Table 3. Univariable and multivariable (adjusted for covariates and random herd effect) logistic regression results of submitted (n = 6,578,245) and confirmed (n = 13,337) bTB lesions from animals slaughtered in Irish factories in the period 2014–2018.
| Variable | Number slaughter | Submission (%) | Confirmation (%) | Univariable | Multivariable | ||
|---|---|---|---|---|---|---|---|
| Submission OR; 95% CI | Confirmation OR; 95% CI | Submission OR; 95% CI | Confirmation OR; 95% CI | ||||
| Year | |||||||
| 2014 | 1,354,005 | 0.20 | 46.14 | Ref. | Ref. | Ref. | Ref. |
| 2015 | 1,273,270 | 0.21 | 42.40 | 1.08; 1.02–1.14 | 0.79; 0.67–0.91 | 1.13; 1.07–1.20 | 0.81; 0.67–0.98 |
| 2016 | 1,323,348 | 0.21 | 37.85 | 1.08; 1.02–1.14 | 0.62; 0.53–0.72 | 1.16; 1.10–1.23 | 0.73; 0.60–0.88 |
| 2017 | 1,399,721 | 0.20 | 39.38 | 1.05; 1.00–1.11 | 0.70; 0.60–0.81 | 1.13; 1.07–1.19 | 0.82; 0.67–0.99 |
| 2018 | 1,227,901 | 0.20 | 37.87 | 1.05; 1.00–1.11 | 0.65; 0.56–0.76 | 1.13; 1.06–1.20 | 0.80; 0.66–0.99 |
| Age (year) | |||||||
| 1 | 1,845,788 | 0.15 | 28.13 | Ref. | Ref. | Ref. | Ref. |
| 2 | 3,190,707 | 0.16 | 37.07 | 1.11; 1.06–1.17 | 1.68; 1.46–1.94 | 1.11; 1.05–1.17 | 1.75; 1.46–2.09 |
| 3 | 363,954 | 0.28 | 36.37 | 1.91; 1.77–2.06 | 1.64; 1.33–2.03 | 1.73; 1.59–1.87 | 1.38; 1.05–1.80 |
| 4 | 176,970 | 0.31 | 42.86 | 2.20; 2.00–2.42 | 2.39; 1.84–3.11 | 1.84; 1.66–2.04 | 2.3; 1.62–3.26 |
| 5 | 160,529 | 0.31 | 41.18 | 2.18; 1.97–2.40 | 2.22; 1.69–2.91 | 1.70; 1.53–1.90 | 1.71; 1.20–2.44 |
| 6 | 150,557 | 0.35 | 48.66 | 2.47; 2.25–2.72 | 3.22; 2.47–4.20 | 1.88; 1.69–2.09 | 3.06; 2.12–4.40 |
| 7 | 140,981 | 0.36 | 54.69 | 2.52; 2.29–2.78 | 4.54; 3.46–5.97 | 1.86; 1.67–2.08 | 3.42; 2.38–4.93 |
| ≥8 | 548,759 | 0.42 | 60.55 | 2.91; 2.75–3.09 | 6.28; 5.25–7.52 | 1.91; 1.77–2.06 | 4.05; 3.17–5.18 |
| Sex | |||||||
| Female | 3,017,843 | 0.25 | 48.50 | Ref. | Ref. | Ref. | Ref. |
| Male | 3,560,402 | 0.17 | 31.03 | 0.67; 0.64–0.70 | 0.36; 0.32–0.40 | 1.05; 1.00–1.10 | 0.66; 0.56–0.76 |
| Animal movement | |||||||
| Homebred | 1,777,728 | 0.21 | 39.21 | Ref. | Ref. | Ref. | Ref. |
| Purchased | 4,800,517 | 0.20 | 41.33 | 0.97; 0.93–1.01 | 1.15; 1.02–1.28 | 0.96; 0.91–1.01 | 0.96; 0.81–1.14 |
| Breed | |||||||
| Cross breed | 4,716,660 | 0.20 | 39.82 | Ref. | Ref. | Ref. | Ref. |
| Pure breed | 1,861,585 | 0.21 | 42.96 | 1.03; 0.99–1.08 | 1.22; 1.10–1.37 | 0.80; 0.76–0.83 | 1.04; 0.89–1.22 |
| Ever inconclusive | |||||||
| No | 6,566,719 | 0.18 | 41.89 | Ref. | Ref. | Ref. | Ref. |
| Yes | 11,526 | 14.34 | 32.49 | 99.04; 93.19–105.26 | 0.64; 0.55–0.75 | 74.24; 69.39–79.43 | 0.44; 0.36–0.54 |
| Ever severe inconclusive | |||||||
| No | 6,560,368 | 0.20 | 39.86 | Ref. | Ref. | Ref. | Ref. |
| Yes | 17,877 | 2.17 | 85.60 | 6.89; 6.02–7.81 | 17.94; 11.27–28.54 | 2.83; 2.44–3.27 | 4.48; 2.66–7.54 |
| Herd type | |||||||
| Beef | 2,435,812 | 0.20 | 40.74 | Ref. | Ref. | Ref. | Ref. |
| Dairy | 1,267,432 | 0.20 | 37.91 | 1.06; 1.00–1.12 | 0.88; 0.75–1.02 | 0.83; 0.77–0.90 | 1.08; 0.85–1.38 |
| Other | 520,788 | 0.18 | 33.19 | 0.85; 0.78–0.93 | 0.61; 0.49–0.77 | 0.99; 0.90–1.08 | 1.11; 0.81–1.51 |
| Suckler | 2,354,213 | 0.21 | 43.51 | 1.13; 1.07–1.18 | 1.21; 1.07–1.38 | 1.08; 1.02–1.14 | 1.31; 1.11–1.55 |
| Herd size | 0.98; 0.96–0.99 | 0.96; 0.59–0.81 | 0.95; 0.93–0.96 | 0.82; 0.78–0.86 | |||
| BTB history (past 3 years) | |||||||
| No | 4,722,722 | 0.12 | 2.44 | Ref. | Ref. | Ref. | Ref. |
| Yes | 1,855,523 | 0.41 | 69.73 | 4.87; 4.66–5.09 | 355.80; 2.65–478.26 | 4.46; 4.28–4.66 | 319.90; 237.98–430.04 |
| Months of slaughter | |||||||
| January | 562,269 | 0.19 | 37.55 | Ref. | Ref. | Ref. | Ref. |
| February | 430,767 | 0.18 | 42.56 | 0.93; 0.85–1.02 | 1.31; 1.01–1.71 | 0.94; 0.86–1.04 | 1.10; 0.79–1.53 |
| March | 562,055 | 0.18 | 39.36 | 0.97; 0.89–1.06 | 1.09; 0.85–1.38 | 0.98; 0.90–1.07 | 1.13; 0.83–1.53 |
| April | 527,150 | 0.20 | 38.06 | 1.07; 0.98–1.16 | 1.06; 0.83–1.34 | 1.04; 0.95–1.14 | 1.01; 0.74–1.36 |
| May | 534,771 | 0.19 | 38.73 | 1.02; 0.93–1.11 | 1.15; 0.90–1.46 | 0.94; 0.86–1.03 | 1.02; 0.75–1.39 |
| June | 536,051 | 0.21 | 40.37 | 1.11; 1.02–1.21 | 1.07; 0.84–1.36 | 1.01; 0.93–1.10 | 0.84; 0.62–1.13 |
| July | 558,296 | 0.22 | 40.87 | 1.16; 1.07–1.26 | 1.24; 0.98–1.56 | 1.05; 0.96–1.15 | 1.11; 0.83–1.50 |
| August | 588,359 | 0.21 | 39.34 | 1.09; 1.01–1.19 | 1.12; 0.89–1.42 | 1.02; 0.94–1.11 | 1.01; 0.75–1.35 |
| September | 622,015 | 0.21 | 41.42 | 1.10; 1.01–1.19 | 1.23; 0.98–1.55 | 1.05; 0.97–1.15 | 1.14; 0.85–1.53 |
| October | 617,809 | 0.20 | 42.92 | 1.05; 0.97–1.14 | 1.29; 1.02–1.63 | 1.01; 0.93–1.10 | 1.39; 1.03–1.87 |
| November | 626,507 | 0.20 | 42.93 | 1.04; 0.95–1.13 | 1.38; 1.10–1.75 | 0.99; 0.91–1.08 | 1.34; 1.00–1.81 |
| December | 412,196 | 0.22 | 44.86 | 1.14; 1.04–1.25 | 1.48; 1.16–1.91 | 1.11; 1.02–1.22 | 1.55; 1.13–2.13 |
| Total | 6,578,245 | 0.20 | 40.72 | ||||