Table 3.
Univariable and multivariable (logistic regression) outputs of risk factors for the confirmation 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 | 1·05 (1·02–1·07) | <0·001 | 1·05 (1·03–1·08) |
| Sex | Male | – | 1 (ref.) | – | 1 (ref.) |
| Female | 0·28 | 1·08 (0·94–1·24) | 0·553 | 0·95 (0·81–1·12) | |
| Bull | 0·98 | 1 (0·66–1·51) | 0·559 | 0·89 (0·58–1·36) | |
| Slaughter season | Jan.–Mar. | – | 1 (ref.) | – | 1 (ref.) |
| Apr.–June | 0·14 | 0·87 (0·71–1·05) | 0·257 | 0·88 (0·73–1·07) | |
| July–Sept. | 0·023 | 1·26 (1·03–1·53) | 0·024 | 1·25 (1·03–1·53) | |
| Oct.–Dec. | 0·529 | 0·94 (0·79–1·13) | 0·627 | 0·95 (0·79–1·14) | |
| Patch incidence | <Q1 | – | 1 (ref.) | – | 1 (ref.) |
| ⩾Q1 to <Med | 1·082 | 1·08 (0·88–1·33) | 0·327 | 1·10 (0·89–1·36) | |
| ⩾Med to <Q3 | 0·203 | 1·14 (0·93–1·4) | 0·112 | 1·17 (0·95–1·44) | |
| ⩾Q3 | 0·004 | 1·33 (1·1–1·61) | 0·002 | 1·35 (1·11–1·64) | |
| OTF time (years) | bTB-restricted | – | 1 (ref.) | – | 1 (ref.) |
| <1 | 0·054 | 0·83 (0·69–1) | 0·005 | 0·77 (0·63–0·93) | |
| 1 to <2 | 0·092 | 0·78 (0·59–1·04) | 0·053 | 0·76 (0·56–1·01) | |
| 2 to<3 | 0·398 | 1·76 (0·48–6·49) | 0·335 | 1·86 (0·49–6·99) | |
| ⩾3 | 0·969 | 1·02 (0·3–3·49) | 0·981 | 1·01 (0·29–3·50) | |
| Purchased | Homebred | – | 1 (ref.) | – | 1 (ref.) |
| Purchased | 0·08 | 0·87 (0·74–1·02) | 0·017 | 0·83 (0·70–0·98) | |
| σ2 (s.e.) | Slh: 0·039 (0·027) | ||||
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).