Table 1.
Number and proportion of non-infected VP shunt revisions by valve feature (gravitational/non-gravitational) and valve subtype
| Valve type | Total n (%) | Mechanical failure failure n (%) | X2 | p value |
|---|---|---|---|---|
| All valves | 391 | 128 (32.7) | ||
| Valve feature | ||||
| Non-gravitational | 236 (60.4) | 72 (30.5) | 1.099 | 0.294 |
| Gravitational | 155 (39.6) | 56 (36.1) | ||
| Non-programmable | 337 (86.2) | 112 (33.2) | 0.135 | 0.713 |
| Programmable | 54 (13.8) | 16 (29.6) | ||
| Valve subtype | ||||
| NGNP | 211 (54.0) | 65 (30.8) | 1.843 | 0.606 |
| NGP | 25 (6.4) | 7 (28.0) | ||
| GNP | 126 (32.2) | 47 (37.3) | ||
| GP | 29 (7.4) | 9 (31.0) | ||