Length-of-stay policies and ascertainment of postdischarge problems in newborns

Objective. The purpose of this study was to evaluate the effects of an early postpartum discharge program and a subsequent legislative mandate for 48 hours of hospital coverage on incidence of newborn jaundice and feeding problems. We tested the hypothesis that heightened postdischarge ascertainment (rather than short stays) is responsible for apparent increases in these outcomes. Methods. Interrupted time series analysis was conducted on retrospective data from the automated medical records of a large Massachusetts health maintenance organization (HMO). A population of 20 366 mother-infant pairs with normal vaginal deliveries between October 1990 and March 1998 was identified. The interventions included a new HMO protocol in 1994 of 1 hospital overnight after delivery, plus a nurse home visit, then the Massachusetts' 1996 minimum coverage law. Postpartum length of stay, clinical evaluation on day 3 or 4 of life, health center visits up to day 21, health center diagnoses of jaundice or feeding problems, bilirubin testing and test severity, rehospitalizations, and emergency department visits were measured. Results. Postpartum stays <2 nights rose from 28% of newborns before implementation of the program to 70% immediately after implementation. Later, this rate fell from 66% before the mandate to 21% just after the law went into effect. Day 3 or 4 evaluation rose from 24.5% to 64% after the program, then dropped somewhat to 53% after the mandate. Controlling for longer-term trends in health center visits, implementation of the early discharge program was associated with approximately 1 extra visit for every 4 newborns within the first 21 days of life. The state mandate did not affect health center visit rates. Jaundice diagnoses were flat at 8% of newborns during the baseline, then rose to a constant 11% throughout the program and postmandate periods. Bilirubin testing of newborns also rose by 3.4 percentage points at the time of program implementation, and the proportion of tested newborns with results calling for at least consideration of phototherapy rose by 6 percentage points. Phototherapy use rose from a flat 1.8% to 2.4% of newborns after program implementation. Feeding problem diagnoses more than doubled at the time of program implementation and remained elevated after the mandate. Rehospitalizations overall and specifically for jaundice were constant over time, whereas more rare emergency department visits for jaundice dropped from 0.3% of newborns to 0 on program implementation. Conclusions. Sudden increases in jaundice-related measures and identification of infant feeding problems were not associated with changes in length of stay in this setting. Instead, these increases seem to be the result of more frequent evaluation of newborns during the critical day 3 to 4 period and may also have been elevated by a new climate of concern about neonatal vulnerability. "Ascertainment bias" may have confounded findings in previous reports that raised concerns about the safety of early discharge.