Introduction:
Recent digitalisation has driven a rapid shift from paper-based documentation to Electronic Patient Record (EPR) systems. At the same time, Early Warning Systems (EWS), used to support detection of patient deterioration, have become widespread. Integrating EWS into EPRs aims to improve scoring accuracy and ultimately reduce preventable in-hospital mortality. However, digital EWS also introduce new cognitive demands, influencing how clinicians monitor patients, construct situational awareness, and communicate clinical concerns. As such, a human factors psychology lens was utilised to understand how digital EWS tools are interpreted, trusted, and operationalised in everyday clinical practice.


Purpose:
To examine the psychological, social, and organisational processes underpinning clinicians' use of a newly implemented digital EWS system, and to identify how human factors influence uptake, sense-making, and escalation behaviours.


Method:
An ethnographic observation study was conducted in Ireland's largest teaching hospital across acute medical and surgical wards. Using a structured guide based on the Systems Engineering Initiative for Patient Safety (SEIPS) 2.0 model, a leading healthcare human factors framework, we conducted non-participant observations of nurses and physicians across the full EWS workflow: vital sign measurement, data entry, score calculation, and escalation.


Results:
Digital EWS use was shaped by multiple interacting factors across individual cognition and motivation, team hierarchies, task demands, and organisational context. Clinicians' trust, perceived usefulness, and cognitive workload influenced how alerts were interpreted and acted upon, while system usability, workflow integration, and temporal delays in data entry and processing affected responsiveness. These dynamics produced variable outcomes in efficiency, communication, and clinician burden, with users frequently relying on compensatory workarounds to maintain clinical sense-making alongside automated alerts.


Conclusions:
The effectiveness of digital EWS systems depends not only on algorithmic accuracy but on careful alignment with cognitive workflows, professional judgement, and interface usability, making explicit attention to human factors essential for safe and meaningful clinical decision-making.