|  | abortion | insemination index | ||||
---|---|---|---|---|---|---|---|
Risk factor | Herds (n) | OR | p | 95% CI | OR | p | 95% CI |
BHV-1 prevalence in cowsa | Â | Â | Â | Â | Â | Â | Â |
0 | 25 | 1 | - | - | 1 | - | - |
1-49% | 24 | 7.3 | 0.003 | 2.0; 26.9 | 5.2 | 0.01 | 1.5; 18.4 |
≥50% | 28 | 4.6 | 0.022 | 1.2; 16.7 | 3.4 | 0.056 | 1.0; 12.3 |
Herd sizeb | Â | Â | Â | Â | Â | Â | Â |
20-99 cows | 25 | 1 | - | - | 1 | - | - |
100-199 cows | 17 | 1.2 | 0.754 | 0.3; 5.0 | 0.8 | 0.725 | 0.2; 3.0 |
200-399 cows | 21 | 1.7 | 0.447 | 0.4; 6.5 | 1.2 | 0.83 | 0.3; 4.2 |
> 400 cows | 14 | 0.3 | 0.165 | 0.1; 1.6 | 0.9 | 0.944 | 0.2; 4.2 |
 |  | aBHV-1 in cows p = 0.009, the Wald test | aBHV-1 cows p = 0.033, the Wald test | ||||
 |  | bHerd size p = 0.193, the Wald test | bHerd size p = 0.957, the Wald test |