Table 3.

Multivariate generalized estimating equation logistic regression model of risk factors associated with HEV seroprevalence in slaughter-age pigs (3341 sera, 90 pig farms, Western France, 2010)

Variables and categories	OR	95% CI	P value
Duration of the down period in nursery (days)
⩽4	1·7	(1·04–2·9)	0·04
>4	–	–
Distance between pit manure and slatted floor in fattening premises (m)
⩽0·80	1·9	(1·1–3·5)	0·02
>0·80	–	–
Mingling of pigs from different premises between farrowing and nursery stages
Yes	1·8	(1·1–2·9)	0·02
No	–	–
Gilts' acclimatization: distribution of placenta and faeces from sows
Yes	0·3	(0·2–0·6)	0·002
No	–	–
Pen size in nursery rooms (pigs/pen)
⩽16	–	–
16–26	1·7	(0·9–3·3)	0·07
>26	2·4	(1·2–4·8)

OR, Odds ratio; CI, confidence interval.