"I want to be able to say that I did everything I could". Exploring the negotiations between the logic of care and the logic of research in clinical trials.

Randomised Controlled Trials (RCTs) are considered the "gold standard" for producing medical evidence due to their emphasis on standardisation, control, and scientific rigour. However, staff often face challenges in adhering to protocols, as running trials can generate tensions with caring for participants as individuals. In this article, drawing on Annemarie Mol's concept of the 'logic of care', we explore how care and research are continually negotiated within clinical trials. We conducted a 17-month ethnography at a UK clinical trial centre. The study draws on 330 h of observation of 170 staff and participants to examine how healthcare professionals navigate competing demands while managing hypertension. Our findings show that strict adherence to research protocols was maintained when deemed essential for running the trial, even when doing so generated discomfort or potential harm for participants. However, there were also moments in which staff prioritised participant wellbeing, for example by offering dietary advice, even when such actions risked influencing trial outcomes. Our analysis offers four contributions to this literature. First, it illustrates how the logic of care and the logic of research co-exist within the everyday conduct of trials. Second, our study highlights how the relationship between care and research is not resolved through the prioritisation of one logic over the other, but through ongoing negotiation. Third, our findings show how these tensions are embodied in the role of the clinician-researcher. Fourth, our analysis contributes to broader debates on the ethics of clinical research.