A systematic review of the quality of burn scar rating scales for clinical and research use

Introduction

Scar rating scales have the potential to contribute to better evaluation of scar properties in both research and clinical settings. Despite a large number of scars assessment scales being available, there is limited information regarding the clinimetric properties of many of these scales. The purpose of the review was to inform clinical and research practice by determining the quality and appropriateness of existing scales. This review summarises the available evidence for the clinimetric properties of reliability, validity (including responsiveness), interpretability and feasibility of existing scales.

Methods

Electronic searches of MEDLINE, CINAHL, EMBASE and The Cochrane Library databases from 1990 onwards were used to identify English articles related to burn scar assessment scales. Scales were critically reviewed for clinimetric properties that were reported in, but not necessarily the focus of studies.

Results

A total of 29 studies provided data for 18 different scar rating scales. Most scar rating scales assessed vascularity, pliability, height and thickness. Some scales contained additional items such as itch. Only the Patient and Observer Scar Assessment Scale (POSAS) received a high quality rating but only in the area of reliability for total scores and the subscale vascularity. The Vancouver Scar Scale (VSS) received indeterminate ratings for construct validity, reliability and responsiveness. Where evidence was available, all other criteria for the POSAS, VSS and the remaining 17 scales received an indeterminate rating due to methodological issues, or a low quality rating. Poorly defined hypotheses limited the ability to give a high quality rating to data pertaining to construct validity, responsiveness and interpretability. No scale had empirical testing of content validity and no scale was of sufficient quality to consider criterion validity.

Conclusions

The POSAS, with high quality reliability but indeterminate validity, was considered to be superior in performance based on existing evidence. The VSS had the most thorough review of clnimetrics although available data received indeterminate quality ratings. On the basis of the evidence, the use of total scores has not been supported, nor has the measurement of pigmentation using a categorical scale.