Possible solutions to the problems of clinical heterogeneity of outcome measures and inadequate reporting of results for randomized controlled trials (RCTs) on carpal tunnel syndrome (CTS) are presented. Meta-analysis was impeded by these problems in 2 systematic reviews concerning conservative and surgical treatment options for CTS. A solution to the problem of inadequate data presentation is to add explicit information on minimal requirements with regard to data presentation to guidelines for the reporting of studies. To resolve the problem of clinical heterogeneity of the outcomes there should be consensus on the (validated) outcomes that should be used in RCTs. For CTS there is little evidence available on the reliability, validity, and responsiveness to change of the commonly used outcomes in RCTs.Resolving both problems will increase the comparability of RCTs, enabling the calculation of a pooled estimate of effect in a meta-analysis. Systematic reviews of high-quality, randomized controlled trials (RCTs) are considered to be the highest level of evidence in research concerning medical interventions. 1 To quantify the effect of the various treatment options, preferably a meta-analysis is performed. By combining individual study results a precise estimate of the magnitude of the treatment effect can be obtained. Meta-analysis is, therefore, an important part of a systematic review. Meta-analysis is only feasible if RCTs are clinically homogeneous, that is, if the patients, interventions, comparisons, outcomes, and timing of follow-up measurements are sufficiently similar. 2 Randomized controlled trials, however, may use a range of different outcome measures. 3,4 Another prerequisite for combining study results is adequate and uniform data presentation. Reporting of results in biomedical journals is often inadequate. 5,6 This article presents possible solutions to the problems of clinical heterogeneity of the outcome measures and inadequate reporting of results for RCTs on carpal tunnel syndrome (CTS). First we show, however, that meta-analysis was impeded by these problems in 2 systematic reviews concerning conservative and surgical treatment options for CTS. 7,8