Development of new physical activity and sedentary behavior change self-efficacy questionnaires using item response modeling

Table 4 Complete sample scale means, standard deviations, intra-class correlations (ICC), and sub-sample correlations between physical activity/sedentary behavior change self-efficacy scores and afternoon physical activity

Self-Efficacy Scale		Complete Sample		Sub-sample (Includes participants with valid accelerometer data)
		Scale	ICC	Correlations
					Males			Females
	n	M (SD)		n	CPM	MV	n	CPM	MV
Physical Activity Self-Efficacy*	586			41			47
Full Item Scale		1.07 (1.58)	0.93		0.18	0.09		0.16	0.09
Reduced Item Scale		1.15 (1.36)			0.18	0.11		0.15	0.09
					Light	Sedentary		Light	Sedentary
Sedentary behavior change Self-Efficacy	555			37			46
Television Self-Efficacy
Full Item Scale		0.44 (2.04)	0.96		0.33*	-0.29		0.09	-0.05
Computer/Video Games	538			37			41
Full Item Scale		1.30 (2.26)	0.97		0.27	-0.21		0.09	-0.04
Telephone*	520			35			39
Full Item Scale		1.23 (2.30)	0.98		0.17	-0.12		-0.04	0.05

Abbreviations: item response modeling (IRM)-derived estimates; intra-class (ICC) correlation between full and reduced estimates; average daily accelerometer counts per minute (CPM); moderate-to-vigorous (MV) minutes between 3 pm to 6 pm; sedentary (sedentary) minutes between 3 pm and 6 pm; light (light) minutes between 3 pm and 6 pm;
Notes: No significant differences between self-efficacy scores for participants with and without accelerometer data
* Significant difference between full and reduced scores at p <.0.05; However, IRM-derived differences were very small (standardized effect sizes of 0.00–0.15)

ISSN: 1479-5868