A key difficulty in the assessment of risk of bias or quality is the obstacle provided by incomplete reporting. While the emphasis should be on the risk of bias in the actual design and conduct of a study, it can be tempting to resort to assessing the adequacy of reporting. Many of the tools reviewed by Moher et al. were liable to confuse these separate issues (Moher 1995). Moreover, scoring in scales was often based on whether something was reported (such as stating how participants were allocated) rather than whether it was done appropriately in the study.