Characteristics associated with willingness to participate in a randomized controlled behavioral clinical trial using home-based personal computers and a webcam

Table 2 Multinomial logit model results: characteristics associated with level of interest in trial participation (n = 983; as compared to the “no interest” reference group)

	Committed with interest			Committed without interest			Interest only
Covariates	OR	95% CI	P-value	OR	95% CI	P-value	OR	95% CI	P-value
Age group (1-6)^a	0.83	(0.74, 0.92)	0.001^**	0.79	(0.65, 0.95)	0.01^**	0.91	(0.74, 1.10)	0.33
Female (vs. male)	0.89	(0.63, 1.25)	0.49	1.10	(0.60, 2.00)	0.76	0.75	(0.42, 1.36)	0.35
Married (vs. unmarried)	0.81	(0.60, 1.11)	0.19	0.88	(0.52, 1.50)	0.64	0.90	(0.51, 1.58)	0.71
Years of education	1.00	(0.94, 1.05)	0.91	1.10	(0.99, 1.21)	0.07	1.08	(0.98, 1.19)	0.11
Social activity index^b	0.98	(0.95, 1.02)	0.33	1.01	(0.96, 1.07)	0.62	1.01	(0.95, 1.06)	0.85
Cognitive activity index^b	1.01	(0.99, 1.04)	0.20	1.00	(0.96, 1.03)	0.84	1.02	(0.98, 1.06)	0.24
Physical activity index^b	1.03	(1.01, 1.06)	0.01^**	1.06	(1.02, 1.10)	0.005^**	0.98	(0.94, 1.03)	0.43
Loneliness scale^c	1.16	(1.02, 1.28)	0.02^*	1.08	(0.89, 1.32)	0.41	1.18	(0.97, 1.43)	0.10
Self-rated health (poor vs. others)	1.71	(0.72, 4.05)	0.23	1.27	(0.26, 6.14)	0.77	0.73	(0.09, 5.93)	0.77
Personal computer usage^d	2.78	(1.80, 4.02)	<0.0001^**	1.19	(0.62, 2.30)	0.60	2.57	(1.16, 5.60)	0.02^*

^**Significant at P < 0.05; ^**significant at P < 0.01.
^aOrdered age groups as used in the survey questionnaire: 1, 62 years or younger (a reference group); 2, 63–74 years; 3, 75–79 years; 4, 80–84 years; 5, 85–89 years; 6, 90 years and older.
^bComposite scores were created by summing the self-reported frequencies: 1, never; 2, less than once a year; 3, once or twice a year; 4, several times a year; 5, about once a month; 6, every week; 7, several times a week; for various cognitive, social and physical activities.
^cThree-item scale developed by Hughes and colleagues [7]. Questions were phrased as: 1, how often do you feel that you lack companionship?; 2, how often do you feel left out?; 3, how often do you feel isolated from others? Composite scores were calculated by taking the sum of frequency scores: 1, hardly ever; 2, some of the time; and 3, often.
^d“Do you use a personal computer?” (Yes/No).
CI, Confidence interval; OR, odds ratio.

ISSN: 1745-6215