concordant and discordant, any dominant, and none. We estimated average health care costs of each comorbidity group by using generalized linear models, adjusting for patient demographics, region, insurance type, and prior-year costs. Most type 2 diabetes patients had discordant conditions only (27%), dominant conditions (25%), or both concordant and discordant conditions (24%); 7% had concordant conditions only. In adjusted analyses, comorbidities were significantly associated with higher health care costs (p < 0.0001) and the magnitude of the association varied with comorbidity type. Diabetes patients with dominant comorbidities incurred substantially higher costs ($38,168) compared with individuals with both concordant and discordant conditions ($20,401), discordant conditions only ($9173), concordant conditions only ($9000), and no comorbidities ($3365). More than half of the total costs in our sample (53%) were attributable to 25% of diabetes patients who had dominant comorbidities. Diabetes patients with both concordant and discordant conditions and with clinically dominant conditions incurred substantially higher health costs than other diabetes patients. Our findings suggest that diabetes management programs must explicitly address concordant, discordant, and dominant conditions because patients may have distinctly different health care needs and utilization patterns depending on their comorbidity profiles. The Piette and Kerr framework may serve as a screening tool to identify high-need, high-cost diabetes patients and suggest targets for tailored interventions. Sanofi.