title: Assessing risk of bias in prevalence studies: modification of an existing tool and evidence of interrater agreement.
abstract: OBJECTIVE
  In the course of performing systematic reviews on the prevalence of low back and neck pain, we required a tool to assess the risk of study bias. Our objectives were to (1) modify an existing checklist and (2) test the final tool for interrater agreement.
  
  
  METHODS
  The final tool consists of 10 items addressing four domains of bias plus a summary risk of bias assessment. Two researchers tested the interrater agreement of the tool by independently assessing 54 randomly selected studies. Interrater agreement overall and for each individual item was assessed using the proportion of agreement and Kappa statistic.
  
  
  RESULTS
  Raters found the tool easy to use, and there was high interrater agreement: overall agreement was 91% and the Kappa statistic was 0.82 (95% confidence interval: 0.76, 0.86). Agreement was almost perfect for the individual items on the tool and moderate for the summary assessment.
  
  
  CONCLUSIONS
  We have addressed a research gap by modifying and testing a tool to assess risk of study bias. Further research may be useful for assessing the applicability of the tool across different conditions.
authors: University of Queensland, Herston Road, Herston, Brisbane, QLD 4006, Australia. damehoy@yahoo.com.au
authors: Damian
authors: D
authors: Hoy
authors: Peter
authors: P
authors: Brooks
authors: Anthony
authors: A
authors: Woolf
authors: Fiona
authors: F
authors: Blyth
authors: Lyn
authors: L
authors: March
authors: Chris
authors: C
authors: Bain
authors: Peter
authors: P
authors: Baker
authors: Emma
authors: E
authors: Smith
authors: Rachelle
authors: R
authors: Buchbinder
mesh_terms: D015982:Bias; D016021:Epidemiologic Studies; D006801:Humans; D017116:Low Back Pain / Q000453:epidemiology; D019547:Neck Pain / Q000453:epidemiology; D015588:Observer Variation; D012196:Review Literature as Topic