Clinical Trials Unit survey of translation and interpretation services: current practice, barriers and broader inclusion considerations

Abstract Background: Language barriers can limit participation in clinical trials among ethnic minority populations, particularly for individuals with low first-language literacy, limited health literacy, or limited English proficiency. Although there is increasing recognition of the need to address these barriers, the provision of translation and interpreting services remains resource-intensive, requiring additional time, expertise, and financial investment. Previous methodological studies show there are key implementation issues of providing language provision in UK clinical trials with no clear processes. Evidence on their use and implementation is limited, and their contribution to improving access to research remains unclear. The INVITE study aims to explore how language barriers are currently addressed in UK clinical trials, to explore experiences and acceptability of current processes, and describe resource use and cost of these services. This paper presents findings from a survey of UK Clinical Trials Units (CTUs) examining current practices relating to the provision of translation and interpreting services. Methods: An online survey was conducted between July and December 2025 with all 52 UKCRC registered CTUs invited to explore current practices relating to translation and interpreting services in clinical trials. Survey responses were grouped under four key topics - implementation, monitoring and oversight, quality management and barriers to language services provision in clinical trials. Free text space allowed respondents to expand on their answers within the survey and to explain barriers to implementing translation and interpreting services in clinical trials. Quantitative data were analysed using descriptive statistics and free-text responses were analysed thematically. Results: There were 35 responses from 31 CTUs. Translation of trial documents was the most used strategy to address language barriers (97%, 34/35), while 66% (23/35) also considered interpreting services. Where translation and interpreting services were implemented, this tended to be on a trial-specific basis rather than routinely across all CTU trials (68%, 22/34 and 65%, 15/23, respectively). Most respondents reported that their CTU provided no training or guidance to site staff on the use of translated documents or interpreting services (91%, 32/35). Monitoring of service use was uncommon, with only 28% (8/29) and 4% (1/29) reporting oversight of translated documents and interpreting services, respectively. Most CTUs did not undertake quality checks of external providers of translation for study documents (62%, 21/34), citing responsibilities were with the sponsor and NHS site, and limited knowledge of how such checks should be conducted. Key barriers included uncertainties around operational aspect of translation and interpreting services, site-level constraints, and broader issues relating to inclusivity. Respondents recognised that translation and interpreting services can improve access to trials but emphasised that addressing language barriers alone is insufficient to overcome wider cultural and trust-related barriers to participation. Conclusion: Translation and interpreting services are widely used by UK CTUs and are an important approach to supporting participation among people with limited English proficiency such as ethnic minority groups. However, opportunities remain to improve the planning, delivery, monitoring and quality assurance of these services, including improved guidance, sustainable funding, validated translated materials and outcome measures, clearer oversight processes, and a wider focus on language support across the entire trial life cycle.