Table 1 Descriptive statistics for the whole sample and the CWP group at baseline in 1995
|  | All n = 975 | Men n = 442 | Women n = 533 | p-value gender difference | All CWP n = 123 | Men n = 33 | Women n = 90 | p-value gender difference |
|---|---|---|---|---|---|---|---|---|
Age, years (1995) | Â | Â | Â | 0.981 | Â | Â | Â | 0.602 |
Mean (sd) | 44 (6) | 45 (6) | 48 (6) | Â | 47 (5) | 48 (5) | 46 (6) | Â |
Educationa, n (%) | 0.010 | Â | Â | Â | 0.894 | |||
 No more than 2 years | 548 (56.4) | 246 (55.9) | 302 (56.9) |  | 87 (71.3) | 23 (69.7) | 64 (71.9) |  |
  >  2 years | 121 (12.5) | 71 (16.1) | 50 (9.4) |  | 10 (8.2) | 3 (9.1) | 7 (7.9) | |
 University | 222 (22.9) | 91 (20.7) | 131 (24.7) |  | 15 (12.3) | 5 (15.2) | 10 (11.2) | |
 Other | 80 (8.2) | 31 (7.3) | 48 (9.0) |  | 10 (8.2) | 2 (6.1) | 8 (9.0) | |
Personal support, n (%) | 0.773 | Â | Â | Â | 0.287 | |||
 Yes | 806 (82.9) | 364 (82.5) | 442 (83.2) |  | 94 (76.4) | 23 (69.7) | 71 (78.9) | |
 No | 166 (17.1) | 77 (17.5) | 89 (16.8) |  | 29 (23.6) | 10 (30.3) | 19 (21.1) | |
Circle of friends, n (%) | 0.380 | Â | Â | Â | 0.026 | |||
 Yes | 615 (63.5) | 273 (62) | 342 (64.8) |  | 64 (52.9) | 12 (36.4) | 52 (59.1) | |
 No | 353 (36.5) | 167 (38) | 186 (35.2) |  | 57 (47.1) | 21 (63.6) | 36 (40.9) | |
Pain group, n (%) | 0.000 | Â | Â | Â | Â | |||
 NCP | 593 (62.2) | 289 (67.1) | 304 (58.1) |  | ||||
 CRP | 238 (24.9) | 109 (25.3) | 129 (24.7) | |||||
 CWP | 123 (12.9) | 33 (7.7) | 90 (17.2) | |||||
Smoking habits, n (%) | 0.325 | Â | Â | Â | 0.918 | |||
 No, never smoked | 452 (46.5) | 194 (44) | 258 (48.6) |  | 55 (44.7) | 15 (45.5) | 40 (44.4) | |
 No, have stopped | 281 (28.9) | 136 (30.8) | 145 (27.3) |  | 33 (26.8) | 8 (24.2) | 25 (27.8) | |
 Yes, smoker | 239 (24.6) | 111 (25.2) | 128 (24.1) |  | 35 (28.5) | 10 (30.3) | 25 (27.8) | |
Alcohol intake, n (%) | 0.000 | Â | Â | Â | 0.125 | |||
 Never/almost never | 313 (32.2) | 96 (21.9) | 217 (40.8) |  | 70 (56.9) | 17 (51.5) | 53 (58.9) | |
 Every month | 407 (41.9) | 198 (45.1) | 209 (39.3) |  | 36 (29.3) | 8 (24.2) | 28 (31.1) | |
 Every week | 246 (25.3) | 143 (32.6) | 103 (19.4) |  | 17 (13.8) | 8 (24.2) | 9 (10.0) | |
  > 4 times a week | 5 (0.5) | 2 (0.5) | 3 (0.6) |  | 0 (0) | 0 (0) | 0 (0) | |
Physical activityb, n (%) | 0.002 | Â | Â | Â | 0.582 | |||
 Never | 463 (28) | 237 (54.2) | 226 (42.9) |  | 54 (43.9) | 17 (51.5) | 37 (41.1) | |
 Moderate | 337 (35) | 134 (30.7) | 203 (38.5) |  | 42 (34.1) | 10 (30.3) | 32 (35.6) | |
 Active | 164 (17) | 66 (15.1) | 98 (18.6) |  | 27 (22) | 6 (18.2) | 21 (23.3) | |
Sleeping problemsc, n (%) | 0.053 | Â | Â | Â | 0.731 | |||
 No | 495 (52.9) | 240 (56.3) | 255 (50) |  | 20 (16.8) | 6 (18.8) | 14 (16.1) | |
 Yes | 441 (47.1) | 186 (43.7) | 255 (50) |  | 99 (83.2) | 26 (81.3) | 73 (83.9) | |