Introduction The past decade has seen a rapid increase in the volume and proportion of testing for sexually transmitted infections that are accessed via online postal self-sampling services in the UK. ASSIST (Assessing the impact of online postal self-sampling for sexually transmitted infections on health inequalities, access to care and clinical outcomes in the UK) aims to assess the impact of these 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 and analysis ASSIST is a mixed-methods, realist evaluated, national study with an in-depth focus of three case study areas (Birmingham, London and Sheffield). An impact evaluation, economic evaluation and implementation evaluation will be conducted. Findings from these evaluations will be analysed together to develop programme theories that explain the outcomes. Data collection includes quantitative data (using national, clinic based and online datasets); qualitative interviews with service users, healthcare professionals and key stakeholders; contextual observations and documentary analysis. STATA 17 and NVivo will be used to conduct the quantitative and qualitative analysis, respectively. Ethics and dissemination This study has been approved by South Central – Berkshire Research Ethics Committee (ref: 21/SC/0223). All quantitative data accessed and collected will be anonymous. Participants involved with qualitative interviews will be asked for informed consent, and data collected will be anonymised.Our dissemination strategy has been developed to access and engage key audiences in a timely manner and findings will be disseminated via the study website, social media, in peer-reviewed scientific journals, at research conferences, local meetings and seminars and at a concluding dissemination and networking event for stakeholders.
Background: Online postal self-sampling (OPSS) allows service users to screen for sexually transmitted infections (STIs) by ordering a self-sampling kit online, taking their own samples, returning them to a laboratory for testing, and receiving their results remotely. OPSS availability and use has increased in both the United Kingdom and globally the past decade but has been adopted in different regions of England at different times, with different models of delivery. It is not known why certain models were decided on or how implementation strategies have influenced outcomes, including the sustainability of OPSS in sexual health service delivery. Objective: This study aims to evaluate the implementation of OPSS in 3 case study areas of England, with a focus on the sustainability of implementation and the relationship between implementation strategies and outcomes. Methods: Qualitative data collection methods were used: interviews with staff and stakeholders involved in the implementation and delivery of OPSS, analysis of local implementation and national policy documents, and observations in sexual health clinics. Analysis of interviews and observations was undertaken using qualitative implementation science frameworks, including normalization process theory, the Consolidated Framework for Implementation Research, and the major system change framework. Documentary sources were used primarily to map processes over time and triangulate against interview and observational evidence. Results: Across the 3 case study areas, 60 staff and stakeholders were interviewed, 12 observations were conducted, and data from 86 documents were collated. Rather than being a discrete digital health intervention, we found that OPSS was part of—or occurred parallel to—major system changes in all areas. These changes were driven by budgetary pressures in all areas, but there was variation in other objectives used to rationalize the decision to adopt. The financial context and organizational relationships in each area determined the implementation strategies available to decision makers, how these strategies were enacted, and, in turn, led to different outcomes at different time points. OPSS implementation was not a one-off outcome but an ongoing process in response to changes in context, which in turn affected how staff perceived and engaged with OPSS. The COVID-19 pandemic had profound but divergent effects on OPSS implementation in each area, accelerating it in some contexts and reversing it in others. Conclusions: In this multisite case study, OPSS implementation was part of systems change to address a wider problem of insufficient funding to deliver sexual health care. Decisions about implementing OPSS were made before sufficient evidence was available to effectively guide the process. The resultant unintended consequences need acknowledgment to enable future commissioners and sexual health services to optimize sexual health service provision.