. Author manuscript; available in PMC: 2012 Oct 1.

Published in final edited form as: Am J Geriatr Psychiatry. 2011 Oct;19(10):859–870. doi: 10.1097/JGP.0b013e318202bf5b

Table 2.

Results of GEE univariate analyses describing the relationships between stimulus, environmental and personal attributes and the three measures of engagement

		Duration			Attention			Attitude
		Odds Ratio	Confidence interval	P	Odds ratio	Confidence interval	P	Odds ratio	Confidence interval	P
Stimulus attributes
Type of Stimulus				<0.0001			<0.0001			<0.0001
	Control - ref^a	1.00			1.00			1.00
	Real human	37.03	26.06–52.62		12.24	8.86–16.91		15.05	10.71–21.16
	Self-Identity	5.41	4.14–7.07		4.57	3.41–6.14		4.21	3.12–5.68
	Simulated soc.	3.32	2.52–4.35		3.18	2.42–4.19		3.89	2.92–5.18
	Reading	3.16	2.42–4.13		2.97	2.21–3.99		2.42	1.80–3.27
	Pet	3.08	2.30–4.13		3.68	2.62–5.18		6.26	4.15–9.45
	Task/work	2.94	2.28–3.79		2.96	2.22–3.95		1.96	1.49–2.58
	Manipulative	2.33	1.83–2.96		2.31	1.78–3.00		1.97	1.52–2.54
	Inanimate social	2.28	1.74–3.00		2.39	1.79–3.18		2.83	2.12–3.78
	Music	1.55	1.17–2.06		0.96	0.72–1.29		1.01	0.75–1.37
Environmental Attributes
Introduction	Short - ref^a	1.00			1.00			1.00
	Long	1.23	1.16–1.30	<0.0001	1.22	1.15–1.30	<0.0001	1.29	1.21–1.38	<0.0001
Sound				<0.0001			<0.0001			<0.0001
	None - ref^a	1.00			1.00			1.00
	Low	2.62	1.11–6.18		2.58	1.07–6.25		2.15	0.94–4.91
	Moderate	4.16	1.80–9.58		4.41	1.87–10.41		3.38	1.52–7.56
	High	3.09	1.30–7.37		3.06	1.27–7.42		2.48	1.06–5.81
Lighting				0.012			0.0004			0.011
	Normal - ref^a	1.00			1.00			1.00
	Bright	0.91	0.63–1.31		0.73	0.50–1.05		0.79	0.56–1.13
	Dark	0.55	0.40–0.77		0.45	0.32–0.62		0.54	0.38–0.76
Social				0.062			0.045			0.004
	0 - ref^a	1.00			1.00			1.00
	1	1.23	0.93–1.63		1.26	0.94–1.68		1.32	1.00–1.75
	2	1.60	1.18–2.18		1.56	1.13–2.16		1.78	1.30–2.45
	3	1.46	1.07–1.99		1.52	1.08–2.13		1.55	1.10–2.18
	4–9	1.40	1.04–1.89		1.38	1.01–1.88		1.39	1.04–1.86
	10–24	1.42	1.10–1.84		1.48	1.12–1.95		1.52	1.17–1.98
	25+	1.03	0.58–1.84		0.97	0.52–1.79		0.83	0.47–1.44
Personal Attributes
Age				0.631			0.676			0.397
	<84.05 - ref^a	1.00			1.00			1.00
	84.05–89.79	1.16	0.85–1.59		1.18	0.81–1.73		1.29	0.89–1.87
	>=89.79	1.11	0.81–1.52		1.14	0.78–1.68		1.16	0.80–1.69
Gender	Male - ref^a	1.00			1.00			1.00
	Female	1.31	0.97–1.78	0.077	1.38	0.95–2.02	0.096	1.35	0.93–1.96	0.121
Marital status	Other than married - ref^a	1.00			1.00			1.00
	Married	0.80	0.59–1.09	0.163	0.71	0.49–1.05	0.091	0.72	0.50–1.05	0.096
Ethnicity	Not Caucasian-ref^a	1.00			1.00			1.00
	Caucasian	1.01	0.73–1.39	0.965	1.11	0.75–1.65	0.590	1.07	0.74–1.57	0.713
Education	Less than HS-ref^a	1.00			1.00			1.00
	More than HS	1.01	0.77–1.33	0.940	0.95	0.88–1.04	0.270	0.96	0.88–1.04	0.276
# of diagnoses				0.175			0.012			0.041
	<=5 - ref^a	1.0			1.00			1.0
	5–7	1.24	0.93–1.65		1.67	1.20–2.32		1.54	1.12–2.14
	>7	1.31	0.96–1.79		1.41	0.96–2.06		1.29	0.89–1.88
MMSE				0.042			<0.0001			<0.0001
	<3 - ref^a	1.00			1.00			1.00
	3–10	1.44	1.06–1.95		2.41	1.70–3.42		2.10	1.49–2.97
	>= 10	1.41	1.01–1.97		3.99	2.80–5.68		3.24	2.28–4.60
ADL				0.014			<0.0001			<0.0001
	<=1.6 - ref^a	1.00			1.00			1.00
	1.6–2.9	1.59	1.16–2.18		2.35	1.65–3.36		2.24	1.58–3.18
	>2.9	1.38	1.02–1.88		2.75	1.92–3.93		2.49	1.77–3.50
Speech clarity				0.025			<0.0001			<0.0001
	Clear speech - ref^a	1.00			1.00			1.00
	Unclear speech	0.75	0.58–0.97		0.45	0.32–0.63		0.47	0.35–0.64
	No speech	0.25	0.12–0.50		0.13	0.08–0.21		0.18	0.12–0.25
Past interest		1.01	0.97–1.04	0.747	1.01	0.97–1.04	0.686	1.01	0.97–1.04	0.620
Vision				0.856			0.518			0.614
	Adequate - ref^a	1.00			1.00			1.00
	Impaired	0.93	0.69–1.26		1.23	0.85–1.78		1.12	0.79–1.59
	Moderately imp	1.07	0.54–2.11		1.22	0.52–2.82		1.19	0.53–2.65
	Highly impaired	0.74	0.34–1.60		0.67	0.28–1.60		0.61	0.27–1.41
Hearing				0.579			0.089			0.121
	Adequate - ref^a	1.00			1.00			1.00
	Min. difficulty	1.03	0.72–1.50		1.56	1.05–2.31		1.52	1.04–2.21
	Special sit. & Highly impaired	0.79	0.51–1.24		1.36	0.82–2.26		1.21	0.73–2.01
No. of meds		1.03	0.99–1.07	0.150	1.05	1.01–1.10	0.023	1.05	1.01–1.09	0.032
No. of psychotr. Meds				0.363			0.188			0.283
	0 - ref^a	1.00			1.00			1.00
	1	0.77	0.52–1.14		0.75	0.47–1.19		0.76	0.48–1.18
	2+	0.77	0.54–1.11		1.03	0.68–1.57		0.97	0.64–1.47

Note: Live human social stimuli included a real baby, and one-on-one socializing with a research assistant; simulated social stimuli included a life-like (“real”) baby doll, a robotic animal, and a respite video; inanimate social stimuli included a childish-looking baby doll and a plush animal.

P-values are based on Wald statistics with 1 degree of freedom for individual categories, and with k-1 degrees of freedom for the overall test of a variable with k categories.

P values under .2 are typed in bold and those variables were included in the multivariate model.

ref^a - the category is the reference value