Objective To describe the development of an Environmental contextual factors (EF)
Item Set (EFIS) accompanying the disease specific Assessment of SpondyloArthritis
international Society Health Index (ASAS HI). Method First, a candidate item pool
was developed by linking items from existing questionnaires to 13 EF previously selected
for the International Classification of Functioning, Disability and Health (ICF) /ASAS
Core Set. Second, using data from two international surveys, which contained the EF
item pool as well as the items from the ASAS HI, the number of EF items was reduced
based on the correlation between the item and the ASAS HI sum score combined with
expert opinion. Third, the final English EFIS was translated into 15 languages and
cross-culturally validated. Results The initial item pool contained 53 EF addressing
four ICF EF chapters: products and technology (e1), support and relationship (e3),
attitudes (e4) and health services (e5). Based on 1754 responses of axial spondyloarthritis
patients in an international survey, 44 of 53 initial items were removed based on
low correlations to the ASAS HI or redundancy combined with expert opinion. Nine items
of the initial item pool (range correlation 0.21-0.49) form the final EFIS. The EFIS
was translated into 15 languages and field tested in 24 countries. Conclusions An
EFIS is available complementing the ASAS HI and helps to interpret the ASAS HI results
by gaining an understanding of the interaction between a health condition and contextual
factors. The EFIS emphasizes the importance of support and relationships, as well
as attitudes of the patient and health services in relation to self-reported health.
