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The validity and reliability of the Swedish version of the Satisfaction with appearance scale for individuals with systemic sclerosis

Mattsson, Malin ; Hesselstrand, Roger LU ; Gunnarsson, Karin ; Dyrsmeds, Elisabet ; Holmner, Monica ; Nordin, Annica and Boström, Carina (2023) In Journal of Scleroderma and Related Disorders 8(1). p.53-63
Abstract

Background: Systemic sclerosis (SSc) can lead to visible changes in appearance which could generate concerns among patients. Thus, valid questionnaires that capture these concerns are valuable to identify and communicate appearance concerns. Objective: To determine aspects of the validity and reliability of the Swedish version of the Satisfaction with Appearance scale for individuals with SSc (SWAP-Swe in SSc). Methods: Content validity was assessed by interviews. In a cross-sectional design, construct validity was evaluated by comparing the self-reported questionnaire SWAP-Swe in SSc to the Scleroderma Health Assessment Questionnaire (SSc HAQ), Patient Health Questionnaire-8 (PHQ-8), RAND-36, modified Rodnan skin score (mRSS), disease... (More)

Background: Systemic sclerosis (SSc) can lead to visible changes in appearance which could generate concerns among patients. Thus, valid questionnaires that capture these concerns are valuable to identify and communicate appearance concerns. Objective: To determine aspects of the validity and reliability of the Swedish version of the Satisfaction with Appearance scale for individuals with SSc (SWAP-Swe in SSc). Methods: Content validity was assessed by interviews. In a cross-sectional design, construct validity was evaluated by comparing the self-reported questionnaire SWAP-Swe in SSc to the Scleroderma Health Assessment Questionnaire (SSc HAQ), Patient Health Questionnaire-8 (PHQ-8), RAND-36, modified Rodnan skin score (mRSS), disease duration and age using Spearman’s rank correlations (rs). Internal consistency was evaluated by Cronbach’s alpha coefficient and corrected item-to-total correlations. Test–retest reliability was investigated using the intraclass correlation coefficient (ICC). Results: Eleven patients and 10 health professionals participated in the assessment of content validity. For the other aspects of validity and reliability 134 patients (median age 62 years, women 81%, limited cutaneous SSc 75%) participated. Overall, the content validity was satisfactory. The SWAP-Swe in SSc correlated with SSc HAQ (HAQ-DI rs = 0.50, visual analogue scales rs = 0.24–0.41), PHQ-8 (rs = 0.46), RAND-36 (rs = −0.21 to −0.47), mRSS (rs = 0.28), disease duration (rs = −0.01) and age (rs = −0.15). The Cronbach’s alpha coefficient was 0.92, corrected item-to-total correlations ⩾ 0.45 and the ICC 0.82. Conclusion: The SWAP-Swe in SSc showed satisfactory content validity, sufficient and good internal consistency and sufficient test–retest reliability. It was more strongly associated with self-reported questionnaires than with physician-assessed skin involvement and age, indicating that appearance concerns in SSc seem to be multidimensional as earlier reported. Our study contributes with a thorough investigation of validity and reliability including aspects that have not been investigated before. However, evaluation of more validity aspects of the SWAP-Swe in SSc is suggested.

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author
; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Body image, patient-reported outcome measure, questionnaire, reliability, systemic sclerosis, validity
in
Journal of Scleroderma and Related Disorders
volume
8
issue
1
pages
53 - 63
publisher
SAGE Publications
external identifiers
  • pmid:36743814
  • scopus:85134402890
ISSN
2397-1983
DOI
10.1177/23971983221107858
language
English
LU publication?
yes
id
4ddbfc33-18c7-4427-b3ed-55111a388549
date added to LUP
2022-09-23 12:43:03
date last changed
2024-07-09 02:37:25
@article{4ddbfc33-18c7-4427-b3ed-55111a388549,
  abstract     = {{<p>Background: Systemic sclerosis (SSc) can lead to visible changes in appearance which could generate concerns among patients. Thus, valid questionnaires that capture these concerns are valuable to identify and communicate appearance concerns. Objective: To determine aspects of the validity and reliability of the Swedish version of the Satisfaction with Appearance scale for individuals with SSc (SWAP-Swe in SSc). Methods: Content validity was assessed by interviews. In a cross-sectional design, construct validity was evaluated by comparing the self-reported questionnaire SWAP-Swe in SSc to the Scleroderma Health Assessment Questionnaire (SSc HAQ), Patient Health Questionnaire-8 (PHQ-8), RAND-36, modified Rodnan skin score (mRSS), disease duration and age using Spearman’s rank correlations (r<sub>s</sub>). Internal consistency was evaluated by Cronbach’s alpha coefficient and corrected item-to-total correlations. Test–retest reliability was investigated using the intraclass correlation coefficient (ICC). Results: Eleven patients and 10 health professionals participated in the assessment of content validity. For the other aspects of validity and reliability 134 patients (median age 62 years, women 81%, limited cutaneous SSc 75%) participated. Overall, the content validity was satisfactory. The SWAP-Swe in SSc correlated with SSc HAQ (HAQ-DI r<sub>s</sub> = 0.50, visual analogue scales r<sub>s</sub> = 0.24–0.41), PHQ-8 (r<sub>s</sub> = 0.46), RAND-36 (r<sub>s</sub> = −0.21 to −0.47), mRSS (r<sub>s</sub> = 0.28), disease duration (r<sub>s</sub> = −0.01) and age (r<sub>s</sub> = −0.15). The Cronbach’s alpha coefficient was 0.92, corrected item-to-total correlations ⩾ 0.45 and the ICC 0.82. Conclusion: The SWAP-Swe in SSc showed satisfactory content validity, sufficient and good internal consistency and sufficient test–retest reliability. It was more strongly associated with self-reported questionnaires than with physician-assessed skin involvement and age, indicating that appearance concerns in SSc seem to be multidimensional as earlier reported. Our study contributes with a thorough investigation of validity and reliability including aspects that have not been investigated before. However, evaluation of more validity aspects of the SWAP-Swe in SSc is suggested.</p>}},
  author       = {{Mattsson, Malin and Hesselstrand, Roger and Gunnarsson, Karin and Dyrsmeds, Elisabet and Holmner, Monica and Nordin, Annica and Boström, Carina}},
  issn         = {{2397-1983}},
  keywords     = {{Body image; patient-reported outcome measure; questionnaire; reliability; systemic sclerosis; validity}},
  language     = {{eng}},
  number       = {{1}},
  pages        = {{53--63}},
  publisher    = {{SAGE Publications}},
  series       = {{Journal of Scleroderma and Related Disorders}},
  title        = {{The validity and reliability of the Swedish version of the Satisfaction with appearance scale for individuals with systemic sclerosis}},
  url          = {{http://dx.doi.org/10.1177/23971983221107858}},
  doi          = {{10.1177/23971983221107858}},
  volume       = {{8}},
  year         = {{2023}},
}