Table 2.
Results of intention-to-treat analysis
| Reference | UV group | Bleach group | Bleach and UV group | |
|---|---|---|---|---|
| All target organisms | ||||
|
| ||||
| Exposed patients | 4916 | 5178 | 5438 | 5863 |
| Incident cases (%) | 115 (2·3%) | 76 (1·5%) | 101 (1·9%) | 131 (2·2%) |
| Exposure days | 22 426 | 22 389 | 24 261 | 28 757 |
| Rate (per 10 000 exposure-days) | 51·3 | 33·9 | 41·6 | 45·6 |
| Risk reduction (95% CI) | Reference | 17·4 (5·8 to 28·9) | 9·7 (–2·7 to 22·0) | 5·7 (–6·2 to 17·7) |
| RR (95% CI); p value | Reference | 0·70 (0·50 to 0·98); 0·036 | 0·85 (0·69 to 1·04); 0·116 | 0·91 (0·76 to 1·09); 0·303 |
|
| ||||
| Clostridium difficile* | ||||
|
| ||||
| Exposed patients | ·· | ·· | 2499 | 2678 |
| Incident cases (%) | ·· | ·· | 36 (1·4%) | 38 (1·4%) |
| Exposure days | ·· | ·· | 11 385 | 12 509 |
| Rate (per 10 000 exposure-days) | ·· | ·· | 31·6 | 30·4 |
| Risk reduction (95% CI) | ·· | ·· | Reference | 1·2 (–12·7 to 15·2) |
| RR (95% CI); p value | ·· | ·· | Reference | 1·0 (0·57 to 1·75); 0·997 |
|
| ||||
| Meticillin-resistant Staphylococcus aureus | ||||
|
| ||||
| Exposed patients | 3300 | 3451 | 3631 | 3848 |
| Incident cases (%) | 73 (2·2%) | 54 (1·6) | 74 (2·0) | 89 (2·3) |
| Exposure days | 14 524 | 14 780 | 15 343 | 18 960 |
| Rate (per 10 000 exposure-days) | 50·3 | 36·5 | 48·2 | 46·9 |
| Risk reduction (95% CI) | Reference | 13·8 (0·1 to 27·3) | 2·1 (–13·8 to 17·8) | 3·4 (–8·9 to 15·5) |
| RR (95% CI); p value | Reference | 0·78 (0·58 to 1·05); 0·104 | 1·00 (0·82 to 1·21); 0·967 | 0·97 (0·78 to 1·22); 0·819 |
|
| ||||
| Vancomycin-resistant enterococci | ||||
|
| ||||
| Exposed patients | 1055 | 1206 | 1468 | 1753 |
| Incident cases (%) | 37 (3·5%) | 17 (1·4%) | 24 (1·6%) | 37 (2·1%) |
| Exposure days | 5838 | 5780 | 7522 | 9488 |
| Rate (per 10 000 exposure-days) | 63·4 | 29·4 | 31·9 | 39·0 |
| Risk reduction (95% CI) | Reference | 34·0 (9·3 to 58·6) | 31·5 (12·7 to 50·2) | 24·4 (0·5 to 48·2) |
| RR (95% CI); p-value | Reference | 0·41 (0·15 to 1·13); 0·084 | 0·43 (0·19 to 1·00); 0·049 | 0·36 (0·18 to 0·70); 0·003 |
|
| ||||
| Multidrug-resistant Acinetobacter† | ||||
|
| ||||
| Exposed patients | 31 | 47 | 28 | 62 |
| Incident cases (%) | 0 | 0 | 1 (3·6) | 0 |
| Exposure days | 156 | 199 | 98 | 244 |
| Rate (per 10 000 exposure-days) | 0 | 0 | 102·4 | 0 |
RR=relative risk.
*
Rooms with patients known or suspected of having C difficile infection were terminally cleaned with bleach-containing solutions in all study disinfection strategies.
†
We created no models for multidrug-resistant Acinetobacter because only one outcome occurred in the nine study hospitals across all four study groups.