A program to text young people at risk of STI infection may have had the opposite effect than intended.

A recent trial found that sending regular texts to young people who have recently had a sexually transmitted infection (STI) to encourage safer sex behaviours does not reduce rates of chlamydia and gonorrhoea reinfection.

In fact, the findings show that more reinfections occurred in the group receiving texts than in the control group, prompting the researchers to call for further evaluation of health communication interventions.

Health communications delivered by text message are cheap and effective for some behaviours, such as stopping smoking, and the World Health Organization (WHO) currently recommends digital health communication for sexual and reproductive health. 

But when a team of UK researchers set out to measure the effects of a series of text messages (‘safetxt’) on rates of chlamydia and gonorrhoea reinfection in young people at one year, they received some surprising results. 

They focused on a group of over 6,000 people aged 16-24 years recruited from 92 sexual health clinics across with a recent diagnosis of, or treatment for, chlamydia, gonorrhoea, or non-specific urethritis.

Half were randomly assigned to the safetxt intervention and received a series of text messages to improve sex behaviours, while control participants received a monthly text message for one year asking for any change to postal or email address.

At one year, the rate of chlamydia or gonorrhoea reinfection was 22 per cent (693 out of 3123) in the safetxt group versus 20 per cent (633 out of 3125) in the control group.

At four weeks, 86 per cent of participants in the intervention group versus 84 per cent in the control group had notified the last partner they had sex with before testing positive to get treatment. 

Also at four weeks, 42 per cent of participants in the intervention group versus 40 per cent in the control group reported using a condom at last sexual encounter, and this difference was sustained at 12 months (34 per cent intervention v 31 per cent control). 

At one year, 54 per cent of participants in the intervention group versus 49 per cent in the control group reported using a condom at first sexual encounter with their most recent new partner, but the number of STIs was not reduced.

The proportion of people with a new partner and with two or more partners at one year was also higher in the intervention group.

The researchers acknowledge several limitations, including the fact that men were under-represented in the trial and that many of their secondary outcomes relied on personal reports, which could be influenced by social desirability bias (when respondents over-report ‘good’ behaviour or under-report ‘bad’ or undesirable behaviour).

However, they say the similarity of findings after further sensitivity analyses is reassuring and suggests that their results are robust.

“Our text message intervention was grounded in psychological theory, incorporating the best evidence on health behaviour change, but it did not have the effects we anticipated,” the research paper states. 

“In light of our results, WHO should revise its endorsement of digital behaviour change communication for strengthening health systems, to specify which topics and content WHO endorses.”

Further research should focus on how to reduce the stigma associated with STIs to benefit wellbeing, treatment, and precautionary behaviours for those with a diagnosis of an STI, without increasing the risk of infection, they add.

The study is accessible here.