Patient preferences for treatment attributes in moderate-to-severe atopic dermatitis: a discrete choice experiment

Figures & data

Figure 1. Example of choice task.

Table 1. Participant demographics and clinical characteristics.

	Overall sample	With systemic experience	Without systemic experience
	N = 300	N = 156 (52%)	N = 144 (48%)
Age (years), mean ± SD (median)	45.0 ± 13.7 (42.0)	43.4 ± 13.1 (41.0)	46.7 ± 14.2 (44.5)
Female, n (%)	210 (70.0%)	94 (60.3%)	116 (80.6%)
Race, n (%)
White or Caucasian	234 (78.0%)	120 (76.9%)	114 (79.2%)
Black or African American	33 (11.0%)	19 (12.2%)	14 (9.7%)
Asian	14 (4.7%)	8 (5.1%)	6 (4.2%)
Mixed	11 (3.7%)	6 (3.9%)	5 (3.5%)
Other^a	8 (2.7%)	3 (1.9%)	5 (3.5%)
Current weight <100 kg, n (%)	258 (86.0%)	135 (86.5%)	123 (85.4%)
Region of residence, n (%)
Northeast	58 (19.3%)	29 (18.6%)	29 (20.1%)
Midwest	64 (21.3%)	30 (19.2%)	34 (23.6%)
South	124 (41.3%)	70 (44.9%)	54 (37.5%)
West	54 (18.0%)	27 (17.3%)	27 (18.8%)
Education level, n (%)
High school diploma or less	116 (38.7%)	53 (40.0%)	63 (43.8%)
Bachelor’s degree	121 (40.3%)	67 (42.9%)	54 (37.5%)
Master’s degree and above	61 (20.3%)	36 (23.1%)	25 (17.4%)
Prefer not to answer	2 (0.7%)	0 (0.0%)	2 (1.4%)
Employed, n (%)	198 (66.0%)	112 (71.8%)	86 (59.7%)
Time since first AD treatment, n (%)
< 1 year ago	17 (5.7%)	5 (3.2%)	12 (8.3%)
1 to < 2 years ago	50 (16.7%)	28 (17.9%)	22 (15.3%)
2 to < 5 years ago	82 (27.3%)	58 (37.2%)	24 (16.7%)
5 or more years ago	149 (49.7%)	64 (41.0%)	85 (59.0%)
I don’t know	2 (0.7%)	1 (0.6%)	1 (0.7%)
Current treatment type, n (%)	271 (90.3%)	154 (98.7%)	117 (81.3%)
Topical	240 (80.0%)	135 (86.5%)	105 (72.9%)
Oral pill	93 (31.0%)	93 (59.6%)	0 (0.0%)
Injection	44 (14.7%)	44 (28.2%)	0 (0.0%)
Phototherapy or light therapy	27 (9.0%)	15 (9.6%)	12 (8.3%)
Other	25 (8.3%)	8 (5.1%)	17 (11.8%)
None	29 (9.7%)	2 (1.3%)	27 (18.8%)
AD symptom severity^b, n (%)
Current severity
Mild	61 (20.3%)	18 (11.5%)	43 (29.9%)
Moderate	206 (68.7%)	116 (74.4%)	90 (62.5%)
Severe	33 (11.0%)	22 (14.1%)	11 (7.6%)
Worst severity experienced at any time
Moderate	149 (49.7%)	66 (42.3%)	83 (57.6%)
Severe	150 (50.0%)	90 (57.7%)	60 (41.7%)
I don’t know	1 (0.3%)	0 (0.0%)	1 (0.7%)
Body regions currently affected, n (%)
Visible body regions	263 (87.7%)	150 (96.2%)	133 (92.4%)
Face	95 (31.7%)	52 (33.3%)	43 (29.9%)
Neck	106 (35.3%)	73 (46.8%)	33 (22.9%)
Hands	176 (58.7%)	96 (61.5%)	80 (55.6%)
Feet	116 (38.7%)	71 (45.5%)	45 (31.3%)
Other parts of the body	173 (57.7%)	84 (53.8%)	89 (61.8%)

Abbreviations: AD: atopic dermatitis; SD: standard deviation.

^aOther includes ‘American Indian or Alaska Native’ and ‘Native Hawaiian or Other Pacific Islander’.

^bThis study only includes participants diagnosed with moderate-to-severe AD; therefore, in order to be eligible, participants needed to report moderate or severe symptoms currently or in the past.

Table 2. Preference weights and willingness to trade off in the overall sample.

	Overall sample
	N = 300
	Coefficient^a (95% CI)		p Value	Willingness to trade off^b
Efficacy
Sustained improvement in skin appearance (months)	0.017	(0.011, 0.024)	<.001*
Itch control (percentage points)	3.818	(3.585, 4.051)	<.001*	Reference
Adverse events
Risk of respiratory infections (percentage points)	−4.513	(−5.028, −3.997)	<.001*	1.182
Risk of cancer (percentage points)	−135.245	(−147.402, −123.088)	<.001*	35.423
Risk of heart problems (percentage points)	−67.467	(−79.637, −55.297)	<.001*	17.671
Frequency and mode of administration
One pill every day (reference)	–		–
One injection every two weeks	−0.118	(−0.255, 0.019)	.091	0.031
One injection every four weeks	−0.038	(−0.177, 0.101)	.594	0.010
Blood tests frequency
Not required (reference)	–		–
Once a year	−0.153	(−0.291, −0.016)	.029*	0.040
Four times a year	−0.133	(−0.264, −0.002)	.046*	0.035

Abbreviations: AD: atopic dermatitis; CI: confidence interval.

* p < .05.

^aRegression coefficients are from a conditional logistic model that regresses participants choice on the attribute’s levels of the treatment selected from each choice task.

^bWillingness to trade off was calculated using the formula –(β_attribute/β_Itch). The number indicates how many percentage points of chance in achieving meaningful itch control an average participant is willing to trade off in order to avoid a particular attribute. For adverse events, the tradeoff is expressed with respect to a 1 percentage point reduction in the risk of having the adverse event. For example, an average participant is willing to trade off 1.2 percentage point chance in achieving meaningful itch control to avoid a 1 percentage point risk in respiratory infection.

Figure 2. Part-worth utilities in the overall sample.

Figure 3. Attributes relative importance in the overall sample.

Table 3. Preference weights and willingness to trade off stratified by systemic experience.

	With systemic experience N = 156				Without systemic experience N = 144
	Coefficient^a (95% CI)		p Value	Willingnessto trade off^b	Coefficient^a (95% CI)		p Value	Willingness to trade off^b
Efficacy
Sustained improvement in skin appearance (months)	0.019	(0.009, 0.028)	<.001*		0.015	(0.005, 0.024)	.004*
Itch control (percentage points)	3.935	(3.613, 4.257)	<.001*	Reference	3.764	(3.422, 4.105)	<.001*	Reference
Adverse events
Risk of respiratory infections (percentage points)	−4.603	(−5.315, −3.890)	<.001*	1.170	−4.600	(−5.361, −3.840)	<.001*	1.222
Risk of cancer (percentage points)	−103.014	(−119.557, −86.472)	<.001*	26.181	−173.193	(−191.505, −154.880)	<.001*	46.016
Risk of heart problems (percentage points)	−51.349	(−68.025, −34.673)	<.001*	13.050	−89.213	(−107.295, −71.131)	<.001*	23.703
Frequency and mode of administration
One pill every day (reference)	–					–
One injection every two weeks	−0.017	(−0.205, 0.172)	.862	0.004	−0.255	(−0.458, −0.053)	.013*	0.068
One injection every four weeks	−0.052	(−0.244, 0.140)	.593	0.013	−0.026	(−0.231, 0.179)	.802	0.007
Blood tests frequency
Not required (reference)	–					–
Once a year	0.026	(−0.164, 0.217)	.785	−0.007	−0.348	(−0.550, −0.146)	.001*	0.092
Four times a year	−0.010	(−0.191, 0.171)	.915	0.002	−0.252	(−0.445, −0.060)	.01*	0.067

Abbreviations: AD: atopic dermatitis; CI: confidence interval.

* p value < .05 indicates statistical significance.

^aRegression coefficients are from a conditional logistic model that regresses participants choice on the attribute’s levels of the treatment selected from each choice task.

^bWillingness to trade off was calculated using the formula −(β_attribute/β_Itch). The number indicates how many percentage points of chance in achieving meaningful itch control an average participant is willing to trade off in order to avoid a particular attribute. For adverse events, the tradeoff is expressed with respect to a 1 percentage point reduction in the risk of having the adverse event. For example, an average participant is willing to trade off 1.2 percentage point chance in achieving meaningful itch control to avoid a 1 percentage point risk in respiratory infection.

Figure 4. Attributes relative importance stratified by systemic experience.

Data availability statement

The data that support the findings of this study are available on reasonable request. The data are not publicly available and cannot be deposited into a public repository, primarily due to the fact that study participants did not consent to this. The project team was responsible for not compromising research participant privacy/consent.