Understanding patient preferences and willingness to pay for hemophilia therapies

Figures & data

Table 1 Treatment characteristics (attributes) and ranges (levels) used to create hypothetical treatment profiles

Attributes	Levels
Treatment effectiveness and frequency of dosing	1) Factor given as needed only when bleeding occurs. No decrease in number of bleeds per year (eg, a person bleeds 44 times per year; there is no decrease in bleeding episodes)
	2) Factor given three times per week. Leads to <3% of current bleeds per year (eg, a person bleeding 44 times per year; after treatment bleeds once per year)
	3) Factor given two times per week. Leads to <3% of current bleeds per year (eg, a person bleeding 44 times per year; after treatment bleeds one time per year)
	4) Factor given one time per week. Leads to <3% of current bleeds per year (eg, a person bleeding 44 times per year; after treatment bleeds one time per year)
	5) Factor given one time in 2 weeks. Leads to <3% of bleeds episodes per year (eg, a person bleeding 44 times per year; after treatment bleeds one time per year)
Dose adjustment	1) Dose adjustment required
	2) Dose adjustment not required
Treatment side effects	1) No treatment-related side effects
	2) A very small chance of having side effects (eg, infusion-site reactions)
Type of dosage	1) Premixed factor solution for infusion; no need to mix factor
	2) Need to mix factor to prepare solution for infusion
Out-of-pocket treatment costs	1) None
	2) $100 per month
	3) $500 per month
	4) $1,000 per month

Note: Currency is in USD.

Figure 1 An example of treatment-choice scenario given to respondents.

Note: Currency is in USD.

Table 2 Survey respondent demographics

Characteristics	Number of patients (n=79)	Percent (n=79)
Age (mean)		40 years (min: 18 years, max: 69 years)
Race
Asian	5	6
African American	10	13
Hispanic	15	19
Non-Hispanic white	49	62
Marital status
Single	18	23
Married	51	65
Widowed	1	1
Divorced	3	4
Separated	1	1
Living together	5	6
Education
Did not complete high school	3	4
Completed high school	29	37
2-year college degree	13	16
4-year college degree	23	29
Advanced graduate degree	11	14
Employment
Working full time	32	41
Working part time	21	27
Not working (not retired)	18	23
Retired	7	9
Other	1	1
Annual household income
<$25,000	11	14
$25,000–$49,999	16	20
$50,000–$74,999	15	19
$75,000–$99,999	7	9
$100,000+	15	19
Chose not to disclose	15	19
Respondent sample
Patients	21	27
Caregivers	58	73
Current therapy – patients only
On demand	5	24
Prophylaxis	16	76
Other	0	0
None	0	0
Bleeding episodes per month – patients only
Three or more episodes per month (severe)	8	38
One or two episodes per month (moderate)	5	24
Experience episodes every few months (mild)	8	38
Inhibitor presence – patients only
Yes	2	9.5
No	19	90.5

Note: Currency is in USD.

Abbreviations: min, minimum; max, maximum.

Table 3 Patient preferences for hemophilia therapies – mixed logit model analysis

Attribute	Level	B parameter estimate (95% CI)	P-value
Treatment effectiveness and dosing frequency	On demand	−1.252 (−1.969, −0.535)	0.001
	Twice-weekly prophylaxis	0.380 (−0.025, 0.785)	0.066
	Once-weekly prophylaxis	0.741 (0.299, 1.183)	0.001
	Biweekly prophylaxis	0.970 (0.543, 1.396)	0.001
	Ref: three times per week prophylaxis
Dose adjustment	No dose adjustment required	0.066 (−0.213, 0.345)	0.642
	Ref: dose adjustment required
Treatment side effects	Small chance of catheter–port-related infections and/or injection site-related skin rashes	−0.716 (−1.032, −0.398)	0.001
	Ref: no complications
Form of dosage	Need to mix factor	−0.179 (−0.501, 0.143)	0.277
	Ref: premixed ready-to-use factor solution for infusion
Out-of-pocket costs per month		−0.002 (−0.002, −0.001)	0.001

Notes: Beta parameter estimate – it indicates the increase or decrease in utility for the chosen treatment after choosing a particular treatment characteristic level with respect to the reference category. For example, choosing on-demand therapy compared to three times weekly prophylaxis therapy decreases the utility associated with the chosen treatment by 1.252.

Abbreviations: CI, confidence interval; Ref, reference category.

Figure 2 Willingness to pay (WTP) for significant treatment characteristics.

Notes: The figure indicates the upper and lower confidence limits (CI) and mean WTP. For example, the mean incremental WTP for thrice-weekly prophylaxis versus on-demand therapy is $410 out of pocket per month. The CI for this mean WTP is $164–$656. Currency is in USD.
Abbreviation: CI, confidence interval.