Table 3.

Results of per-protocol analysis

	Reference group	UV group	Bleach group	Bleach and UV group
All target organisms
Exposed patients	4916	2848	5438	3701
Incident cases (%)	115 (2·3%)	46 (1·6%)	101 (1·9%)	93 (2·5%)
Exposure days	22 426	12 299	24 261	17 354
Rate (per 10 000 exposure-days)	51·3	37·4	41·6	53·6
Risk reduction (95% CI)	Reference	13·9 (–0·1 to 27·9)	9·7 (–2·7 to 22·0)	–2·3 (–15·7 to 11·1)
RR (95% CI); p value	Reference	0·69 (0·50 to 0·95); 0·025	0·74 (0·61 to 0·91); 0·004	1·0 (0·81 to 1·23); 1·00
Clostridium difficile*
Exposed patients	··	··	2499	1712
Incident cases (%)	··	··	36 (1·4%)	30 (1·8%)
Exposure days	··	··	11 385	8015
Rate (per 10 000 exposure-days)	··	··	31·6	37·4
Risk reduction (95% CI)	··	··	Reference	–5·8 (–17·1 to 5·5)
RR (95% CI); p value	··	··	Reference	1·22 (0·68 to 2·17); 0·511
Meticillin-resistant Staphylococcus aureus
Exposed patients	3300	1872	3631	2425
Incident cases (%)	73 (2·2%)	28 (1·5%)	74 (2·0%)	63 (2·6%)
Exposure days	14 525	7934	15 343	10 681
Rate (per 10 000 exposure-days)	50·3	35·3	48·2	59·0
Risk reduction (95% CI)	Reference	15·0 (–0·6 to 30·6)	2·1 (–13·8 to 17·8)	–8·7 (–18·0 to 0·5)
RR (95% CI); p value	Reference	0·67 (0·48 to 0·94); 0·019	0·89 (0·72 to 1·09); 0·260	1·09 (0·85 to 1·39); 0·503
Vancomycin-resistant enterococci
Exposed patients	1055	659	1468	1134
Incident cases (%)	37 (3·5%)	13 (2·0%)	24 (1·6%)	24 (2·1%)
Exposure days	5838	3265	7522	6237
Rate (per 10 000 exposure-days)	63·4	39·8	31·9	38·5
Risk reduction (95% CI)	Reference	23·6 (–6·1 to 53·2)	31·5 (12·7 to 50·2)	24·9 (–0·6 to 50·4)
RR (95% CI); p value	Reference	0·56 (0·21 to 1·50); 0·248	0·35 (0·16 to 0·78); 0·010	0·41 (0·22 to 0·77); 0·006

Data are unchanged for multidrug-resistant Acinetobacter baumaunii (table 2).

^*Rooms with patients known or suspected of having C difficile infection were terminally cleaned with hypochlorite-containing solutions.