Variable (outcome = VL) | N-positive (% positive) |  | N | OR (95%CI) | P-value |
---|---|---|---|---|---|
Risk factors at animal level | Â | Â | Â | Â | Â |
b-a PPD reaction size | Â | Â | 5698 | Â | <0.001 |
 | 18 (11.92%) | <0 mm |  | 2.39 (1.19–4.82) |  |
 | 22 (4.7%) | 0 mm |  | Ref. |  |
 | 211 (25%) | 1-4 mm |  | 7.16 (4.32–11.87) |  |
 | 691 (36.64%) | 5-9 mm |  | 15.97 (9.8–26.01) |  |
 | 884 (59.81%) | 10-19 mm |  | 45.47 (27.8–74.37) |  |
 | 649 (74.51%) | >20 mm |  | 109.53 (65.52–183.10) |  |
Reason for removal | Â | Â | 6242 | Â | <0.001 |
 | 30 (5.12%) | Negative in contact |  | Ref. |  |
 | 30 (6.55%) | Removed due to IFN-γ result |  | 1.32 (0.72–2.38) |  |
 | 2444 (47.02%) | Removed due to SICCT result |  | 20.83 (13.58–31.95) |  |
BVD | Â | Â | 6242 | Â | 0.106 |
 | 2500 (99.84%) | BVD Negative |  | Ref. |  |
 | 4 (0.16%) | BVD positive |  | 0.33 (0.08–1.26) |  |
BVD (indirect) | Â | Â | 6242 | Â | 0.165 |
 | 2407 (40.41%) | BVD Negative |  | Ref. |  |
 | 97 (33.92%) | BVD positive |  | 0.60 (0.29–1.23) |  |
Fascioliasis | Â | Â | 6242 | Â | 0.292 |
 | 2372 (40.33%) | Fascioliasis Negative |  | Ref. |  |
 | 132 (36.57%) | Fascioliasis Positive |  | 0.86 (0.65–1.13) |  |
Liver fluke damage | Â | Â | 6242 | Â | 0.997 |
 | 2161 (40.27%) | Liver damage Negative |  | Ref. |  |
 | 343 (39.16%) | Liver damage Positive |  | 1.00 (0.83–1.2) |  |
Liver fluke exposure | Â | Â | 6242 | Â | 0.55 |
 | 2029 (40.53%) | Facioliasis and damage Negative |  | Ref. |  |
 | 475 (38.43%) | Facioliasis or damage Positive Mean |  | 0.95 (0.81–1.11) |  |
Age-quartiles | Â | Â | 6231 | Â | <0.001 |
 | 612 (39.74%) | ≤ 1.53 years |  | 0.77 (0.64–0.92) |  |
 | 704 (45.48%) | 1.53–2.86 years |  | Ref. |  |
 | 580 (36.64%) | 2.86–5.58 years |  | 0.69 (0.58–0.83) |  |
 | 607 (38.91%) | ≥5.58 years |  | 0.76 (0.63–0.91) |  |
Breed | Â | Â | 6242 | Â | <0.001 |
 | 1517 (44.29%) | Non-dairy |  | Ref. |  |
 | 987 (35.04%) | Dairy |  | 0.73 (0.61–0.86) |  |
Sex | Â | Â | 6242 | Â | 0.406 |
 | 517 (39.26%) | Male |  | Ref. |  |
 | 1987 (40.35%) | Female |  | 1.07 (0.90–1.26) |  |
Associated herds | Â | Â | 6242 | Â | <0.001 |
 |  | Log(No. associated herds) |  | 2.84 (2.45–3.30) |  |
No. Market moves | Â | Â | 6242 | Â | 0.028 |
 |  | Market moves |  | 1.04 (1–1.08) |  |
Time since last test | Â | Â | 5831 | Â | <0.001 |
 |  | Log(Time in days between tests) |  | 1.59 (1.40–1.80) |  |
Herd bTB history | Â | Â | 6242 | Â | <0.001 |
 | 1188 (35.83%) | No bTB |  | Ref. |  |
 | 1316 (44.98%) | bTB |  | 2.13 (1.76–2.57) |  |
Penultimate herd bTB history | Â | Â | 6242 | Â | 0.044 |
 |  | No bTB |  | Ref. |  |
 |  | bTB |  | 2.02 (1.02–4.00) |  |
Penultimate test results | Â | Â | 6242 | Â | <0.001 |
 | 2246 (39.94%) | Severe interpretation negative on penultimate test |  | Ref. |  |
 | 84 (59.15%) | Severe interpretation positive on penultimate test |  | 2.42 (1.57–3.72) |  |
 | 174 (36.48%) | No previous test result |  | 0.84 (0.64–1.09) |  |
Breakdown size | Â | Â | 6242 | Â | 0.001 |
 |  | per additional reactor |  | 0.99 (0.98–0.99) |  |
Herd size | Â | Â | 6237 | Â | 0.044 |
(quartiles) | 716 (45.99%) | ≤71 |  | Ref. |  |
 | 637 (41.26%) | 72–158 |  | 0.86 (0.66–1.1) |  |
 | 491 (33.22%) | 159–279 |  | 0.71 (0.54–0.93) |  |
 | 658 (39.69%) | ≥280 |  | 0.72 (0.54–0.94) |  |
Purchases | Â | Â | 6017 | Â | 0.114 |
(quartiles) | 593 (41.61%) | ≤7 |  |  | Ref. |
 | 683 (43.98%) | 8–31 |  | 1.12 (0.86–1.46) |  |
 | 542 (35.38%) | 32–100 |  | 1.22 (0.91–1.64) |  |
 | 582 (38.62%) | ≥101 |  | 1.44 (1.06–1.94) |  |
Region | Â | Â | 6242 | Â | 0.171 |
 | 629 (46.35%) | 1. North (Derry, Larne, Ballymena and Coleraine) |  | Ref. |  |
 | 863 (38.2%) | 2. South-West (Omagh, Enniskillen and Dungannon) |  | 0.91 (0.7–1.18) |  |
 | 1012 (38.54%) | 3. South-east (Newtownards, Newry and Armagh) |  | 0.78 (0.61–1.01) |  |