Objective: To determine the impact of managed care on effectiveness of diabetes management in Tennessee, where a statewide Medicaid program (TennCare) delivers services through capitated managed care organizations (MCOs).
Research design and methods: This retrospective cohort study documented the health care utilization experiences and clinical outcomes of a convenience sample of Tennessee Medicaid enrollees with chronic diabetes before and after the initiation of TennCare. Exposures to recommended diabetic services and outcomes were compared before and after TennCare for 171 enrollees with diabetes in the state's largest academic MCO who met age, continuous enrollment, insurance, and diagnostic criteria for two years before (1992 and 1993) and two years after TennCare (1995 and 1996). Claims data were used to assess baseline characteristics and chart review data were used to assess health services utilization for 71% of cohort members (n = 121) for whom complete medical records were available. The paired t-test was used to compare exposures and outcomes before and after TennCare.
Results: Participants had an average of 6.4 outpatient clinic visits per year before TennCare vs. 8.2 visits per year after TennCare (P = .0009), 0.6 vs. 1.0 diabetic eye examinations (P = .0042), 0.2 vs. 0.5 foot examinations (P = .0358), 0.4 vs. 0.6 cholesterol assessments (P < .0001), and 0.5 vs. 1.0 glycosylated hemoglobin assessments annually (P < .0001). Average glycosylated hemoglobin decreased from 10.3 to 8.2 (P < .0001). Although hospitalizations and hospital days increased overall, there was no increase in emergency visits, preventable emergency visits, or preventable hospitalizations.
Conclusions: Enrollees with diabetes experienced increases in utilization of recommended health services and improved glucose control following the initiation of Medicaid managed care. These improvements may reflect improved chronic disease care in a primary care gatekeeper system.