Validity of the PROMIS-29 in a large Australian cohort of patients with systemic sclerosis

This is the authors' abstract. We don't add key points for this paper.

Background We aimed to evaluate the construct validity of the Patient-Reported Outcomes Measurement Information System 29 (PROMIS-29) in Australian systemic sclerosis (SSc) patients. Methods SSc patients, identified through the Australian Scleroderma Cohort Study database, completed two quality-of-life instruments concurrently, the PROMIS-29 and the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36). The construct validity of the PROMIS-29 was assessed by the correlations between the PROMIS-29 and the SF-36 and Health Assessment Questionnaire Disability Index (HAQ-DI). Cronbach's alpha was used to test the internal reliability of all instruments in Australian SSc patients and non-parametric correlation, including Spearman's correlation, was used to test the construct validity of PROMIS-29 against the SF-36 and HAQ-DI. Results A total of 477 completed questionnaires were returned, equating to a response rate of 59.6%. The mean (±SD) age of respondents at the time of the survey was 64.1 (±11.1) years. They were predominantly female (87.4%), with limited disease subtype (lcSSc) (77.8%) and long disease duration from onset of first non-Raynaud's phenomenon symptom at the time of survey (10.9 ± 11.1 years). For the correlation analysis between the PROMIS-29 and the legacy instruments, all Spearman correlation coefficients were in the logical direction and highly significant suggesting that the PROMIS-29 is a good alternative to other validated measures of disease burden. Conclusions Our study indicates that the PROMIS-29 questionnaire is a valid instrument for measuring health-related quality of life in Australian females with lcSSc of long duration.