Background/Purpose:

Systemic Sclerosis (SSc) affects multiple organs with complex combinations of disability. Skin fibrosis, ischemic pain, ulceration, arthritis, joint contractures, myopathy and cardiopulmonary, renal as well as gastrointestinal involvement affect emotional, social and physical functioning.

International Classification of Functioning, Disability, and Health (ICF), introduced by the World Health Organization (WHO), is a universal framework that describes the disabilities associate with a health condition in terms of the bio-psycho-social model with consideration of environmental and personal factors.

Methods:

Comprehensive literature review identified all validated outcome measures in SSc.   Five instruments were selected to represent the broadest range of SSc manifestations (OD, LAS), deconstructed to concepts and linked separately by 2 health professionals familiar with updated ICF linkage rules (RE, LAS). Inter-reviewer agreement was analyzed (KK).  Remaining instruments were deconstructed and linked. Five formal meetings with 27 patients (4 males) and 24 SSc specialists (physicians, therapists and nurses) from 16 countries provided data which were deconstructed, confirmed by participants and then linked to the ICF.

Results:

27 validated instruments were identified. 5 validated SSc instruments were linked to ICF codes  and tested inter-linker agreement. The proportion of agreement ranged from 0.8611 (95% CI: 0.7500, 0.9444) to 0.9647 (0.9175, 1.000) (Table 1) with the overall proportion of agreement 0.9359 (0.9172, 0.9506). 228 and 618 categories were linked in instrument and group data respectively. All instrument linkages were captured within the expert group data collection (Table 2).

Conclusion:

SSc is the most complex disease linked to the ICF. Important challenges exist in ICF Core Set development for SSc. Occurrences in the data suggest ICF level of specificity was insufficient to describe the SSc experience, e.g. Raynaud’s and specific aspects of pain. 618 linkages are unusually high for ICF item collection, SSc is likely to require the development of an advanced ICF Core Set model to accommodate its complexity and ensure utility.

Further face, content and construct validation strategies with item reduction are now underway. Very importantly, the weight of these results implies that the global, regional and personal impact of SSc across cultures, age and socioeconomic status is likely to be severely under-estimated. Efforts to establish fair assessment for use in policy making and provision of services and funding are essential towards optimal health and functioning in SSc.