Abstract: Two RCTs from Kenya were included in the review. One trial compared short weekly text messages against standard care. The other trial compared short daily, long daily, short weekly and long weekly messages against standard care. Both trials were with adult patients. In the trial comparing only short weekly messages to standard care, text messaging was associated with a lower risk of non-adherence at 12 months (RR 0.77, 95% CI 0.63 to 0.93) and with the non-occurrence of virologic failure at 12 months (RR 0.83, 95% CI 0.69 to 0.99). In the trial that compared different intervals and lengths for text-messaging to standard care, long weekly text-messaging was not significantly associated with a lower risk of non-adherence compared to standard care (RR 0.79, 95% CI 0.60 to 1.04). Patients receiving weekly text-messages of any length were at lower risk of non-adherence at 48 weeks than were patients receiving daily messages of any length (RR 0.79, 95% CI 0.64 to 0.99). There were no significant differences between weekly text-messaging of any length (RR 1.01, 95% CI 0.75 to 1.37) and between short or long messaging at either interval (RR 0.99, 95% CI 0.78 to 1.27). Compared to standard care, any daily text-messaging, whether short or long, did not reduce the risk for non-adherence (RR 0.99, 95% CI 0.82 to 1.20). In meta-analysis of both trials, any weekly text-messaging (i.e. whether short or long messages) was associated with a lower risk of non-adherence at 48-52 weeks (RR 0.78, 95% CI 0.68 to 0.89). The effect of short weekly text-messaging was also significant (RR 0.77, 95% CI 0.67 to 0.89). There is high-quality evidence from the two RCTs that mobile phone text-messaging at weekly intervals is efficacious in enhancing adherence to ART, compared to standard care. There is high quality evidence from one trial that weekly mobile phone text-messaging is efficacious in improving HIV viral load suppression. Policy-makers should consider funding programs proposing to provide weekly mobile phone text-messaging as a means for promoting adherence to antiretroviral therapy. Clinics and hospitals should consider implementing such programs. There is a need for large RCTs of this intervention in adolescent populations, as well as in high-income countries.

Plain-language summary: Two randomised controlled trials from Kenya were included in the review. One trial compared short weekly text messages against standard care. The other trial compared short daily, long daily, short weekly and long weekly messages against standard care. In the trial comparing only short weekly messages to standard care, text messaging was associated with lower risk of non-adherence at 12 months, and with the non-occurrence of virologic failure at 12 months. Combining the data from both trials, weekly mobile phone text-messaging was associated with greater ART adherence at 48-52 weeks. The effect of short weekly text-messaging was also significant. In the trial that compared different intervals and lengths for text-messaging to standard care, long weekly text-messaging was not significantly associated with a lower risk of non-adherence compared to standard care. Patients receiving weekly text-messages of any length were at lower risk of non-adherence at 48 weeks than were patients receiving daily messages of any length. There were no significant differences between weekly text-messaging of any length and between short or long messaging at either interval. Compared to standard care, any daily text-messaging, whether short or long, did not reduce the risk for non-adherence. Weekly mobile phone text messages to patients on ART can help them to take their medication every day. It can also help to reduce the amount of HIV in their bloodstream. Because the two included trials were with adult patients only, there is a need for trials of this intervention with adolescents. Also, as the two trials were conducted in Kenya, a low-income country, there is a need for trials of this intervention in high-income countries.