Table 1.

Factor analyses and standardized coefficient alphas of the latent construct indices.

Latent Construct and Items	M (SD)	Factor Loading	M (SD)	Factor Loading

	Adolescent Scores		Parent Scores

Physician-Investigator Relationship
1. This doctor really seems to know what she/he is talking about.	5.9 (1.4)	.81	5.9 (1.3)	.85
2. This doctor would give me the opportunity to ask questions.	6.0 (1.2)	.85	6.0 (1.1)	.85
3. This doctor cares about me.	5.4 (1.6)	.82	5.2 (1.4)	.81
4. I would be able to get along well with this doctor.	5.3 (1.5)	.74	5.6 (1.3)	.80
5. This doctor explained things so I could remember them.	5.5 (1.6)	.77	6.0 (1.1)	.74
6. This doctor appeared confident in this study she/he told me about? ¹	5.7 (1.5)	.87	6.2 (1.0)	.74
	Std. α= .90		Std. α = .89

Study Procedures
1. How much did the number of visits (12) influence your decision?	3.9 (1.6)	.85	4.0 (1.7)	.88
2. How much did the time it takes to have medical tests influence your decision?	4.1 (1.5)	.78	4.0 (1.4)	.86
3. How much did the length of the study (26wks) influence your decision?	3.7 (1.6)	.82	3.8 (1.6)	.89
4. How much did taking study medication 4 times a day influence your decision? ¹	4.0 (1.6)	.77	3.9 (1.5)	.74
5. How much did filling out diary cards influence your decision? ⁵	3.6 (1.5)	.78	4.3 (1.4)	.75
	Std. α = .86		Std. α = .88

Risk
1. How risky do you think this study is for you (your child)? ^2,3	3.3 (1.7)	.78	3.6 (1.9)	.79
2. How uncomfortable/stressful would taking a placebo be for you (your child)? ^2,4	3.6 (2.1)	.76	3.7 (2.0)	.83
3. How risky would stopping regular medication be for you (your child)? ⁴	3.5 (2.0)	.89	3.8 (2.0)	.92
	Std. α = .74		Std. α = .80

Benefit
1. How much did the potential to help your asthma influence you?	5.9 (1.4)	.84	6.5 (1.0)	.90
2. How much did the regular monitoring of your asthma influence you? ⁵	5.1 (1.6)	.82	6.2 (1.0)	.81
3. How much did the scientific value of the study influence you?	5.3 (1.4)	.84	6.2 (1.0)	.86
	Std. α = .78		Std. α = .82

Compensation
1. How influenced would your mother (your child) be to participate because of the amount of compensation?	4.7 (1.7)	.88	5.6 (1.6)	.60
2. How influenced would your father (child’s other parent) be to participate because of the amount of compensation?	4.4 (1.9)	.87	3.3 (2.0)	.80
3. How influenced would you be to participate because of the amount of compensation?	5.4 (1.6)	.84	3.7 (1.9)	.88
	Std. α = .83		Std. α = .64

Discomfort
1. How physically unpleasant do you feel the study is for you (your child)?	3.4 (1.5)	.78	3.9 (1.8)	.86
2. How stressful do you think this study is for you (your child)? ³	3.2 (1.5)	.83	3.7 (1.8)	.92
3. How much of an inconvenience is this study for you (your child)?	3.4 (1.7)	.74	4.2 (1.7)	.83
	Std. α = .68		Std. α = .84

Participation Decision
1. How likely would you be to enroll in this study?	5.3 (1.4)	.90	5.2 (1.7)	.94
2. If you had to say for sure?	0.9 (.39)	.90	0.7 (.45)	.94
	Std. α = .77		Std. α = .86

Note: Std. α = Standardized Alpha. Items that shared a common superscript had significant residual (error) correlations included in the model. Superscripts 1-3 were for the adolescent model and 4-5 were for the parent model.