Total | Low Education | High Education | p | Low Income | High Income | p | |
---|---|---|---|---|---|---|---|
N (% of total) | 2023 | 869 (43) | 1122 (55.5) | 747 (37) | 1243 (61.4) | ||
Age, mean ± SD (n) | 52.86 ± 15.49 (1990) | 57.51 ± 14.72 (869) | 49.25 ± 15.12 (1122) | < 0.001 | 52.97 ± 16.28 (746) | 52.77 ± 15.00 (1243) | 0.791 |
Meets 2010 ACR/EULAR criteria, % (n) | 77.6 (1544) | 79.6 (692) | 76.1 (852) | 0.059 | 80.8 (603) | 75.8 (941) | 0.009 |
Symptom duration, mean days ± SD (n) | 184.24 ± 117.85 (1984) | 178.0 ± 92.5 (868) | 189.1 ± 134.2 (1116) | 0.03 | 187.96 ± 107.48 (746) | 181.94 ± 123.70 (1237) | 0.270 |
Female, % (n) | 73.0 (1453) | 67.3 (585) | 77.4 (868) | < 0.001 | 75.0 (560) | 71.8 (893) | 0.128 |
Rheumatoid factor+, % (n) | 57.6 (1013) | 56.8 (442) | 58.1 (571) | 0.574 | 60.5 (398) | 55.8 (615) | 0.055 |
Anti-CCP+, % (n) | 50.6 (672) | 49.6 (288) | 51.4 (384) | 0.507 | 47.4 (227) | 52.4 (444) | 0.082 |
Smoking status, % (n) | < 0.001 | < 0.001 | |||||
Smoker | 18.9 (375) | 23.1 (199) | 15.7 (176) | 23.3 (174) | 16.3 (201) | ||
Ex-smoker | 37.1 (735) | 46.7 (351) | 34.3 (384) | 36.3 (271) | 37.5 (463) | ||
Never | 44.0 (873) | 36.3 (313) | 50.0 (560) | 40.3 (301) | 46.3 (572) | ||
Ethnicity | |||||||
White, % (n) | 82.2 (1636) | 82.6 (718) | 81.8 (918) | < 0.001 | 75.1 (561) | 86.4 (1074) | < 0.001 |
Marital status, % (n) | < 0.001 | < 0.001 | |||||
Single | 14.1 (280) | 10.0 (87) | 17.2 (193) | 20.3 (152) | 10.3 (128) | ||
Common law | 10.6 (211) | 10.2 (89) | 10.9 (122) | 9.2 (69) | 11.4 (142) | ||
Married | 60.3 (1200) | 60.5 (526) | 60.1 (674) | 50.5 (377) | 66.2 (823) | ||
Employment, % (n) | < 0.001 | < 0.001 | |||||
Employed | 54.2 (1080) | 41.0 (356) | 64.5 (724) | 45.6 (341) | 59.5 (739) | ||
Retired | 25.8 (513) | 35.6 (309) | 18.2 (204) | 29.2 (218) | 23.7 (293) | ||
Homemaker | 6.7 (134) | 9.1 (79) | 4.9 (55) | 5.8 (43) | 7.3 (91) | ||
Student | 3.2 (63) | 2.3 (20) | 3.8 (43) | 5.5 (41) | 1.8 (22) | ||
Disabled | 2.2 (43) | 2.8 (24) | 1.7 (19) | 3.6 (27) | 1.3 (16) | ||
Maternity | 1.2 (23) | 0.5 (4) | 1.7 (19) | 0.8 (6) | 1.4 (17) | ||
Sick leave | 3.3 (65) | 4.5 (39) | 2.3 (26) | 3.6 (27) | 3.1 (38) | ||
Unemployed | 3.5 (70) | 4.4 (38) | 2.9 (32) | 5.9 (44) | 2.1 (26) | ||
Income, % (n), $Canadian | < 0.001 | ||||||
None | 2.9 (57) | 3.0 (26) | 2.8 (31) | ||||
< $20,000 | 11.1 (220) | 13.2 (115) | 9.4 (105) | ||||
$20,000–$50,000 | 23.6 (470) | 26.8 (233) | 21.1 (237) | ||||
$50,000–$100,000 | 17.9 (356) | 10.6 (92) | 23.6 (264) | ||||
> $100,000 | 9.1 (182) | 2.9 (25) | 14.0 (157) | ||||
Did not wish to answer | 35.4 (705) | 43.5 (378) | 29.2 (327) | ||||
Education, % (n) | < 0.001 | ||||||
Elementary | 10.2 (76) | 8.0 (100) | |||||
High school | 39.9 (298) | 31.8 (395) | |||||
College | 34.1 (255) | 28.7 (357) | |||||
University | 9.6 (72) | 22.4 (278) | |||||
Masters | 1.5 (11) | 3.9 (48) | |||||
PhD | 0.3 (2) | 1.1 (14) | |||||
Other | 4.4 (33) | 4.1 (51) | |||||
BMI, mean ± SD (n) | 27.88 ± 6.01 (975) | 28.04 ± 5.74 (392) | 27.72 ± 6.18 (576) | 0.426 | 27.54 ± 6.02 (397) | 28.06 ± 6.00 (572) | 0.185 |
DAS28-ESR, mean ± SD (n) | |||||||
Baseline | 4.91 ± 1.50 (1780) | 4.99 ± 1.46 (768) | 4.85 ± 1.52 (1000) | 0.045 | 4.92 ± 1.51 (665) | 4.91 ± 1.49 (1102) | 0.809 |
6 mos | 3.23 ± 1.47 (1203) | 3.33 ± 1.41 (511) | 3.16 ± 1.51 (685) | 0.024 | 3.25 ± 1.46 (444) | 3.22 ± 1.47 (752) | 0.759 |
12 mos | 2.88 ± 1.42 (940) | 2.90 ± 1.38 (399) | 2.86 ± 1.45 (535) | 0.428 | 2.94 ± 1.46 (375) | 2.83 ± 1.39 (559) | 0.321 |
HAQ score, mean ± SD (n) | |||||||
Baseline | 0.982 ± 0.707 (1954) | 0.974 ± 0.669 (841) | 0.98 ± 0.73 (1084) | 0.755 | 1.02 ± 0.69 (730) | 0.95 ± 0.71 (1194) | 0.017 |
6 mos | 0.558 ± 0.595 (1291) | 0.57 ± 0.58 (548) | 0.549 ± 0.606 (732) | 0.308 | 0.586 ± 0.617 (537) | 0.516 ± 0.581 (885) | 0.033 |
12 mos | 0.495 ± 0.586 (1143) | 0.524 ± 0.579 (494) | 0.474 ± 0.588 (642) | 0.100 | 0.545 ± 0.613 (433) | 0.456 ± 0.555 (647) | 0.019 |
Pain, mean ± SD (n) | |||||||
Baseline | 5.49 ± 2.83 (1915) | 5.57 ± 2.74 (819) | 5.40 ± 2.90 (1067) | 0.237 | 5.65 ± 2.85 (719) | 5.37 ± 2.81 (1194) | 0.035 |
6 mos | 3.29 ± 2.74 (1263) | 3.33 ± 2.65 (533) | 3.27 ± 2.81 (719) | 0.484 | 3.27 ± 2.77 (532) | 3.25 ± 2.74 (863) | 0.941 |
12 mos | 2.87 ± 2.60 (1127) | 2.95 ± 2.55 (487) | 2.81 ± 2.64 (633) | 0.191 | 3.02 ± 2.73 (424) | 2.74 ± 2.54 (635) | 0.130 |
ESR, mean ± SD (n) | |||||||
Baseline | 26.78 ± 23.00 (1872) | 27.77 ± 22.88 (809) | 25.97 ± 23.09 (1048) | 0.019 | 26.03 ± 22.60 (693) | 27.18 ± 23.26 (1167) | 0.212 |
6 mos | 17.02 ± 15.58 (1157) | 17.51 ± 15.44 (488) | 16.62 ± 15.71 (663) | 0.083 | 16.24 ± 14.83 (477) | 17.13 ± 15.87 (789) | 0.351 |
12 mos | 15.86 ± 15.65 (1034) | 16.01 ± 16.39 (440) | 15.75 ± 15.13 (588) | 0.847 | 14.95 ± 14.95 (392) | 15.89 ± 16.01 (600) | 0.421 |
PGA, mean ± SD (n) | |||||||
Baseline | 4.64 ± 2.50 (1931) | 4.66 ± 2.45 (829) | 4.62 ± 2.54 (1072) | 0.700 | 4.64 ± 2.49 (715) | 4.64 ± 2.51 (1187) | 0.943 |
6 mos | 2.09 ± 2.11 (1276) | 2.05 ± 2.06 (549) | 2.11 ± 2.15 (716) | 0.681 | 2.00 ± 2.04 (529) | 2.03 ± 2.13 (879) | 0.650 |
12 mos | 1.58 ± 1.93 (1145) | 1.60 ± 1.93 (499) | 1.55 ± 1.92 (638) | 0.709 | 1.52 ± 1.86 (426) | 1.50 ± 2.01 (663) | 0.209 |
PtGA, mean ± SD (n) | |||||||
Baseline | 57.07 ± 29.73 (1949) | 56.7 ± 29.18 (836) | 56.92 ± 30.16 (1085) | 0.850 | 59.41 ± 29.29 (728) | 55.31 ± 29.90 (1192) | 0.004 |
6 mos | 34.67 ± 28.10 (1339) | 36.07 ± 28.10 (580) | 33.67 ± 28.14 (748) | 0.133 | 34.54 ± 28.46 (539) | 33.61 ± 27.71 (941) | 0.662 |
12 mos | 30.30 ± 27.17 (1174) | 32.16 ± 27.26 (515) | 28.82 ± 27.13 (651) | 0.033 | 30.63 ± 27.50 (435) | 29.10 ± 27.02 (687) | 0.304 |
CDAI, mean ± SD (n) | |||||||
Baseline | 77.46 ± 36.32 (1870) | 77.70 ± 35.12 (802) | 76.92 ± 37.20 (1042) | 0.669 | 79.62 ± 35.72 (696) | 75.85 ± 36.57 (1148) | 0.027 |
6 mos | 42.67 ± 33.53 (1230) | 43.69 ± 33.26 (526) | 41.94 ± 33.82 (693) | 0.231 | 41.62 ± 33.38 (507) | 41.04 ± 33.13 (847) | 0.707 |
12 mos | 35.98 ± 31.23 (1102) | 37.65 ± 30.62 (478) | 34.65 ± 31.77 (616) | 0.049 | 36.72 ± 32.19 (414) | 34.65 ± 31.23 (631) | 0.264 |
SDAI, mean ± SD (n) | |||||||
Baseline | 90.52 ± 44.24 (1716) | 91.00 ± 43.19 (733) | 89.66 ± 44.95 (959) | 0.577 | 92.93 ± 43.29 (644) | 88.63 ± 44.65 (1048) | 0.022 |
6 mos | 49.31 ± 36.44 (1021) | 50.19 ± 36.37 (432) | 48.53 ± 36.54 (580) | 0.308 | 48.00 ± 35.14 (407) | 47.17 ± 36.24 (703) | 0.511 |
12 mos | 40.98 ± 33.64 (938) | 42.65 ± 32.75 (403) | 39.63 ± 34.38 (530) | 0.095 | 43.12 ± 35.46 (355) | 39.24 ± 33.32 (539) | 0.106 |
PCS, mean ± SD (n) | |||||||
Baseline | 37.13 ± 10.54 (1725) | 36.44 ± 10.21 (722) | 37.63 ± 10.75 (1003) | 0.022 | 36.88 ± 10.44 (698) | 37.31 ± 10.61 (1026) | 0.403 |
12 mos | 45.00 ± 10.77 (796) | 44.16 ± 10.69 (336) | 45.61 ± 10.80 (460) | 0.062 | 44.23 ± 11.19 (315) | 45.50 ± 10.47 (481) | 0.102 |
Withdrawals, n | 468 | 204 | 264 | 0.892 | 199 | 268 | 0.266 |
Significant p values are bolded. ACR/EULAR: American College of Rheumatology/European League Against Rheumatism; anti-CCP: anticyclic citrullinated peptide; BMI: body mass index; DAS28-ESR: 28-joint Disease Activity Score–erythrocyte sedimentation rate; HAQ: Health Assessment Questionnaire; PGA: physician’s global assessment; PtGA: patient’s global assessment; CDAI: Clinical Disease Activity Index; SDAI: Simplified Disease Activity Index; PCS: physical component score of SF-12v2 Health Survey.