Objectives: The Scleroderma Health Assessment Questionnaire (SHAQ) is a functional scale which consists of five scleroderma-specific items (overall disease severity, Raynaud's phenomenon, digital ulcers, respiratory and intestinal involvement) in addition to Health Assessment Questionnaire Disability Index (HAQ-DI). The objective of this study was to perform an adaptation and validation of a Turkish version of the SHAQ.
Method: We validated psychometric properties of the scale with 70 consecutive systemic sclerosis (SSc) patients, who fulfilled the 2013 ACR/EULAR classification criteria for SSc. We evaluated test-retest reliability with the intraclass correlation coefficient (ICC), discriminant validity by stratifying patients according to organ involvements and disease subtypes, and convergent validity by testing the correlation between SHAQ and related components of Short Form 36 version 2 (SF-36v2). Internal consistency of the questionnaire was evaluated by Cronbach's alpha coefficient.
Results: The SHAQ-global, visual analogue scales (VAS) of pulmonary, digital ulcer, and Raynaud's phenomenon were significantly correlated with the physical component score of the SF-36v2 (r = - 0.274, r = - 0.295, r = - 0.326, r = - 0.308, p < 0.05, respectively) for the convergent validity. The instruments could not discriminate between disease subtypes, except the digital ulcer VAS which was significantly higher in patients with dcSSc (1.00 ± 0.93 vs 0.55 ± 0.88, p = 0.026) for the discriminant validity. The HAQ-DI, SHAQ-global, digital ulcer VAS, and pulmonary VAS showed moderate correlation with an increase in the number of the organs involved (r = 0.319, r = 0.329, r = 0.341, r = 0.278, p < 0.05, respectively). We demonstrated high reproducibility for HAQ-DI (ICC = 0.962, 95% confidence interval = 0.934-0.978) and the other items of SHAQ. The overall internal consistency of the SHAQ was satisfactory (Cronbach's alpha = 0.953).
Conclusions: The Turkish version of the SHAQ met the requirements of validity and reproducibility.
Keywords: Scleroderma Health Assessment Questionnaire Disability Index; Systemic sclerosis; Turkish; Validation.