Evaluating the Home-based Intervention Strategy (HIS-UK) to reduce new chlamydia infection among young men aged 16-25 years by promoting correct and consistent condom use: What is the cost effectiveness of two different delivery models (face-to-face and digital delivery)? Protocol for a randomised controlled trial. (Preprint)

BACKGROUND The health, social, and economic costs of sexually transmitted infections (STIs) represent a major public health concern. Young people are considered one of the groups most at risk for acquiring and transmitting STIs. Correct and consistent condom use has been shown to be the most effective method for reducing STIs; however, condoms are often not used properly. Evidence has shown that brief behavioural change interventions that focus on skills, communication, and motivation to acquire safe sex practices, should be adopted into routine care to reduce STIs. Funding for sexual health services (SHS) in England has declined dramatically, so novel ways of reducing clinic attendance are being sought. The Home-based Intervention Strategy (HIS-UK) to promote condom use among young men has shown promise in feasibility and pilot studies by demonstrating high acceptability of the intervention in participant and health professional feedback, including aiding men to find condoms that they like and to feel more confident when using condoms. OBJECTIVE To determine the effectiveness and cost-effectiveness of HIS-UK when compared to usual condom distribution care in young men. The three trial arms consisting of ‘eHIS’ (HIS-UK delivered digitally), ‘proHIS’ (HIS-UK delivered face-to-face) and control condition (usual NHS care) will be compared against three primary outcomes: the extent to which they increase correct and consistent condom use, improve condom use experiences (pleasure, fit-and-feel), and reduce chlamydia test positivity. METHODS The study aims to address skills acquisition and motivation to use condoms. Eligibility criteria include men aged 16-25 years at risk of STIs through reporting of condom use errors (i.e. breakage/slippage) or condomless penile-vaginal or penile-anal intercourse with casual/non-regular or new sexual partners during the previous three months. Prospective participants will be recruited through targeted advertisements and an opportunistic direct approach at selected sexual health and genitourinary medicine services and University-associated health centres and GP practices. Community and educational establishments will be used to further advertise the study and signpost men to recruitment sites. Participants will be randomly allocated to one of three trial arms. A repeated measures design will assess the three parallel arms with baseline and 12 monthly follow-up questionnaires post intervention and three chlamydia screening points (baseline, 6 and 12 months). RESULTS Recruitment commenced in March 2020. Due to the COVID-19 pandemic the study was halted and has since reopened for recruitment in Summer 2021. CONCLUSIONS If effective and cost-effective, HIS-UK can be scaled up into routine NHS usual care to reduce both STI transmission in young people and pressure on NHS resources. This intervention may further encourage SHSs to adopt further digital technologies, allowing for such services to become more widely available to young people whilst also decreasing health inequalities and fear of stigmatisation. CLINICALTRIAL ISRCTN: 11400820, October 2019