Abstract: Five RCTs met our inclusion criteria. Three trials aimed to improve adherence to a specific method of contraception amongst existing or new contraception users by comparing automated text message interventions versus standard care. Two trials aimed to improve both uptake and adherence, not limited to one method, in both users and non-users of contraception. No trials were at low risk of bias in all areas assessed. One trial in the USA reported improved self reported oral contraceptive (OC) continuation at six months from an intervention comprising a range of uni-directional and interactive text messages (RR 1.19, 95% CI 1.05 to 1.35). One trial in Cambodia reported increased self reported use of effective contraception at four months post abortion from an intervention comprising automated interactive voice messages and phone counsellor support (RR 1.39, 95% CI 1.17 to 1.66). One feasibility trial in the USA reported a lower mean number of days between scheduled and completed attendance for the first but not subsequent Depo-Provera appointments using clinic records from an intervention comprising reminders and healthy self management text messages (mean difference (MD) -8.60 days, 95% CI -16.74 to -0.46). Simple text message OC reminders had no effect on missed pills as assessed by electronic medication monitoring in a small trial in the USA (MD 0.5 missed pills, 95% CI -1.08 to 2.08). No effect on self reported contraception use was noted amongst isotretinoin users from an intervention that provided health information via two uni-directional text messages and mail (RR 1.26, 95% CI 0.84 to 1.89). One trial assessed potential adverse effects of the intervention and reported no evidence of road traffic accidents or domestic abuse. Our review provides limited evidence that interventions delivered by mobile phone can improve contraception use. Whilst evidence suggests that a series of interactive voice messages and counsellor support can improve post-abortion contraception, and that a mixture of uni-directional and interactive daily educational text messages can improve OC adherence, the cost-effectiveness and long-term effects of these interventions remain unknown. Further high-quality trials are required to robustly establish the effects of interventions delivered by mobile phone to improve contraception use.

Plain-language summary: In 2014, we undertook computer searches for randomised trials evaluating mobile phone-based interventions to increase contraception use. We found five trials. Three trials used text messaging to support women in continuing to use a specific method of contraception. Two trials aimed to improve both uptake and continued use of contraception - one with voice and one with text messaging. Our review provides limited evidence that interventions delivered by mobile phone improve contraception use. One trial in the USA reported that women were more likely to continue to take the contraceptive pill from an intervention comprising a range of educational text messages. One trial in Cambodia reported increased use of contraception at four months post abortion from an intervention comprising voice messages and phone counsellor support. Another trial in the USA reported improved attendance for the first but not subsequent contraceptive injection appointments from an intervention comprising reminders and healthy self management text messages. Simple text message contraceptive pill reminders did not reduce missed pills in a small trial in the USA. No difference in contraception use was reported amongst users of isotretinoin (a drug used for acne) from an intervention that provided health information via text messages and mail. In conclusion, evidence indicates that a series of voice messages and counsellor support can improve contraception amongst women seeking abortion services not wanting to get pregnant again at the current time, and data suggest that daily educational text messages can improve continued use of the contraceptive pill. However, the cost value and long-term effectiveness of these interventions remain unknown. More good quality trials are needed to establish the effectiveness of interventions delivered by mobile phone to increase contraception use.