Use of a disease severity index for evaluation of healthcare costs and management of comorbidities of patients with diabetes mellitus.

OBJECTIVES: To evaluate a stratification system for patients with diabetes mellitus according to severity of illness and care requirements and to correlate severity of illness with total medical and pharmaceutical costs of care. STUDY DESIGN, PATIENTS, AND METHODS: A cohort of 697 patients with diabetes mellitus was followed in a diabetes clinic under a managed care plan. Patients were stratified according to severity of illness in 6 clinical areas: glycemic control, cardiovascular disease, peripheral vascular disease/peripheral neuropathy, eye disease, renal disease, and autonomic neuropathy. Stratification was based on clinical elements in patients' medical records related to diabetes mellitus care and its comorbidities. Total medical and pharmaceutical costs were identified for 508 patients who participated in the managed care program for at least 8 months.
RESULTS: Patients in high- and very high-risk categories for cardiovascular disease, peripheral vascular disease/peripheral neuropathy, eye disease, and renal disease had markedly increased medical and pharmaceutical costs compared with those in low-risk categories. Pharmaceutical costs for patients in the glycemic control clinical area show a trend toward lower costs at higher risk. Pregnancy and depression were also associated with markedly increased healthcare costs. Patients who were in multiple high- and very high-risk categories had dramatically increased medical costs, as much as 10-fold those of patients who were in none of these categories.
CONCLUSIONS: A diabetes mellitus-specific risk stratification system related to required care intensity can be used to identify patients with high medical costs and can enable care providers to select patients for case management and triage into specific care programs.