HRs for EVD infection rate using Cox regression model
| HR | 95% CI | p Value | |
| Catheter type | |||
| Plain | Ref | – | – |
| Antibiotic-impregnated | 0.87 | 0.37 to 2.03 | 0.75 |
| Silver-bearing | 1.35 | 0.63 to 2.88 | 0.44 |
| Length of tunnelling | |||
| 0–5 cm | Ref | – | – |
| >5 cm | 0.75 | 0.36 to 1.55 | 0.44 |
| CSF sampling frequency | |||
| 1–2 times per week | Ref | - | - |
| Alternate days | 5.28 | 2.25 to 12.38 | <0.01 |
| Daily | 4.73 | 1.28 to 17.42 | 0.02 |
| Unknown | 1.26 | 0.56 to 2.82 | 0.58 |
| Duration of EVD use | |||
| 0–7 days | Ref | - | - |
| ≥8 days | 2.47 | 1.12 to 5.45 | 0.03 |
*Cox regression model adjusted for age and sex based on 441 EVDs where date of exit (infection, death or 30 days) was available.
CSF, cerebrospinal fluid; EVD, external ventricular drain.