Table 3. Univariate analyses of risk factors for outcome and quarter recovery.

Variables	Category	Outcome				Quarter recovery
		Survival	Culling	Odds ratio	P value	Yes	No	Odds ratio	P value
Onset in summer	Yes	25	13	1.17	0.82	5	32	1.02	1
	No	28	17	Reference		6	39	Reference
Body temperature	≥39.5°C	27	23	0.30	0.03	4	46	0.28	0.09
	<39.5°C	24	6	Reference		7	22	Reference
Tie stall barn	Yes	45	23	1.70	0.38	9	59	0.92	1
	No	8	7	Reference		2	12	Reference
Dry therapy	Yes	39	23	0.85	0.80	8	53	0.91	1
	No	14	7	Reference		3	18	Reference
Isolation of anaerobic bacteria	Yes	2	2	0.55	0.62	0	4	0.00	1
	No	51	28	Reference		11	67	Reference
Severity	Severe	28	28	0.09	<0.001	3	53	0.12	<0.01
	Mild-moderate	24	2	Reference		8	17	Reference
Teat trauma	Yes	7	6	0.72	0.76	0	13	0.00	0.34
	No	39	24	Reference		8	54	Reference
Mammary irrigation regimen	Yes	10	7	0.73	0.58	2	15	0.77	1
	No	41	21	Reference		9	52	Reference
Period	Lactation	31	12	2.09	0.12	8	35	2.71	0.20
	Dry	22	18	Reference		3	36	Reference
Concurrent disease	Yes	13	19	0.20	<0.001	1	31	0.13	<0.05
	No	39	11	Reference		10	39	Reference
History of blind quarter	Yes	8	4	1.15	1	2	10	1.35	0.66
	No	45	26	Reference		9	61	Reference