Table 3

Guiding principles to inform the optimisation of the intervention

Design objectives	Key intervention features
Help couples feel close to each other, recognising the positive aspects of their relationship and providing motivation to look after their health together.	Activities to promote focus on the positive aspects of the relationship.
Encourage effective communication to address fears and outcome expectancies about testing. Address negative emotions.	Ask open questions to enable couples to identify their barriers to CHTC and come up with their own solutions. Provide effective communication skills training to help couples explore their perceived barriers to testing together.
Increase understanding about risk of HIV transmission, serodiscordance and effectiveness of treatment.	Interactive single-gender group activities Open dialogue facilitated by a peer mentor with experience of couples HIV testing Provide standard guidance on HIV prevention to reduce risk of transmission, for example, condom demonstration.