Given the profusion of scales used in dermatology (there are at least 13 named and at least 30 unnamed scales in atopic eczema alone15), it is quite easy to introduce bias by choosing a scale which contains features that will enhance your product when compared with competing products. Introduction of a new scale is another potential source of bias since they can increase the likelihood of showing a treatment benefit.16 Lack of suitable long-term outcomes is another problem frequently encountered in dermatology clinical trials. For example, atopic eczema is a long-term condition for most sufferers, yet of the 272 RCTs conducted to date, most have been less than 6 weeks' duration.12 Other factors such as frequency and duration of the remission are key components in evaluating the value of therapy. It is therefore important when reading a trial report to think of the time frame for outcomes as well as the type of outcome.
Was this article helpful?