Table 4

To explore if the statistically significant associations in table 2 are mediated via the protective effect of childhood farming on atopy and asthma, the models were further adjusted for atopy and asthma

Farm-related factors during infancy	FEV₁ difference (mL)			FVC difference (mL)
Farm-related factors during infancy	Adj	Adj+A*	Adj+A*+DDA	Adj	Adj+A*	Adj+A*+DDA
Parental professional farming	36	27	22	40	36	31
Family had farm animals	32	23	16	11	6	−1
Family had dogs†	36	33	30	37	36	33

Adj: multivariate model, for more detailed information see Methods section.
A: also adjusted for atopy at the age of 31 years.
DDA: also adjusted for doctor-diagnosed asthma ever at the age of 31 years.
*Participants with a weal reaction ≥3 mm to one or more of the four allergens tested were considered to be atopic.
†Before the age of 7 years.
FEV₁, forced expiratory volume in 1 s; FVC, forced vital capacity.