Aim: To analyse rehospitalisation of newborns of all gestations.

Methods: A total of 33,276 surviving infants of all gestations born between 1 October 1998 and 31 March 2000 at seven Kaiser Permanente Medical Care Program (KPMCP) delivery services were studied retrospectively.

Results: Rehospitalisation rates within two weeks after nursery discharge ranged from 1.0% to 3.7%. The most common reason for rehospitalisation was jaundice. Among babies > or =34 weeks, the most important factor with respect to rehospitalisation was use of home phototherapy. Among babies who were not rehospitalised for jaundice, African-American race (adjusted odds ratio (AOR) = 0.56), and having a scheduled outpatient visit (AOR = 0.73) or a home visit (AOR = 0.59) within 72 hours after discharge were protective. Factors associated with increased risk were: being small for gestational age (AOR = 1.83), gestational age of 34-36 weeks without admission to the neonatal intensive care unit (AOR = 1.65), Score for Neonatal Acute Physiology, version II, > or =10 (AOR = 1.95), male gender (AOR = 1.24), having both a home as well as a clinic visit within 72 hours after discharge (AOR = 1.84), and birth facility (range of AORs = 1.52-2.36). Asian race was associated with rehospitalisation (AOR = 1.49) when all hospitalisations were considered, but this association did not persist if hospitalisations for jaundice were excluded.

Conclusions: In this insured population with access to integrated care, rehospitalisation rates for jaundice were strongly affected by availability of home phototherapy and by follow up. For other causes, moderate prematurity and follow up visits played a large role, but variation between centres persisted even after controlling for multiple factors. Future research should include development of better process measures for evaluation of follow up strategies.