Background Nowadays, remission is a realistic treatment goal for patients with rheumatoid arthritis (RA). Conflicting results regarding the effect of age on remission rates have been shown.
Objectives To investigate the relationship between age and remission rates after one year of treatment with either adalimumab or etanercept in patients with RA.
Methods A total of 887 RA patients treated with adalimumab or etanercept were consecutively included in a prospective observational cohort at the Jan van Breemen Research Institute | Reade, Amsterdam and followed for 1 year (yr). Drug choice was decided by the treating rheumatologist. Remission was defined as Disease Activity Score in 28 joints (DAS28)<2.6 or as Simplified Disease Activity Index (SDAI)≤3.3. All patients were stratified into tertiles, according to age. The association between age and remission was analysed using logistic regression analysis. Baseline variables related to disease status (disease duration, DAS28, C-reactive protein, anti-cyclic citrullinated peptide and Health Assessment Questionnaire), which were significantly different between the groups, were considered as potential confounders and were included in the model if the beta changed ≥10%.
Results Four hundred eighty five patients started with etanercept treatment (52%) and 429 started with adalimumab (48%). Mean (range) age per group was: youngest 39 (18-48) yrs (n=296), intermediate 54 (49-59) yrs (n=296) and oldest 67 (60-90) yrs (n=295). Percentages of patients in SDAI or DAS28 remission at 1 yr of treatment are shown in the figure. The odds ratios (ORs) of being in SDAI remission for the youngest group compared to the intermediate and the oldest group were 1.7 [95% confidence interval (CI) 1.1-2.6, p=0.011] and 2.8 [95% CI 1.7-4.4, p<0.001]), respectively. Similar results were shown for DAS28 remission; youngest group compared to intermediate group OR 1.8 [95% CI 1.3-2.6, p=0.001] and the youngest group compared to the oldest group OR 2.1 [95% CI 1.5-3.1, p<0.001]. Confounding factor DAS28 at baseline did not significantly change the OR in both SDAI and DAS28 remission (data not shown). Other factors related to disease status were not proven as confounding factors.
Conclusions Patients <48 yrs are more likely to be in DAS28 and SDAI remission after 1 yr of adalimumab or etanercept treatment than patients >48 yrs. Awareness of the association between age and remission could influence the treatment strategy in RA patients.
Disclosure of Interest M. l'Ami: None declared, C. Krieckaert: None declared, E. Kneepkens: None declared, C. Plasencia: None declared, M. Nurmohamed Grant/research support: AbbVie,BMS,Pfizer,UCB,Roche, Consultant for: Abbott,BMS,Pfizer,Roche, Speakers bureau: AbbVie,Pfizer,Roche, G. Wolbink Grant/research support: Pfizer, Speakers bureau: Pfizer, Amgen