Table 2.
Univariable and multivariable (logistic regression) model outputs of risk factors for the disclosure of bTB lesions in cattle at routine slaughter (LRS)
| Univariable | Multivariable | ||||
|---|---|---|---|---|---|
| Variable | Category | P value | OR (95% CI) | P value | OR (95% CI) |
| Age (years) | Per year older | <0·001 | 1·07 (1·06–1·08) | <0·001 | 1·06 (1·04–1·07) |
| Sex | Male | – | 1 (ref.) | – | 1 (ref.) |
| Female | <0·001 | 1·31 (1·23–1·4) | <0·001 | 1·20 (1·11–1·30) | |
| Bull | 0·175 | 1·15 (0·94–1·41) | 0·323 | 1·11 (0·9–1·36) | |
| Slaughter season | Jan.–Mar. | – | 1 (ref.) | – | 1 (ref.) |
| Apr.–June | 0·025 | 0·90 (0·82–0·99) | 0·042 | 0·91 (0·83–1) | |
| July–Sept. | 0·036 | 0·90 (0·82–0·99) | 0·007 | 0·89 (0·80–0·96) | |
| Oct.–Dec. | 0·942 | 1 (0·92–1·1) | 0·604 | 0·98 (0·89–1·07) | |
| Patch incidence | <Q1 | – | 1 (ref.) | – | 1 (ref.) |
| ⩾Q1 to <Med | 0·226 | 0·94 (0·85–1·04) | 0·589 | 0·97 (0·88–1·08) | |
| ⩾Med to <Q3 | 0·539 | 0·97 (0·88–1·07) | 0·486 | 0·96 (0·87–1·07) | |
| ⩾Q3 | <0·001 | 1·28 (1·16–1·4) | <0·001 | 1·19 (1·08–1·31) | |
| OTF time (years) | bTB-restricted | – | 1 (ref.) | – | 1 (ref.) |
| <1 | 0·025 | 0·90 (0·82–0·99) | 0·020 | 0·90 (0·82–0·98) | |
| 1 to <2 | 0·023 | 0·85 (0·74–0·98) | 0·027 | 0·85 (0·74–0·98) | |
| 2 to<3 | 0·003 | 2·39 (1·35–4·22) | 0·016 | 2·01 (1·14–3·56) | |
| ⩾3 | 0·157 | 1·53 (0·85–2·78) | 0·167 | 1·53 (0·84–2·76) | |
| Purchased | Homebred | – | 1 (ref.) | – | 1 (ref.) |
| Purchased | 0·034 | 1·09 (1·01–1·17) | <0·001 | 1·22 (1·12–1·32) | |
| σ2 (s.e.) | Slh: 0·305 (0·151) | ||||
OR, Odds ratio; CI, confidence interval; OTF, officially tuberculosis free; Q1, first quartile; Med, median; Q3, third quartile; σ2, variance; s.e., standard error of the random effect slaughterhouse (Slh).