Table 3.

Assumptions and inputs used for each cow-side test to evaluate the economic benefit of using propylene glycol to treat cows with ketosis, and sensitivity and specificity of each cow-side test used to diagnose ketosis and the number of true positives, false positives, and false negatives within each testing method, assuming a herd size of 1 cow and a cumulative incidence of 40% for ketosis

	Precision XTRA	Keto-Test	Ketostixa
Sensitivityb	0.90	0.8	0.79
Specificityb	0.965	0.94	0.96
True positive	0.360	0.328	0.190
False positive	0.021	0.036	0.254
False negative	0.040	0.072	0.210
Cost of test	$3.0	$2.0	$0.25
Cows providing urine	—	—	60%
Cost of 4 doses of PG	$12	$12	$12
Total cost of PG	$4.57	$4.37	$5.33
Total cost of labor	$0.76	$0.73	$0.89

^aSensitivity and specificity of Ketostix is only applied to cows from which a urine sample can be obtained. The baseline used in this model was 60% of cows will provide a urine sample resulting in a sensitivity and specificity of 47.4% and 57.6% respectively, for Ketostix.

^bFrom reference 6.