Feasibility trials should watch, listen and adapt—not just measure outcomes, Bristol researchers say

Research from NIHR Biomedical Research Centre: Bristol and Southmead Hospital suggests early studies assessing innovative invasive devices should:

• Embed qualitative observation and stakeholder interviews throughout
• Involve patients, clinicians, and industry partners from the start
• Expect to iteratively update key documents and training as evidence emerges

Using the ASSIST feasibility study of the OdonAssist™ device for assisted vaginal birth as a case study, the authors argue that feasibility work needs to do more than ask whether recruitment and data collection are possible.

Instead, it should systematically capture how clinicians use the device, what influences its use (such as context and clinical factors), and what needs to change before researchers attempt a larger study.

The paper, published in Pilot and Feasibility Studies, sets out a practical model for feasibility studies of complex, invasive devices. It suggests researchers should:

Embed qualitative case-study research alongside quantitative feasibility outcomes – combining researcher observations of real clinical use with stakeholder interviews

Use rapid triangulation and feedback loops so insights can inform practice quickly – feeding findings back to clinical teams and, where relevant, to engineers and manufacturers during the study

Treat the documents and training as adaptable – reviewing and refining procedural steps and clinical parameters as evidence accumulates, rather than freezing technique too early

Work with stakeholders from the start, including patient and public involvement (PPI) to shape recruitment materials, consent processes and which outcomes matter most to participants

Engage ethics committees early, using their expertise to strengthen study design – especially around recruitment timing and safety outcomes in fast-moving clinical settings

Collaborate closely with industry partners, enabling timely device refinements where issues are identified

Dr Emily Hotton, Obstetrics and Gynaecology Specialist Registrar and lead author, said:

“This study shows why innovative devices must be evaluated in real clinical settings—because it’s only through observing practice that we uncover the issues that matter most for safety and success.

“What’s striking is that the most important insights didn’t come from standard quantitative data, but from observing real-world use—allowing us to identify practical issues and improve the device in real time.

“Although the success rate was lower than expected, this was consistent with a learning curve, and importantly, the study demonstrated a positive safety profile while enabling rapid, data-driven improvements to the device.

“These findings directly informed a larger follow-on feasibility study, ASSIST II. Our research supported the device in achieving CE marking 2025, enabling its launch across Europe.”