Variation in the use of alternative levels of hospital care for newborns in a managed care organization

Objective(s). To assess the extent to which variation in the use of neonata l intensive care resources in a managed care organization is a consequence of variation in neonatal health risks and/or variation in the organization and delivery of medical care to newborns. Study Design. Data were collected on a cohort of all births from four sites in Kaiser Permanente by retrospective medical chart abstraction of the bir th admission. Likelihood of admission into a neonatal intensive care unit ( NICU) is estimated by logistic regression. Durations of NICU stays and of h ospital stay following birth are estimated by Cox proportional hazards regr ession. Results. The likelihood of admission into NICU and the duration of both NIC U care and hospital stay are proportional to the degree of illness and comp lexity of diagnosis. Adjusting for variation in health risks across sites, however, does not fully account for observed variation in NICU admission ra tes or for length of hospital stay. One site has a distinct pattern of high rates of NICU admissions; another site has a distinct pattern of low rates of NICU admission but long durations of hospital stay for fullterm newborn s following NICU admission as well as for all newborns managed in normal ca re nurseries. Conclusions. Substantial variations exist among sites in the risk-adjusted likelihood of NICU admission and in durations of NICU stay and hospital sta y. Hospital and NICU affiliation (Kaiser Permanente versus contract) or aff iliation of the neonatologists (Kaiser Permanente versus contract) could no t explain the variation in use of alternative levels of hospital care. The best explanation for these variations in neonatal resource use appears to b e the extent to which neonatology and pediatric practices differ in their p olicies with respect to the management of newborns of minimal to moderate i llness.