Table 2.

Protective measures reported by infected and non-infected staff

		Infected	Non-infected	p*	Odds ratio
		Staff (n=13)	staff (n=241)		(95% CI)†
Protective measures‡
Masks§		2 (15%)	169 (70%)	0·0001	13 (3–60)
	Paper mask	2	26	0·511¶
	Surgical mask	0	51	0·007¶
	N95	0	92	0·0004¶
Gloves		4 (31%)	117 (48%)	0·364	2 (0·6–7)
Gowns		0 (0%)	83 (34%)	0·006	NC
Hand-washing		10 (77%)	227 (94%)	0·047	5 (1–19)
	All measures	0 (0%)	69 (29%)	0·022	NC

NC=not calculatable.

^*Two-tailed.

^†Odds ratio of staff with specific protection not getting infected.

^‡”Yes” and “most of the time” were grouped together.

^§Total cases 254 by forward stepwise (Waldesian) logistic regression using 0·05 as entry probability and 0·10 as removal probability. Forward and backward stepwise regression result in same model with mask in the model (p=0·011).

^¶Comparing proportion of infected over non-infected staff, with those without mask (11 infected and 72 non-infected).