Effectiveness of a behavioural intervention delivered by text messages (safetxt) on sexually transmitted reinfections in people aged 16-24 years: randomised controlled trial

Abstract

Objective To quantify the effects of a series of text messages (safetxt) delivered in the community on incidence of chlamydia and gonorrhoea reinfection at one year in people aged 16-24 years. Design Parallel group randomised controlled trial. Setting 92 sexual health clinics in the United Kingdom. Participants People aged 16-24 years with a diagnosis of, or treatment for, chlamydia, gonorrhoea, or non-specific urethritis in the past two weeks who owned a mobile phone. Interventions 3123 participants assigned to the safetxt intervention received a series of text messages to improve sex behaviours: four texts daily for days 1-3, one or two daily for days 4-28, two or three weekly for month 2, and 2-5 monthly for months 3-12. 3125 control participants received a monthly text message for one year asking for any change to postal or email address. It was hypothesised that safetxt would reduce the risk of chlamydia and gonorrhoea reinfection at one year by improving three key safer sex behaviours: partner notification at one month, condom use, and sexually transmitted infection testing before unprotected sex with a new partner. Care providers and outcome assessors were blind to allocation. Main outcome measures The primary outcome was the cumulative incidence of chlamydia or gonorrhoea reinfection at one year, assessed by nucleic acid amplification tests. Safety outcomes were self-reported road traffic incidents and partner violence. All analyses were by intention to treat. Results 6248 of 20 476 people assessed for eligibility between 1 April 2016 and 23 November 2018 were randomised. Primary outcome data were available for 4675/6248 (74.8%). At one year, the cumulative incidence of chlamydia or gonorrhoea reinfection was 22.2% (693/3123) in the safetxt arm versus 20.3% (633/3125) in the control arm (odds ratio 1.13, 95% confidence interval 0.98 to 1.31). The number needed to harm was 64 (95% confidence interval number needed to benefit 334 to ∞ to number needed to harm 24) The risk of road traffic incidents and partner violence was similar between the groups. Conclusions The safetxt intervention did not reduce chlamydia and gonorrhoea reinfections at one year in people aged 16-24 years. More reinfections occurred in the safetxt group. The results highlight the need for rigorous evaluation of health communication interventions. Trial registration ISRCTN registry ISRCTN64390461 .

A qualitative study exploring experiences of the safetxt digital health intervention to reduce sexually transmitted infections in young people in the UK

“…At the later stages of thematic analysis, Microsoft Word 2019 was used to integrate and triangulate themes developed by both researchers from both data sources, based on comparisons and team discussions. During analysis meetings with the research team, results from open feedback comments (source 1) and interviews (source 2) were triangulated with quantitative trial data (including primary, secondary and intermediate outcomes)19 20 and data from telephone interviews conducted as part of the 2013 feasibility trial 2–3 weeks after starting messages17 looking for consistencies and inconsistencies across the different data sources and searching for deviant cases.…”

“…Control group participants received a monthly untailored text message asking for information about changes in postal or email addresses. The safetxt intervention did not reduce STIs, there were slightly more infections in the intervention group with 22.2% (693/3123) versus 20.3% (633/3125) in the control group (OR 1.13, 95% CI 0.98 to 1.31) 19 20. There were some increases in self-reported precautionary behaviours such as condom use at last sex, OR 1.14, 95% CI 1.01 to 1.28 19 20.…”

“…The safetxt intervention did not reduce STIs, there were slightly more infections in the intervention group with 22.2% (693/3123) versus 20.3% (633/3125) in the control group (OR 1.13, 95% CI 0.98 to 1.31) 19 20. There were some increases in self-reported precautionary behaviours such as condom use at last sex, OR 1.14, 95% CI 1.01 to 1.28 19 20. Although our intervention did not target sexual partnerships, we assessed at 1-year follow-up the proportion of people who had two or more partners since joining the trial and found that it was slightly higher in the intervention vs control group (56.9% vs 54.8%, OR 1.11, 95% CI 1.00 to 1.24).…”

“…This result, however, was not statistically significant (p=0.06) but could have contributed to the unexpected trial outcome. Other quantitative results, including on intermediate outcomes, did not clarify either, why a statistically significant effect was shown for the condom use outcome, but not for the biologic trial outcome 19 20…”

“…Intervention text messages were sent with decreasing frequency over the period of 12 months (online supplemental file 1). 18 Our randomised controlled trial to establish the effects of the intervention on STI, condom use, partner notification and STI testing before sex with new partners was conducted among 6250 people aged 16–24 diagnosed at UK sexual health clinics with chlamydia, gonorrhoea or non-specific urethritis 19 20. Control group participants received a monthly untailored text message asking for information about changes in postal or email addresses.…”