Assessing the impact of introducing online postal self-sampling for sexually transmitted infections into sexual health provision within the UK on health inequalities, access to care and clinical outcomes. Short title: ASSIST

Research questions: 1.Does channelling to online postal self-sampling for sexually transmitted infections (STIs) and HIV: a. Impact on health inequalities b. Increase access to sexual health care, especially for those most at risk? c. Improve clinical and public health outcomes? d. Provide desired economic outcomes?

2.How are online services implemented and what affects their sustainability? 3.How do online implementation models affect the impact on health inequalities, clinical- and cost-effectiveness?

Background: Sexual health is a UK public health priority. Over 3.6 million people attend sexual health services annually with significant morbidity and substantial costs. STI diagnoses and antibiotic resistance are increasing, yet funding has reduced and services are fragmented. Online services are seen as a means to address these challenges, yet their effectiveness and cost-effectiveness is unknown.

Aims and objectives: To assess the impact of online postal self-sampling services on health inequalities, access to care, and clinical and economic outcomes, and to identify the factors that influence the implementation and sustainability of these services.

Methods: A theoretically informed evaluation of 3 case study areas (Birmingham, London and Glasgow) implementing online services. Our proposed work uses realist methodology within 4 inter-linking work streams (WS):

WS1 examines the impact of online services on health inequalities, access and clinical outcomes, using existing surveillance data, clinic/OPSS datasets, and qualitative interviews with service users and healthcare professionals.

WS2 analyses the costs and outcomes associated with online services compared to clinic-based services, by undertaking an economic analysis based on the resource use, clinical outcomes and cost data collected from each case-study area.

WS3 describes and evaluates how implementation processes and service delivery models contribute to observed variation in clinical and cost-effectiveness. It uses document analysis, in-depth and contextual observational interviews and normalisation process theory.

WS4 ensures that the initial programme theories of impact and implementation of OPSS are iteratively refined into detailed realist programme theories using relevant data from across WSs. Timelines: Over 39 months (1/01/2021 – 31/03/2024): HRA approvals (Month (M) 0-6) WS1(M3-33), WS2(M3-36), WS3(M3-28), WS4(M3-36) Writing up and dissemination (M33-39), dissemination event (M39)

Impact and dissemination: We will generate impact by providing: • Evidence of the impact on health inequalities, effectiveness, and cost effectiveness of online postal self-sampling

• A description of the feasibility and acceptability of the different components of the intervention; unexpected adverse events; equity; and tested causal assumptions • An evidence base around what works best, how and for whom, to inform delivery of online services

• Information highly relevant to other regions planning similar service transformation. Leadership, management and governance requirements for the successful implementation and scale up of online services

• Evidence to develop national quality measures and standards of care for online services and inform sexual health policy.

A robust dissemination strategy, underpinned by strong patient and public involvement and engagement, will enable timely dissemination of findings and translation into practice