Intensified hand-hygiene campaign including soap-and-water wash may prevent acute infections in office workers, as shown by a recognized-exposure -adjusted analysis of a randomized trial

Table 4 Reported-exposure –dependent efficacy of interventions on weekly prevalence of reported symptoms of respiratory tract infection (RTI)

Weeks with or without reported exposure Arm and number of weeks	Symptoms reported for
	Same week			Following week
	Number and proportion^a	Predictive margin (CI^b)	Risk ratio^c (CI^b)	Number and proportion	Predictive margin (CI)	Risk ratio (CI^b)
Exposure reported
Control n = 3279	976/0.298	0.292 (0.258, 0.329)	NR	805/0.246	0.216 (0.192, 0.246)	NR
Soap-and-water n = 4031	1151/0.286	0.306 (0.276, 0.339)	1.050^d (0.870, 1.260)	848/0.210	0.188 (0.168, 0.208)	0.868^e (0.709, 1.038)
Alcohol rub n = 3507	1042/0.297	0.281 (0.245, 0.317)	0.937^f (0.771, 1.145)	838/0.239	0.207 (0.185, 0.235)	0.962^g (0.790, 1.16)
Exposure not reported
Control n = 8365	494/0.059	0.063 (0.055, 0.072)	NR	594/0.071	0.084 (0.074, 0.096)	NR
Soap-and-water n = 10983	495/0.045	0.042 (0.037, 0.048)	0.678^h (0.546, 0.823)	707/0.064	0.073 (0.065, 0.081)	0.868ⁱ (0.709, 1.038)
Alcohol rub n = 8476	504/0.059	0.062 (0.054, 0.071)	0.986^j (0.803, 1.211)	627/0.074	0.081 (0.072, 0.091)	0.962^k (0.790, 1.161)

NR not relevant
^aNumber of weeks with reported RTI symptoms representing indicated proportion out of weeks with reported exposure
^bCI, 95% credible interval of predictive margins
^cRisk ratio is the ratio of predictive margin in the intervention arm to that of the control arm
^defghijkProbabilities that the risk ratio is less than 1.0; ^d, 0.30; ^e, 0.94; ^f, 0.75; ^g, 0.66; ^h, 1.0; ⁱ, 0.94; ^j, 0.55; ^k, 0.66
Note! e = i and g = k; no statistically significant interaction was found in the following week data between arm and exposure. Thus, a single estimate was calculated for the entire arm

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