Table 4

Definitions of farm-level predictors grouped into their cross classifications as used in statistical analyses

Original variables*

Description of cross-classification

Predictor variable ID

Farm frequency


House count/

Bird count

house count = small, bird count = small

hbSS

128

house count = small, bird count = large

hbSL

53

house count = large, bird count = small

hbLS

50

house count = large, bird count = large

hbLL

117

Indoor/

Free-range

indoor = no, free-range = no

ifNN

26

indoor = no, free-range = yes

ifNY

79

indoor = yes, free-range = no

ifYN

229

Indoor = yes, free-range = yes

ifYY

14


*see Table 3

Nickbakhsh et al. BMC Veterinary Research 2011 7:66   doi:10.1186/1746-6148-7-66

Open Data