safetxt: a randomised controlled trial of a safer sex intervention delivered through mobile phone messaging

Problem

The number of sexually transmitted infection (STI) diagnoses in the United Kingdom (UK) is rising, with the biggest increase in chlamydia and gonorrhoea diagnoses. Young people aged 16-24 have the highest prevalence of genital chlamydia and gonorrhoea compared to other age groups and re-infection rates following treatment are high. The risk of adverse health effects increases with repeated infections, including long-term adverse health effects such as sub-fertility and ectopic pregnancy. There is some evidence that existing interventions delivered face-to-face may be effective, but are limited in their reach or too costly for widespread application. Phone ownership in the UK is high, and young people in particular tend to constantly interact with their mobile phones. An intervention delivered by mobile phone message therefore has the potential to be a widely accessible and inexpensive health behaviour support. Previous research has found support for sexual health via mobile phone messaging to be acceptable, and the ability to receive support anywhere and anytime facilitated confidentiality and privacy. However, no trials to date provide conclusive evidence of their effectiveness as support for safer sex behaviours. We developed the safetxt intervention delivered by mobile phone message to reduce STI by increasing partner notification, condom use and STI testing among young people in the UK.

Approach

We conducted a single blind randomised controlled trial to reliably establish the effect of the safetxt intervention delivered by mobile phone messaging on chlamydia or gonorrhoea infection at one year. We recruited 6250 people aged 16-24 years who had recently been diagnosed with chlamydia, gonorrhoea or non-specific urethritis from 52 sexual health services in the UK. Participants were allocated to receive either the safetxt intervention (text messages designed to promote safer sexual health behaviours) or to receive the control text messages (monthly messages asking participants for contact detail updates). The primary outcome is the cumulative incidence of chlamydia and gonorrhoea infection at one year. Secondary outcomes include partner notification, correct treatment of infection, condom use, and STI testing prior to sex with new partners.

Findings

Follow up for the safetxt trial will be complete in March 2020. We will present preliminary findings from the trial.

Consequences

If effective, a safer sex intervention delivered by mobile phone messaging has the potential to increase safer sex behaviours in young people, and reduce the number of chlamydia or gonorrhoea infections. This would be an important impact on the sexual health of young people in the UK. The intervention would likely have a global impact, as short written messages delivered via mobile phones are increasingly used for behavioural support worldwide and STIs remain an important cause of morbidity and mortality. Identifying which intervention components are effective has the potential to inform similar interventions in the future.