NICU Admission Rates Rising for Infants of All Weights

Beth Skwarecki

July 28, 2015

Neonatal intensive care (NICU) admissions increased from 2007 to 2012, and admitted infants were increasingly likely to be born full term and normal birth weight, according to a study published online July 27 in JAMA Pediatrics. Although the investigators could not identify causes of the trend, they warn that the rising admission rates raise the possibility that NICUs are being overused.

The study "does not prove that the increased NICU admissions we are seeing are fraudulent or even merely wasteful. It is entirely possible that the admissions are justified. However, there is no doubt that they are expensive and carry potential harm. If hospitals want to argue that NICUs are necessary, they will need to prove that the need exists, especially in light of the increasing share of infants admitted who are at or near full term," Aaron E. Carroll, MD, from the Center for Pediatric and Adolescent Comparative Effectiveness Research and the Center for Health Policy and Professionalism Research at Indiana University, who was not involved in the study, writes in an accompanying editorial.

Wade Harrison, MPH, and David Goodman, MD, from the Dartmouth Institute for Health Policy & Clinical Practice, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, and colleagues found that from 2007 to 2012, the NICU admission rate increased from 64.0 to 77.9 per 1000 live births (relative rate, 1.22; 95% confidence interval, 1.21 - 1.22; P < .001). The investigators used data from the US Standard Certificate of Live Birth from 38 states and the District of Columbia. They excluded data on infants with a birth weight lower than 500 g because they are not always viable and not always recorded as live births. NICU admission, as defined by birth certificate reporting, corresponds to a level III or IV nursery.

When stratified by weight category, the rate of ICU admission remained nearly flat for infants in the lowest weight category (500 - 1499 g), rising from 800.1 per 1000 live births in 2007 to 844.1 in 2012. However, for each weight category beyond that, the proportion of infants admitted to NICU rose substantially, going from 361.2 to 411.8 among infants weighing 1500 to 2499 g and going from 32.0 to 43.0 among those weighing 2500 to 3999 g and from 36.5 to 49.3 among those weighing 4000 g or more.

The relative risk increase for each of the four weight categories was 5%, 15%, 35%, and 34%, respectively, after adjusting for gestational age, weight for gestational age, sex, multiple gestation, delivery method, Apgar score, race/ethnicity, maternal age, educational level, and parity.

"Initially developed to care for very premature and low-birth-weight infants, NICUs are now caring for a growing population of newborns that are larger and less ill," write the authors. "Although they would be exposed to fewer interventions and invasive procedures than other NICU infants, this level of care may still be unnecessary, with the potential for negative effects" such as family distress and higher costs.

The authors note that without data on level II nursery admissions, they cannot be sure whether the increased NICU admissions might represent infants who would previously have stayed in level II NICUs receiving similar care. The study was also unable to measure neonatal mortality, complications, or costs of care.

The authors and Dr Carroll have disclosed no relevant financial relationships.

JAMA Pediatr. Published online July 27, 2015. Article full text, Editorial full text


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.