Table 2.

Study population characteristics compared by quartile of the 2004 Index of Multiple Deprivation^*

Characteristics	No.	Quartile 1 (n = 392)	Quartile 2 (n = 569)	Quartile 3 (n = 283)	Quartile 4 (n = 149)	P
Age at symptom onset, years	1,393	56 (43–65)	55 (45–67)	55 (45–68)	55 (41–66)	> 0.999
Women, no. (%)	1,393	260 (66)	386 (68)	191 (67)	90 (60)	0.383†
Symptom duration at registration, months	1,393	5 (2–12)	5 (2–12)	6 (3–12)	7 (2–17)	0.638
Current smoker, no. (%)	1,334	65 (17)	138 (25)	70 (25)	55 (39)	< 0.001†
Baseline HAQ score	1,393	0.75 (0.25–1.38)	0.75 (0.25–1.38)	0.75 (0.25–1.50)	1.13 (0.38–1.63)	0.349
Year 3 HAQ score	1,393	0.63 (0–1.38)	0.75 (0.13–1.50)	0.63 (0.13–1.50)	1.13 (0.38–2.00)	0.145
Change in HAQ from baseline to year 3, mean ± SD	1,393	−0.08 ± 0.68	0.03 ± 0.65	−0.06 ± 0.66	0.09 ± 0.70	0.019‡
Baseline swollen and tender joint count	1,393	2 (0–6)	2 (0–6)	2 (0–6)	1 (0–6)	0.662§
Year 3 swollen and tender joint count	1,314	0 (0–3)	0 (0–2)	0 (0–2)	1 (0–3)	0.353§
Change in swollen and tender joint count from baseline to year 3, mean ± SD	1,314	−2.3 ± 6.3	−2.1 ± 7.0	−3.1 ± 7.7	−1.6 ± 7.4	0.157
Baseline RF positivity (titer ≥1:80), no. (%)	1,247	107 (30)	145 (29)	80 (31)	53 (39)	0.148†
Year 3 RF positivity (titer ≥1:80), no. (%)	1,284	155 (43)	204 (39)	113 (42)	68 (49)	0.218†
Baseline DAS28 score	1,069	3.7 (2.9–4.7)	3.8 (2.8–4.8)	3.8 (2.6–5.0)	3.8 (2.9–5.0)	0.858
Satisfy ACR criteria at baseline, no. (%)	1,393	185 (47)	255 (45)	123 (43)	70 (47)	0.762†
Satisfy ACR criteria by year 3, no. (%)	1,393	276 (70)	392 (69)	184 (65)	112 (75)	0.166†

^*Values are the median (interquartile range) and the model used is median regression, unless otherwise indicated. Scale is quartile 1 = least deprived and quartile 4 = most deprived. HAQ = Health Assessment Questionnaire; RF = rheumatoid factor; DAS28 = Disease Activity Score in 28 joints; ACR = American College of Rheumatology.

^†Logistic regression.

^‡Linear regression.

^§Negative binomial regression.