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BEST - Baseline Emergency Staffing Tool 

About BEST

This tool has been developed by the RCN Emergency Care Association (ECA) and Faculty of Emergency Nursing (FEN).

BEST is a workforce planning tool for use at local level in your Emergency Department (ED) to allow any disparity between nursing workload and staffing to be highlighted. The tool allows you to:

  • analyse the volume and pattern of nursing workload in your ED
  • track this against your rostered staffing level
  • calculate the whole time equivalent workforce and skill mix which would be required to provide the nursing care needed in the department during the audit period.
The tool does not produce recommended staffing levels but will allow EDs to work locally to reduce any disparity between workload and staffing. This can be achieved for example by improving patients pathways, departmental and hospital processes, roster designs and actual staffing.

What's required

The BEST calculation requires data to be collected and input for a seven-day period on an hour-by-hour basis. A user guide is provided below, together with the various data collection appendices to explain how to gather your data, how to enter it and what the results portray.

It is important to pay particular attention to the definitions and instructions relating to:
  • how to measure patients dependency in adults and children
  • which staff to include and which to exclude.
Every ED is different and it is important that your results are used by the people who know most about your ED, you. BEST is not designed to define a minimum staffing number or to compare organisations to each other.

How it works

The calculations work by using nurse-to-patient ratios in the various dependency categories.
It is important that these ratios reflect how care is actually delivered in your department, if they do not then the outputs from the tool will not be accurate.

The ratios used by BEST are:
  • total dependency - 2 nurses to 1 patient
  • high dependency – 1 nurse to 1 patient
  • moderate dependency - 1 nurse to 2 patients
  • low dependency - 1 nurse to 3.5 patients

The hourly data sets used by BEST are:
  • patient dependency volume in the department using the Jones Dependency Tool
  • the total number of staff rostered to be clinical on shift in the department.
A calculation will also provide an indication of what skill mix breakdown is required in the whole time equivalent workforce in your ED using the ECA National Curriculum and Competency framework.

For help and advice or to offer feedback please email us at
The tool can be accessed and downloaded 

Page last updated - 12/12/2021