| Baseline characteristic | Baseline | Followed-up and included in analysis (%) | Non-responders* (%) | Died (%) | Excluded (%) |
| Patients: | |||||
| Sex | |||||
| Male | 244 | 112 (46) | 64 (26) | 50 (20) | 18 (7) |
| Female | 413 | 213 (52) | 109 (26) | 71 (17) | 20 (5) |
| Age (years) | |||||
| <70 | 277 | 158 (57) | 75 (27) | 20 (7) | 24 (9) |
| 70–75 | 154 | 81 (53) | 28 (18) | 39 (25) | 6 (4) |
| >75 | 226 | 86 (38) | 70 (31) | 62 (27) | 8 (4) |
| BMI (kg/m2) † | |||||
| <25 | 114 | 45 (39) | 37 (32) | 23 (20) | 9 (8) |
| 25 to <30 | 292 | 155 (53) | 66 (23) | 55 (19) | 16 (5) |
| ⩾30 | 215 | 112 (52) | 55 (26) | 36 (17) | 12 (6) |
| Kellgren and Lawrence grade of knee listed for surgery‡ | |||||
| Grade 0–2 | 137 | 62 (45) | 35 (26) | 27 (20) | 13 (9) |
| Grade 3 | 286 | 144 (50) | 73 (26) | 52 (18) | 17 (6) |
| Grade 4 | 188 | 96 (51) | 54 (29) | 32 (17) | 6 (3) |
| All subjects | 657 | 325 (49) | 173 (26) | 121 (18) | 38 (6) |
| Controls: | |||||
| Sex | |||||
| Male | 244 | 139 (57) | 60 (25) | 43 (18) | 2 (1) |
| Female | 413 | 224 (54) | 115 (28) | 72 (17) | 2 (0) |
| Age (years) | |||||
| <70 | 266 | 174 (65) | 69 (26) | 21 (8) | 2 (1) |
| 70–75 | 153 | 89 (58) | 38 (25) | 25 (16) | 1 (1) |
| >75 | 238 | 100 (42) | 68 (29) | 69 (29) | 1 (0) |
| BMI (kg/m2)† | |||||
| <25 | 298 | 163 (55) | 71 (24) | 64 (21) | 0 (0) |
| 25 to <30 | 266 | 156 (59) | 72 (27) | 35 (13) | 3 (1) |
| ⩾30 | 78 | 38 (49) | 28 (36) | 11 (14) | 1 (1) |
| All subjects | 657 | 363 (55) | 175 (27) | 115 (18) | 4 (1) |
*Non-response for reasons other than death; †BMI was missing for 36 patients and 15 controls; ‡Kellgren and Lawrence grade was missing for 46 patients.
BMI, body mass index.