Table 3

Multivariable linear regression model of the effect of infection with different Trypanosoma species and other significant confounding factors on the packed cell volume (PCV) of 241 horses and donkeys from the Central River Division, The Gambia 2006.

Variable
Coefficient
± S.E
P-value

Intercept
36.1
1.2

T. congolense




-ve
Ref



+ve
-11.9
0.8
<0.001
T. Brucei sp




-ve




+ve
-2.0
0.9
0.03
T. vivax




-ve
Ref



+ve
-3.3
1.2
0.007
Gender




Male
Ref



Female
-1.6
0.7
0.03
Species




Horse
Ref



Donkey
-1.9
0.8
0.02
Trypanosoma status on microscopic examination




-ve
Ref



+ve
-5.3
1.0
<0.001
T. congolense* T. vivax interaction term





Ref



+ve
6.4
2.3
0.006

Ref – Reference category

Pinchbeck et al. BMC Veterinary Research 2008 4:7   doi:10.1186/1746-6148-4-7