Patient-reported outcomes in primary Sjögren's syndrome: comparison of the long and short versions of the Profile of Fatigue and Discomfort—Sicca Symptoms Inventory

• Published in: Rheumatology (Oxford, England) Vol. 48; no. 2; pp. 140 - 143
• Main Authors: Bowman, S. J., Hamburger, J., Richards, A., Barry, R. J., Rauz, S.
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01-02-2009; Oxford Publishing Limited (England)
• Subjects: Aged; Biological and medical sciences; Disability Evaluation; Diseases of the osteoarticular system; Fatigue; Female; Humans; Medical sciences; Middle Aged; Patient-reported outcomes; Psychometrics; Sarcoidosis. Granulomatous diseases of unproved etiology. Connective tissue diseases. Elastic tissue diseases. Vasculitis; Severity of Illness Index; Sjogren's Syndrome - physiopathology; Sjogren's Syndrome - psychology; Sjögren's syndrome; Surveys and Questionnaires; Sjögren's syndrome; Patient-reported outcomes; Human; Immunopathology; Prognosis; Stomatology; Rheumatology; Autoimmune disease; Fatigue; Sjögren syndrome; Symptomatology; Eye disease; Systemic disease; Comparative study
• ISSN: 1462-0324; 1462-0332
• DOI: 10.1093/rheumatology/ken426

Objectives. The long-form 64-item Profile of Fatigue and Discomfort—Sicca Symptoms Inventory (PROFAD-SSI) questionnaire was developed as a patient-reported assessment tool for use in primary SS (PSS) and other rheumatic disorders. In this study, we assess whether the (shorter and more practical) 19-item PROFAD-SSI-SF (short form) gives similar results and whether a still briefer version using visual analogue scales (VASs) is feasible. Methods. Questionnaire surveys comprising the long and short versions of the PROFAD-SSI were mailed to 43 patients with PSS and 50 patients with RA, who were asked to complete these contemporaneously as well as repeating the process 1 month later. PSS patients also completed a series of VASs comprising fatigue and sicca domains of the SSI. Results. Surveys were returned from 35 PSS patients and 35 RA patients. All domains of the long- and short-form PROFAD-SSI showed strong correlations (Spearman ρ between 0.779 and 0.996, P < 0.01). Factor analysis generally confirmed the previously validated domain structure with Cronbach's α = 0.99. The PROFAD-SF somatic fatigue domain correlated more strongly with a fatigue VAS than did the mental fatigue domain. The SSI-SF domain scores correlated with equivalent VAS scores. Conclusion. The long- and short-form PROFAD-SSI questionnaires correlate closely suggesting that the PROFAD-SF is valid as an outcome tool. Preliminary data also suggest that an even briefer form with compression of the domains into single VAS is also feasible.