Objectives: Anti-TNF therapy has improved outcomes for patients with highly active RA. Less is known about its effectiveness in patients with lower disease activity. The aim of this analysis is to compare the response to anti-TNF therapy between RA patients with high (DAS28 > 5.1) and moderate (DAS28 > 3.2-5.1) disease activity.
Methods: A total of 4687 anti-TNF and 344 DMARD patients with high disease activity despite treatment with two standard DMARDs (including MTX) and 224 anti-TNF- and 300 DMARD-treated patients with moderate disease activity were selected from the British Society For Rheumatology Biologics Register. Mean change in HAQ over the first 12 months of enrolment was compared first between anti-TNF-treated and untreated patients in each DAS28 group, and then between anti-TNF-treated patients in the moderate and high DAS28 groups, using doubly robust estimates, adjusting for age, gender, disease duration, baseline HAQ and DAS28 score, number of previous DMARDs and steroid use.
Results: Compared with anti-TNF-untreated patients within each DAS group, treated patients were younger, had higher DAS28 and HAQ and had failed a higher number of previous DMARDs. The mean adjusted change in HAQ over 12 months was similar in anti-TNF-treated patients with moderate and high disease activity at baseline: moderate -0.26 (95% CI -0.35, -0.16), high -0.28 (95% CI -0.34, -0.23) and mean difference -0.03 (95% CI -0.14, 0.08).
Conclusions: Improvement in HAQ score 12 months after start of anti-TNF therapy was not dependent on baseline DAS28 scores, suggesting that substantial benefits may also be gained by treating those with moderately active disease despite standard DMARD therapy.