ASSESSING THE QUALITY OF REPORTS OF RANDOMIZED CLINICAL-TRIALS - IS BLINDING NECESSARY

It has been suggested that the quality of clinical trials should be as sessed by blinded raters to limit the risk of introducing bias into me ta-analyses and systematic reviews, and into the peer-review process. There is very little evidence in the literature to substantiate this. This study describes the development of an instrument to assess the qu ality of reports of randomized clinical trials (RCTs) in pain research and its use to determine the effect of rater blinding on the assessme nts of quality. A multidisciplinary panel of six judges produced an in itial version of the instrument. Fourteen raters from three different backgrounds assessed the quality of 36 research reports in pain resear ch, selected from three different samples. Seven were allocated random ly to perform the assessments under blind conditions. The final versio n of the instrument included three items. These items were scored cons istently by all the raters regardless of background and could discrimi nate between reports from the different samples. Blind assessments pro duced significantly lower and more consistent scores than open assessm ents. The implications of this finding for systematic reviews, meta-an alytic research and the peer-review process are discussed.