# Reliability and Validity Testing of the Persian Version of the Derriford Appearance Scale 24 in a Sample of Individuals with Craniofacial Irregularity and Amputation

## TL;DR

This study tested the Persian version of a 24-item appearance scale for people with craniofacial irregularities or amputations, finding it reliable and valid for assessing self-consciousness about appearance.

## Contribution

The paper provides validation of the Persian Derriford Appearance Scale 24 (P-DAS24) for use in individuals with craniofacial irregularity and limb loss.

## Key findings

- The P-DAS24 showed high internal consistency (Cronbach's alpha = 0.89) and excellent test-retest reliability (r = 0.96).
- The P-DAS24 scores significantly differed between disfigured and non-disfigured individuals (P=0.01).
- Scores varied significantly with participants' level of involvement (P<0.001) and gender differences were observed across DAS versions.

## Abstract

Despite the recent advancements in the design and manufacture of prostheses for individuals with craniofacial irregularity and amputation, these individuals tend to become self-conscious about their appearance. The aim of this study was to investigate the reliability and validity of Persian version of the Derriford Appearance Scale24 (P-DAS24) for a sample of individuals with craniofacial irregularity and limb loss.

Reliability of the P-DAS24 was determined by computing internal consistency and test-retest reliability utilizing Cronbach's alpha coefficient and Pearson's correlation coefficient. Discriminant validity was investigated with comparing the total score of the P-DAS24 between disfigured participants and those with no appearance problem. Known-groups validity was evaluated regarding the participants' gender and their level of involvement.

The sample size comprised of 251 individuals with disfigurement and 101 without disfigurement who were deemed normal in appearance. The P-DAS24 showed satisfactory internal consistency (Cronbach's alpha = 0.89) and excellent test-retest reliability (r = 0.96). The total score of the P-DAS24 showed a statistically significant difference between individuals deemed disfigured or normal (P=0.01). The total scores P-DAS24 in individuals with different levels of involvement were significantly different (P<0.001). The scores of the DAS2, DAS18, DAS21, and DAS24 were significantly different between men and women (P<0.01, <0.01, 0.03, and 0.01, respectively).

The P-DAS24 is a valid and reliable tool that may be utilized in clinical practice and researches to assess the outcomes of prosthetic reconstructions in individuals with disfigurement.