Number of assessments according to HRV measure, across time since injury
| Number of assessments across time postconcussion | |||||
| 1–15 days | 16–30 days | 31–45 days | 46–60 days | 60+ days | |
| SDNN | 32 | 21 | 7 | 8 | 11 |
| RMSSD | 32 | 21 | 7 | 8 | 11 |
| pNN50 | 32 | 21 | 7 | 8 | 11 |
| HF | 16 | 11 | 3 | 3 | 6 |
| HFnu | 16 | 11 | 3 | 3 | 6 |
HRV, heart rate variability.