| Variable | Low PCS (n = 152) | Full RTW (n = 153) | |||||
| n (%) | OR | 95% CI | p Value | OR | 95% CI | p Value | |
| Pre-injury | |||||||
| Age (y) (mean (SD)) | 35.6 (12.3) | 1.0 | 1.0 to 1.0 | 0.507 | 1.0 | 1.0 to 1.0 | 0.756 |
| Gender: female | 78 (39) | 1.0 | 0.5 to 1.9 | 0.996 | 0.9 | 0.5 to 1.8 | 0.831 |
| Education | 0.0001† | 0.0001† | |||||
| Low* | 56 (28) | ||||||
| Middle | 63 (31) | 2.3 | 0.9 to 5.4 | 0.071 | 4.9 | 1.9 to 12.7 | 0.0001 |
| High | 82 (41) | 5.4 | 2.3 to 12.6 | 0.0001 | 6.4 | 2.5 to 16.5 | 0.0001 |
| Emotional problems: no | 137 (68) | 1.9 | 1.0 to 3.7 | 0.059 | 0.9 | 0.4 to 1.7 | 0.649 |
| Physical comorbidity: no‡ | 130 (65) | 5.5 | 2.7 to 10.9 | 0.0001 | 1.8 | 0.9 to 3.5 | 0.083 |
| Prior head injury: no | 129 (64) | 0.9 | 0.5 to 1.6 | 0.850 | 0.8 | 0.4 to 1.5 | 0.450 |
| Peri-injury | |||||||
| Admission GCS: 15 | 150 (75) | 1.6 | 0.8 to 33 | 0.180 | 0.6 | 0.3 to 1.2 | 0.149 |
| LOC: no | 73 (36) | 1.0 | 0.5 to 1.9 | 0.944 | 0.6 | 0.3 to 1.3 | 0.189 |
| PTA duration (n = 7 missing) | 0.220† | ||||||
| No PTA | 77 (38) | 2.0 | 0.9 to 4.5 | 0.092 | 1.7 | 0.8 to 3.7 | 0.174 |
| PTA 1–30 minutes | 69 (34) | 1.6 | 0.7 to 3.5 | 0.251 | 0.8 | 0.4 to 1.8 | 0.629 |
| PTA >30 min* | 55 (27) | 0.186 | |||||
| CT characteristics | 0.300† | 0.010† | |||||
| No CT made | 28 (14) | 2.6 | 0.7 to 9.0 | 0.141 | 7.8 | 1.6 to 37.7 | 0.011 |
| No traumatic abnormalities | 133 (66) | 2.0 | 0.6 to 6.1 | 0.236 | 4.0 | 0.9 to 17.6 | 0.071 |
| Traumatic abnormalities* | 40 (20) | ||||||
| Mechanism of injury | 0.514† | 0.022† | |||||
| Traffic* | 110 (55) | – | – | ||||
| Fall | 40 (20) | 1.5 | 0.6 to 3.7 | 0.364 | 2.2 | 0.9 to 5.0 | 0.078 |
| Sports | 21 (10) | 1.0 | 0.4 to 3.1 | 0.943 | 0.2 | 0.0 to 1.3 | 0.082 |
| Other | 30 (15) | 0.7 | 0.3 to 1.6 | 0.335 | 0.9 | 0.4 to 2.2 | 0.884 |
| Headache on admission: no | 135 (67) | 1.1 | 0.6 to 2.2 | 0.750 | 0.8 | 0.4 to 1.6 | 0.535 |
| Nausea or vomiting: no | 170 (85) | 1.9 | 0.8 to 4.3 | 0.122 | 2.4 | 1.0 to 5.3 | 0.039 |
| Additional extracranial injuries: no | 125 (62) | 1.3 | 0.7 to 2.5 | 0.403 | 3.9 | 2.0 to 7.6 | 0.0001 |
| Early post-injury§ | |||||||
| RPQ severe complaints: no | 109 (54) | 6.3 | 3.0 to 13.3 | 0.0001 | 2.0 | 1.0 to 3.8 | 0.047 |
| IES Total score >26: no | 186 (92) | 16.1 | 4.3 to 60.0 | 0.0001 | 2.3 | 0.8 to 6.8 | 0.137 |
| General self efficacy <28: no | 172 (86) | 4.4 | 1.9 to 9.9 | 0.0001 | 1.3 | 0.5 to 3.1 | 0.613 |
| Pain | 0.268† | 0.007† | |||||
| Low (0–2) | 53 (26) | 1.9 | 0.8 to 4.3 | 0.146 | 2.3 | 1.0 to 5.3 | 0.046 |
| Moderate (3–4) | 65 (32) | 1.2 | 0.5 to 2.9 | 0.720 | 0.7 | 0.2 to 1.9 | 0.462 |
| High (>4)* | 83 (41) | ||||||
| AFQ Total ⩾20: no | 113 (56) | 4.8 | 2.2 to 10.6 | 0.0001 | 2.0 | 1.0 to 4.0 | 0.047 |
*Reference category.
†Overall p value for the factor.
‡The following comorbidities were reported: chronic back problems, spinal disk herniation (n = 21), asthma, chronic bronchitis or chronic obstructive pulmonary disease (n = 12), osteoarthritis (n = 7), epilepsy (n = 4), diabetes (n = 3), severe cardiac disease, cardiac arrest (n = 2), rheumatoid arthritis (n = 2), malignancies, cancer (n = 2), other: chronic headache (n = 4), high blood pressure (n = 4), chronic kidney problems (n = 2), hypothyroidism (n = 2), Crohn’s disease (n = 1), Ménière’s disease (n = 1), chronic skin problems (n = 1), unspecified (n = 3).
§Mean 9 days after injury (SD 7.1, range 0–37).
AFQ, Abbreviated Fatigue Questionnaire; GCS, Glasgow Coma Score; IES, Impact of Events Scale; PTA, Post Traumatic Amnesia; RPQ, Rivermead Postconcussional Complaints Questionnaire.