Prognostic accuracy of emergency department triage tools for adults with suspected COVID-19: the PRIEST observational cohort study

Abstract

BackgroundThe WHO and National Institute for Health and Care Excellence recommend various triage tools to assist decision-making for patients with suspected COVID-19. We aimed to compare the accuracy of triage tools for predicting severe illness in adults presenting to the ED with suspected COVID-19.MethodsWe undertook a mixed prospective and retrospective observational cohort study in 70 EDs across the UK. We collected data from people attending with suspected COVID-19 and used presenting data to determine the results of assessment with the WHO algorithm, National Early Warning Score version 2 (NEWS2), CURB-65, CRB-65, Pandemic Modified Early Warning Score (PMEWS) and the swine flu adult hospital pathway (SFAHP). We used 30-day outcome data (death or receipt of respiratory, cardiovascular or renal support) to determine prognostic accuracy for adverse outcome.ResultsWe analysed data from 20 891 adults, of whom 4611 (22.1%) died or received organ support (primary outcome), with 2058 (9.9%) receiving organ support and 2553 (12.2%) dying without organ support (secondary outcomes). C-statistics for the primary outcome were: CURB-65 0.75; CRB-65 0.70; PMEWS 0.77; NEWS2 (score) 0.77; NEWS2 (rule) 0.69; SFAHP (6-point rule) 0.70; SFAHP (7-point rule) 0.68; WHO algorithm 0.61. All triage tools showed worse prediction for receipt of organ support and better prediction for death without organ support. At the recommended threshold, PMEWS and the WHO criteria showed good sensitivity (0.97 and 0.95, respectively) at the expense of specificity (0.30 and 0.27, respectively). The NEWS2 score showed similar sensitivity (0.96) and specificity (0.28) when a lower threshold than recommended was used.ConclusionCURB-65, PMEWS and the NEWS2 score provide good but not excellent prediction for adverse outcome in suspected COVID-19, and predicted death without organ support better than receipt of organ support. PMEWS, the WHO criteria and NEWS2 (using a lower threshold than usually recommended) provide good sensitivity at the expense of specificity.Trial registration numberISRCTN56149622.

Prognostic accuracy of triage tools for adults with suspected COVID-19 in a prehospital setting: an observational cohort study

“…18 19 The NEWS2 and PMEWS thresholds used are lower than previously proposed (0-3 vs 4+ NEWS and 0-3 vs 4+ PMEWS) for triaging patient acuity and are based on the assessment of their performance in a UK ED population of patients with suspected COVID-19 infection, where higher thresholds gave suboptimal sensitivity. 11 The threshold for the PRIEST score is also based on performance in this ED cohort. 11 These tools were compared with the sensitivity, specificity, PPV and NPV of EMS clinicians' decision to transfer patients to hospital.…”

“…11 The threshold for the PRIEST score is also based on performance in this ED cohort. 11 These tools were compared with the sensitivity, specificity, PPV and NPV of EMS clinicians' decision to transfer patients to hospital. The International Severe Acute Respiratory Infection Consortium (Coronavirus Clinical Characterisation Consortium) prediction model was not validated as it requires investigations that are available in a hospital setting, including blood tests, and is intended for prediction of inpatient mortality.…”

“…The high sensitivity of NEWS2 and PMEWS was achieved by using lower thresholds (NEWS2 0-1 vs 2+ and PMEWS 0-2 vs 3+) than previously recommended, based on performance in an ED population of patients with suspected COVID-19 infection. 11 At index attendance, 65% of patients were transported to hospital. Although a useful comparator for triage tool performance, the observed accuracy of EMS decision making to transfer patients to hospital does not account for clinical best interest decisions not to covey patients to hospital who subsequently deteriorated, or patient wishes not to be conveyed.…”

Accuracy of telephone triage for predicting adverse outcome in suspected COVID-19: An observational cohort study

“…Telephone triage performed comparably to triage methods used for patient acuity in the ED and, given the limited information available, including a lack of physiological parameters, this may reflect the best accuracy that could be achievable. 17 25 In 2019, the estimated population of Yorkshire and the Humber was 5,502,967 (including children). 26 On the basis of the number of patients in our cohort and study period, not using telephone triage could have led to around 61 extra ambulances or urgent clinical assessments being provided each day per 1 000, 000 population, without considering diversion to the national centre.…”

Palliative care in COVID-19

“…Other patients, even with comorbidities, were living much longer than expected [ 15 ]. Triage tools are only able to predict adverse outcomes for individuals with COVID-19 to a limited extent [ 16 ].…”