Table 2.

Patient preferences and valuation of venous thromboembolism prophylaxis attributes

Attribute	Level	Marginal utility	95% CI	WTP	p Value
Route	Oral tablet	0.16	0.11 to 0.21	$117.45	<0.0001
	Subcutaneous injection	−0.16	−0.21 to −0.11	–	–
Side effects	Bruising on leg	−0.04	−0.11 to 0.02	-$45.94	0.11
	Stomach pain	−0.04	−0.12 to 0.04	-$44.08	–
	No side effects	0.08	0.003 to 0.16	$45.08	–
Bleeding complications requiring transfusion	Reduce risk by 1%	0.05	0.04 to 0.05	$16.83	<0.0001
Wound complications requiring another surgery	Reduce risk by 1%	0.07	0.06 to 0.08	$25.91	<0.0001
Blood clot requiring long-term medication	Reduce risk by 1%	0.25	0.15 to 0.36	$92.29	<0.0001
Death due to PE	Reduce risk by 1%	4.57	3.26 to 5.89	$1686.90	<0.0001
Cost	$10 increase	−0.03	−0.04 to −0.02	Reference	<0.0001

Marginal utility quantifies the additional satisfaction gained by the patient for each described attribute/level. Negative marginal utility values signify an aversion to or dissatisfaction with the described attribute/level. All risk reductions are absolute. Willingness to pay for the route and side effect category is based on the full treatment course, not per dose. Willingness to pay for all other attributes is based on the incremental change in level.

PE , pulmonary embolism; WTP, willingness to pay.