Table 5.

Results of multivariable logistic and robust Poisson regression models for factors associated with likelihood of joining clinical studies (n=221, missing=30)

Factor	Logistic model		Robust Poisson model
	Odds ratio (95% CI)	p-value	Prevalence ratio (95% CI)	p-value
Agea (ref = <65 years)	1.60 (0.84, 3.05)	0.2	1.24 (0.88, 1.74)	0.2
Gender (ref = m)	1.22 (0.55, 2.68)	0.6	1.11 (0.71, 1.72)	0.6
Education (ref = Kindergarten–12)	0.95 (0.49, 1.85)	0.9	0.98 (0.68, 1.39)	0.9
Relationship Statusb (ref = single)	1.49 (0.72, 3.06)	0.3	1.25 (0.88, 1.78)	0.2
Social Support	0.83 (0.58, 1.17)	0.3	0.91 (0.77, 1.08)	0.3
Crisis Support (age <65 years)	1.21 (0.76, 1.93)	0.4	1.13 (0.86, 1.48)	0.4
Crisis Support (age ≥65 years)	0.57 (0.34, 0.98)	0.04*	0.81 (0.68, 0.96)	0.02*
Basic Ability (for single participants)	3.25 (1.16, 9.10)	0.03*	2.08 (1.24, 3.48)	0.005*
Basic Ability (for participants with a partner)	0.80 (0.32, 2.05)	0.6	0.92 (0.67, 1.27)	0.6
Strength and Mobility	1.11 (0.79, 1.58)	0.5	1.09 (0.87, 1.36)	0.5
Social Ability	1.77 (1.09, 2.87)	0.02*	1.42 (1.09, 1.86)	0.009*
Errand Transportation	2.10 (1.22, 3.60)	0.007*	1.57 (1.13, 2.19)	0.008*
Interaction of Age and Crisis Support	0.47 (0.23, 0.95)	0.04*	0.71 (0.52, 0.99)	0.04*
Interaction of Relationship Status and Basic Ability	0.25 (0.06, 1.09)	0.07	0.44 (0.23, 0.86)	0.02*

Notes:

^aEffect of age when Crisis Support is 0 (the mean factor score),

^beffect of Relationship Status when Basic Ability is 0 (the mean factor score),

^*p<0.05.

Abbreviations: CI, confidence interval; m, male; ref, reference.