Physician workload and the Canadian Emergency Department Triage and Acuity Scale: the Predictors of Workload in the Emergency Room (POWER) study.(EM Advances)(Report)

INTRODUCTION

The emergency department (ED) is an environment in which large numbers of patients with a variety of complaints and acuities are seen on a daily basis. In many Canadian hospitals emergency physician (EP) staffing levels are influenced in part by ED patient census and acuity as determined by the Canadian Emergency Department Triage and Acuity Scale (CTAS), (1) waiting times, and arrivals by time of the day. However, there is no evidence-based or commonly accepted method of predicting physician staffing needs. At a time when ED crowding is common, and patient waiting times are increasing, (2) there is widespread concern about optimizing patient throughput and staff productivity. This includes the provision of appropriate physician staffing.

CTAS was first described in 1995 as a standard tool for triage in Canadian EDs and was introduced for general use in 1999. (3,4) The scale delineates 5 levels of acuity: level 1 (resuscitation), level 2 (emergent), level 3 (urgent), level 4 (less urgent) and level 5 (nonurgent). The scale was published with sentinel diagnoses for each category, as well as guidelines for the maximum time a patient should wait before the first assessment by a nurse and by a physician.

Many hospitals in Ontario use a case-mix formula, based solely on patient volume at each triage level, to determine EP workload and staffing needs (Dr. Michael Murray, Chief of Staff and Emergency Physician, Royal Victoria Hospital, Barrie, Ont.: presentation to the Ontario Physician Services Committee, July 2001). This is linked with a funding mechanism that offers EPs sessional or hourly rates of remuneration as an alternative to fee-for-service billings. The formula assigns a specific number of minutes to patients at each CTAS level. The sum of all patient times during 1 year establishes the number of hours of EP coverage for that ED. In 2003/04, the estimates of physician time used in the funding formula were loosely based on studies from Australia5,6 and the United States. (7)

Very few studies have attempted to predict EP staffing levels or to determine the amount of time that it actually takes an EP to treat a patient. (7-11) As total patient time in the ED is at least in part related to the activities of EPs, it is important to understand how EPs spend their time on a task-by-task basis while working. Without knowing how EPs spend their time during an ED shift, it is challenging and perhaps impossible to accurately determine adequate physician staffing levels.

Our objectives were to describe the distribution of EP time by activity during a shift, to estimate the amount of time required by an EP to assess and treat patients in each triage category, to describe the variability in the distribution of CTAS scoring between hospital sites and to thus determine if CTAS alone can be used to establish EP staffing levels.

METHODS