Accounting for variation in length of NICU stay for extremely low birth weight infants.

OBJECTIVE: To develop a length of stay (LOS) model for extremely low birth weight (ELBW) infants.

STUDY DESIGN: We included infants from the California Perinatal Quality Care Collaborative with birth weight 401 to 1000 g who were discharged to home. Exclusion criteria were congenital anomalies, surgery and death. LOS was defined as days from admission to discharge. As patients who died or were transferred to lower level of care were excluded, we assessed correlation of hospital mortality rates and transfers to risk-adjusted LOS.

RESULTS: There were 2012 infants with median LOS 79 days (range 23 to 219). Lower birth weight, lack of antenatal steroids and lower Apgar score were associated with longer LOS. There was negligible correlation between risk-adjusted LOS and hospital mortality rates (r=0.0207) and transfer-out rates (r=0.121).

CONCLUSION: Particularly because ELBW infants have extended hospital stays, identification of unbiased and informative risk-adjusted LOS for these infants is an important step in benchmarking best practice and improving efficiency in care.