Can an intervention delivered by text messages targetting safer sex behaviours be acceptable to young people and effective?

Talk Code: 
Ona McCarthy
Ona McCarthy, Rebecca S French, Paula Baraitser, Susan Michie, Ford Hickson, Karen Devries, Julia V Bailey, Melissa Palmer, Kaye Wellings, Cari Free
Author institutions: 
LSHTM, Kings College London, UCL


The prevalence of genital chlamydia and gonorrhoea is high among young people aged 16-24 in the UK. Long-term adverse health effects include sub-fertility and ectopic pregnancy, particularly among those with repeated infections, . It is estimated that 20-30% of young people diagnosed with chlamydia and about 10% of those diagnosed with gonorhoea are reinfected within a year. Stigma and shame associated with being diagnosed with an STI make it hard for people to notify partners. Exisitng e-health interventions can be prone to few people receiving the whole intervention. Our systematic review shows that existing interventions delivered by mobile phone targetting safer sex behaviours have not attempted to support people in notifying partners or evaluated the effects of interventions on objective outcomes. We aimed to develop an acceptable intervention informed by behavioural theory, expert and user views. We are currently conducting a RCT to evaluate its effects on the cumulative incidence of chlamydia and gonorhhoea at one year.


A mixed methods design. Identification of barriers to safer sex; coding the content of existing effective face-to-face interventions; selection of behaviour change functions and techniques; focus groups discussions; survey and telephone interviews.Setting: Community Sexual and Reproductive Health ServicesParticipants: 89 focus group participants, 100 survey participants, 8 telephone interview participants aged 16-24 recruited from sexual health services in SE London, rural Cambridgeshire and Manchester. Pilot trial with 200 participantsOutcomes: Participants’ preferences for and views of the intervention reported in focus group discussions and interviews. Survey participant scores regarding messages: relevant/unsure/not relevant, whether any messages were hard to understand or disliked. The proportion of recipients receiving the intervention.


We designed the messages to be educational and enabling and to address evidence based barriers to safer sex behaviours. Preferences revealed in the focus groups related to the tone (non-judgemental, credible and friendly, non-patronising), style (short, positive, offering practical information and support, realistic, non-didactic), language and punctuation of the messages. We adapted some behaviour change techniques. Survey feedback indicated that messages were liked and easy to understand. Feedback after receiving the text messages was that the content, frequency and duration of the intervention was acceptable and that the intervention helped participants talk to partners about being diagnosed with an STI and negotiate condom use. In our pilot trial 84% of participants in the intervention group opted to receive the whole intervention.


It was feasible to develop an intervention delivered by text message that is acceptable to young people. Most recipients opted to receive the whole intervention. The effectiveness of the intervention on cumulative incidence of clamydia and gonorrhoea is being evaluated in a randomised controlled trial funded by the NIHR with 5000 young people diagnosed with chlamydia, gonhorhea or NSU. The first 1000 participants have been recruited.

Submitted by: 
Cari Free
Funding acknowledgement: