OBJECTIVES : The type, not just the increased number, of comorbidities may affect diabetes care. This study characterized how health care utilization and costs among people with diabetes may vary by comorbidity type, based on the Piette and Kerr framework.

METHODS : Using data from the 2014-2016 Optum Clinformatics® Data Mart, we identified individuals age ≥18 years newly diagnosed with Type 2 diabetes (n=138,466). We categorized patients into five comorbidity groups: concordant only (e.g., macro- and micro-vascular diseases), discordant only (e.g., musculoskeletal illness), both concordant and discordant, dominant (e.g., cancer), and none. We estimated average health care costs of each comorbidity group by using generalized linear models, adjusting for demographics, region, insurance and baseline costs.

RESULTS : Most diabetes patients in our sample (27%) had discordant conditions only, followed by dominant (25%) and both concordant and discordant conditions (24%); 7% had concordant conditions only. More than half of the total costs in our sample (53%) were attributable to individuals with dominant comorbidities. In adjusted analyses, comorbidities were significantly associated with higher health care costs (p<0.0001) and the magnitude of the association varied by comorbidity type. Patients with dominant comorbidities incurred substantially higher annual health care costs ($38,168), compared with individuals with both concordant and discordant conditions ($20,401), discordant conditions only ($9,173), concordant conditions only ($9,000), and no comorbidities ($3,365).

CONCLUSIONS : Our findings suggest that the Piett and Kerr framework may serve as a screening tool for identification of high-need, high-cost cases among the diabetes population. 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. Incorporating a clinically meaningful classification of comorbidities such as the Piett and Kerr framework into risk adjustment measures may help enhance the performance of value-based payment models in diabetes care.