Background: Multiple scoring systems to assess scars have been developed and are been used to measure the efficacy of the treatments for scar. There is no synthesis about those used in keloids.

Objective: To summarise and critically appraise the evidence of the reported outcomes in clinical trials for the treatment of keloid scars.

Methods: Data sources: electronic databases including Medline (PubMed), Embase (Ovid) and CINAHL (Ebsco) were searched using the following terms: cicatrix, keloid and acne keloid. Study selection: two authors independently screened all records for elegibility. For inclusion, the study design and population had to be clinical trials for the treatment of adults with the diagnosis of keloid scars. The initial search retrieved 1446 records, of which 33 met the inclusion criteria. Data extraction: outcomes and intervals for measurements were extracted.

Results: Seventeen of the 33 clinical trials used the Vancouver Scar Scale to measure vascularity, pigmentation, pliability and height of the keloids. Only two clinical trials used the Patient and Observer Scar Assessment Scale (POSAS) to measure the efficacy of the treatment. Six out of 33 clinical trials used the flattening of the keloid as their main outcome. The remaining studies used modified visual analog scales, clinical photographs and other devices to measure the characteristics of the keloids at baseline and at the end of the trial. Most of the trials, 69.7% (n=23) measured the scars at weeks 0, 8 and 12. Only 18.2% of the clinical trials assessed the main outcome at 6 month and only two for at least one year.

Conclusions: Vancouver Scale Scale is the most common outcome measure in the clinical trials for the treatment of keloids. However, flattening or height is the main characteristics that should be measure in these trials. Patient-reported instruments have to be included as an outcome in these trials.