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

Abstract

Objective: To assess accuracy of telephone triage in identifying patients who need emergency care amongst those with suspected COVID-19 infection and identify factors which affect triage accuracy. Design: Observational cohort study Setting: Community telephone triage in the Yorkshire and Humber, Bassetlaw, North Lincolnshire and North East Lincolnshire region. Participants: 40, 261 adults who contacted NHS 111 telephone triage services provided by Yorkshire Ambulance Service NHS Trust between the 18th March 2020 and 29th June 2020 with symptoms indicating possible COVID-19 infection were linked to Office for National Statistics death registration data, hospital and general practice electronic health care data collected by NHS Digital. Outcome: Accuracy of triage disposition (self-care/non-urgent clinical assessment versus ambulance dispatch/urgent clinical assessment) was assessed in terms of death or need for organ support at 30, 7 and 3 days from first contact with the telephone triage service. Results: Callers had a 3% (1, 200/40, 261) risk of adverse outcome. Telephone triage recommended self-care or non-urgent assessment for 60% (24, 335/40, 261), with a 1.3% (310/24, 335) risk of subsequent adverse outcome. Telephone triage had 74.2% sensitivity (95% CI: 71.6 to 76.6%) and 61.5% specificity (61% to 62%) for adverse outcomes at 30 days from first contact. Multivariable analysis suggested some co-morbidities (such as chronic respiratory disease) may be over-estimated as predictors of adverse outcome, while the association of diabetes with adverse outcome may be under-estimated. Repeat contact with the service appears to be an important under recognised predictor of adverse outcomes with both 2 contacts (OR 1.77 95% CI: 1.14 to 2.75) and 3 or more contacts (OR 4.02 95% CI: 1.68 to 9.65) associated with clinical deterioration when not provided with an ambulance or urgent clinical assessment. Conclusion: Patients advised to self-care or receive non-urgent clinical assessment had a small but non-negligible risk of serious clinical deterioration. The sensitivity and specificity of telephone triage was comparable to other tools used to triage patient acuity in emergency and urgent care. Repeat contact with telephone services needs recognition as an important predictor of subsequent adverse outcomes.

Accuracy of emergency medical service telephone triage of need for an ambulance response in suspected COVID-19: an observational cohort study

“…This is around four times greater than the adverse outcome rate in callers who contacted the NHS 111 telephone service and half that seen in an ED population with suspected COVID-19. 18 21 Ambulances were dispatched to the majority of callers (84.2%) and the decision to dispatch an ambulance achieved a sensitivity of 95% (95% CI: 93.7% to 96.1%) for the primary outcome (death or organ support). Callers for whom an ambulance was not dispatched had a 3.5% or around 1/29 (NPP: 96.5%–95% CI: 95.6% to 97.2%) risk of the primary composite adverse outcome.…”