Preference for Immunotherapy with Tablets by People with Allergic Rhinitis

Figures & data

Table 1 Attributes and Levels in the Discrete Choice Experiment

Main Attributes	Levels
Administration	Tablet at home every day with annual visits to an allergy clinic
	Weekly injections at an allergy clinic
	Monthly injections at an allergy clinic
Risk of a systemic reaction	No risk at all
	1 out of 200,000
	100 out of 200,000
Cost per month (co-payment), USD	0
	20
	70
	150

Table 2 Example of a DCE Question

	Treatment A	Treatment B
Administration	Tablet at home every day with annual visits to an allergy clinic	Monthly injections at an allergy clinic
Risk of a systemic reaction	1 out of 200,000	100 out of 200,000
Cost per month (co-payment), USD	150	20
Which would you prefer?

Abbreviation: DCE, discrete choice experiment.

Figure 1 Flowchart of the study population selection.

Table 3 Demographics and Disease-Specific Characteristics

	Adults	Caregivers Answering for Their Children
Demographics of adults and caregivers
Male	256 (35%)	185 (28%)^a
Female	468 (65%)	480 (72%)^a
Mean age, years	52	43^a
Median household income category, USD	40,000–49,999	50,000–74,999^a
Median EQ-5D score	0.83	-
Age of allergy debut and diagnosis
Mean age when experienced first symptoms, years	21.3	5.7
Mean age of diagnosis, years	22.0	6.3
Comorbidities
Asthma	157 (22%)	147 (22%)
Allergies affecting the respondents the most
Allergies towards animals (dogs, cats, horses, etc.)	60 (8%)	102 (15%)
Allergies related to pollen (grasses, weeds, trees, etc.)	539 (74%)	474 (71%)
Allergies related to house dust mites	56 (8%)	56 (8%)
Other year-round allergies (cockroaches, mold, etc.)	69 (10%)	33 (5%)
Allergy symptoms
Stuffy nose, runny nose, sneezing or post-nasal drip	694 (96%)	640 (96%)
Itchy, red or watery eyes	571 (79%)	505 (76%)
Shortness of breath, chest tightness or pain, coughing or wheezing	231 (32%)	192 (29%)
Itchy skin reactions or skin pain or redness of the skin	197 (27%)	277 (42%)
Mono- vs polyallergic
Monoallergic	253 (35%)	198 (30%)
Polyallergic	471 (65%)	467 (70%)
Medication use
Oral antihistamines	558 (81%)	602 (91%)
Decongestants	389 (54%)	424 (64%)
Nasal sprays and drops	415 (57%)	397 (60%)
Eye drops	395 (55%)	311 (47%)

Note: ^aCaregivers demographics.

Table 4 Estimates from the Conditional Logit Regression Analysis

	Estimate	Standard Error	P-value
Adults with AR
Tablets vs weekly injections	1.2208	0.0500	<0.0001
Monthly injections vs weekly injections	0.5001	0.0455	<0.0001
No risk vs risk 100/200,000	1.0266	0.0487	<0.0001
Risk 1/200,000 vs risk 100/200,000	0.4364	0.0436	<0.0001
Monthly payment in USD	−0.0138	0.0005	<0.0001
Caregivers of children with AR
Tablets vs weekly injections	1.1466	0.0519	<0.0001
Monthly injections vs weekly injections	0.5276	0.0487	<0.0001
No risk vs risk 100/200,000	1.4603	0.0550	<0.0001
Risk 1/200,000 vs risk 100/200,000	0.7358	0.0445	<0.0001
Monthly payment in USD	−0.0110	0.0004	<0.0001

Figure 2 Disutility for the various attributes corresponding to value in USD per month.

Table 5 Results of the Sub-Analyses for Caregivers of Children with AR, Estimated Preferences (Standard Error)

	Tablets vs Weekly Injections	Monthly Injections vs Weekly Injections	No Risk vs Risk 100/200,000	Risk 1/200,000 vs Risk 100/200,000	Monthly Payment in USD
Caregivers of children ages 5 to 12 (n = 328)	1.089 (0.0733)	0.4147 (0.0691)	1.5849 (0.0792)	0.8145 (0.0632)	−0.0109 (0.0006)
Caregivers of children ages 13 to 17 (n = 323)	1.1999 (0.0738)	0.635 (0.0692)	1.3473 (0.077)	0.6604 (0.0630)	−0.0112 (0.0006)
P-value	0.8477	0.9878	0.0152	0.0374	0.3653
Caregivers of monoallergic children (n = 191)	1.2237 (0.0972)	0.5307 (0.0903)	1.4606 (0.1023)	0.7185 (0.0825)	−0.0111 (0.0008)
Caregivers of polyallergic children (n = 460)	1.1153 (0.0614)	0.5266 (0.0579)	1.4603 (0.0653)	0.7429 (0.0529)	−0.0109 (0.0005)
P-value	0.1810	0.4704	0.4937	0.5755	0.5501
Male caregivers (n = 180)	1.0437 (0.0959)	0.4292 (0.0901)	1.4086 (0.1017)	0.7837 (0.0832)	−0.009442 (0.0008)
Female caregivers (n = 471)	1.19 (0.0619)	0.5694 (0.0581)	1.4843 (0.0655)	0.7181 (0.0528)	−0.0116 (0.0005)
P-value	0.8955	0.9097	0.7244	0.2339	0.0117
Caregivers who want AIT for free (n = 452)	1.2146 (0.0626)	0.5689 (0.0583)	1.4035 (0.0656)	0.7012 (0.0532)	−0.0107 (0.0005)
Caregivers who do not want AIT for free (n = 199)	0.9926 (0.0932)	0.4265 (0.0893)	1.6021 (0.1018)	0.8215 (0.0817)	−0.0118 (0.0008)
P-value	0.0240	0.0988	0.9371	0.8869	0.1118

Table 6 Results of the Sub-Analyses for Adults with AR, Estimated Preferences

Parameter Estimates (Standard Error)	Tablets vs Weekly Injections	Monthly Injections vs Weekly Injections	No Risk vs Risk 100/200,000	Risk 1/200,000 vs Risk 100/200,000	Monthly Payment in USD
Monoallergic adults (n = 250)	1.4881 (0.0901)	0.5458 (0.0776)	0.8782 (0.0827)	0.2994 (0.0759)	−0.0144 (0.0008)
Polyallergic adults (n = 466)	1.0972 (0.0605)	0.4814 (0.0563)	1.1024 (0.0606)	0.5038 (0.0535)	−0.0135 (0.0006)
P-value	0.0001	0.2498	0.9835	0.9848	0.8400
Males (n = 252)	1.331 (0.0859)	0.4501 (0.0759)	1.0243 (0.083)	0.3722 (0.073)	−0.0131 (0.0007)
Females (n = 464)	1.1651 (0.0615)	0.5282 (0.0568)	1.0308 (0.0603)	0.4722 (0.0545)	−0.0142 (0.0006)
P-value	0.0577	0.7947	0.5212	0.8643	0.1134
Adults who want AIT for free (n = 443)	1.3296 (0.0654)	0.5613 (0.0593)	1.0485 (0.0631)	0.4544 (0.057)	−0.015 (0.0006)
Adults who do not want AIT for free (n = 273)	1.0646 (0.0777)	0.415 (0.0711)	0.9986 (0.077)	0.4153 (0.068)	−0.012 (0.0007)
P-value	0.0058	0.0546	0.3043	0.3323	0.9994