Table 2

BARFOT: number of autoantibodies and clinical characteristics at presentation

n=8020 (n=265)1 (n=111)2 (n=195)3 (n=231)Ordinal
OR (95% CI)
p ValueMultivariable
ordinal OR (95% CI)†
p Value
Age (years), M±SD61±1756±1755±1558±14Per 10 years: 0.92 (0.85 to 0.99)†0.0340.85 (0.78 to 0.93)<0.001
Female, n (%)169 (64)78 (70)136 (70)143 (62)0.95 (0.73 to 1.24)0.707
BMI (kg/m2), M±SD25.7±4.225.1±4.225.0±4.425.5±4.60.99 (0.96 to 1.03)0.629
Smoking (ever), n (%)137 (52)58 (53)121 (63)153 (67)1.59 (1.23 to 2.06)<0.001*1.62 (1.25 to 2.10)<0.001
Family history of RA, n (%)87 (34)34 (31)71 (37)78 (35)1.07 (0.82 to 1.40)0.628
(Sub-)Acute onset symptoms, n (%)141 (55)51 (47)93 (49)119 (52)0.91 (0.71 to 1.17)0.452
Symptom duration (months), M±SD5.6±3.15.9±3.16.4±3.06.3±3.0Per 3 months: 1.19 (1.05 to 1.34)0.0061.22 (1.07 to 1.39)0.002
ESR (mm/hour), M±SD31±2531±2337±2446±27Per 10 mm/hour: 1.19 (1.13 to 1.25)<0.001*1.24 (1.17 to 1.30)<0.001
CRP (mg/L), M±SD29±3426±3131±3044±441.01 (1.01 to 1.01)†<0.001*
SJC in 28 joints, M±SD11±610±610±511±51.00 (0.98 to 1.03)0.786
TJC in 28 joints, M±SD9±78±76±68±60.98 (0.96 to 1.00)†0.0240.98 (0.95 to 1.00)0.018
HAQ score, M±SD1.0±0.70.9±0.61.0±0.61.1±0.61.05 (0.86 to 1.28)†0.638
SHS score, M±SD3±83±55±84±71.01 (0.99 to 1.03)0.351
VAS general health, M±SD45±2544±2545±2646±251.00 (1.00 to 1.01)0.758
DAS28-ESR, M±SD5.1±1.35.0±1.45.1±1.25.5±1.11.19 (1.07 to 1.32)†0.001*
  • Significant p values (p<0.05) are shown in bold typeface.

  • BARFOT univariable and multivariable ordinal regression analyses for increasing number of autoantibodies present. ORs of imputed data sets are pooled.

  • *Significant after correction for multiple testing (only performed in univariable analysis).

  • †Test of parallel lines significant. Joint symptoms refer to any signs or symptoms of synovitis (eg, pain, swelling and tenderness). Onset of symptoms was (sub-)acute when symptoms started within 1 week. Patient data were partly missing for a number of baseline variables, in particular for BMI. Multivariable analysis was performed after exclusion of DAS28-ESR and CRP due to high correlation.

  • BARFOT, Better Anti-Rheumatic Farmaco-Therapy; CRP, C-reactive protein; DAS28-ESR, 28 joints-Disease activity score using erythrocyte sedimentation rate; RA, rheumatoid arthritis; SHS, Sharp–van der Heijde Score; VAS, Visual Analog Scale.