Background Emergency departments have been characterised as complex adaptive systems and patient flow is one area that affects the efficiency and quality of care in emergency departments. Complex systems may comprise complex processes but the system may still be effective if the processes have the least number of steps required to produce an outcome. Improving patient flow requires an understanding of how ED processes work. However, there is little existing qualitative literature exploring ED patient flow. This study aimed to understand the ED patient flow process and identify the factors that influence it.

Multiple qualitative methods were used to explore ED patient flow in a single case study site in Trinidad and Tobago. Data was collected from May 2017 to March 2018. Non-participant observations (48 hours), observational process mapping (155 hours) and informational conversational interviews (90) were used to explore patient flow. Observational process mapping involved directly observing patient journeys across all levels of urgency. Thematic analysis was used to analyse the data.

Six broad themes were identified as factors influencing ED patient flow- 1) ED organizational work processes, 2) ED design and layout, 3) Material resources within and outside the ED, 4) ED nursing staff levels, roles, skill mix and use, 5) ED non-clinical staff, 6) External clinical and non-clinical departments. Within the themes there were primary factors that influenced patient flow as well as secondary factors. The secondary factor represented the staff response to either enhance the primary factor or to compensate for limitations in the process. A conceptual model of the factors influencing ED patient flow was developed.

The conceptual model of ED patient flow developed in this study can be used to systematically examine the factors influencing ED patient flow and may be used by policy and decision makers to improve patient flow.