title: Diagnostic accuracy of developmental screening in primary care at the 18-month health supervision visit: a cross-sectional study.
abstract: BACKGROUND
  Communication delays are often the first presenting problem in infants with a range of developmental disabilities. Our objective was to assess the validity of the 18-month Nipissing District Developmental Screen compared with the Infant Toddler Checklist, a validated tool for detecting expressive language and other communication delays.
  
  
  METHODS
  A cross-sectional design was used. Children aged 18-20 months were recruited during scheduled health supervision visits. Parents completed both the 18-month Nipissing District Developmental Screen and the Infant Toddler Checklist. We assessed criterion validity (diagnostic test properties, overall agreement) for 1 or more "no" responses (1+NDDS flag) and 2 or more "no" responses (2+NDDS flag) using the Infant Toddler Checklist as a criterion measure.
  
  
  RESULTS
  The study included 348 children (mean age 18.6 ± 0.7 mo). The 1+NDDS flag had good sensitivity (94%, 95% confidence interval [CI] 70%-100%, and 86%, 95% CI 64%-96%), poor specificity (63%, 95% CI 58%-68%, and 63%, 95% CI 58%-69%), and fair agreement (0.26) to identify expressive speech and other communication delays, respectively. The 2+NDDS flag had low to fair sensitivity (50%, 95% CI 26%-74%, and 73%, 95% CI 50%-88%), good specificity (86%, 95% CI 82%-90%, and 88%, 95% CI 84%-92%) and moderate agreement (0.45) to identify expressive speech and other communication delays, respectively.
  
  
  CONCLUSIONS
  The low specificity of the 1+NDDS flag may lead to overdiagnosis, and the low sensitivity of the 2+NDDS flag may lead to underdiagnosis, suggesting that infants who could benefit from early intervention may not be identified. The Nipissing District Developmental Screen does not have adequate characteristics to accurately identify children with a range of communication delays.
authors.affiliation: Paediatric Outcomes Research Team (PORT) (van den Heuvel, Borkhoff, Koroshegyi, Zabih, Birken, Maguire, Parkin), Division of Paediatric Medicine, Department of Paediatrics, The Hospital for Sick Children; Institute for Health Policy, Management and Evaluation (Borkhoff, Birken, Maguire, Parkin); The Applied Health Research Centre of the Li Ka Shing Knowledge Institute, and Department of Pediatrics, St. Michael's Hospital (Maguire), University of Toronto; Department of Paediatrics (van den Heuvel, Birken, Maguire, Parkin), Faculty of Medicine, University of Toronto, Toronto, Ont.; Department of Health Sciences (Reijneveld), University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
authors.forename: Meta
authors.initials: M
authors.lastname: van den Heuvel
authors.affiliation: Paediatric Outcomes Research Team (PORT) (van den Heuvel, Borkhoff, Koroshegyi, Zabih, Birken, Maguire, Parkin), Division of Paediatric Medicine, Department of Paediatrics, The Hospital for Sick Children; Institute for Health Policy, Management and Evaluation (Borkhoff, Birken, Maguire, Parkin); The Applied Health Research Centre of the Li Ka Shing Knowledge Institute, and Department of Pediatrics, St. Michael's Hospital (Maguire), University of Toronto; Department of Paediatrics (van den Heuvel, Birken, Maguire, Parkin), Faculty of Medicine, University of Toronto, Toronto, Ont.; Department of Health Sciences (Reijneveld), University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
authors.forename: Cornelia M
authors.initials: CM
authors.lastname: Borkhoff
authors.affiliation: Paediatric Outcomes Research Team (PORT) (van den Heuvel, Borkhoff, Koroshegyi, Zabih, Birken, Maguire, Parkin), Division of Paediatric Medicine, Department of Paediatrics, The Hospital for Sick Children; Institute for Health Policy, Management and Evaluation (Borkhoff, Birken, Maguire, Parkin); The Applied Health Research Centre of the Li Ka Shing Knowledge Institute, and Department of Pediatrics, St. Michael's Hospital (Maguire), University of Toronto; Department of Paediatrics (van den Heuvel, Birken, Maguire, Parkin), Faculty of Medicine, University of Toronto, Toronto, Ont.; Department of Health Sciences (Reijneveld), University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
authors.forename: Christine
authors.initials: C
authors.lastname: Koroshegyi
authors.affiliation: Paediatric Outcomes Research Team (PORT) (van den Heuvel, Borkhoff, Koroshegyi, Zabih, Birken, Maguire, Parkin), Division of Paediatric Medicine, Department of Paediatrics, The Hospital for Sick Children; Institute for Health Policy, Management and Evaluation (Borkhoff, Birken, Maguire, Parkin); The Applied Health Research Centre of the Li Ka Shing Knowledge Institute, and Department of Pediatrics, St. Michael's Hospital (Maguire), University of Toronto; Department of Paediatrics (van den Heuvel, Birken, Maguire, Parkin), Faculty of Medicine, University of Toronto, Toronto, Ont.; Department of Health Sciences (Reijneveld), University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
authors.forename: Weeda
authors.initials: W
authors.lastname: Zabih
authors.affiliation: Paediatric Outcomes Research Team (PORT) (van den Heuvel, Borkhoff, Koroshegyi, Zabih, Birken, Maguire, Parkin), Division of Paediatric Medicine, Department of Paediatrics, The Hospital for Sick Children; Institute for Health Policy, Management and Evaluation (Borkhoff, Birken, Maguire, Parkin); The Applied Health Research Centre of the Li Ka Shing Knowledge Institute, and Department of Pediatrics, St. Michael's Hospital (Maguire), University of Toronto; Department of Paediatrics (van den Heuvel, Birken, Maguire, Parkin), Faculty of Medicine, University of Toronto, Toronto, Ont.; Department of Health Sciences (Reijneveld), University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
authors.forename: Sijmen A
authors.initials: SA
authors.lastname: Reijneveld
authors.affiliation: Paediatric Outcomes Research Team (PORT) (van den Heuvel, Borkhoff, Koroshegyi, Zabih, Birken, Maguire, Parkin), Division of Paediatric Medicine, Department of Paediatrics, The Hospital for Sick Children; Institute for Health Policy, Management and Evaluation (Borkhoff, Birken, Maguire, Parkin); The Applied Health Research Centre of the Li Ka Shing Knowledge Institute, and Department of Pediatrics, St. Michael's Hospital (Maguire), University of Toronto; Department of Paediatrics (van den Heuvel, Birken, Maguire, Parkin), Faculty of Medicine, University of Toronto, Toronto, Ont.; Department of Health Sciences (Reijneveld), University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
authors.forename: Jonathon
authors.initials: J
authors.lastname: Maguire
authors.affiliation: Paediatric Outcomes Research Team (PORT) (van den Heuvel, Borkhoff, Koroshegyi, Zabih, Birken, Maguire, Parkin), Division of Paediatric Medicine, Department of Paediatrics, The Hospital for Sick Children; Institute for Health Policy, Management and Evaluation (Borkhoff, Birken, Maguire, Parkin); The Applied Health Research Centre of the Li Ka Shing Knowledge Institute, and Department of Pediatrics, St. Michael's Hospital (Maguire), University of Toronto; Department of Paediatrics (van den Heuvel, Birken, Maguire, Parkin), Faculty of Medicine, University of Toronto, Toronto, Ont.; Department of Health Sciences (Reijneveld), University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
authors.forename: Catherine
authors.initials: C
authors.lastname: Birken
authors.affiliation: Paediatric Outcomes Research Team (PORT) (van den Heuvel, Borkhoff, Koroshegyi, Zabih, Birken, Maguire, Parkin), Division of Paediatric Medicine, Department of Paediatrics, The Hospital for Sick Children; Institute for Health Policy, Management and Evaluation (Borkhoff, Birken, Maguire, Parkin); The Applied Health Research Centre of the Li Ka Shing Knowledge Institute, and Department of Pediatrics, St. Michael's Hospital (Maguire), University of Toronto; Department of Paediatrics (van den Heuvel, Birken, Maguire, Parkin), Faculty of Medicine, University of Toronto, Toronto, Ont.; Department of Health Sciences (Reijneveld), University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
authors.forename: Patricia
authors.initials: P
authors.lastname: Parkin