Table 1.

Probabilities and Costs Used in Decision Model^a

Probabilities	Low	Base	High
Probability of sequelae if EM is treated	0.001	0.005	0.01
Probability of sequelae if EM is not treated	0.54	0.83	0.99
Cardiac		0.05
Neurologic		0.15
Arthritic		0.6
Treatment
Probability of major adverse reaction	0.0001	0.0005	0.001
Probability of minor adverse reaction	0.03	0.05	0.1
Serology
Sensitivity - P(Positive | Lyme)		0.35
Specificity - P(Negative | No Lyme)		0.98

Costs (2010 dollars)	Low	Base	High
Cost of amoxicillin or doxycycline for EM	4	4	216
Major adverse reaction	3140	5000	8258
Minor adverse reaction	91	250	429
Cost of Lyme disease sequelae	2003	4000	11496
Serology	37	80	127

^aCosts are in 2010 US dollars.

EM, erythema migrans.