Reliability and validity of a new five-level triage instrument

Objectives: Triage is the initial clinical sorting process in hospital emer gency departments (EDs). Because of poor reproducibility and validity of th ree-level triage, the authors developed and validated a new five-level tria ge instrument, the Emergency Severity Index (ESI). The study objectives wer e: 1) to validate the triage instrument against ED patients' clinical resou rce and hospitalization needs, and 2) to measure the interrater reliability (reproducibility) of the instrument. Methods: This was a prospective, obse rvational cohort study of a population-based convenience sample of adult pa tients triaged during 100 hours at two urban referral hospitals. Validation by resource use and hospitalization (criterion standards) and reproducibil ity by blinded paired triage assignments compared with weighted kappa analy sis were assessed. Results: Five hundred thirty-eight patients were enrolle d; 45 were excluded due to incomplete evaluations. The resulting cohort of 493 patients was 52% female, was 26% nonwhite, and had a median age of 40 y ears (range 16-95); overall, 159 (32%) patients were hospitalized. Weighted kappa for triage assignment was 0.80 (95% Cl = 0.76 to 0.84). Resource use and hospitalization rates were strongly associated with triage level. For patients in category 5, only one-fourth (17/67) required any diagnostic tes t or procedure, and none were hospitalized (upper confidence limit, 5%). Co nversely, in category 1, one of twelve patients was discharged (upper confi dence limit, 25%), and none required fewer than two resources. Conclusions: This five-level triage instrument was shown to be both Valid and reliable in the authors' practice settings. It reproducibly triages patients into fi ve distinct strata, from very high hospitalization/resource intensity to ve ry low hospitalization/resource intensity.