Triage prioritises a person’s need for medical care on arrival at the emergency department (ED). It aims to expedite emergency treatment for patients with life-threatening conditions and ensures that all persons requiring emergency care are categorised according to severity.1 The French physician Baron Larré, who served as Napoleon’s Chief Surgeon, already recognised the need to decrease the time soldiers spent waiting for surgeons in 1792.2 Doctor Jonathan Letterman, head of medical services of the Army of Potomac, reorganised emergency services in the American Civil War (1861), and reduced the retrieval time of injured soldiers from the battlefield to field dressing stations.2 3 The biggest benefit for those injured was to get to an area where wounds could be attended to within the shortest possible time.

In evaluating the efficiency of triage systems, researchers have measured patient waiting time or time to treatment as an important variable directly impacting upon patient outcomes.1 4^–7 Walk-out rate and total length of stay are also frequently evaluated but do not generally impact on patient outcomes.8 Table 1 lists the most recent literature on the impact of triage on waiting times.

There is currently no formal triage system in use in South Africa.9 Still, the benefits of introducing triage to patients accessing South African state EDs are potentially much greater than those demonstrated in the developed world. The need to streamline emergency services in a setting where patient numbers are vast and the pathology often more advanced is clear.9

The Cape Triage Group (CTG) convened April 2004, as part of the Joint Emergency Medicine Division of the University of Cape Town and Stellenbosch University, in order to design a triage system suitable for use in a busy, resource-constrained setting.9 The first draft of the Cape Triage Score (CTS) was produced by June 2004, and the tool was finalised in 2005. The CTS prioritises into the following categories: (1) red—immediate care needed; (2) orange—very urgent care needed; (3) yellow—urgent care needed; (4) green—routine care needed; and (5) blue—dead. The most important expected benefit of the proposed triage system was the rapid sorting of patients, separating those requiring immediate medical care from those who could wait before being evaluated and treated.10

In our related paper, we have described part of the CTS development process. The purpose of this study was to determine the impact on patient waiting times following the introduction of nurse triage using the CTS in the ED of a South African public health service hospital.

METHODS

Setting

GF Jooste Hospital, a 200 bed acute hospital situated in Cape Town, South Africa, serves more than 1.3 million people with a disease profile representative of the country’s quadruple burden of disease. Approximately 43% of this population are unemployed, 41% live in informal dwellings and 65% live below the poverty margin.11 The ED of this hospital deals with approximately 4500 consultations per month and about 13% of patients require inpatient treatment.

Study design

A retrospective and prospective, cross-sectional study was conducted in the ED of GF Jooste Hospital in order to evaluate the introduction of nurse triage on patient waiting times. The study was approved by the Research Ethics Committee of the University of Cape Town.

Selection of subjects

Prospective data were collected over a 4 month period from 1 December 2004 to 31 March 2005 and, to compare, a retrospective data arm from four randomly selected months (March, June, August and November). Given the facility’s under resourced and overloaded central records library and the lack of electronic record keeping, retrospective data had to be adopted from the ED arm of a 10 month audit of medical inpatient flow from the ED to the ward.12 This was allowed as all patients entered into this audit were ED patients. The “first contact” data (arrival time and observations) reflected in the audit was gained from ED records before filing. Patient records still needed to be accessed in order to capture additional ED information not included in the audit. Staffing numbers, facilities available and patient loads were comparable for both prospective and retrospective periods, with the unavoidable exception that all retrospective cases ended in admission. An enrolled nursing auxiliary performed triage using the CTS. Data capture was performed between 08:00 and 17:00 on weekdays. Cases were included in the study if the following data were available: (1) time of first contact at the ED; (2) physiological parameters and clinical information required to calculate the CTS and determine the colour coded priority of the patient; and (3) the time at which the patient was attended to by the medical officer on duty in the ED.

Outcomes

The outcomes measured in this study were the waiting times before and after introduction of a nurse triage system in the ED. Waiting time was defined as the time that elapsed between the first contact in the ED to the time attended to by the doctor on duty in the ED. The CTS colour code assigned to patients was also recorded.

Data analysis

Data were entered into a Microsoft Access database. Descriptive statistics were obtained using Statistica version 7 (Tulsa Inc, USA) software. The student t test was used to compare continuous variables and the χ² test was used to compare categorical data. A value of p⩽0.05 was regarded as significant.

Sample size

An on-line calculator was used to calculate sample sizes (with a 5% margin of error and 95% confidence interval (CI)).13 The population estimates were calculated by hand and are presented in table 2 with the respective sample sizes.

RESULTS

The sample size for the cohort studied after implementation of the triage system (prospective) was 823; 9 of 832 patients were excluded because of incomplete data capture. The sample size of the study cohort before implementation of the triage system (retrospective) was 323; 396 of 719 patients were excluded because of incomplete data capture.

Waiting times

As shown in table 3, waiting times were significantly reduced in all but one category. The most dramatic reduction in waiting time was observed in the red category. The waiting time for green category patients was reduced but did not reach significance.

DISCUSSION

Reducing the waiting time for critically ill patients presenting to an ED is the most important reason for introducing triage systems worldwide. This study demonstrates the dramatic reduction in waiting times that can be achieved by introducing a nurse driven triage system in a grossly overcrowded public hospital ED in South Africa. The introduction of triage appears to be the single largest contributor to the reduced waiting times as staffing numbers, facilities available, patient loads and medical and nursing skill level were comparable for the two periods. Only one unavoidable difference between the prospective and retrospective groups, besides the introduction of triage, is notable: patients from the retrospective group were all referred for admission following ED treatment. As both groups were managed in the ED on arrival, waiting times can be compared with minor bias. The dramatic reduction in waiting time in fact becomes more relevant when one considers that patients from the retrospective group were presumably more ill for requiring admission (compared to the mixed cohort of the prospective group) though still waited significantly longer for all priority groups. Reducing the waiting time of priority colour code red patients from 216 min to 38 min without increasing the human resources in the ED is a considerable achievement. A similarly significant reduction was seen for priority colour code orange and yellow patients. The reduction in waiting time for priority colour code green patients was not significantly reduced. This was not an unexpected finding since the available human and infrastructural resources were not increased during the study. Of interest is that the waiting time for these patients did not increase, as might have been expected. Indeed, there was an overall trend toward reduced waiting times for all patients, suggesting that the introduction of an effective triage system may have improved the overall efficiency of service delivery in the ED.

The sample size of data captured before the implementation of the triage system was slightly smaller than calculated. The difference in outcome was, however, much larger than predicted, allowing for significant results despite the sample size limitation.

The principal investigator set waiting time targets based upon available best practice4 6 14; these were longer than those set by the CTG for the roll out of the CTS in the state health sector (table 4).9

Only the waiting time target for green priority patients was reached. None of the other priority groups met any of the waiting time targets set by the principal investigator or those proposed by the CTG. Despite not reaching ideal targets, the significant reduction in waiting time for the higher priority colour codes represents a major success of the implementation of a nurse driven triage system in a busy public hospital.

This study only looked at the effect of triage on waiting times. Other factors that may have had an impact include: number and training of medical staff; acuity of the patients seen; total case load; delays in patient transfers and delays in special investigations (both contributing to overcrowding). Except for a steady increase in annual caseload, there has been no recent restructuring of any of the services governing other factors that would account for the significant changes seen. Further study is required to determine whether waiting times could be further reduced by minimising the impact of these variables. The external validity of this study requires investigation in a separate health care setting. This is currently underway.15^–17

The pronounced reduction in patient waiting times following the introduction of a triage system is extremely encouraging. Although these times may still raise concern in developed countries, the impact of triage in a developing country such as South Africa should not be underestimated.