title: Evaluating the role of quality assessment of primary studies in systematic reviews of cancer practice guidelines.
abstract: BACKGROUND
  The purpose of this study was to evaluate the role of study quality assessment of primary studies in cancer practice guidelines.
  
  
  METHODS
  Reliable and valid study quality assessment scales were sought and applied to published reports of trials included in systematic reviews of cancer guidelines. Sensitivity analyses were performed to evaluate the relationship between quality scores and pooled odds ratios (OR) for mortality and need for blood transfusion.
  
  
  RESULTS
  Results found that that whether trials were classified as high or low quality depended on the scale used to assess them. Although the results of the sensitivity analyses found some variation in the ORs observed, the confidence intervals (CIs) of the pooled effects from each of the analyses of high quality trials overlapped with the CI of the pooled odds of all trials. Quality score was not predictive of pooled ORs studied here.
  
  
  CONCLUSIONS
  Had sensitivity analyses based on study quality been conducted prospectively, it is highly unlikely that different conclusions would have been found or that different clinical recommendations would have emerged in the guidelines.
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Canada. mbrouwer@mcmaster.ca
authors.forename: Melissa C
authors.initials: MC
authors.lastname: Brouwers
authors.forename: Mary E
authors.initials: ME
authors.lastname: Johnston
authors.forename: Manya L
authors.initials: ML
authors.lastname: Charette
authors.forename: Steve E
authors.initials: SE
authors.lastname: Hanna
authors.forename: Alejandro R
authors.initials: AR
authors.lastname: Jadad
authors.forename: George P
authors.initials: GP
authors.lastname: Browman
mesh_terms: D001803:Blood Transfusion / Q000706:statistics & numerical data; D002986:Clinical Trials as Topic; D016001:Confidence Intervals; D006801:Humans; D020380:Needs Assessment; D009369:Neoplasms / Q000401:mortality / Q000628:therapy*; D016017:Odds Ratio; D017410:Practice Guidelines as Topic; D011785:Quality Assurance, Health Care; D012196:Review Literature as Topic; D012680:Sensitivity and Specificity
references.citation: JAMA. 2001 Sep 26;286(12):1509-11
references.pmid: 11572746
references.citation: Jt Comm J Qual Improv. 1999 Sep;25(9):470-9
references.pmid: 10481816
references.citation: J Clin Oncol. 1995 Feb;13(2):502-12
references.pmid: 7844612
references.citation: JAMA. 1995 Feb 1;273(5):408-12
references.pmid: 7823387
references.citation: J Clin Oncol. 1998 Mar;16(3):1226-31
references.pmid: 9508211
references.citation: Lancet. 1998 Aug 22;352(9128):590-1
references.pmid: 9746014
references.citation: Stat Med. 1989 Apr;8(4):441-54
references.pmid: 2727468
references.citation: Int J Technol Assess Health Care. 1996 Spring;12(2):195-208
references.pmid: 8707495
references.citation: JAMA. 2002 Jun 12;287(22):2973-82
references.pmid: 12052127
references.citation: Control Clin Trials. 1990 Oct;11(5):339-52
references.pmid: 1963128
references.citation: Lancet. 1998 Aug 22;352(9128):609-13
references.pmid: 9746022
references.citation: Int J Technol Assess Health Care. 2000 Autumn;16(4):1136-46
references.pmid: 11155833
references.citation: Control Clin Trials. 1995 Feb;16(1):62-73
references.pmid: 7743790
references.citation: Br J Surg. 1998 Feb;85(2):171-8
references.pmid: 9501809
references.citation: Dis Colon Rectum. 1997 Jan;40(1):35-41
references.pmid: 9102259
references.citation: JAMA. 1999 Sep 15;282(11):1054-60
references.pmid: 10493204
references.citation: Urology. 1997 Jan;49(1):71-8
references.pmid: 9000189
references.citation: Control Clin Trials. 1996 Feb;17(1):1-12
references.pmid: 8721797
references.citation: J Clin Epidemiol. 1992 Mar;45(3):255-65
references.pmid: 1569422
references.citation: J Epidemiol Community Health. 1998 Jun;52(6):377-84
references.pmid: 9764259
references.citation: Cancer Prev Control. 1997 Aug;1(3):241-8
references.pmid: 9765749
references.citation: Cancer Prev Control. 1997 Dec;1(5):379-92
references.pmid: 9765760
references.citation: J Clin Oncol. 2001 Jul 15;19(14):3392-6
references.pmid: 11454887
references.citation: Cancer. 1986 Sep 15;58(6):1378-86
references.pmid: 3091243
references.citation: Int J Technol Assess Health Care. 2002 Winter;18(1):11-23
references.pmid: 11987433
references.citation: J Adv Nurs. 1997 Jun;25(6):1262-8
references.pmid: 9181425
references.citation: JAMA. 1994 Jul 13;272(2):101-4
references.pmid: 8015115
references.citation: Head Neck. 2001 Jul;23(7):579-89
references.pmid: 11400247
references.citation: Evid Rep Technol Assess (Summ). 2002 Mar;(47):1-11
references.pmid: 11979732
references.citation: Health Technol Assess. 1999;3(12):i-iv, 1-98
references.pmid: 10374081