A systematic review & meta-analysis in the effectiveness of mobile phone interventions used to improve adherence to ART in HIV
There are over 36 million people in the world with HIV. Antiretroviral therapy is effective in preventing the progression of HIV to AIDs but more than 95% adherence is required to suppress viral load. Adherence to HIV medication is lower than ideal. Mobile technologies could deliver low cost interventions to increase adherence to medication. A previous Cochrane review included two trials and concluded that SMS interventions increased adherence to HIV medication, but further trials with mixed results have since been published. Our review aims to provide an up to date synthesis of the evidence and report the effects of interventions delivered using different mobile phones functions (phone calls / SMS) and frequencies of contact. We explore the effects of interventions which include interactivity, links to services and interventions which include at least 3 behaviour change techniques.
We searched Cochrane, Medline, CINAHL, EMBASE and Global for randomised control trials of interventions delivered by mobile phone designed to increase adherence to antiretroviral medication. All reference lists of relevant articles were manually screened and risk of bias assessed. Primary outcome adherence measures were objective (CD4, viral load) and the secondary outcome measure was self-reporting. We calculated relative risk ratios (RR) or standardised mean difference (SMD) with 95% confidence interval (CI). Where appropriate meta-analysis using STATA version 11 has been used to pool data. Two independent reviewers extracted data.
Thirteen articles were selected. Interventions included up to 6 behaviour change techniques. No primary outcomes could be pooled due to lack of objective measures. Secondary outcome measures were pooled but at risk of bias as participants could not be blinded and measures are subjective. The pooled effects of interventions delivered by text messages on self-reported adherence was RR 1.11 (1.00 to 1.24) and weekly messaging was RR 1.16 (0.98 to 1.37). Voice call interventions increased self-reported adherence RR 1.20 (1.06 to 1.37) and SMD 0.32 (0.06 to 0.58). Subgroup analyses showed that neither interactivity RR 1.07 (0.81 to1.40) or links to service support RR 1.11 (0.91 to 1.36) improved self-reported adherence. Interventions with at least 3 behavioural change techniques increased self-reported adherence, SMD 0.77 (0.08 to 1.46).
Existing interventions include few behaviour change techniques. Individual trials report beneficial effects of adherence interventions, but pooled analyses of SMS interventions is heterogeneous. The overall pooled effect almost achieved statistical significance at p=0.05. Pooled analysis showed statistically significant increases in adherence to medication for interventions employing mobile phone calls. WHO should reconsider current advice that text messaging in general is effective and should focus on specific interventions, which have been shown to be effective. High quality trials of optimal interventions on objective measure are needed in high middle and low income countries.