Table 1.

Constructs identified from relevant behaviour change theories with the corresponding a priori themes

Theory and construct	Identified a priori theme
Theory I: Trans-theoretical or Stages-of-change model for behaviour change
• Stage construct	1. Identifying stages-of-change
	This was considered as one theme with the focus on identifying cues to differentiate households to three stages-of-change, instead of the original five. Hence for this study:
	• Pre-contemplation = Pre-contemplation
	• Intention = Contemplation + Preparation
	• Action = Action + Maintenance
• Decisional balance	2. Perceived pros and cons
• Self-efficacy	3. Self-efficacy
• Change processes	4. Awareness
	5. Emotional reaction
	6. Effect of behavior on others
	7. Social alternatives for disadvantaged
	8. Self-evaluation
	9. Identifying temptations
	10. Helpful relationship
	11. Substitution
	12. Reinforcement or rewards
	13. Commitment
Theory II: Health Belief Model
• Perceived susceptibility	14. Perceived susceptibility
• Perceived benefits	15. Perceived benefits
• Perceived barriers	16. Perceived barriers
• Perceived seriousness	17. Perceived seriousness
• Cues to action	18. Perceived facilitators
• Modifying variables	19. Personal modifiers
• Self efficacy	3. Self-efficacy*
Theory III: Theory of Planned Behaviour
• Attitude (towards the behaviour)	20. Attitude
• Subjective norms	21. Subjective norms
• Perceived behavioural control	3. Self-efficacy*
Theory IV: Social Cognitive Model
• Knowledge	4. Awareness*
• Perceived self-efficacy	3. Self-efficacy*
• Outcome expectations	15. Perceived benefits*
• Goals	22. Goal setting
• Perceived facilitators and impediments	18. Perceived facilitators*
	16. Perceived barriers*

*Constructs from different health behaviour theories having similar definitions are identified as one a priori theme.