Background Fatigue is a major symptom in ankylosing spondylitis (AS). Clinical trials revealed its correlation with mental health and disease activity .
Objectives Evaluation of fatigue in relation with efficacy parameters in a population of AS patients treated with biologics in outpatient care.
Methods Cross – sectional study over a sample of 55 patients. Data were gathered from the medical files of the patients (outpatient department).
Results 55 patients with AS, treated with biologics, with a mean age of 43.78 yrs (±11.11), 67.3% males, 80% living in urban areas, 65.5% profesionally active, with mean AS duration of 12.24yrs (±9.48), 72.7% having peripheral arthritis. Mean duration of the TNF-alfa blockers therapy was 3.42yrs (±1.44), and the persistance time on a certain biological product was 2.13 yrs (±1.18). 45.5% of the AS patients were treated with etanercept, 30.9% infliximab, and 23.6% adalimumab. After 2 years of unchanged biological treatment, mean BASDAI score was 1.68 (±2.13), mean ASDAS score was 1.71 (±1.20). Mean ESR 17.75 (±14.95), mean CRP 9.47 (±18.59); self reporting BASDAI domains, common to ASDAS domains, on visual analog scale (VAS) were: back pain =23.27 (±26.80); peripheral pain =9.64 (±21.34); vertebral stiffness =19.45 (±25.19). Patient global-health (GH) evaluation (on a 0-10 VAS) was 2.50 (±2.59) and fatigue score was 22.55 (±27.90). There were no associations between demography characteristics, disease type, the biological product and the treatment efficacy. BASDAI has a a significant positive correlation with ESR (r =0.5, p<0.01), CRP (r =0.6, p<0.01) and ASDAS (r =0.9, p<0.01) and a negative association with treatment duration (r = - 0.4, p<0.01). Linear regression revealed that the most predictive parameter of BASDAI domains for CRP and ESR was fatigue (B=0.4, Rsquare =0.32, p<0.01, CI95%: 0.23-0.53). We proceeded into insert fatigue (from BASDAI) on GH place in a modified AS DAS score. The results were calculated using the standardized formula. Mean modified AS-DAS score was 1.68 (±1.23). There was a high significant positive association between modified AS-DAS and BASDAI (r =0.88, p<0.001), as well as with classic AS-DAS (r =0.99, p<0.001). BASDAI and modified AS-DAS have a reciprocal highly prediction value (B =1.53, R square =0.8, p<0.001, CI 95%:1.31-1.75).
Conclusions Cantitative evaluation of self-reporting fatigue (rapid and cheap test) can be used as a unique marker of disease activity, being a usefull tool in monitoring AS patients.
Dagfinrud H, Vollestad NK, Loge JH et all Fatigue in patients with ankylosing spondylitis: A comparison with the general population and associations with clinical and self-reported measures. Arthritis Rheum. 2005 Feb 15;53(1):5-11
Disclosure of Interest None declared