Abstract Background Randomised implementation trials evaluate the effects of implementation strategies on implementation outcomes and may also monitor clinical effectiveness. Routine healthcare data are used in implementation trials for participant identification, intervention delivery, and/or outcome ascertainment. Trial efficiency (scientific, operational, statistical, and economic) is operationalised across trial design, processes, superstructure, infrastructure, and stakeholder engagement (the Trial Efficiency Pentagon). Despite frequent usage, the contribution of routine data to implementation trial efficiency remains underexplored. We aimed to investigate how the use of routine healthcare data affects trial efficiency in two implementation trials. Methods We conducted a qualitative comparative case study of two implementation trials, one UK-based and one US-based. Participants were purposively sampled from trial teams involved in the use and management of routine healthcare data. Data were collected through semi-structured interviews, document analysis, and feedback workshops. Framework analysis guided by the Trial Efficiency Pentagon was used to analyse the data, and data flow diagrams were developed to visualise routine data pathways within each trial. Results The two trials (DIGITS and IMP 2 ART) used routine data to characterise the practice population of eligible patients, support clinical and economic outcome evaluation, facilitate audit and feedback, and assist in intervention delivery. Common facilitators that supported the use of routine data included sufficient IT and hardware capacity, relatively low cost, centralised regulatory approval for multi-site studies, and strong collaboration and partnerships. Common barriers included administrative complexity, redundant bureaucratic processes, and challenges with data sharing requirements. Key differences included the DIGITS trial’s in-house data warehouses within an integrated healthcare system ensured high data quality and enabled preliminary analyses. In contrast, the IMP 2 ART trial, managing a larger national sample, employed an external research database to integrate data from various EHR systems but faced challenges such as legacy systems, diverse coding practices and site-specific approvals. Data quality can act as either a facilitator or a barrier. Conclusions Routine data has an impact on implementation trial efficiency across trial design, processes, superstructure, infrastructure, and stakeholder engagement. To improve trial efficiency in public healthcare systems, researchers must address technological and regulatory barriers to accessing data. In private healthcare systems, data use and access hinges on investing in robust IT infrastructure and ensuring comprehensive organisational commitment. Trial registration IMP 2 ART trial registration: ISRCTN15448074; DIGITS trial Clinicaltrials.gov Identifier: NCT05160233.
Xie et al. (Sat,) studied this question.