The Effect of Stopping Smoking on Disease Activity in Rheumatoid Arthritis (RA). Data from BARFOT, a Multicenter Study of Early RA

Table 1: Disease Activity Variables and Demographics at Inclusion in the Study for the Patients who Answered and Did Not Answer the 2010 Postal Questionnaire. Values are Median (Interquartile Range) Unless Otherwise Stated

	Answered the 2010 Postal Questionnaire, Baseline at Inclusion in the Study	Did Not Answer the 2010 Postal Questionnaire, Baseline at Inclusion in the Study	P Value
Variable	N = 1525	N = 579
Age, years	56 (47-65)	58 (42-70)	0.06
Female, %	70	68	0.32
HAQ	0.9 (0.5-1.4)	1.0 (0.51.5)	0.25
DAS28	5.3 (4.4-6.1)	5.4 (4.6-6.2)	0.01
VAS global, mm	46 (2463)	49 (2767)	0.008
VAS pain, mm	46 (2865)	49 (2968)	0.09
Number of swollen joints (of 28)	10 (614)	10 (615)	0.03
Number of tender joints (of 28)	7 (312)	8 (413)	0.06
ESR	28 (1546)	28 (1649)	0.49
CRP	16 (939)	17 (943)	0.13
Number of ongoing DMARDs, %	80%	80%	0.37
Ongoing glucocorticoids, %	36	39	0.14
Smoker,%	24	30	0.01
RF, %	63	58	0.02

HAQ = Health Assessment Questionnaire, VAS = visual analog scale, DMARDs = disease-modifying anti-rheumatic drugs, DAS28 = Disease Activity Score (28 joints), ESR = erythrocyte sedimentation rate, CRP = C-reactive protein, RF = rheumatoid factor.