Cs. Phibbs et al., THE EFFECTS OF PATIENT VOLUME AND LEVEL OF CARE AT THE HOSPITAL OF BIRTH ON NEONATAL-MORTALITY, JAMA, the journal of the American Medical Association, 276(13), 1996, pp. 1054-1059
Objective.-To examine the effects of neonatal intensive care unit (NIC
U) patient volume and the level of NICU care available at the hospital
of birth on neonatal mortality. Design.-Birth certificate data linked
to infant death certificates and to infant discharge abstracts were u
sed in a logistic regression model to control for differences in each
patient's clinical and demographic risks. Hospitals were classified by
the level of NICU care available (no NICU: level I; intermediate NICU
: level II; expanded intermediate NICU: level II+: tertiary NICU: leve
l III) and by the average patient census in the NICU. Setting.-All non
federal hospitals in California with maternity services. Patients.-All
births in nonfederal hospitals in California in 1990 (N=594 104), 473
209 (singletons only) of which were successfully linked with discharg
e abstracts. Of these infants, 53 229 were classified as likely NICU a
dmissions. Main Outcome Measures.-Death within the first 28 days of li
fe, or within the first year of life, if continuously hospitalized. Re
sults.-Patient volume and level of NICU care at the hospital of birth
both had significant effects on mortality. Compared with hospitals wit
hout an NICU, infants born in a hospital with a level III NICU with an
average NICU census of at least 15 patients per day had significantly
lower risk-adjusted neonatal mortality (odds ratio, 0.62; 95% confide
nce interval, 0.47-0.82; P=.002). Risk-adjusted neonatal mortality for
infants born in smaller level III NICUs, and in level II+ and level I
I NICUs, regardless of size, was not significantly different from hosp
itals without an NICU, and was significantly higher than hospitals wit
h large level III NICUs. Conclusions.-Risk-adjusted neonatal mortality
was significantly lower for births that occurred in hospitals with la
rge (average census, >15 patients per day) level III NICUs. Despite th
e differences in outcomes, costs for the birth of infants born at hosp
itals with large level III NICUs were not more than those for infants
born at other hospitals with NICUs, Concentration of high-risk deliver
ies in urban areas in a smaller number of hospitals that could provide
level III NICU care has the potential to decrease neonatal mortality
without increasing costs.