Exposure to persons with symptoms of respiratory or gastrointestinal infection and relative risk of disease: self-reported observations by controls in a randomized intervention trial

Table 1 Overall association of reported exposures with reported symptoms of respiratory tract infection (RTI) during the same or the following week

Reported exposure to RTI		Reported homologous symptoms: Person-week in relation to exposure/Number and proportion of weeks with symptoms of RTI infection/Statistical analysis
Record	Number of weeks	Same week		Following week		Either week
Record	Number of weeks	Number	Proportion/predictive margin^a	Number	Proportion/predictive margin^a	Number	Proportion/predictive margin^a
Yes	3,279	976	0.298/0.290 (CI^b 0.254 to 0.324) RR^c(exposed/unexposed) = 4.9 (CI 4.0 to 5.9), P < 0.001	805	0.246/0.249 (CI 0.215 to 0.282) RR(exposed/unexposed) = 3.3 (CI 2.8 to 3.8), P < 0.001	1,282	0.391/0.392 (CI 0.352 to 0.431) RR(exposed/unexposed) = 3.4 (CI 3.0 to 3.9), P < 0.001
No	8,365	494	0.059/0.060 (CI 0.050 to 0.069)	594	0.071/0.076 (CI 0.066 to 0.085)	904	0.108/0.115 (0.101 to 0.129)

^aGEE logistic regression model using Stata was fitted for RTI outcome with seasonality, triplet and homologous reported exposure (same or previous week) as covariates. The working correlation matrix was ‘independent’ and chosen by the quasi-likelihood model criterion (QIC).
^b95% confidence interval.
^cRR, risk ratio.

ISSN: 1745-6215