The Systemic Sclerosis Questionnaire (SySQ): Validation of the translation of the original German version into Spanish and its relationship to the disease and to quality of life

Psychometric analysis and validation of the Persian translation of the systemic sclerosis questionnaire (SySQ)

BACKGROUND

Scleroderma is a complex multisystem disorder that could have effects on the quality of patients' lives. This study was conducted by determining the psychometric properties of the Persian version of the systemic sclerosis questionnaire (SySQ) that specifically assesses indications and functional limitations of scleroderma patients.

MATERIALS AND METHODS

In the present cross-sectional study, the method included: translation and back translation. Psychometric properties of the questionnaire including its content and face validity were assessed. Internal consistency with the SySQ (Cronbach's alpha) and reproducibility was by test-retest method. The factor structure of the questionnaire was evaluated using exploratory factor analysis. The convergent validity of the SySQ was assessed using the General Health Assessment Scale (HAQ).

RESULTS

Altogether 32 SySQ items, the internal consistency coefficient (Cronbach's alpha) of the whole tool was 0.906. The content validity index was 0.98 and the content validity ratio was 0.796, there was a significant relationship between the questions and the relevant factors in the factor analysis. The correlation coefficient = 0.953 for the instrument. The correlation of SySQ dimensions with HAQ questionnaire dimensions in convergent validity showed that musculoskeletal dimensions, general condition, and cardiorespiratory of the questionnaire are correlated with all dimensions of the HAQ questionnaire.

CONCLUSION

The Persian version of the questionnaire SySQ with competency is valid and reliable and is suitable for measuring specific changes in Persian systemic sclerosis patients.

Impact of foot functionality in patients with systemic sclerosis: Cross-sectional study

BACKGROUND

Progressive systemic sclerosis or systemic scleroderma (SS) is a chronic and rare autoimmune disease that mainly affects the skin and various internal organs. Raynaud's phenomenon and digital ulcers are some of the symptoms that affect the foot, causing a decrease in the quality of life of patients. The objective of this study is to determine the functionality of the feet in patients with SS and determine the impact on their daily lives.

METHODS

A sample of 165 patients (154 women, 11 men) diagnosed with SS with a mean age of 46.29 ± 11.36 years and a mean body mass index (BMI) of 24.90 ± 5.77 was recruited. Each participant completed the Foot Function Index (FFI) questionnaire and the Systemic Sclerosis Questionnaire (SySQ). A multivariate analysis was performed to determine which factors were related to a higher score in both questionnaires.

RESULTS

32.1% of the participants (n = 53) had claw toe deformities, 79.4% (n = 131) Raynaud's disease and 20% (n = 33) a history of foot ulcers. 51.5% of the participants (n = 85) presented symptoms in their nails, the most frequent sign being thickening, hardening and yellow coloration. The final score of the FFI questionnaire was 3.51 ± 2.41 (0-9.9), the pain subscale being the highest, with a score of 5.06 ± 2.75, followed by foot disability (3.26 ± 2.91) and difficulty performing activities (1.55 ± 2.22). The final score of the SySQ questionnaire was 0.95 ± 0.45 (0.18-2.45), and the subscales with the highest score were symptom frequency (1.30 ± 0.47), symptom intensity (1.11 ± 0.55), and general skill limitation (0.47 ± 0.51). A high correlation was observed between the final FFI score and the final SySQ score (r = 0.712; p=<0.001). Also, between foot activity limitation and general skill limitation (r = 0.658; p=<0.001). A moderate correlation was observed between foot pain score and overall symptom intensity (r = 0.482; p=<0.001). Also, between foot disability and overall symptom frequency (r = 0.556; p=<0.001). The multivariate analysis (R2 0.51) showed that the final FFI score had a significant relationship with the final SySQ score (p < 0.001). No significant correlation was found between age (p = 0.15), gender (p = 0.49), BMI (p = 0.74) or time of diagnosis (p = 0.57) and FFI.

CONCLUSION

SS is a disease that affects foot functionality in patients, with a greater impact on the pain scale. There is a correlation between the final FFI score and the final SySQ score, so improving foot functionality could help to improve the overall functionality of the patient with sclerosis.