Objective: The Assessments of SpondyloArthritis international Society Health Index (ASAS HI), estimates
the impact of Spondyloarthritis (SpA) on global
functioning and health. This article assesses the construct validity, reliability and responsiveness of the Portuguese version of the ASAS HI.
Patients And Methods: Patients fulfilling ASAS classification criteria for axial (axSpA) or peripheral SpA
(pSpA) were included. Construct validity was assessed
through Spearman’s correlation analysis with other
health outcomes. Discriminant validity wastested comparing the ASAS HI across disease activity and functionalstates using the Kruskal–Wallistest. Internal consistency was assessed by Cronbach’s a, and test-retest
reliability by intraclass correlation coefficients (ICC).
Responsiveness was evaluated by the standardized response mean (SRM) in patients with active disease who
required therapy escalation.
Results: Among the 91 patients included, 67% were
male, mean (SD) age 47.2 (12.9) years, 63 patients with
axSpA and 28 patients with pSpA. The hypothesis defined a priori to test construct validity were confirmed.
The ASAS HI showed ability to discriminate between
patients with different disease activity and functional
states (p<0.001). Internal consistency (Cronbach’s a:
0.88) and test-retest reliability [ICC=0.76 (95%CI
0.09-0.91)] were good. Responsiveness was moderate\ud
(SRM=-0.53). The smallest detectable change was 3.0.
Conclusions: The Portuguese version of the ASAS HI
is a comprehensible questionnaire that is valid, reliable
and responsive. It can be used to assess the impact of
SpA and its treatment on functioning and health, in
clinical practice and for research purposes