Current smoking status is a strong predictor of radiographic progression in early rheumatoid arthritis: results from the SWEFOT trial.
OBJECTIVE
To study clinical predictors for radiographic progression after 1 year in an early rheumatoid arthritis (RA) trial.


METHODS
In the SWEFOT trial population, disease modifying antirheumatic drug (DMARD) naïve RA patients started methotrexate; 3-month responders (DAS28 <3.2) continued (n=147), while non-responders were randomised to addition of sulfasalazine+hydroxychloroquine (n=130) or infliximab (n=128). X-rays were scored by the Sharp-van der Hejde score (SHS) method and radiographic progression was defined as a ≥5 increase after 1 year. Potential baseline predictors of radiographic progression were tested using multivariable logistic regression, adjusted for potential confounders.


RESULTS
79 of 311 patients with available radiographs at baseline and follow-up had radiographic progression. The following baseline parameters were independent predictors of radiographic progression at 1 year: baseline erosions (adjusted OR=2.29, 95% CI 1.24 to 4.24), erythrocyte sedimentation rate (adjusted OR per tertile increase=1.72, 95% CI 1.12 to 2.65) and C-reactive protein (adjusted OR per tertile increase=1.52, 95% CI 1.03 to 2.26). Current smoking was an independent predictor of radiographic progression (adjusted OR=2.17, 95% CI 1.06 to 4.45). These results remained after further adjustment for treatment strategy. Three-dimensional matrix including current smoking status, erosions and C-reactive protein tertiles showed a 12-63% risk gradient from patients carrying none compared with all predictors. Rheumatoid factor (RF)/anti-cyclic citrullinated peptide (anti-CCP) positivity did not significantly predict radiographic progression using SHS increase ≥5 as cut-off. In a secondary exploratory analysis using cut-off >1, both RF and anti-CCP positivity were significant predictors in the unadjusted, but not the adjusted analyses. The other parameters also remained significant using this lower cut-off.


CONCLUSIONS
In addition to previously described predictors, we identified smoking as a strong independent risk factor for radiographic progression in early RA.


BACKGROUND
NCT00764725.
Rheumatology Unit, Department of Medicine, Karolinska University Hospital and Karolinska Institute, Stockholm, Sweden Unit for Clinical Therapy Research, Karolinska Institute, Stockholm, Sweden.
Saedis
S
Saevarsdottir
Rheumatology Unit, Department of Medicine, Karolinska University Hospital and Karolinska Institute, Stockholm, Sweden Unit for Clinical Therapy Research, Karolinska Institute, Stockholm, Sweden.
Hamed
H
Rezaei
Section of Rheumatology, Institution of Clinical Science, University Hospital, Lund, Sweden.
Pierre
P
Geborek
Skane University Hospital, Epi-centrum Skane, Lund, Sweden.
Ingemar
I
Petersson
Rheumatology Unit, Department of Medicine, Karolinska University Hospital and Karolinska Institute, Stockholm, Sweden.
Sofia
S
Ernestam
Department of Rheumatology, Danderyd Hospital, Stockholm, Sweden.
Kristina
K
Albertsson
Section of Rheumatology, Institution of Clinical Science, University Hospital, Lund, Sweden Department of Medicine, Section of Rheumatology, Helsingborg Hospital, Helsingborg, Sweden.
Kristina
K
Forslind
Unit for Clinical Therapy Research, Karolinska Institute, Stockholm, Sweden.
Ronald F
RF
van Vollenhoven
D018501:Antirheumatic Agents / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000453:epidemiology*; D002097:C-Reactive Protein / Q000032:analysis; D018450:Disease Progression; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D006886:Hydroxychloroquine / Q000627:therapeutic use; D000069285:Infliximab / Q000627:therapeutic use; D008297:Male; D008727:Methotrexate / Q000627:therapeutic use; D008875:Middle Aged; D011859:Radiography; D012907:Smoking / Q000453:epidemiology*; D012460:Sulfasalazine / Q000627:therapeutic use; D016896:Treatment Outcome
D018501:Antirheumatic Agents; D012460:Sulfasalazine; D006886:Hydroxychloroquine; D002097:C-Reactive Protein; D000069285:Infliximab; D008727:Methotrexate
Early Rheumatoid Arthritis; Outcomes research; Smoking