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 3 Overall association of reported exposures with symptoms of gastrointestinal infection (GTI) during the same or the following week

Reported exposure to GTI		Reported homologous symptoms: Person-week in relation to exposure/Number and proportion of weeks with GTI symptoms/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	767	159	0.207/0.213 (CI^b 0.17 to 0.26) RR^c(exposed/unexposed) = 15.1 (CI 10.4 to 21.8), P < 0.001	67	0.087/0.0931 (CI 0.066 to 0.120) RR(exposed/unexposed) = 4.3 (CI 3.1 to 5.8), P < 0.001	194	0.253/0.262 (CI 0.215 to 0.309) RR(exposed/unexposed) = 7.8 (CI 6.0 to 10.3), P < 0.001
No	10,877	154	0.014/0.014 (CI 0.009 to 0.019)	226	0.021/0.022 (CI 0.016 to 0.028)	345	0.032/0.033 (CI 0.025 to 0.042)

^aGEE logistic regression model using Stata was fitted for GTI 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