BackgroundSafeBoosC-III is a pragmatic, multinational clinical trial evaluating cerebral oximetry-guided treatment for extremely preterm infants. In total, 1601 infants were randomised across 70 sites in Asia, Europe, and USA. To enhance data quality and patient care, a web-based training program was implemented for staff. We now report on the processes.MethodsAll training modules consisted of initial learning material followed by a case-based quiz, with elaborate responses to correct as well as to wrong answers. Modules covered trial introduction, cerebral oximetry monitoring, treatment guidelines, cerebral ultrasound, and Good Clinical Practice. The introduction module was accessible in eight languages on an online platform, while language versions varied for other modules, due to different needs. Certification was earned upon module completion, relevant to the staff category. The training was not mandatory, but for motivational purposes, principal investigators continuously received local certification rate reports.ResultsA total of 926 out of 2347 staff (39%) obtained certification. Amongst 295 staff who completed the evaluation, 83% rated the program as overall good and 94% found it relevant to clinical practice. Sites exhibited varying certification rates, with 10 at 0%, 43 between 0.1 and 79.9%, and 17 exceeding 80%. There was no correlation between the rate of certification in individual sites and how often the clinical management was changed due to cerebral hypoxia nor a correlation to site-specific estimates of the intervention effect.ConclusionDespite language barriers and a low budget, our web-based training and certification program proved feasible. Only a minority of sites reached 80% certification of staff and an impact on the trial could not be detected.Trial registrationThe SafeBoosC-III trial is registered at ClinicalTrials.gov NCT03770741. The first participant was randomised in June 2019 and recruitment was completed in December 2021.