VALIDATION DATA

1. RELIABILITY
A. Internal Consistency	Tested
Cronbach's (Describe)	Cronbach's alpha = 0.95
B. Reliability intraobserver or test-retest	Tested
Continuous scores: intraclass correlation coefficient (ICC) Dichotomus: Cohen kappa (Describe)	Reliability of the HAQ and SHAQ VAS was demonstrated using data from a Raynaud's phenomenon trial. A therapist observed and graded the activities of the HAQ in patients with SSc. The therapist versus patient ICC ranged from 0.38–0.76, and there were significant differences between the observer and subjects' responses for 4 items, whereas the other items had moderate to good agreement.
C. Reliability interobserver or Measurement error	Not Tested
Standard error of measurement (SEM), smallest detectable change (SDC) or Limits of agreement (LoA) (Describe)

2. VALIDITY
A. Content validity: face validity	Tested
Expert opinion (relevance and comprehensiveness) (Describe)	The SHAQ has further face and content validity over the HAQ since it includes SSc‐specific manifestations.
B. Construct Validity: Structural validity	Tested
Hypotheses-testing	Tested
Cross-cultural validity	Tested
Brief Description	Cole et al compared the HAQ in SSc and early rheumatoid arthritis (ERA), and structural validity was demonstrated. HAQ scores have also been compared between established RA and SSc, where the HAQ is on average higher in SSc.
C. Criterion validity	Tested
Comparison with a 'gold standard' Continuous scores: correlations, ROC curves Dichotomus: Sensitivity & Specificity (Describe)	HAQ and pain were found to be related to the physical component score of the Medical Outcomes Study Short Form 36 (SF‐36; R = 0.70) in a cross‐sectional study of 89 patients with SSc. Also, the criterion validity of the SHAQ by comparing the clinician's assessment of the patient's activities (observed disability) with the scores noted by the patient in the questionnaire (referred disability);(r = 0.87)