title: Do research studies in the UK reporting child neurodevelopment adjust for the variability of assessors: a systematic review.
abstract: OBJECTIVE
  Neurodevelopment is a key outcome for many childhood trials and observational studies. Clinically important decisions may rest on finding relatively small differences in neurodevelopment between groups receiving complex and costly interventions. Our purpose was to determine whether studies which measure neurodevelopment report the numbers, training, and auditing of assessors and, for multiple assessor studies, whether the results were adjusted and if so by which method?
  
  
  METHODS
  Electronic searches were conducted using Medline, Embase, Cinahl, PsycINFO, and the Cochrane Library. A study was eligible if it reported neurodevelopmental outcome in children resident in the UK, less than or equal to 18 years and was published between 2000 and 2015. Trials and observational studies were included.
  
  
  RESULTS
  Three hundred and seven full papers were reviewed: 52% of papers did not report the number of assessors used; 21% used a single assessor; and 27% used multiple assessors. Thirty-five per cent mentioned that assessors were trained in the use of the neurodevelopmental tool; 13% of assessors were audited; and only 1% of studies adjusted statistically for the number of assessors.
  
  
  CONCLUSIONS
  At the very least, the quality of reporting the use of assessors in these research publications is poor, while at worst, the variability of assessors may mask the true relationship between an intervention/observation and neurodevelopmental outcome.
authors.affiliation: Population Health Sciences, Medical School, University of Dundee, Dundee, UK.
authors.forename: Rahila
authors.initials: R
authors.lastname: Khalid
authors.affiliation: Department of Psychology, University of Dundee, Dundee, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Willatts
authors.affiliation: Population Health Sciences, Medical School, University of Dundee, Dundee, UK.
authors.forename: Fiona L R
authors.initials: FL
authors.lastname: Williams
mesh_terms: D035843:Biomedical Research / Q000592:standards*; D002648:Child; D002657:Child Development; D002986:Clinical Trials as Topic / Q000592:standards*; D006801:Humans; D008606:Mental Processes; D009484:Neuropsychology / Q000592:standards*; D064887:Observational Studies as Topic / Q000592:standards*; D006113:United Kingdom; D000078329:Workforce