Emergency Department Triage in a Resource Constrained Setting: Application of the World Health Organization Triage Scale in Regional Papua New Guinea
Emergency Department Triage in a Resource Constrained Setting: Application of the World Health Organization Triage Scale in Regional Papua New Guinea
Triage is an important component of emergency care (EC). It aims to sort patients based on
 the urgency of their condition such that the highest acuity patients are prioritised for
 assessment and treatment. Grounded in the ethical principles of equity and justice, triage is
 necessary whenever there is a mismatch between demand for EC and the availability of
 resources.

 Globally, a large number of triage scales are in use. These differ in the data required to
 categorise patients as well as the number of tiers. Developed settings tend to utilise
 five-tier systems.

 Little is known about the prevalence of triage in low- and middle-income countries (LMICs),
 including in the Pacific region. There is also limited evidence about the utility, validity
 and reliability of triage scales in these contexts. While a landmark study in a paediatric
 Emergency Department (ED) in Malawi demonstrated that training staff in emergency skills,
 introducing triage and improving flow substantially reduced case fatality rates, the
 mortality reduction attributable to triage is unknown.

 A small number of triage scales have been developed for resource-limited (RL) environments.
 The most widely studied is the four-tier South African Triage Scale (SATS), which has
 demonstrated reasonable reliability and validity. In the Pacific region, SATS has provided a
 foundation for the three-tier Solomon Islands Triage Scale (SITS), which has recently been
 piloted in Honiara. The World Health Organization (WHO) has also recently released a
 three-tier triage scale. Neither of these instruments has been validated.

 Although the potential value of triage systems in resource-limited EDs is increasingly
 recognised, the current evidence base is limited. The impact on process indicators (eg, time
 to assessment) and clinical outcomes (eg, mortality) for time-critical conditions is largely
 unknown. This study aims to address this knowledge gap.
BACKGROUND

 Triage is an important component of emergency care (EC). It aims to sort patients based on
 the urgency of their condition such that the highest acuity patients are prioritised for
 assessment and treatment. Grounded in the ethical principles of equity and justice, triage is
 necessary whenever there is a mismatch between demand for EC and the availability of
 resources.

 Globally, a large number of triage scales are in use. These differ in the data required to
 categorise patients as well as the number of tiers. Developed settings tend to utilise
 five-tier systems, principally based on validation studies performed in Australia in the
 1990s. The triage process is less efficient in these models, because triage nurses (who
 typically perform emergency department triage) take longer to assess and differentiate
 category three and four patients.

 There have been few attempts to compare the performance of triage scales. A 2011 systematic
 review concluded that current scales were supported by limited or insufficient evidence, and
 suggested that "head-to-head comparisons are required to determine whether any of the scales
 have advantages over the others".

 Triage in developing emergency care systems

 Despite the established role of emergency departments (EDs) in developed countries, most of
 the world's population does not have access to timely and effective emergency care. This
 situation is slowly being addressed as the global health community recognises the value of EC
 systems.

 Little is known about the prevalence of triage in low- and middle-income countries (LMICs),
 including in the Pacific region. There is also limited evidence about the utility, validity
 and reliability of triage scales in these contexts.5 While a landmark study in a paediatric
 ED in Malawi demonstrated that training staff in emergency skills, introducing triage and
 improving flow, substantially reduced case fatality rates, the mortality reduction
 attributable to triage is unknown.

 A small number of triage scales have been developed for resource-limited (RL) environments.
 The most widely studied is the four-tier South African Triage Scale (SATS), which has
 demonstrated reasonable reliability and validity. A recent systematic review of adult triage
 scales in LMICs found that the evidence supporting any particular triage scale was moderate
 at best.

 In the Pacific region, SATS has provided a foundation for the three-tier Solomon Islands
 Triage Scale (SITS), which has recently been piloted in Honiara. The World Health
 Organization (WHO) is also preparing to release a three-tier triage scale [personal
 communication, T Reynolds]. Neither of these instruments has been prospectively validated.

 Although the potential value of triage systems in resource-limited EDs is increasingly
 recognised, the current evidence base is limited. The impact on process indicators (eg, time
 to assessment) and clinical outcomes (eg, mortality) for time-critical conditions is largely
 unknown.

 Evaluating triage systems

 One of the challenges in evaluating and comparing triage systems is a lack of consistent
 methodology. Most studies have focussed on reliability and validity as markers of
 performance.

 Reliability is an essential component of a triage system, and refers to the degree to which
 repeated assessments of the same patient will deliver the same category of urgency. This is
 typically assessed using inter-rater agreement.

 The validity of a triage system refers to its ability to reflect the true urgency of the
 patient's condition. A major challenge in validity assessment is the absence of a definitive
 or 'gold standard' measure of urgency. A range of surrogate markers have therefore been used
 to assess criterion and predictive validity, namely ED outcomes such as admission rate,
 mortality and length of stay. Some authors have suggested that a Delphi approach might also
 be useful for the evaluation of triage systems in developing settings.

 Several studies have calculated under- and over-triage rates as a measure of validity. These
 typically use acceptable limits defined by the American College of Surgeons Committee on
 Trauma (ACS COT) as a reference standard.

 Emergency care and triage in Papua New Guinea

 Papua New Guinea (PNG), a Pacific Island Country (PIC) with a population of approximately 8
 million, is faced by significant challenges in healthcare delivery. These include
 sunder-resourcing, a limited health workforce, a high burden of communicable disease
 (including significant rates of HIV/AIDS and tuberculosis) as well an increasing prevalence
 of non-communicable illness and injury.

 Despite an increasing number of emergency physicians, most provinces outside of Port Moresby
 (the nation's capital) have under-developed primary and secondary care systems to facilitate
 emergency care. There is little data on the epidemiology of emergency presentations, and most
 EDs are not utilising triage scales. Triage has been identified as a priority for emergency
 care development for PICs, including PNG [personal communication, G Phillips].

 AIMS

 The primary objective of this study is to measure the impact of a triage system on process
 indicators and clinical outcomes in a regional ED in PNG.

 The secondary objective of this study is to determine the validity and reliability of the
 World Health Organization Triage Scale in this setting.

 METHODS

 Setting

 This study will be conducted in the ED of the Mount Hagen Provincial Hospital (MHPH) in the
 Western Highlands Province of PNG. The hospital is managed by the Western Highlands
 Provincial Health Authority (WHPHA).

 Mount Hagen is the third largest city in PNG, with a population of approximately 50,000. It
 is the capital of the Western Highlands Province (population approximately 400,000), and a
 major administrative centre for the Highlands region.

 MHPH is the city's major health facility. There is limited primary care infrastructure within
 the province, so patients rely on MHPH for the majority of their healthcare needs. As in
 other parts of the country, there is a large burden of both communicable and non-communicable
 disease, including HIV/AIDS, tuberculosis diabetes, cardiovascular disease, chronic
 respiratory conditions and trauma.

 The ED receives approximately 150 presentations per day, and is staffed by one emergency
 physician, three registrars (specialists in training), five health extension officers (HEOs)
 and approximately thirty nurses. The ED has recently been redeveloped, and now includes four
 resuscitation bays, 16 acute beds and five short-stay beds. Basic pathology and radiology
 services are available.

 Under current arrangements, the ED has no triage system and manual data collection processes
 are leading to gross under-reporting of presentation numbers. Major challenges for the ED
 include understaffing, a large burden of primary care patients and access block.

 A new electronic database of ED patients has recently been implemented to capture basic
 attendance data. This system will facilitate data capture for the study.

 Design

 This study will utilise pre-post intervention methodology and will be prospectively
 registered as a clinical trial with the United States National Library of Medicine Clinical
 Trials Register at clinicaltrials.gov.

 Pre-intervention

 A new MHPH ED Patient Registration and Triage Form (PRTF) will be created to facilitate the
 new system and capture relevant data items, such as demographics and initial vital signs.
 This form will be based on an existing MHPH ED discharge form, as well as a triage form
 successfully implemented in another Pacific setting.

 Data from the PRTF will be entered by ward clerks into the ED's electronic patient
 registration system (recently implemented as part of a hospital-wide data improvement
 project). This system forms part of the MHPH medical records database.

 After a trial period of staff testing the new form, the PRTF will be implemented and baseline
 data captured in the database. During this period, the PRTF will not include any triage
 information. Based on a power calculation (see below), two months of pre-intervention data
 will be collected.

 In order to identify patients who meet inclusion criteria, as defined below, the PRTF will
 require the treating clinician to indicate whether the patient had one of the ten sentinel
 conditions (listed below).

 Intervention

 The intervention will comprise implementation of a new triage and patient flow system
 facilitated through staff training and clinical redesign.

 The three-tier World Health Organization Triage Scale (WHOTS) will be used as the triage
 instrument. This tool, developed collaboratively by the WHO, International Committee of the
 Red Cross (ICRC) and Médecins Sans Frontières (MSF), incorporates features of the SATS but
 has been modified for application in a wide variety of RL settings.

 At the end of the baseline data collection period, MHPH ED staff will be trained in the new
 system. A variety of ED clinicians (who will subsequently take on the triage role) will be
 the focus of this training program. This will include nurses, community health workers and
 health extension officers in order to provide flexibility in the staffing model. Triage
 training will be delivered by an experienced Australasian volunteer nurse(s) and comprise
 workshops on triage principles, paper-based scenarios and simulation exercises.

 Signage will be introduced to facilitate the new system of flow, and the ED will begin
 utilising the version of the PRTF that incorporates triage data. The triage instrument will
 be piloted over a one-month period (approximately). Modifications will be made based on
 real-time feedback as well as observations by the visiting team.

 Post-intervention

 After completion of the trial period, the new triage and flow system will be implemented
 under the leadership of local clinicians. The ED registration database will be updated to
 capture triage category data.

 For admitted patients, hospital length-of-stay (LOS) and inpatient mortality data will be
 obtained from the WHPHA medical records database. These patients will be identified by the
 patient's unique hospital identification number.

 Outcomes

 Primary objective

 The primary outcome will be time-to-assessment (TTA) by an ED clinician for ten time-critical
 conditions:

 -  Severe trauma

 -  Major burns

 -  Severe head injury

 -  Ruptured ectopic pregnancy

 -  Septic shock

 -  Myocardial infarction

 -  Severe asthma/COPD

 -  Severe pneumonia

 -  Meningitis

 -  Appendicitis

 The primary outcome will also be analysed by the proportion of patients with these clinical
 syndromes that are seen within a clinically appropriate timeframe (defined as 15 minutes, as
 discussed below).

 Secondary outcomes will include:

 -  Length of hospital stay

 -  ED mortality

 -  Inpatient mortality

 Secondary objectives

 Validity of the WHOTS will be assessed through its ability to predict ED outcomes. This will
 include the relationship between triage category and admission rates and ED mortality.

 Under- or over-triage rates will also be calculated using disposition as a reference
 standard. This approach has limitations (see below) but is widely used in triage research.

 Over-triage will be defined as the proportion of emergency (category 1) patients who are
 discharged. Under-triage will be defined as the proportion of non-urgent (category 3)
 patients who are admitted. Rates will be compared with the acceptable under- and over-triage
 rates recommended by ACS COT13 (and widely referenced in triage research) and then
 benchmarked against other published data. This approach has limitations (given that not all
 category 1 patients will required admission, and many category 3 patients could reasonably be
 expected to; recommendations for triage in trauma do not necessarily apply to other disease
 categories; and the performance targets provided by an American society do not necessarily
 apply to other contexts) but will be undertaken to enable comparison with other triage
 research from LMICs.

 Reliability will be assessed through inter-rater agreement between two local triage nurses as
 well as a local nurse and independent expert triage nurse.

 Analysis

 All data will be obtained from the MHPH medical records database. Hospital medical records
 staff will export de-identified into an Excel document, which will be provided to researchers
 and stored on a secure, password protected Monash University drive. All data will be analysed
 using Stata. No identifiable data will be available to the researchers.

 Primary objectives

 For the primary outcomes, Student's t-test will be used to compare the difference in TTA for
 the ten sentinel conditions (assuming parametric data). Chi-Square will be used to determine
 the difference in proportions of patients seen within 15 minutes.

 For the secondary outcomes of ED mortality, hospital mortality and hospital LOS, Student's
 t-test or Chi-Square will be used as appropriate.

 Secondary objectives

 For predictive validity, Chi-Square and correlation coefficient derived by Cramer's V will be
 used to investigate the relationship between triage category and admission rates & ED
 mortality.

 Under- and over-triage rates will be calculated using the definitions above. Acceptable
 limits set by the American College of Surgeons Committee on Trauma (an under-triage rate of
 less than 10% and an over-triage rate of 30-50%) will be used as the reference standard. This
 approach is consistent with that used in other triage research, despite the limitations
 discussed above.

 For reliability, the modified Kappa statistic will be used to test inter-rater agreement
 between triage nurses.

 Sample size

 It is estimated that approximately 15 patients per day present with one of the ten sentinel
 syndromes and wait an average of 20 minutes to be seen. A clinically significant improvement
 in the TTA for these patients is thought be five minutes. Although Australasian guidelines
 recommend that high acuity presentations (equivalent to categories one and two in the
 Australasian Triage Scale) are seen within 10 minutes of arrival,16 a target of 15 minutes is
 thought to be acceptable in the resource limited context of MHPH.

 Based on these figures, a sample size of 34 (17 per group) will be required to demonstrate a
 clinically significant decrease in TTA for the selected time-critical conditions at an alpha
 of 0.05 and beta of 0.8.

 The primary outcome will also be analysed by the proportion of patients seen within 15
 minutes of arrival. Assuming baseline performance is 45%, an absolute improvement of 10% (to
 55%) will require a sample size of 784 (392 per group) at an alpha of 0.05 and beta of 0.8.

 The secondary outcome of mortality will require a larger sample. In order to demonstrate an
 absolute reduction in mortality of 5% (from an estimated baseline mortality rate of 15%), a
 sample size of 1372 (686 per group) is required at an alpha of 0.05 and beta of 0.8.

 To ensure a satisfactory sample size to demonstrate all outcomes, pre- and post-intervention
 periods of 8 weeks will be utilised. This is based on a total sample size of 1372 for the
 secondary outcome of mortality (with a buffer of 10%) at an estimated presentation rate of 15
 per day. This requires pre- and post-intervention periods of at least 50 days.

 Ethics

 Ethics approval, including a waiver of consent, will be sought from Monash University.
 Consistent with local processes, approval to conduct this research will then be sought from
 the Medical Research Advisory Committee within the Papua New Guinean National Department of
 Health.

 Limitations

 This study has been designed to ensure it is methodologically robust. There are, however,
 several limitations that will be need to be considered when interpreting the results.

 The pre-post nature of the design means that the study may be subject to confounding. A
 particular risk is that a new and efficient triage system may prompt an increase in ED
 presentations, and a change in the overall acuity of the patient cohort. For this reason, the
 primary outcome will focus on ten clearly-defined time critical conditions.

 Other factors may also influence the primary outcome, such as changes in staffing levels and
 acute fluctuations in demand for emergency care (for instance, in the setting of disaster or
 outbreak). Within the influence of the researchers, attempts will be made to control these
 factors and minimise variation across the study period.

 There is a risk that the study will be subject to the Hawthorne effect. Although treating
 clinicians will be blinded to the primary outcome, they will have knowledge of the ten
 sentinel conditions by virtue of their inclusion on the PTRF. It is therefore possible that
 patients presenting with these syndromes will be prioritised for care.

 These limitations reflect the real-world challenges of conducting research in developing
 settings. The proposed study design is an attempt to balance methodological rigour with the
 practical considerations of emergency care delivery and research at MHPH.

 CONCLUSION

 Triage is an essential component of EC systems, especially in developing settings where
 demand for care typically exceeds the available resources. This study, using pre-post
 intervention methodology, will determine whether the introduction of a triage system leads to
 a clinically significant decrease in TTA for selected time-critical syndromes. It will also
 describe the impact on ED mortality, hospital mortality and total LOS.

 A secondary objective of this study is to assess the validity and reliability of the WHO
 triage scale. There is currently no published data on the performance of this system.

 This study will provide important data on the impact of triage on clinical and process
 outcomes for patients presenting with time-critical conditions to a resource-limited ED. It
 will help inform the future development and application of triage systems in other developing
 settings, and allow comparison of the WHOTS with other triage instruments.

 REFERENCES

 See research protocol.
Inclusion criteria:

 All patients presenting to Mount Hagen Provincial Hospital during the study period.

 The inclusion criteria for the primary outcome is any patient presenting to Mount Hagen
 Provincial Hospital diagnosed by the treating clinician with any of severe trauma, major
 burns, severe head injury, ruptured ectopic pregnancy, septic shock, myocardial infarction,
 severe asthma/COPD, severe pneumonia, meningitis or appendicitis.

 Exclusion criteria:

 None.