Improvements in Fatigue Lag Behind Disease Remission in Early Rheumatoid Arthritis: Results From the Canadian Early Arthritis Cohort.

OBJECTIVE

To examine the relationship between disease activity and fatigue over time in early rheumatoid arthritis (RA).

METHODS

Data were from patients with early RA (duration of symptoms ≤12 months) enrolled in the Canadian Early Arthritis Cohort (CATCH). Patients rated their fatigue over the past week using an 11-point numerical rating scale (NRS) for up to 5 years of follow-up. Fatigue severity was classified as low (≤2), moderate (>2 but <5), or high (≥5). Differences in fatigue ratings in patients who achieved a low disease state (Disease Activity Score in 28 joints [DAS28] <3.2) and those who did not within 3-months of cohort entry were compared.

RESULTS

Of 1,864 patients included, 88% met RA criteria, and 72% were women. The mean ± SD baseline DAS28 was 4.9 ± 1.5. Nineteen percent of the patients reported moderate baseline fatigue, and 59% reported severe baseline fatigue. Fatigue was correlated with pain and patient global ratings (r = 0.56-0.67, P < 0.001), and was weakly correlated with DAS28, tender joint count, swollen joint count, physician global assessment of disease activity, erythrocyte sedimentation rate, and C-reactive protein level. Patients who reported low fatigue by 3 months had significantly lower fatigue throughout follow-up compared to those who had moderate or high fatigue at 3 months (P < 0.001). Patients who achieved a DAS28 <3.2 within 3 months had significantly lower fatigue ratings (mean ± SD 2.7 ± 2.6) than those with a DAS28 >3.2 (4.6 ± 3.0) (P < 0.001), with improvements in fatigue that persisted through 5 years of follow-up. Maximal improvements in fatigue lagged behind remission by 6 months.

CONCLUSION

Fatigue is common in early RA, and improvements may occur after remission. Early treatment response within 3-months was associated with short-term and long-term benefits in fatigue over time.