THU0241 Association Between Tobacco Smoking and Response to Tumor Necrosis Factor Alpha Inhibitor Treatment in Ankylosing Spondylitis: Results from the Danish Nationwide Danbio Registry. (9th June 2015) - Glintborg, B.
Abstract : Background: Studies on the impact of smoking among patients with akylosing spondylitis (AS) treated with tumor necrosis factor alpha inhibitor therapy (TNFi) are few. Objectives: To investigate the association between tobacco smoking and disease activity, treatment adherence and treatment responses among patients with AS initiating the first TNFi in routine care. Methods: Observational cohort study based on the Danish nationwide DANBIO registry. Patient inclusion was from year 2000 until January 1st 2014. Kaplan-Meier plots, logistic and Cox regression analyses by smoking status (current/previous/never smoker) were calculated for treatment adherence and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) 50%/20mm-response. Additional stratified analyses were performed according to gender and TNFi-subtype. Results: Among 1576 AS patients included in the study, 1425 (90%) had known smoking status (43% current, 40% never and 16% previous smokers). Median follow-up time was 2.02 years (IQR 0.69-5.01). At baseline, current smokers had longer disease duration (4 years (1-12)/2 years (0-10)), higher BASDAI score (61 mm (47-73)/58 mm (44-70)), Bath ankylosing spondylitis function index (BASFI) (53 mm (35-69)/46 mm (31-66)) and Bath ankylosing spondylitis metrology index (BASMI) (40 mm (20-60)/30 mm (10-50)) than never smokers (all p<0.01). Current and previous smokers had shorter treatment adherence than never smokers (current: 2.30 years (1.81-2.79), previous: 2.48 years (1.56-3.40), never: 4.12 years (3.29-4.95), (median (95% CI)), log rank p<0.0001) (Figure ). Similar results were found in multivariate analyses (current vs. never smokers, HR 1.41 (1.21-1.65), p<0.001) most pronounced among men. Current smokers had poorer 6 months' BASDAI50%/20mm response rates than never smokers (overall: 42%/58%, men: 43%/50%, women: 31%/54%, all p<0.01). In multivariate analyses, current smokers had lower odds of achieving response than never smokers both overall (OR 0.48 (95% CI 0.35-0.65), p<0.0001) and stratified by gender (both p<0.001) and TNFi drug type (adalimumab 0.45 (0.27-0.76), etanercept 0.24 (0.10-0.61), infliximab 0.57 (0.34-0.95)). Conclusions: In this study of AS patients treated with TNFi in clinical practise, current smokers had poorer baseline patient-reported outcomes, shorter treatment adherence and poorer treatment response compared to never smokers. Acknowledgements: Thank you to all the departments of rheumatology in Denmark for reporting to the DANBIO registry Disclosure of Interest: B. Glintborg: None declared, P. Højgaard: None declared, M. Hetland: None declared, S. Chrysidis: None declared, J. Espesen: None declared, M. Holland-Fischer Consultant for: Roche, Abbvie, Speakers bureau: UCB, MSD, F. Johansen: None declared, J. Jensen: None declared, I. M. Hansen: None declared, T. Hansen: None declared, G. Kollerup Speakers bureau: MSD, N. S. Krogh: None declared, A. G. Loft Consultant for: MSD, AbbVie, Speakers bureau: MSD, Pfizer, AbbVie, T. Lorenzen: None declared, P. Mosborg: None declared, C. Nilsson: None declared, H. Nordin: None declared, S. Oeftiger: None declared, R. Pelck: None declared, C. Rasmussen: None declared, B. Unger: None declared, L. Dreyer: None declared