title: Association between tobacco smoking and response to tumour necrosis factor α inhibitor treatment in psoriatic arthritis: results from the DANBIO registry.
abstract: OBJECTIVE
  To investigate the association between tobacco smoking and disease activity, treatment adherence and treatment responses among patients with psoriatic arthritis (PsA) initiating the first tumour necrosis factor α inhibitor therapy (TNFi) in routine care.
  
  
  METHODS
  Observational cohort study based on the Danish nationwide DANBIO registry. Kaplan-Meier plots, logistic and Cox regression analyses by smoking status (current/previous/never smoker) were calculated for treatment adherence, ACR20/50/70-responses and EULAR-good-response. Additional stratified analyses were performed according to gender and TNFi-subtype (adalimumab/etanercept/infliximab).
  
  
  RESULTS
  Among 1388 PsA patients included in the study, 1148 (83%) had known smoking status (33% current, 41% never and 26% previous smokers). Median follow-up time was 1.22 years (IQR 0.44-2.96). At baseline, current smokers had lower Body Mass Index (27 kg/m(2) (23-30)/28 kg/m(2) (24-31)) (median (IQR)), shorter disease duration (3 years (1-8)/5 years (2-10)), lower swollen joint count (2 (0-5)/3 (1-6)), higher visual-analogue-scale (VAS) patient global (72 mm (54-87)/68 mm (50-80)), VAS fatigue (72 mm (51-86)/63 mm (40-77)) and Health Assessment Questionnaire (HAQ) score (1.1 (0.7 to 1.5)/1.0 (0.5 to 1.5)) than never smokers (all p<0.05). Current smokers had shorter treatment adherence than never smokers (1.56 years (0.97 to 2.15)/2.43 years (1.88 to 2.97), (median (95% CI)), log rank p=0.02) and poorer 6 months' EULAR-good-response rates (23%/34%), ACR20 (24%/33%) and ACR50 response rates (17%/24%) (all p<0.05), most pronounced in men. In current smokers, the treatment adherence was poorer for infliximab (HR) 1.62, 95% CI 1.06 to 2.48) and etanercept (HR 1.74, 1.14 to 2.66) compared to never smokers, but not for adalimumab (HR 0.80, 0.52 to 1.23).
  
  
  CONCLUSIONS
  In PsA, smokers had worse baseline patient-reported outcomes, shorter treatment adherence and poorer response to TNFi's compared to non-smokers. This was most pronounced in men and in patients treated with infliximab or etanercept.
authors: Department of Rheumatology, Gentofte Hospital, Copenhagen, Denmark Department of Rheumatology, Frederiksberg Hospital, Copenhagen, Denmark.
authors: Pil
authors: P
authors: Højgaard
authors: Department of Rheumatology, Gentofte Hospital, Copenhagen, Denmark Copenhagen Center for Arthritis Research, Center for Rheumatology and Spine Diseases, Copenhagen University Hospital Glostrup, Denmark The Danish Rheumatologic Database (DANBIO), Copenhagen University Hospital Glostrup, Denmark.
authors: Bente
authors: B
authors: Glintborg
authors: Copenhagen Center for Arthritis Research, Center for Rheumatology and Spine Diseases, Copenhagen University Hospital Glostrup, Denmark The Danish Rheumatologic Database (DANBIO), Copenhagen University Hospital Glostrup, Denmark Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors: Merete Lund
authors: ML
authors: Hetland
authors: Department of Rheumatology, Holbæk Hospital, Holbæk, Denmark.
authors: Torben Højland
authors: TH
authors: Hansen
authors: Department of Rheumatology, Esbjerg Hospital, Esbjerg, Denmark.
authors: Philip Rask
authors: PR
authors: Lage-Hansen
authors: Department of Rheumatology, Svendborg Hospital, Svendborg, Denmark.
authors: Martin H
authors: MH
authors: Petersen
authors: Department of Rheumatology, Aalborg University Hospital, Aalborg,Denmark.
authors: Mette
authors: M
authors: Holland-Fischer
authors: Department of Rheumatology, Odense University Hospital, Odense, Denmark.
authors: Christine
authors: C
authors: Nilsson
authors: Department of Rheumatology, Vejle Sygehus, Sygehus Lillebælt, Vejle, Denmark.
authors: Anne Gitte
authors: AG
authors: Loft
authors: Department of Infectious Diseases and Rheumatology, Rigshospitalet, Copenhagen, Denmark.
authors: Bjarne Nesgaard
authors: BN
authors: Andersen
authors: Department of Rheumatology, Helsingør and Hillerød Hospital, Hillerød, Denmark.
authors: Thomas
authors: T
authors: Adelsten
authors: Department of Rheumatology, Køge Hospital, Køge, Denmark.
authors: Jørgen
authors: J
authors: Jensen
authors: Copenhagen Center for Arthritis Research, Center for Rheumatology and Spine Diseases, Copenhagen University Hospital Glostrup, Denmark.
authors: Emina
authors: E
authors: Omerovic
authors: Department of Rheumatology, Gentofte Hospital, Copenhagen, Denmark.
authors: Regitse
authors: R
authors: Christensen
authors: Department of Rheumatology, Aarhus University Hospital, Aarhus, Denmark.
authors: Ulrik
authors: U
authors: Tarp
authors: Department of Rheumatology, Silkeborg Hospital, Denmark.
authors: René
authors: R
authors: Østgård
authors: Department of Rheumatology, Gentofte Hospital, Copenhagen, Denmark The Danish Rheumatologic Database (DANBIO), Copenhagen University Hospital Glostrup, Denmark.
authors: Lene
authors: L
authors: Dreyer
mesh_terms: D000328:Adult; D018501:Antirheumatic Agents / Q000627:therapeutic use; D015535:Arthritis, Psoriatic / Q000188:drug therapy* / Q000378:metabolism; D000068800:Etanercept / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D000069285:Infliximab / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D018124:Receptors, Tumor Necrosis Factor / Q000037:antagonists & inhibitors*; D012042:Registries; D012189:Retrospective Studies; D012907:Smoking / Q000009:adverse effects*; D016896:Treatment Outcome
chemical_list: D018501:Antirheumatic Agents; D018124:Receptors, Tumor Necrosis Factor; D000069285:Infliximab; D000068800:Etanercept
keywords: Outcomes research; Psoriatic Arthritis; Smoking; TNF-alpha; Treatment