Objective: To examine the trends in hospital admissions in the first year of life and identify whether changes in maternal and infant risk factors explain any changes Design: Population-based study using de-identified linked health data. Participants: All 788,798 liveborn infants delivered in New South Wales from 2001 to 2009 with a linked birth and hospital record. Main outcome measures: The number of infants readmitted to hospital at least once, up to one year of age, per 100 livebirths each year; changes in maternal and infant risk factors were assessed using logistic regression. Results: The number of infants admitted to hospital up to age one decreased 10.5%, from 18.4 per 100 births in 2001 to 16.5 in 2009. Fifty five per cent of this decrease could be explained by changes in factors that are associated with likelihood of hospitalisation; length of stay during the birth admission, maternal age and maternal smoking. The rate of admissions for jaundice and feeding difficulties increased significantly over the study period, while admissions for infections decreased. Conclusions: There has been a decrease in the rate of infants admitted to hospital in the first year of life, which can be partly explained by increasing maternal age, decreasing maternal smoking and a shift to shorter length of hospital stay at birth. Improved maternal and neonatal care in hospital and increased postnatal support at home may have contributed to reduced risk of readmission. The introduction of government policies may explain the rest of the decrease
