Table 1. Associations of hematocrit, non-esterified fatty acid, antithrombin activity, platelet count and dysstasia with the fatal outcome of naturally occurring acute Escherichia coli mastitis in 24 clinical cases.
| Parameters | Cutpoint | Odds ratio a) | 95% CI a) | P a) | Sensitivity (%) |
Specificity (%) |
Predictive value (%) |
Likelihood ratio |
|---|---|---|---|---|---|---|---|---|
| Measured at onset (Day 1, n=24) | ||||||||
| Hematocrit (%) | >32 | 3.3 | 0.5 to 22.9 | 0.24 | 50.0 | 76.5 | 42.9 | 2.1 |
| Non-esterified fatty acid (mEq/l) | >0.4 | 4.8 | 0.7 to 35.2 | 0.13 | 66.7 | 70.6 | 44.4 | 2.3 |
| Antithrombin activity (%) | <120 | –b) | –b) | 0.29 | 14.3 | 100.0 | 100.0 | –b) |
| Platelet count (×104/ml) | <15 | 0.8 | 0.1 to 5.0 | 0.60 | 42.9 | 52.9 | 27.3 | 0.9 |
| Dysstasia | positive | –b) | –b) | <0.01 | 71.4 | 100.0 | 100.0 | –b) |
| At least 3 parameters fell within the ranges | 12.0 | 1.0 to 148.3 | 0.06 | 42.9 | 94.1 | 75.0 | 7.29 | |
| Measured in one day after onset (Day 2, n=24) | ||||||||
| Hematocrit (%) | >32 | –b) | –b) | <0.01 | 71.4 | 100.0 | 100.0 | –b) |
| Non-esterified fatty acid (mEq/l) | >0.4 | –c) | –c) | <0.01 | 100.0 | 62.5 | 53.8 | 2.7 |
| Antithrombin activity (%) | <120 | 10.0 | 1.2 to 81.8 | 0.04 | 57.1 | 88.2 | 66.7 | 4.9 |
| Platelet count (×104/ml) | <15 | 3.6 | 0.5 to 24.0 | 0.19 | 71.4 | 58.8 | 41.7 | 1.7 |
| Dysstasia | positive | –b) | –b) | <0.01 | 100.0 | 100.0 | 100.0 | –b) |
| At least 3 parameters fell within the ranges | –b) | –b) | <0.01 | 100.0 | 94.1 | 87.5 | 17 | |
| Measured in two day after onset (Day 3, n=18) | ||||||||
| Hematocrit (%) | >32 | –c) | –c) | <0.01 | 100.0 | 91.7 | 85.7 | 12.0 |
| Non-esterified fatty acid (mEq/l) | >0.4 | –c) | –c) | 0.03 | 100.0 | 58.3 | 54.5 | 2.4 |
| Antithrombin activity (%) | <120 | –c) | –c) | <0.01 | 100.0 | 75.0 | 66.7 | 4.0 |
| Platelet count (×104/ml) | <15 | 7.0 | 0.6 to 79.9 | 0.12 | 83.3 | 58.3 | 50.0 | 2.0 |
| Dysstasia | positive | –b) | –b) | <0.01 | 83.3 | 100.0 | 100.0 | –b) |
| At least 3 parameters fell within the ranges | –b) | –b) | <0.01 | 100.0 | 83.3 | 75.0 | 6 | |
a) From Fisher’s exact probability test. 95% CI=95% confidence interval around the odds ratio. b) Odds ratio, 95% CI and likelihood were not calculated, because none of surviving cows was less than the cutpoint. c) Odds ratio and 95% CI were not calculated, because all of these values of non-surviving cows were included a range designated by each cutpoint.