Effects of Medicaid managed care on health care use: Infant emergency department and ambulatory services

Objective. Many urban children rely on emergency departments (ED) for ambulatory care. The objective of this study was to determine whether enrollment in Medicaid managed care (MMC) alters ED or other ambulatory care compared with fee-for-service Medicaid (FFSM). Methods. A prospective cohort study of infants born between May 1994 and April 1995 with a 6-month follow-up period was conducted in an urban, teaching hospital and surrounding ambulatory settings. A consecutive sample of 644 infants enrolled in MMC or FFSM was studied; 92% of eligible patients were enrolled, and 94% completed follow-up. The main outcome measures were 1) proportion of patients in each group visiting an ED, primary care practitioner (PCP), or specialist; 2) mean number of visits per group; and 3) ED reliance (EDR) defined as the proportion of all ambulatory visits occurring in an ED. Results. Fifty-six percent of MMC and 54% of FFSM patients visited an ED (relative risk: 1.03; 95% confidence interval [CI]: 0.83, 1.27). More MMC patients had a sick visit to their PCP (relative risk: 1.34; 95% CI: 1.03, 1.74); no difference in proportion with well-child or specialty visits was found. Although the mean number of total ambulatory, ED, and specialty visits was the same, MMC patients had fewer well-child and more sick visits to the PCP than FFSM patients (P = .01). EDR was 21% for both groups (P = .95). After adjustment for other factors in multivariate analysis, insurance status remained unassociated with EDR (adjusted odds ratio [OR]: 0.91; 95% CI: 0.56, 1.69). Factors associated with EDR included United States-born mother (OR: 5.34; 95% CI: 1.61, 17.68) and use of a hospital-based primary care physician (OR: 2.00; 95% CI: 1.34, 2.98). Variables that characterized infants who were less likely to be ED reliant included adequate maternal prenatal care (OR: 0.52; 95% CI: 0.34, 0.78) and having a mother who completed high school (OR: 0.67; 95% CI: 0.45, 0.99). Conclusions. Enrollment in MMC did not alter ED usage patterns when compared with FFSM. Some variation in use of other ambulatory services was detected.