Table 1.
Patient characteristics; table of participants and non-responders of the BIOS Study
| Participants* | Non-responders | P value | |
| N (%) | 4883 | 4891 | |
| Male (%) | 2329 (48) | 2407 (49) | 0.13 |
| Age (median, IQR) | 68 (53–80) | 70 (46–84) | 0.26 |
| 18–24 years (N, %) | 217 (4) | 400 (8) | |
| 25–44 years (N, %) | 516 (11) | 767 (16) | |
| 45–64 years (N, %) | 1364 (28) | 1006 (21) | |
| 65–74 years (N, %) | 963 (20) | 563 (12) | |
| ≥75 years (N, %) | 1823 (37) | 2155 (44) | |
| ASA classification (N, %) | |||
| 1 (healthy) | 1531 (31) | 1195 (24) | 0.00 |
| 2 | 2348 (48) | 1657 (34) | |
| 3 | 950 (19) | 1046 (21) | |
| 4 (severe systemic disease) | 54 (1) | 40 (1) | |
| Missing | – | 953 (20) | |
| Injury Severity Score (median, IQR) | 5 (4–9) | 5 (2–9) | 0.00 |
| Length of stay at hospital (median, IQR) | 4 (2–8) | 4 (2–8) | 0.02 |
| 1–2 days (N, %) | 1444 (30) | 1528 (31) | |
| 3–7 days (N, %) | 2081 (43) | 1642 (34) | |
| 8–14 days (N, %) | 995 (20) | 911 (19) | |
| ≥15 days (N, %) | 363 (7) | 421 (9) | |
| Missing | – | 389 (8) | |
| Functional Capacity Index (N, %) | 0.00 | ||
| 1–2 (worse state) | 248 (5) | 169 (4) | |
| 3–4 | 2074 (42) | 1721 (35) | |
| 5 (best possible state) | 2561 (52) | 2473 (51) | |
| Missing | – | 528 (11) | |
| Injury classification (N, %) | |||
| Pelvic injury | 293 (6) | 151 (3) | |
| Hip fracture | 1266 (26) | 1099 (23) | |
| Tibia, complex foot or femur fracture | 569 (12) | 505 (10) | |
| Shoulder and upper arm injury | 473 (10) | 417 (9) | |
| Radius, ulna or hand fracture | 308 (6) | 283 (6) | |
| Head injury with AIS <2 | 1324 (27) | 1443 (30) | |
| Head injury with AIS >3 | 186 (4) | 181 (4) | |
| Facial injury | 249 (5) | 303 (6) | |
| Thoracic injury | 198 (4) | 162 (3) | |
| Rib fracture | 451 (11) | 398 (8) | |
| Mild abdominal injury | 87 (2) | 89 (2) | |
| Severe abdominal injury | 36 (1) | 30 (1) | |
| Spinal cord injury | 27 (1) | 10 (0) | |
| Stable vertebral fracture or disc injury | 301 (6) | 249 (5) | |
| Admission to intensive care unit (N, %) | 358 (7) | 292 (6) | 0.00 |
| Educational level (N, %)† | |||
| Low | 2670 (55) | – | |
| Middle | 1305 (27) | – | |
| High | 908 (19) | – | |
| Pre-injury work status† | 1278 (38) | – | |
| Pre-injury frailty† | 762 (16) | ||
| Pre-injury health status† | |||
| EQ-5D utility (mean, SD) | 0.85 (0.23) | – | |
| EQ-VAS (mean, SD) | 79.4 (18.2) | – | |
| % problems mobility | 1051 (32) | – | |
| % problems self-care | 530 (16) | – | |
| % problems usual activities | 856 (26) | – | |
| % problems pain/discomfort | 1044 (32) | – | |
| % problems anxiety/depression | 540 (16) | – | |
| % problems cognition | 651 (19) | – | |
| Missing | 1517 (31) |
*Patients who completed at least one follow-up questionnaire. Missing variables were imputed.
†Variables were only collected in responders.
AIS, Abbreviated Injury Scale; ASA, American Society of Anaesthesiologists; EQ-5D, EuroQol-5-dimensions-3-levels; EQ-VAS, EuroQol Visual Analogue Scale; N, number.