OBJECTIVES: To investigate the frequency and predictors of sustained 28-joint DAS (DAS28) remission and low disease activity (LDA) in patients receiving anti-TNF therapy and changes in responses over a 12 year period.
METHODS: Data from the British Society for Rheumatology Biologics Registry for Rheumatoid Arthritis were used. Sustained remission and LDA were defined according to DAS28-ESR thresholds sustained for 6 months. The dataset was dichotomized into sequential chronological subgroups (2001-2010 and 2010-2013). Predictive variables were identified from a previous systematic review and modelled using multivariable logistic regression.
RESULTS: Overall, 2144 (14.9%) and 3802 (26.3%) patients achieved sustained remission or LDA, respectively. Positive predictors of sustained remission/LDA included adalimumab (vs etanercept), greater patient global assessment, never- and ex-smoker status (vs current smoking), greater swollen joint count, more recent commencement of anti-TNF and MTX co-prescription (except in the 2010-2013 subgroup). Negative predictors of sustained remission and LDA included poor baseline functional status (HAQ), female gender, older age at starting anti-TNF, infliximab use (vs etanercept), increasing BMI and greater baseline ESR. Increasing tender joint count was negatively associated with sustained LDA only. The overall proportion of patients achieving sustained remission and LDA has increased significantly over time.
CONCLUSION: Sustained remission/LDA on anti-TNF treatment remains uncommon. Adalimumab use, greater patient global assessment, never- and ex-smoker status, greater swollen joint count, more recent commencement of anti-TNF and MTX co-prescription are associated with achievement of sustained remission/LDA. However, co-prescription of MTX was not associated with an increased likelihood of achieving sustained remission or LDA in the analysis of more recent anti-TNF responses.