Table 6. Multivariate logistic regression models for identifying significant associations between study variables and predicted mortality in calves of the present study population.

For this analysis euthanized calves were allocated to the survival group if the calf would likely have lived if unlimited financial resources were available. For this purpose medical records were independently reviewed by three experienced clinicians.

Variable	Coefficient	± SE	OR	95% CI for OR	P-value
Clinical and laboratory model 1(n = 1,350)
Intercept	-3.151	0.158
Ileus/Abdominal emergency	4.200	0.570	66.67	21.81–203.77	< 0.001
CNS involvement	3.147	0.377	23.27	11.12–48.70	< 0.001
Rectal temperature < 35.2°C	1.736	0.399	5.67	2.60–12.40	< 0.001
Total protein < 43.8 g/L	1.271	0.260	3.56	2.14–5.94	< 0.001
Presence of pneumonia	1.234	0.206	3.44	2.29–5.14	< 0.001
Respiratory rate ≥ 62 breaths/min	1.211	0.315	3.36	1.81–6.23	< 0.001
Recumbency (posture score 3)	1.110	0.187	3.04	2.11–4.37	< 0.001
AST activity ≥ 152 U/L	1.060	0.243	2.89	1.79–4.65	< 0.001
pCO2 ≥ 65.2 mm Hg	1.012	0.266	2.75	1.63–4.64	< 0.001
Laboratory model2 (n = 1,398)
Intercept	-2.161	0.104
Glucose concentration < 2.9 mmol/L	1.371	0.198	3.94	2.67–5.81	< 0.001
AST activity > 79 U/L	1.227	0.148	3.41	2.55–4.56	< 0.001

Entered predictors were identified by means of classification tree analysis.

¹Hosmer-Lemeshow goodness-of-fit χ² = 5.55, df = 4, P = 0.24.

²Hosmer-Lemeshow goodness-of-fit χ² = 0.11, df = 1, P = 0.74.