VALIDATION DATA

1. RELIABILITY
A. Internal Consistency	Tested
Cronbach's (Describe)	The Cronbach’s Alpha value was found 0.88
B. Reliability intraobserver or test-retest	Tested
Continuous scores: intraclass correlation coefficient (ICC) Dichotomus: Cohen kappa (Describe)	The reliability of the scale was compared with the Health Assessment Questionnaire, based on the Item-Total correlation. Item-total correlation was found at the lowest 14th (r=0.293, p=0.02) and the highest correlation was found at the 9th (r=0.635, p<0.001). When Spearman correlation analysis was used for the concurrent validity of the scale, there was a correlation of 0.582 with HAQ over 71 patients. The test–retest method was used to test the reliability of BETY-BQ. A very high correlation (r=0.844, p<0.001) was found between the results of the first measurement and the results of the second measurement, which was performed 1 week later using Pearson's correlation analysis. ICC values were analyzed to determine the reliability of the test–retest results, and the test–retest reliability of the scale was found to be excellent (r=0.915, p<0.001).
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 scale’s validity was tested based on expert opinions and by testing the scale on a separate group of patients with rheumatic conditions who were not in the exercise group.
B. Construct Validity: Structural validity	Tested
Hypotheses-testing	Tested
Cross-cultural validity	Not Tested
Brief Description	In the factor analysis over 84 patients, four subgroups were allocated. Hypothesis testing was conducted for construct validity.
C. Criterion validity	Not Tested
Comparison with a 'gold standard' Continuous scores: correlations, ROC curves Dichotomus: Sensitivity & Specificity (Describe)