title: Temporal trends in cerebral palsy by impairment severity and birth gestation.
abstract: OBJECTIVE
  Our aim was to build on previous research indicating that rates of cerebral palsy (CP) in the Australian state of Victoria are declining, and examine whether severity of impairments is also decreasing.
  
  
  METHODS
  Data on individuals with CP were extracted from the Victorian Cerebral Palsy Register for birth years 1983 to 2009. The yearly rates of dichotomized categories for gross motor function, motor laterality, intellectual impairment, and epilepsy per 1000 neonatal survivors and proportions in the CP cohort were tabulated and plotted by birth gestation. Linear regression modelling was used to fit prediction curves; likelihood ratio tests were used to test for differences in trends between impairment severity groups.
  
  
  RESULTS
  Since the mid-1990s, CP rates declined in neonatal survivors of birth at all gestations. Our data suggest that the decreasing CP rates were associated with relatively greater decreases in the rates of Gross Motor Function Classification System levels III to V, bilateral CP, epilepsy, and intellectual impairment (all p<0.005). Some variation was seen between birth gestation groups.
  
  
  CONCLUSIONS
  Declines in rates of CP of all levels of severity and complexity from the mid-1990s provides 'real-world' support for the effectiveness of concurrent neuroprotective strategies and continual innovation in perinatal practices.
authors.affiliation: Developmental Disability and Rehabilitation Research, Murdoch Childrens Research Institute, Melbourne, VIC, Australia.|Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Reid
authors.affiliation: Developmental Disability and Rehabilitation Research, Murdoch Childrens Research Institute, Melbourne, VIC, Australia.|Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia.
authors.forename: Elaine
authors.initials: E
authors.lastname: Meehan
authors.affiliation: Cerebral Palsy Alliance, The University of Sydney, Sydney, NSW, Australia.|Telethon Kids Institute, University of Western Australia, Perth, WA, Australia.
authors.forename: Sarah
authors.initials: S
authors.lastname: McIntyre
authors.affiliation: Cerebral Palsy Alliance, The University of Sydney, Sydney, NSW, Australia.
authors.forename: Shona
authors.initials: S
authors.lastname: Goldsmith
authors.affiliation: Cerebral Palsy Alliance, The University of Sydney, Sydney, NSW, Australia.|Telethon Kids Institute, University of Western Australia, Perth, WA, Australia.|Grace Centre for Newborn Care, Sydney Children's Hospital Network, Sydney, NSW, Australia.
authors.forename: Nadia
authors.initials: N
authors.lastname: Badawi
authors.affiliation: Developmental Disability and Rehabilitation Research, Murdoch Childrens Research Institute, Melbourne, VIC, Australia.|Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia.|Developmental Medicine, The Royal Children's Hospital, Melbourne, VIC, Australia.
authors.forename: Dinah S
authors.initials: DS
authors.lastname: Reddihough
mesh_terms: D000293:Adolescent; D000328:Adult; D001315:Australia; D002547:Cerebral Palsy / Q000175:diagnosis / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D004827:Epilepsy / Q000453:epidemiology; D005260:Female; D005865:Gestational Age; D006801:Humans; D008607:Intellectual Disability / Q000453:epidemiology; D015995:Prevalence; D012042:Registries; D012720:Severity of Illness Index; D055815:Young Adult