"Friendly reminder: hi! It is that time again ☺": understanding PMTCT care text message design preferences amongst pre- and post-partum women and their male partners.

Background: Prevention of mother-to-child HIV transmission (PMTCT) services in Kenya can be strengthened through the delivery of relevant and culturally appropriate SMS messages.

Methods: This study reports on the results of focus groups conducted with pre and postnatal women living with HIV (5 groups, n = 40) and their male partners (3 groups, n = 33) to elicit feedback and develop messages to support HIV+ women's adherence to ART medication, ANC appointments and a facility-based birth. The principles of message design informed message development.

Results: Respondents wanted ART adherence messages that were low in verbal immediacy (ambiguous), came from an anonymous source, and were customized in timing and frequency. Unlike other studies, low message immediacy was prioritized over customization of message content. For retention, participants preferred messages with high verbal immediacy-direct appointment reminders and references to the baby-sent infrequently from a clinical source.

Conclusion: Overall, participants favored content that was brief, cheerful, and emotionally appealing.