Background SSc affects multiple organ systems resulting in an unlimited combination of types and degrees of disability in patients. Skin fibrosis, ischemic pain, ulceration, arthritis, contractures of small and large joints, and myopathy as well as cardiopulmonary, renal and gastrointestinal effects carry significant burden on emotional, social and physical functioning.
ICF is a universal framework introduced by the World Health Organization (WHO) to describe and quantify the impact caused by health conditions on functioning and disability. The ICF uses a standardized alphanumerical language to describe health states in terms of the bio-psycho-social model. The ICF is accepted by national and international health care and policy-making systems to assess the impact of disease on personal, scientific, economic and service levels.
Methods A comprehensive literature search in PubMed was performed with the following keywords: outcome measures, SSc, health, rehabilitation, function, quality of life, mental, sexual, pain and disease activity to identify 5 validated measures representing the broadest range of SSc manifestations (OD, LAS). Meaningful concepts were identified in the instruments and linked to the ICF by two health professionals familiar with ICF linking rules (RE, LAS). Their agreement was analyzed (KK).
Results Nine new codes were created to address the absence of ICF codes to describe the SSc disease experience as contained within the instruments.
ICF codes were linked to 5 validated SSc instruments:5 ICF codes to the Hand Mobility in Scleroderma Test, 5 the Modified Rodnan Skin Score, 9 to the Raynaud’s Condition Score, 40 to the Scleroderma Health Assessment Questionnaire, and 25 to the SSc Gastrointestinal Tract Instrument. These 5 instruments identified 71 distinct categories for the folllowing domains: 26 for Body Function, 6 for Body Structure, 33 for Activity and Participation and 6 for External Factors.
The proportion of agreement ranged from 0.8611 (95% CI: 0.7500, 0.9444) for HAMIS to 0.9647 (0.9175, 1.000) for mRSS, when corrected for chance ranged from 0.7097 (0.5291, 0.8835) to 0.8964 (0.7631, 1.0000). Overall, the proportion of agreement was 0.9359 (0.9172, 0.9506), which when adjusted for chance was 0.7230 (0.6453, 0.7797). By either measure, the degree of agreement between the linkers, a physiotherapist and a rheumatologist, was high.
Conclusions This first step, in a methodological series to establish an ICF language for SSc, was successful in both high agreement of linking and in exploring the potential challenges of linking a complex multi-organ system disease. Further face, content and construct validation strategies are now underway. Of the diseases already linked to ICF, SSc is the most complex thus requiring precise strategies to gain knowledge from SSc experts– including patients, rehabilitation and nurse experts. A composite of all validated SSc outcome measures is soon to be available for ICF engaged health systems. Thus, the global, regional and personal impact of SSc across cultures, age and socioeconomic status may be assessed fairly for use in policy making and provision of services and funding.
Disclosure of Interest L. A. Saketkoo Grant/Research support from: Actelion, United Therapeutics, R. Escorpizo: None Declared, K. Keen Speakers Bureau: Merck, K. Fligelstone: None Declared, O. Distler Consultant for: Actelion, BMS, Fibrogen, Egonex, Pfizer, Sonofi Aventis, Genetech, Active Biotech, Novartis, UCB, 4D Science