Table 4. Results of the ROC analysis of standardized serum total LDH values in differentiating AL from IBD cats stratified according to breed, gender, age and body weight.
| Factors tested | Accuracy (AUC±SE) | Maximum LR | Best cut-off (xURL) | Sensitivity | Specificity | PPV | NPV |
|---|---|---|---|---|---|---|---|
| Breed: | |||||||
| - European shorthair | 0.615±0.072 (P = 0.113) | 2.05 | 0.88–0.89 | 19/32 (59.4%) | 24/32 (75.0%) | 19/27 (70.4%) | 24/37 (64.9%) |
| - Others | 0.833±0.152 (P = 0.317) | 11.0 | 1.06–3.84 | 1/1 (100%) | 5/6 (83.3%) | 1/2 (50.0%) | 5/5 (100%) |
| P = 0.195 | |||||||
| Gender: | |||||||
| - Neutered males | 0.805±0.087 (P = 0.006) | 3.64 | 0.85–1.04 | 10/13 (76.9%) | 12/15 (80.0%) | 10/13 (76.9%) | 12/15 (80.0%) |
| - Spayed females | 0.498±0.092 (P = 0.981) | 1.49 | 0.88–0.89 | 10/20 (50.0%) | 16/23 (69.6%) | 10/17 (58.8%) | 16/26 (61.5%) |
| P = 0.015 | |||||||
| Age: | |||||||
| - Up to 8 years | 0.833±0.089 (P = 0.017) | 3.98 | 0.85–1.04 | 5/6 (83.3%) | 13/17 (76.5%) | 5/9 (55.6%) | 13/14 (92.9%) |
| - Over 8 years | 0.536±0.086 (P = 0.670) | 1.78 | 1.04–1.06 | 14/27 (51.9%) | 16/21 (76.2%) | 14/19 (73.7%) | 16/29 (55.2%) |
| P = 0.016 | |||||||
| Weight: | |||||||
| - Less than 4 kg | 0.507±0.103 (P = 0.945) | 1.62 | 0.88–0.89 | 10/16 (62.5%) | 11/18 (61.1%) | 10/17 (58.8%) | 11/17 (64.7%) |
| - 4 kg or more | 0.715±0.090 (P = 0.026) | 2.84 | 1.06–1.07 | 9/17 (52.9%) | 19/20 (95.0%) | 9/10 (90.0%) | 19/27 (70.4%) |
| P = 0.128 |
AUC: area under the curve; LR: likelihood ratio; N/e: not evaluable; NPV: negative predictive value; PPV: positive predictive value; ROC: receiver operating characteristics; SE: standard error; xURL: fraction of the upper reference limit.