Abstract
Objective To assess the association between self-reported and performance-based physical functioning and to evaluate which performance tests are most frequently impaired in patients with axSpA.
Methods Consecutive axSpA patients underwent standardized assessments including patient and disease characteristics, patient-reported outcomes for disease activity, functioning, depression, mobility and physical activity and performance tests. Patients were defined as being impaired if they were not able to perform ≥ 1 of the performance tests. Validated cut-offs were used to define impaired physical performance. Impairment of performance tests as well as discrimination between subgroups were analyzed.
Results A total of 200 patients (r-axSpA 65.5%, nr-axSpA 34.5%) was included: 69% males, mean age 44.3 (SD 12.5) years and mean symptom duration 17.9 (12.6) years. The two most frequently impaired performance tests were the repeated chair stand test (n=75, 37.5%) and putting on socks (n=44, 22%). An impairment in ≥ 1 performance test was seen in 91 patients (45.5%). Patients with impairments were older (48.9 vs. 40.8 years), had a higher body mass index (28.7 vs. 26.1 kg/m2), a more active disease (ASDAS 3.0 vs. 2.1), higher BASFI (5.7 vs. 2.8), BASMI (4.3 vs. 2.8) and ASAS HI scores (9.6 vs. 5.0), and higher depression screen values (PHQ 12.1 vs. 6.3), all p<0.01.
Conclusion Many patients with axSpA had impairments in physical performance tests. Importantly, this was frequently seen in tasks requiring coordination and muscle power of the lower extremity. Performance tests provide qualitatively different information than BASFI and BASMI assessments in patients with axSpA.