title: Association of Gestational Age at Birth with Reasons for Subsequent Hospitalisation: 18 Years of Follow-Up in a Western Australian Population Study.
abstract: BACKGROUND
  Preterm infants are at a higher risk of hospitalisation following discharge from the hospital after birth. The reasons for rehospitalisation and the association with gestational age are not well understood.
  
  
  METHODS
  This was a retrospective birth cohort study of all live, singleton infants born in Western Australia between 1st January 1980 and 31st December 2010, followed to 18 years of age. Risks of rehospitalisation following birth discharge by principal diagnoses were compared for gestational age categories (<32, 32-33, 34-36, 37-38 weeks) and term births (39-41 weeks). Causes of hospitalisations at various gestational age categories were identified using ICD-based discharge diagnostic codes.
  
  
  RESULTS
  Risk of rehospitalisation was inversely correlated with gestational age. Growth-related concerns were the main causes for rehospitalisation in the neonatal period (<1 month of age) for all gestational ages. Infection was the most common reason for hospitalisation from 29 days to 1 year of age, and up to 5 years of age. Injury-related hospitalisations increased in prevalence from 5 years to 18 years of age. Risk of rehospitalisation was higher for all preterm infants for most causes.
  
  
  CONCLUSIONS
  The highest risks of rehospitalisation were for infection related causes for most GA categories. Compared with full term born infants, those born at shorter GA remain vulnerable to subsequent hospitalisation for a variety of causes up until 18 years of age.
authors.affiliation: Department of Paediatrics, Joondalup Health Campus, The University of Western Australia, Perth, Western Australia, 6027, Australia.
authors.forename: Ravisha
authors.initials: R
authors.lastname: Srinivasjois
authors.affiliation: Telethon Kids Institute, The University of Western Australia, Perth, Western Australia, 6008, Australia.
authors.forename: Claudia
authors.initials: C
authors.lastname: Slimings
authors.affiliation: Telethon Kids Institute, The University of Western Australia, Perth, Western Australia, 6008, Australia.
authors.forename: Kristjana
authors.initials: K
authors.lastname: Einarsdóttir
authors.affiliation: Murdoch Childrens Research Institute, Flemington Road, Parkville, Victoria, 3052, Australia; Department of Paediatrics, University of Melbourne, Parkville, Victoria, 3052, Australia; Department of Paediatrics, Monash University, Clayton, Victoria, 3168, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Burgner
authors.affiliation: Telethon Kids Institute, The University of Western Australia, Perth, Western Australia, 6008, Australia.
authors.forename: Helen
authors.initials: H
authors.lastname: Leonard
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D005865:Gestational Age; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D012189:Retrospective Studies