. 2017 Sep 19;61(3):337–343. doi: 10.1515/jvetres-2017-0044

Table 3.

Analysis of the relation between contact with a pathogen and the abortion in cows: a case-control study

Pathogen	Status	+	–	Total	Exposition rate	OR	CI95%	p	EAF	PAF	P(A/P)
N.caninum	case	21	61	82	25.6%	2.56	1.38–4.73	<0.01	60.9%	15.6%	0.39
N.caninum	control	33	245	278	11.9%	2.56	1.38–4.73	<0.01	60.9%	15.6%	0.39

BoHV1	case	0	82	82	0.0%	0.67^*	0.03–14.1	0.8	ND	ND	0.0
BoHV1	control	2	276	278	0.7%	0.67^*	0.03–14.1	0.8	ND	ND	0.0

BoHV4	case	9	73	82	11.0%	8.45	2.53–28.2	<0.01	88.2%	9.7%	0.69
BoHV4	control	4	274	278	1.4%	8.45	2.53–28.2	<0.01	88.2%	9.7%	0.69

BVD	case	4	78	82	4.9%	14.21	1.57–128.93	<0.05	93.0%	4.5%	0.8
BVD	control	1	277	278	0.4%	14.21	1.57–128.93	<0.05	93.0%	4.5%	0.8

B. abortus	case	6	76	82	7.3%	4.31	1.28–14.51	<0.05	76.8%	5.6%	0.55
B. abortus	control	5	273	278	1.8%	4.31	1.28–14.51	<0.05	76.8%	5.6%	0.55

S. Dublin	case	4	78	82	4.9%	14.21	1.57–128.93	<0.05	93.0%	4.5%	0.7
S. Dublin	control	1	277	278	0.4%	14.21	1.57–128.93	<0.05	93.0%	4.5%	0.7

L. Hardjo	case	10	72	82	12.2%	9.44	2.88–30.99	<0.01	89.4%	10.8%	0.76
L. Hardjo	control	4	272	278	1.4%	9.44	2.88–30.99	<0.01	89.4%	10.8%	0.76

C. abortus	case	0	82	82	0.0%	0.48^*	0.02–9.33	0.63	ND	ND	0.0
C. abortus	control	3	275	278	1.1%	0.48^*	0.02–9.33	0.63	ND	ND	0.0

C. burnetii	case	4	78	82	4.9%	7.08	1.27–39.36	<0.05	85.9%	4.2%	0.67
C. burnetii	control	2	276	278	0.7%	7.08	1.27–39.36	<0.05	85.9%	4.2%	0.67

At least one pathogen	case	36	46	82	43.9%	4.16	2.42–7.16	<0.01	76%	33.4%	0.45
At least one pathogen	control	44	234	278	15.8%	4.16	2.42–7.16	<0.01	76%	33.4%	0.45

: The OR normally has an infinite value due to the presence of 0 negative samples in case farms. In this case, we added 0.5 at each value.

Exposed attributable fraction = EAF = (OR–1)/OR

Population attributable fraction = PAF = Po(OR–1)/(1+(Po(OR–1))

Po = number of exposed in controls/number of controls

P(A/P) = probability of abortion (A) if pathogen (P) = p (A∩P)/P(P)

ND – not determined