. Author manuscript; available in PMC: 2017 Aug 23.

Published in final edited form as: Psychol Health. 2017 Feb 6;32(5):509–529. doi: 10.1080/08870446.2017.1283038

Table 6.

Prediction of sugar-sweetened beverage behavioural intentions from theory of planned behaviour constructs with the same IVR call.

	Call	TB n = 155	IVR1 n = 153	IVR2 n = 154	IVR3 n = 155	IVR4 n = 155	IVR5 n = 154	IVR6 n = 154	IVR7 n = 155	IVR8 n = 155	IVR9 n = 154	IVR10 n = 155	IVR11 n = 155
Step 1 Model	R²	.10^***	.05^**	.04^**	.09^***	.21^***	.23^***	.12^***	.15^***	.27^***	.26^***	.24^***	.35^***
Step 2 Model	R²	.09^***	.11^***^ˆ	.06^*	.09^***	.24^***^ˆ	.22^***	.14^***	.20^***^ˆ	.33^***^ˆ	.31^***^ˆ	.29^***^ˆ	.38^***^ˆ
Perceived behavioural control	β Step 2	−.28^**	−.12	−.12	−.33^***	−.47^***	−.55^***	−.30^**	−.26^**	−.40^***	−.69^***	−.45^***	−.54^***
Affective attitudes	β Step 2	−.08	−.21^*	−.16	−.02	−.03	.07	−.04	−.14	−.21	.29^**	.01	<.01
Instrumental attitudes	β Step 2	.07	.13	.13	.03	.17^*	<−.01	.07	−.06	.07^**	.11	−.13	−.05
Subjective norms	β Step 2	<.01	.22^**	.05	.11	.11	.08	−.19^*	−.19^*	−.15^*	−.11	−.24^***	−.21^***

Notes: Step 1 included PBC and Step 2 included addition of instrumental attitudes, affective attitudes, and SN. Analysis performed using last observation carried forward imputation methods; variations in sample size are due to exclusion of cases based on outlier analysis.

^ˆ

R²Δ < 0.05

p < 0.05;

^**

p < 0.01;

^***

p < 0.001.