Patient preferences for treatment of multiple sclerosis with disease-modifying therapies: a discrete choice experiment

Figures & data

Table 1 Final attributes and levels used in the discrete choice experiment

Attributes	Levels
Route and frequency of administration
The treatment is administered…	Orally every day
	Intramuscularly weekly
	Subcutaneously several times per week
Prevents relapses
A relapse that needs the administration of corticosteroids may occur…	During the first 5 years after starting treatment
	After >5 years after starting treatment
Delays progression
The treatment prevents the progression of disability associated with the disease in the…	Short term (there is no progression of disability in 2 years)
	Medium term (there is no progression of disability in 5 years)
	Long term (there is no progression of disability in 10 years)
Side effects
__________ side effects may occur.	Mild (treatment discontinuation is not required)
	Moderate (treatment discontinuation is required temporarily)
	Severe (serious or life-threatening)
Impact on daily life
Discomfort may occur that…	Does not affect your daily life or everyday activities
	Affects your daily life or everyday activities
Treatment follow-up
Treatment follow-up needing you to visit the doctor…	Once a month
	Every 3 months
	Every 6 months

Table 2 Example of the choice set

	Treatment A	Treatment B
The treatment is administered…	Intramuscular weekly	Oral daily
A relapse that needs the administration of corticosteroids may occur…	During the first 5 years after starting treatment	During the first 5 years after starting treatment
The treatment prevents the progression of disease-related disability in the…	Long term (there is no progression of disability in 10 years)	Medium term (there is no progression of disability in 5 years)
__________ side effects may occur.	Mild (treatment discontinuation is not required)	Mild (treatment discontinuation is not required)
Discomfort may occur that…	Affects your daily life or everyday activities	Affects your daily life or everyday activities
Treatment follow-up needing you to visit the doctor…	1 visit per month	Every 6 months
	□ prefer A	□ prefer B

Table 3 Participant sociodemographic and clinical characteristics (n=125)

Characteristic	% of patients or mean (SD)
Age, years, mean (SD)	44.5 (10.9)
Female (%)	62.9
Marital status
Married/living with partner	63.2
Single	32.8
Separated/divorced	4.0
Level of education
Primary school	10.4
Secondary school	33.6
University	42.4
Postgraduate	8.0
Other studies	5.6
Employment status
Employed, full-time or part-time	36.8
Unemployed/student	12.0
Long-term sick leave/disabled/retired	51.2
MS type
RRMS	71.5
SPMS	28.5
Time since MS diagnosis, years, mean (SD)	13.4 (7.9)
Time from diagnosis to treatment initiation, years, mean (SD)	4.8 (7.3)
Time on MS treatment, years, mean (SD)	9.3 (6.2)
Time on current MS treatment, years, mean (SD)	4.3 (5.2)
Type of administration for current medication (n=99)
Oral	43.4
IM	26.3
SC	6.1
IV	15.2
Not specified	9.0
Naïve patient	8.0

Abbreviations: IM, intramuscular; IV, intravenous; MS, multiple sclerosis; RRMS, relapsing-remitting MS; SPMS, secondary-progressive MS; SC, subcutaneous; SD, standard deviation.

Figure 1 Preferences for levels within each attribute.

Note: *P<0.01.
Abbreviations: IM, intramuscular; OR, odds ratio; ref, reference; SC, subcutaneous.

Table 4 MS patient preferences

Attribute	Level	Coefficients	OR	SE	P-value
Route and frequency of administration	Oral daily (reference)	0	1	–	–
	Intramuscular weekly	−0.849	0.428	0.113	<0.01
	Subcutaneous several times per week	−0.943	0.389	0.103	<0.01
Prevents relapses	<5 years (reference)	0	1	–	–
	>5 years	0.066	1.068	0.101	0.513
Delays progression	Per year	0.128	1.137	0.013	<0.01
	2 years	0.256	1.292	–	–
	5 years	0.640	1.896	–	–
	10 years	1.280	3.597	–	–
Side effects	Per 100% of severity	−3.388	0.034	0.204	<0.01
	Mild	−1.118	0.327	–	–
	Moderate	−2.236	0.107	–	–
	Severe	−3.388	0.034	–	–
Impact on daily life	No impact (reference)	0	1	–	–
	Impact	−0.760	0.468	0.099	<0.01
Treatment follow-up	Per monthly visit	−0.149	0.862	0.134	0.267
	1 visit every 6 months	−0.025	0.975	0.89	0.92
	1 visit every 3 months	−0.050	0.952	0.8	0.85
	1 visit per month	−0.149	0.862	0.54	0.68

Note: Bold text indicates statistically significant value.

Abbreviations: MS, multiple sclerosis; OR, odds ratio; SE, standard error.

Figure 2 Relative importance in patients’ decisons.

Figure 3 Preference for side effects by patients’ age and level of education.

Notes: 20 years high: patient aged 20 years with high level of education; 20 years nonhigh: patient aged 20 years without high level of education; 40 years high: patient aged 40 years with high level of education; 40 years nonhigh: patient aged 40 years without high level of education; 60 years high: patient aged 60 years with high level of education; 60 years nonhigh: patient aged 60 years without high level of education. Patients’ age: P=0.0224; level of education: P=0.0254.

Figure 4 Preference for the route and frequency of administration by duration of the current treatment and type of multiple sclerosis.

Notes: 1-year SP: patient with 1 year in current treatment and diagnosis of SPMS; 1-year RR: patient with 1 year in current treatment and diagnosis of RRMS; 10-year SP: patient with 10 years in current treatment and diagnosis of SPMS; 10-year RR: patient with 10 years in current treatment and diagnosis of RRMS; 20-year SP: patient with 20 years in current treatment and diagnosis of SPMS; 20-year RR: patient with 20 years in current treatment and diagnosis of RRMS. Duration of the current treatment: P=0.004 for subcutaneous several times per week and P=0.00341 for intramuscular weekly; type of MS (SP): P=0.03233.
Abbreviations: MS, multiple sclerosis; RR, relapse-remitting; RRMS, relapsing-remitting MS; SPMS, secondary-progressive MS; SP, secondary progressive.

Table 5 Stepwise multilinear regression of partial utilities

Attribute	Coefficient	P-value
Route and frequency of administration: subcutaneously several times per week
(Intercept)	−1.055	<0.001*
Age	−0.011	0.107
SPMS (1)	−0.298	0.084
Actual treatment duration	0.046	0.004*
Actual treatment: oral (2)	−0.241	0.051
Route and frequency of administration: intramuscular weekly
(Intercept)	−1.412	<0.001*
SPMS	−0.418	0.032*
Actual treatment duration	0.049	0.003*
Prevents progression
(Intercept)	0.051	0.597
Age	0.005	0.050
Higher education (3)	0.059	0.160
Time with MS	−0.006	0.112
Prevents relapses
(Intercept)	0.381	<0.001*
Woman (4)	−0.069	0.144
Side effects
(Intercept)	−4.932	<0.001*
Age	−0.061	0.022*
Higher education	1.042	0.025*
Total treatment duration	0.080	0.064
Impact on daily life
(Intercept)	−1.291	<0.001*
Age	0.010	0.062
Actual treatment duration	−0.026	0.031*
Treatment follow-up
Age	−0.017	<0.001
Actual treatment duration	0.029	0.023

Notes: (1) Ref. level: RRMS; (2) Ref. level: nonoral current treatment; (3) Ref. level: nonuniversity level education; (4) Ref. level: male

* Statistically significant.

Abbreviations: RRMS, relapsing-remitting MS; SPMS, secondary-progressive MS; MS, multiple sclerosis; Ref., reference.

Table 6 Stepwise multilinear regression of relative importance

Attribute	Coefficient	P-value
Route and frequency of administration
(Intercept)	13.42%	<0.001
Total treatment duration	0.28%	0.069
Actual treatment duration	−0.49%	0.022
Prevents relapses
(Intercept)	3.30%	<0.001
Age	−0.03%	0.075
Higher education (1)	0.80%	0.011
Time with MS	0.06%	0.025
Prevents progression
(Intercept)	16.22%	<0.001
Higher education	5.05%	0.034
Side effects
(Intercept)	53.40%	<0.001
Higher education	−7.73%	0.003
Impact on daily life
(Intercept)	14.02%	<0.001
Age	−0.17%	0.028
Actual treatment duration	0.50%	0.004
Treatment follow-up
(Intercept)	3.18%	0.0129
Age	0.07%	0.0255
Actual treatment duration	−0.11%	0.1403

Note: (1) Ref. level: nonuniversity level education.

Abbreviations: MS, multiple sclerosis; Ref., reference.

Figure 5 MRI of attributes by route of administration.

Abbreviation: MRI, mean relative importance.

Figure 6 MRI of attributes by total time on treatment.

Abbreviation: MRI, mean relative importance.

Table S1 Search terms and search strategy

Search terms
#1	“Multiple sclerosis”
#2	“MS”
#3	#1 OR #2
#4	“Conjoint analysis”
#5	“Choice model”
#6	“Stated preference”
#7	“DCE”
#8	“Discrete choice”
#9	“Decision analysis”
#10	“Preference”
#11	“Multi-criteria decision analysis”
#12	“Multi-attribute utility”
#13	“Analytic hierarchy process”
#14	“Trade-off”
#15	“Risk-benefit trade-off”
#16	“Preference weight”
#17	“Willingness to pay”
#18	“WTP”
#19	“Willingness to accept”
Research search	#3 AND #4 OR #5 OR #6 OR #7 OR #8 OR #9 OR #10 OR #11 OR #12 OR #12 OR #13 OR #14 OR #15 OR #16 OR #17 OR #18 OR #19

Abbreviations: DCE, discrete choice experiments; MS, multiple sclerosis; WTP, willingness to pay.