The effect of health maintenance organization vs commercial insurance status on obstetrical management and outcome
M. E. Aitken, C. R. Warden and C. W. Critchlow
Department of Pediatrics, School of Medicine, and Epidemiology, University of Washington, Seattle, USA.
OBJECTIVE: To compare obstetrical management and birth outcomes between
patients with health maintenance organization (HMO) insurance and those
with private commercial insurance. DESIGN: Retrospective population-based
cohort study. SETTING: King County, Washington. PATIENTS: Among newborns
delivered in 1992 and 1993, a random sample of 4000 birth records listing
HMO insurance for prenatal care was compared with a random sample of 4000
birth records listing private commercial insurance as the primary coverage.
MAIN OUTCOME MEASURES: Use of ultrasonography and amniocentesis; rate of
primary cesarean section performed; adequacy of prenatal care; incidence of
maternal medical complications, low birth weight, and congenital
malformations; and length of hospital stay. RESULTS: Women covered by HMO
compared with commercial insurance were more likely to undergo
ultrasonography (relative risk [RR], 1.4; 95% confidence interval [CI],
1.3-1.4). Inadequate prenatal care was less frequent among HMO-insured
patients (RR, 0.6; 95% CI, 0.5-0.7), as was the incidence of birth weight
below 2500 g (RR, 0.7; 95% CI, 0.6-0.9). No differences in rates of
cesarean section and congenital anomalies were observed. Among women
without obstetrical risk factors, HMO-insured mothers were at an increased
risk of labor and delivery complications (RR, 1.4; 95% CI, 1.3-1.5); their
infants were at an increased risk of infant distress (RR, 1.8; 95% CI,
1.5-2.2). CONCLUSIONS: Patients with HMO insurance have improved access to
prenatal care and screening when compared with privately insured patients.
The reasons for increased risks of abnormal maternal and infant outcomes
observed among a subset of HMO-insured patients are unclear. A study with
more detailed prospective data collection is warranted.
