Development of an interventional pain management specific instrument for methodologic quality assessment of nonrandomized studies of interventional techniques.

BACKGROUND: The major component of a systematic review is assessment of the methodologic quality and bias of randomized and nonrandomized trials. While there are multiple instruments available to assess the methodologic quality and bias for randomized controlled trials (RCTs), there is a lack of extensively utilized instruments for observational studies, specifically for interventional pain management (IPM) techniques. Even Cochrane review criteria for randomized trials is considered not to be a "gold standard," but merely an indication of the current state of the art review methodology. Recently a specific instrument to assess the methodologic quality of randomized trials has been developed for interventional techniques. OBJECTIVES: Our objective was to develop an IPM specific instrument to assess the methodological quality of nonrandomized trials or observational studies of interventional techniques. METHODS: The item generation for the instrument was based on a definition of quality, to the extent to which the design and conduct of the trial were congruent with the objectives of the study. Applicability was defined as the extent to which procedures produced by the study could be applied using contemporary IPM techniques. Multiple items based on Cochrane review criteria and Interventional Pain Management Techniques - Quality Appraisal of Reliability and Risk of Bias Assessment for Nonrandomized Studies (IPM-QRBNR) were utilized. RESULTS: A total of 16 items were developed which formed the IPM-QRBNR tool. The assessment was performed in multiple stages. The final assessment was 4 nonrandomized studies. The inter-rater agreement was moderate to good for IPM-QRBNR criteria. LIMITATIONS: Limited validity or accuracy assessment of the instrument and the large number of items to be scored were limitations. CONCLUSION: We have developed a new comprehensive instrument to assess the methodological quality of nonrandomized studies of interventional techniques. This instrument provides extensive information specific to interventional techniques is useful in assessing the methodological quality and bias of observational studies of interventional techniques.