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

INTERVENTION: Participants will be randomly allocated, using a remote computer based randomised system, to a safer sex intervention delivered by text messaging or to a control group. The allocation will be by simple randomisation. Control group: Participants receive a monthly text message asking the participant to provide information about changes in postal or email addresses Intervention group: Participants receive regular messages delivered by text message to influence safer sex behaviours. The intervention employs education, enabling and incentivising behaviour change functions and twelve behaviour change techniques identified in effective face to face safer sex interventions. The information on safer sexual practices is in accordance with existing guidelines. The intervention text message content has been developed in collaboration with young people and has been shown to be acceptable, comprehensible and relevant. Participants will be sent messages at the following frequencies: 1. 4 messages per day for days 1‐3 2. 1‐2 messages per day for days 4‐28 3. 2‐3 messages per week for month 2 4. 2‐5 messages per month for months 3‐12 CONDITION: Topic: Infectious Diseases; Subtopic: Infectious Diseases; Disease: Infectious Diseases and Microbiology ; Infections and Infestations ; Sexually transmitted infections PRIMARY OUTCOME: Cumulative incidence of Chlamydia and gonorrhoea infection at one year assessed by NAAT (nucleic acid amplification test) tests: urine for men with pharyngeal and anal swabs for MSM (men who have sex with men) and self‐taken vulvo‐vaginal swab for women. SECONDARY OUTCOME: 1. Clinic attendance by partner for treatment is determined at four weeks; 2. Whether participants took the treatment and avoided sex for 7 days after treatment is determined at four weeks INCLUSION CRITERIA: 1. Aged 16 to 24 inclusive 2. Received a positive chlamydia or gonorrhoea test result or have been diagnosed with NSU in the last 2 weeks 3. Own a personal mobile phone 4. Able to provide informed consent