Safety of patient self-triage: real-life prospective evaluation of a symptom-checker in adult patients visiting an interdisciplinary emergency care center.

Abstract

Symptom-checkers have become important tools for self-triage, assisting patients to determine the urgency of medical care. To be safe and effective, these tools must be validated, particularly to avoid potential hazardous undertriage without leading to inefficient overtriage. Only limited safety data from studies including small sample sizes have been available so far. The objective of our study was to prospectively investigate the safety of patients' self-triage in a large patient sample. We used SMASS pathfinder, a symptom-checker based on a computerized transparent neural network. We recruited 2543 patients into this single centre, prospective clinical trial conducted at the cantonal hospital of Baden, Switzerland. Patients with an Emergency Severity Index of 1-2 were treated by the team of the emergency department, while those with an index of 3-5 were seen at the walk-in clinic by general physicians. We compared the triage recommendation obtained by the patients' self-triage with the assessment of the clinical urgency made by three successive interdisciplinary panels of physicians (Panel A, B, C). Using a Clopper-Pearson confidence interval, we assumed that in order to confirm the symptom-checkers safety, the upper confidence bound for the probability of a potentially hazardous undertriage should lie below 1%. A potentially hazardous undertriage was defined as a triage in which either all (consensus criterion) or the majority (majority criterion) of the experts of the last panel (Panel C) rated the triage of the symptom-checker to be "rather likely" or "likely" life-threatening or harmful. Of the 2543 patients, 1227 (48.3%) were female and 1316 (51.7%) male. None of the patients reached the pre-specified consensus criterion for a potentially hazardous undertriage. This resulted in an upper 95% confidence bound of 0.1184%. 4 cases met the majority criterion. This resulted in an upper 95% confidence bound for the probability of a potentially hazardous undertriage of 0.3616%. The two-sided 95% Clopper-Pearson confidence interval for the probability of overtriage (450 cases, 17.7%) was 16.23% to 19.24%, which is considerably lower than figures reported in the literature. The symptom-checker proved to be a safe triage tool, avoiding potentially hazardous undertriage in a real-life clinical setting of emergency consultations at a WIC/ED, whithout causing undesirable overtriage. Our data suggest the symptom-checker may be safely used in clinical routine. ClinicalTrials.gov identifier NCT04055298.