Table 2 Time course of head injury and its characteristics among TBI group
From: Mild traumatic brain injury affects the features of migraine
| Â | mTBI group | Â |
|---|---|---|
Number | 413 | Â |
Having headaches before head injury | ||
 Yes | 268 | (64.8%) |
 No | 139 | (33.7%) |
 Missing | 6 | – |
Duration between head injury and baseline enrollment (years) | ||
 Mean ± SD | 18.3 ± 16.0 |  |
 Median (IQR) | 14.4 (4.7–28.5) |  |
Either new headache or worsening headache after the head injury | ||
 Yes | 145 |  |
 No | 189 |  |
 I don’t know/Missing | 79 |  |
Either new headache or worsening headache within 7 days after the head injury | ||
 Yes | 92 |  |
 No | 27 |  |
 I don’t know/Missing | 294 |  |