title: Quality of systematic reviews in pediatric oncology--a systematic review.
abstract: BACKGROUND
  To ensure evidence-based decision making in pediatric oncology systematic reviews are necessary. The objective of our study was to evaluate the methodological quality of all currently existing systematic reviews in pediatric oncology.
  
  
  METHODS
  We identified eligible systematic reviews through a systematic search of the literature. Data on clinical and methodological characteristics of the included systematic reviews were extracted. The methodological quality of the included systematic reviews was assessed using the overview quality assessment questionnaire, a validated 10-item quality assessment tool. We compared the methodological quality of systematic reviews published in regular journals with that of Cochrane systematic reviews.
  
  
  RESULTS
  We included 117 systematic reviews, 99 systematic reviews published in regular journals and 18 Cochrane systematic reviews. The average methodological quality of systematic reviews was low for all ten items, but the quality of Cochrane systematic reviews was significantly higher than systematic reviews published in regular journals. On a 1-7 scale, the median overall quality score for all systematic reviews was 2 (range 1-7), with a score of 1 (range 1-7) for systematic reviews in regular journals compared to 6 (range 3-7) in Cochrane systematic reviews (p<0.001).
  
  
  CONCLUSIONS
  Most systematic reviews in the field of pediatric oncology seem to have serious methodological flaws leading to a high risk of bias. While Cochrane systematic reviews were of higher methodological quality than systematic reviews in regular journals, some of them also had methodological problems. Therefore, the methodology of each individual systematic review should be scrutinized before accepting its results.
authors.affiliation: Department of Pediatric Oncology, Emma Children's Hospital/Academic Medical Center, University of Amsterdam, 1100 DD Amsterdam, The Netherlands. chcrg@amc.uva.nl
authors.forename: Andreas
authors.initials: A
authors.lastname: Lundh
authors.forename: Sebastiaan L
authors.initials: SL
authors.lastname: Knijnenburg
authors.forename: Anders W
authors.initials: AW
authors.lastname: Jørgensen
authors.forename: Elvira C
authors.initials: EC
authors.lastname: van Dalen
authors.forename: Leontien C M
authors.initials: LC
authors.lastname: Kremer
mesh_terms: D015982:Bias; D015706:Bibliometrics; D002648:Child; D019317:Evidence-Based Medicine; D006801:Humans; D018156:Journalism, Medical / Q000592:standards*; D008495:Medical Oncology; D015201:Meta-Analysis as Topic; D010372:Pediatrics; D012107:Research Design / Q000592:standards*; D012196:Review Literature as Topic