Establishing test-retest reliability and the smallest detectable change of FACE-Q Aesthetic Module scales

Abstract

BACKGROUNDThe test re-test (TRT) reliability of FACE-Q Aesthetic scales has yet to be assessed. The aim of this study was to establish the TRT reliability of 17 FACE-Q Aesthetic scales, and to determine the smallest detectable change (SDC) that can be identified by these scales. METHODSData were collected from an online international sample (i.e., Prolific). Participants ≥20 years old, who had been to a dermatologist or plastic surgeon for a facial aesthetic treatment within the past 12 months were asked to provide demographic and clinical information and complete an online REDcap survey consisting of 17 FACE-Q Aesthetic scales. Participants were asked if they would be willing to complete the survey again in 7 days. Only participants who reported no important change in the scale construct and completed the re-test within 14 days were included. RESULTSA total of n=342 unique participants completed the TRT survey. The mean age of the sample was 36.6 (±11.5) years and 82.4% were female. With outlier data removed, all FACE-Q scales demonstrated an ICC>0.70 indicating ‘good’ TRT reliability. The standard error of measurement for included scales ranged from 3.37 – 11.87, corresponding to a range of SDCgroup from 0.95 to 3.23 and SDCind from 9.34 to 32.91. CONCLUSIONAll included FACE-Q scales demonstrated sufficient TRT reliability and stability overall after outlier data were removed. The authors provide values for the smallest detectable change for these scales.