Evaluating the role of quality assessment of primary studies in systematic reviews of cancer practice guidelines.
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.
Brouwers
Melissa C
MC
Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Canada. mbrouwer@mcmaster.ca
Johnston
Mary E
ME
Charette
Manya L
ML
Hanna
Steve E
SE
Jadad
Alejandro R
AR
Browman
George P
GP
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
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