Table 4.

GEE Serial Mediation Analysis of Intervention Effects (Health Promotion versus Attention Control) on Self-Reported Adherence to Physical Activity Guidelines Averaged Over 6 and 12 months Post-Intervention Assessments, Eastern Cape Province, South Africa, 2007–2010.

	α-path			β-path			γ-path			αβγ
	α	SE	P value	β	SE	P value	γ	SE	P value	αβγ	95% ACI
Attitude	0.23	0.05	<.0001	0.25	0.04	<.0001				0.019	0.008, 0.035
Subjective Norm	0.25	0.04	<.0001	0.36	0.04	<.0001				0.031	0.017, 0.047
Descriptive Norm	−0.03	0.06	.6474	0.03	0.02	.0391				0.000	−0.002, 0.001
Self-Efficacy	0.15	0.04	.0004	0.30	0.04	<.0001				0.015	0.005, 0.029
Intention							0.35	0.08	<.0001

Note. The α-paths are the effects of the health promotion intervention (mean difference compared with the attention-control) on the potential mediators except intention adjusted for the baseline of physical activity and the potential mediators. The β-paths are the relations of the potential mediators to intention adjusted for the intervention and the baseline of physical activity and the potential mediator. The γ path is the relation of intention to physical activity adjusted for the intervention and the baseline of physical activity and intention. The αβγ product is the indirect or mediated effect. ACI is the asymmetric confidence interval for the αβγ product by bootstrap percentile method using 2,000 bootstrap iterations.