Operative data for 495 EVD catheters
| Operative characteristics | No. | % |
| Length of tunnelling | ||
| 0–5 cm | 119 | 24.0 |
| 5–10 cm | 359 | 72.5 |
| >10 cm | 17 | 3.4 |
| Postoperative CT head scan | ||
| No | 100 | 20.2 |
| Yes | 395 | 79.8 |
| CSF sampling frequency | ||
| No sampling | 129 | 26.1 |
| 1–2 times per week | 234 | 47.3 |
| Alternate days | 24 | 4.9 |
| Daily | 7 | 1.4 |
| Unknown | 101 | 20.4 |
| Catheter type | ||
| Plain | 161 | 32.5 |
| Antibiotic-impregnated | 188 | 38 |
| Silver-bearing | 146 | 29.5 |
| Primary surgeon | ||
| Intern/Foundation doctor | 5 | 1.0 |
| Junior neurosurgery trainee | 97 | 19.6 |
| Senior neurosurgery trainee | 327 | 66.1 |
| Consultant/Attending | 66 | 13.3 |
CSF, cerebrospinal fluid; EVD, external ventricular drain.