title: Impact of tobacco smoking on response to tumour necrosis factor-alpha inhibitor treatment in patients with ankylosing spondylitis: results from the Danish nationwide DANBIO registry.
abstract: OBJECTIVE
  To investigate the association between tobacco smoking and disease activity, treatment adherence and treatment responses in patients with AS treated with their first tumour necrosis factor-alpha inhibitor (TNFi) therapy in routine care.
  
  
  METHODS
  Observational cohort study based on the Danish nationwide DANBIO registry. Kaplan-Meier plots, Cox and logistic regression analyses by smoking status (current/never/previous) were calculated for treatment adherence and BASDAI 50%/20 mm-response. Additional stratified analyses were performed for gender and TNFi-type.
  
  
  RESULTS
  Of 1576 AS patients included in the study, 1425(90%) had known smoking status (current/never/previous: 43%/41%/16%). The median follow-up time was 2.02 years (IQR 0.69-5.01). At baseline, current smokers compared with never smokers had longer disease duration (4 years (1-12)/2 years (0-10)), higher BASDAI (61 mm (47-73)/58 mm (44-70)), BASFI (53 mm (35-69)/46 mm (31-66)) and BASMI (40 mm (20-60)/30 mm (10-50)) scores (all P < 0.01). Current and previous smokers had shorter treatment adherence than never smokers (current: 2.30 years (1.81-2.79) (median (95% CI)); previous: 2.48 years (1.56-3.40), never: 4.12 years (3.29-4.95)), P < 0.0001). Similar results were found in multivariate analyses (current versus never smokers, HR 1.41 (95% CI 1.21-1.65), P < 0.001), most pronounced among men. Current smokers had poorer 6 months' BASDAI50%/20 mm-response rate than never smokers (42%/58%, P < 0.001). In multivariate analyses, current smokers had lower odds of achieving BASDAI50%/20 mm-response than never smokers, both overall (OR 0.48 (95% CI 0.35-0.65), P < 0.0001) and for the different TNFi-types (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 TNFi-treated AS patients in clinical practice, current and previous smokers had significantly poorer patient-reported outcomes at baseline, shorter treatment adherence and poorer treatment response compared with never smokers.
authors.affiliation: Department of Rheumatology, Gentofte University Hospital, Copenhagen, Denmark, The Danish Rheumatologic Database, Rigshospitalet, Glostrup Hospital, Glostrup, Denmark, glintborg@dadlnet.dk.
authors.forename: Bente
authors.initials: B
authors.lastname: Glintborg
authors.affiliation: Department of Rheumatology, Gentofte University Hospital, Copenhagen, Denmark.
authors.forename: Pil
authors.initials: P
authors.lastname: Højgaard
authors.affiliation: The Danish Rheumatologic Database, Rigshospitalet, Glostrup Hospital, Glostrup, Denmark, Copenhagen Centre for Arthritis Research, Centre for Rheumatology and Spine Diseases, Rigshospitalet, Glostrup Hospital, Glostrup, Denmark, Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark'
authors.forename: Merete
authors.initials: M
authors.lastname: Lund Hetland
authors.affiliation: Zitelab Aps, Copenhagen, Denmark.
authors.forename: Niels
authors.initials: N
authors.lastname: Steen Krogh
authors.affiliation: Department of Rheumatology, Frederiksberg Hospital, Frederiksberg, Denmark.
authors.forename: Gina
authors.initials: G
authors.lastname: Kollerup
authors.affiliation: Department of Rheumatology, Rigshospitalet, Glostrup Hospital, Glostrup, Denmark.
authors.forename: Jørgen
authors.initials: J
authors.lastname: Jensen
authors.affiliation: Department of Rheumatology, Esbjerg Hospital, Esbjerg, Denmark.
authors.forename: Stavros
authors.initials: S
authors.lastname: Chrysidis
authors.affiliation: Department of Rheumatology, Svendborg Hospital, Svendborg, Denmark.
authors.forename: Inger Marie
authors.initials: IM
authors.lastname: Jensen Hansen
authors.affiliation: Department of Rheumatology, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Mette
authors.initials: M
authors.lastname: Holland-Fischer
authors.affiliation: Department of Rheumatology, Holbæk Hospital, Holbæk, Denmark.
authors.forename: Torben
authors.initials: T
authors.lastname: Højland Hansen
authors.affiliation: Department of Rheumatology, Odense University Hospital, Odense, Denmark.
authors.forename: Christine
authors.initials: C
authors.lastname: Nilsson
authors.affiliation: Department of Rheumatology, Vejle Hospital, Vejle, Denmark.
authors.forename: Jakob
authors.initials: J
authors.lastname: Espesen
authors.affiliation: Department of Rheumatology, Rigshospitalet, Glostrup Hospital, Glostrup, Denmark.
authors.forename: Henrik
authors.initials: H
authors.lastname: Nordin
authors.affiliation: Department of Rheumatology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Anne Gitte
authors.initials: AG
authors.lastname: Rasmussen Loft
authors.affiliation: Department of Rheumatology, Køge Hospital, Køge, Denmark.
authors.forename: Randi
authors.initials: R
authors.lastname: Pelck
authors.affiliation: Department of Rheumatology, Silkeborg University Hospital, Silkeborg, Denmark.
authors.forename: Tove
authors.initials: T
authors.lastname: Lorenzen
authors.affiliation: Department of Rheumatology, Slagelse Hospital, Slagelse, Denmark.
authors.forename: Sussi
authors.initials: S
authors.lastname: Flejsborg Oeftiger
authors.affiliation: Department of Rheumatology, Horsens Hospital, Horsens, Denmark.
authors.forename: Barbara
authors.initials: B
authors.lastname: Unger
authors.affiliation: Department of Rheumatology, Holstebro Hospital, Holstebro, Denmark.
authors.forename: Frank
authors.initials: F
authors.lastname: Jaeger
authors.affiliation: Department of Rheumatology, Randers Hospital, Randers, Denmark and.
authors.forename: Peter
authors.initials: P
authors.lastname: Mosborg Petersen
authors.affiliation: Department of Rheumatology, Sygehus Vendsyssel, Hjørring, Denmark.
authors.forename: Claus
authors.initials: C
authors.lastname: Rasmussen
authors.affiliation: Department of Rheumatology, Gentofte University Hospital, Copenhagen, Denmark.
authors.forename: Lene
authors.initials: L
authors.lastname: Dreyer
mesh_terms: D000328:Adult; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D012042:Registries; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology*; D013167:Spondylitis, Ankylosing / Q000188:drug therapy* / Q000453:epidemiology; D016896:Treatment Outcome; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*; D016903:Drug Monitoring
chemical_list: D018501:Antirheumatic Agents; C439524:TNF protein, human; D014409:Tumor Necrosis Factor-alpha
keywords: Ankylosing spondylitis; Outcome; Routine care; Smoking; Tumour necrosis factor-alpha inhibitors