Cluster randomised trials (CRTs) can be at risk of bias driven by differential identification and recruitment of participants across treatments, posing a threat to the validity of findings. We explored the awareness and importance, among CRT researchers, of the recommended bias mitigation measures.

Qualitative interview study using semistructured interviews.

Participants were researchers involved in conducting CRTs, including investigators, statisticians and trial coordinators. 24 participants, including statisticians (n=13, 54.2%), clinical investigators (n=9, 37.5%) and trial coordinators (n=2, 8.3%), were interviewed; with representation from the UK (n=10, 41.7%), Australia (n=5, 20.8%) and the USA (n=4, 16.7%).

Participants exhibited differing levels of knowledge related to biases. Some participants demonstrated high levels of knowledge, but we also identified prevalent misconceptions, with some evidence of superficial knowledge. While some participants worked in collaborative teams, other teams’ responsibilities were delineated, and this impacted on how knowledge of biases was shared and acted on. Logistical and practical issues could prevent known solutions to mitigate biases being implemented. Biases also manifested because of a perception from participant recruiters that the purpose of research is for participant benefit rather than producing generalisable knowledge; and a normalisation or expectation that CRTs produce a lower level of evidence.

There is an urgent need to ensure that CRTs are free from risks of bias. Mitigation measures are either not known, not practical or unconsciously subverted. More education and collaborative working might help. Preventing subconscious bias during participant recruitment and dispelling the myth that CRTs produce lower levels of evidence would require a change in culture.

Injury is a major cause of death in Rwanda, with many deaths occurring before hospital admission. Timely transport of injured patients to appropriate hospitals is crucial, ideally within an hour for severely injured patients. However, delays in reaching treatment facilities are common, with ambulance services using inefficient mobile phone communication. This project aims to evaluate the effectiveness and implementation of an innovative electronic communication platform (912Rwanda).

The study will be conducted through the public ambulance service, Service d’Aide Médicale d’Urgence (SAMU), and receiving health facilities in Kigali city and Musanze district in Rwanda. The 912Rwanda intervention will be rolled out in the two locations at different times. The primary effectiveness outcome is the time from ambulance deployment to patient arrival at the health facility. Secondary effectiveness outcomes include disaggregated times of the primary outcome and clinical outcomes, such as length of stay and requirement for intensive care. These outcomes will be evaluated using an interrupted time series analysis, accounting for non-homogeneous variances, auto-regressive errors and non-linear trends where appropriate. Implementation outcomes will be evaluated using the Reach, Effectiveness, Adoption, Implementation, Maintenance (RE-AIM) Qualitative Evaluation for Systematic Translation (QuEST) framework. Cost-effectiveness will be evaluated using a cost-consequence analysis with consequences as determined by the interrupted time series analysis.

Ethical approval was obtained from the Rwanda National Research Ethics Committee (Ref No: 99/RNEC/2023). Dissemination will occur through open-access peer-reviewed publications, relevant national and international conferences.

ISRCTN97674565.