Factors Driving Patient Preferences for Growth Hormone Deficiency (GHD) Injection Regimen and Injection Device Features: A Discrete Choice Experiment

Figures & data

Figure 1 Example of r-hGH injection and device descriptions.

Table 1 Attribute and Level Grid

	Attributes	Level 1	Level 2	Level 3	Level 4	Level 5
1	Storage	Refrigerator (must be stored in the refrigerator)	Refrigerator (must be stored in the refrigerator)	Refrigerator (must be stored in the refrigerator)	Room Temp (store at room temperature)	Room Temp (store at room temperature)
1b	Preparation	Mix (mix the medicine before use)	Ready to Use (no mixing required)	Mix, Then Room Temp (mix the medicine before use; once mixed can be stored at room temperature)	Mix (mix the medicine before use)	Ready to Use (no mixing required)
2	Injection device	Injection Device (continuous push on the button/plunger while injecting)	Autoinjector (single push of the button to inject)	Needle Free Device (pushes medicine through the skin using high pressure)
3	Maintenance	Single Use, Disposable Syringe (throw away after one use)	Multi Use, Disposable Pen (use for up to 28 days, then throw away)	Multi Use, Disposable Pen (use for up to 28 days, then throw away)	Multi Use, Reusable Pen (use for up to 28 days, then replace cartridge)	Multi Use, Reusable Pen (use for up to 28 days, then replace cartridge)
3b	Dose setting	Pre-Set Dose (dose is already pre-set)	Set the Dose (must set the dose each time)	Dose Memory (set the dose the first time, then device remembers it)	Set the Dose (must set the dose each time)	Dose Memory (set the dose the first time, then device remembers it)
4	Injection schedule	Once Daily	Once Weekly	Once Every 2 Weeks	Once a Month

Table 2 Fixed Attribute Grid Profiles for Hypothetical Products X, Y, Z

Attributes	Profile X	Profile Y	Profile Z
Storage	Refrigerator (must be stored in the refrigerator)	Refrigerator (must be stored in the refrigerator)	Refrigerator (must be stored in the refrigerator)
Preparation	Ready to Use (no mixing required)	Ready to Use (no mixing required)	Ready to Use (no mixing required)
Injection device	Injection Device (continuous push on the button/plunger while injecting)	Injection Device (continuous push on the button/plunger while injecting)	Injection Device (continuous push on the button/plunger while injecting)
Maintenance	Multi Use, Disposable Pen (use for up to 28 days, then throw away)	Multi Use, Disposable Pen (use for up to 28 days, then throw away)	Multi Use, Disposable Pen (use for up to 28 days, then throw away)
Dose setting	Set the Dose (must set the dose each time)	Set the Dose (must set the dose each time)	Set the Dose (must set the dose each time)
Injection schedule	Once Weekly	Once Every 2 Weeks	Once a Month

Figure 2 Example discrete choice experiment question.

Table 3 Patient Characteristics

Characteristic	Total Participants (N=224)*
	Children (3–11 Years) (n=70)	Adolescents (12–18 Years) (n=79)	Adults (≥25 Years) (n=75)
Age (years)
Mean (SD)	8.7 (2.2)	13.9 (1.4)	50.3 (11.7)
Min-Max	3.0-11.0	12.0-17.0	28.0-87.0
Gender (n, %)
Male	44 (62.9%)	60 (75.9%)	25 (33.3%)
Female	26 (37.1%)	19 (24.1%)	50 (66.7%)
Location of residency (n, %)
Arizona	2 (2.9%)	5 (6.3%)	1 (1.3%)
Arkansas	--	--	1 (1.3%)
California	8 (11.4%)	9 (11.4%)	--
District of  Columbia	--	--	1 (1.3%)
Florida	12 (17.1%)	--	2 (2.7%)
Georgia	1 (1.4%)	--	--
Kansas	--	--	2 (2.7%)
Louisiana	--	--	3 (4.0%)
Nevada	28 (40.0%)	38 (48.1%)	--
North Carolina	--	1 (1.3%)	--
Ohio	18 (25.7%)	25 (31.6%)	14 (18.7%)
Pennsylvania	1 (1.4%)	--	13 (17.3%
Texas	--	--	38 (50.7%)
West Virginia	--	1 (1.3%)	--
Race (n, %)
Asian	5 (7.1%)	4 (5.1%)	0 (0.0%)
Black or  African-American	2 (2.9%)	2 (2.5%)	1 (1.3%)
Native Hawaiian or Other Pacific Islander	0 (0.0%)	1 (1.3%)	0 (0.0%)
White	55 (78.6%)	63 (79.7%)	71 (94.7%)
Other	8 (11.4%)	9 (11.4%)	3 (4.0%)
Ethnicity (n, %)
Hispanic or  Latino	6 (8.6%)	14 (17.7%)	5 (6.7%)
Not Hispanic  or Latino	64 (91.4%)	65 (82.3%)	70 (93.3%)
Not answered	0 (0.0%)	0 (0.0%)	0 (0.0%)
Education (n, %)
5th grade	16 (8.0%)
2nd grade	11 (5.5%)
4th grade	11 (5.5%)
3rd grade	6 (3.0%)
Preschool	4 (2.0%)
1st grade	3 (1.5%)
7th grade		16 (8.0%)
8th grade		15 (7.5%)
6th grade		12 (6.0%)
9th grade		12 (6.0%)
10th grade		7 (3.5%)
11th grade		3 (1.5%)
12th grade		1 (0.5%)
Other	6 (3.0%)	6 (3.0%)
College or university degree (2- or 4-year)			32 (16.0%)
Graduate degree			17 (8.5%)
High school diploma (or GED) or less			16 (8.0%)
Some college or certificate program			7 (3.5%)
Overall health (n, %)
Excellent	28 (40.0%)	40 (50.6%)	6 (8.0%)
Very good	31 (44.3%)	28 (35.4%)	17 (22.7%)
Good	10 (14.3%)	10 (12.7%)	38 (50.7%)
Fair	1 (1.4%)	1 (1.3%)	8 (10.7%)
Poor	0 (0.0%)	0 (0.0%)	6 (8.0%)
Participant impression of overall GHD severity (n, %)
Very mild	0 (0.0%)	0 (0.0%)	0 (0.0%)
Mild	2 (2.9%)	7 (8.9%)	6 (8.0%)
Moderate	33 (47.1%)	40 (50.6%)	29 (38.7%)
Severe	28 (40.0%)	27 (34.2%)	27 (36.0%)
Very severe	7 (10.0%)	5 (6.3%)	13 (17.3%)

Notes: *A total of 302 patients were screened, and of these 224 patients were eligible to participate and completed the study.

Table 4 Caregiver Characteristics (Caregivers of Patients 3–18 Years [N=149])

Characteristic	Caregivers of Patients 3–18 Years (N=149)
Age (Years)
Mean (SD)	23.0–59.0
Min-Max	42.7 (6.9)
Gender (n, %)
Male	22 (14.8%)
Female	127 (85.2%)
Race (n, %)
Asian	9 (6.0%)
Black or African-American	5 (3.4%)
Native Hawaiian or Other Pacific Islander	1 (0.7%)
White	126 (84.6%)
Other	8 (5.4%)
Ethnicity (n, %)
Hispanic or Latino	14 (9.4%)
Not Hispanic or Latino	0 (0.0%)
Not answered	135 (90.6%)
Education (n, %)
College or university degree (2- or 4-year)	49 (24.5%)
Graduate degree	35 (17.5%)
Some college or certificate program	30 (15.0%)
High school diploma (or GED) or less	8 (4.0%)
Living Status (n, %)
Living alone	12 (8.1%)
Living with family or friends	125 (83.9%)
Other	12 (8.1%)
Not answered	0 (0.0%)
Work Status (n, %)
Working full-time	82 (55.0%)
Working part-time	22 (14.8%)
Homemaker	37 (24.8%)
Student	1 (0.7%)
Retired	2 (1.3%)
Unemployed	2 (1.3%)
On disability	1 (0.7%)
Other	2 (1.3%)
Not answered	0 (0.0%)

Figure 3 Average relative importance of attributes. Base: All patients (Total weighted, n=224).

Figure 4 Average relative importance of attributes by patient cohort. Base: All patients (Total weighted, Adult, n=75; Adolescent Dyad, n=79; Pediatric Dyad, n=70).

Figure 5 Average relative utility of injection schedule attribute. Base: All patients (Total weighted, n=224).

Figure 6 Average relative utility of preparation attribute. Base: All patients (Total weighted, n=224).

Figure 7 Average relative utility of injection device attribute. Base: All patients (Total weighted, n=224).

Figure 8 Percentage of participants that would choose the new profile over current treatment. Base: All patients (Total weighted, n=224; Adult, n=75; Adolescent Dyad, n=79; Pediatric Dyad, n=70).