A four-system comparison of patients with chronic illness: the Military Health System, Veterans Health Administration, Medicaid, and commercial plans.

We compared chronic care utilization in four major health systems in the U.S.: the military health system (TRICARE), the Department of Veterans Affairs (VA), Medicaid, and employer-sponsored commercial plans. Prevalence rates and key performance indicators were constructed from administrative data in federal fiscal year 2003 for eight chronic conditions: hypertension, major depression, diabetes, tobacco dependence, ischemic heart disease, severe mental illness, persistent asthma, and stroke. Continuously enrolled beneficiaries under 65 years old were studied: TRICARE (N = 2,963,987), VA (N = 2,114,739), Medicaid enrollees in five states (N = 5,554,974), and commercial insurance (N = 5,212,833). Condition-specific adjusted prevalence rates and measures were compared using the standardized rate ratio. For the majority of the conditions, the estimated prevalence rates were highest in the VA and Medicaid populations. Prevalence rates were generally lower in TRICARE and commercial plans. Medicaid beneficiaries had the highest hospitalization rates in four of the six conditions where hospitalization rates were measured. These results provide empirical evidence of differences in chronically ill patient populations in several of the major U.S. health insurance systems.