Objective: The emergency department (ED) and HIV specialty clinics are primary sources of care for persons infected with HIV. HIV disease may be complicated by vague and complex symptomatology, and determining the degree of illness at triage is often difficult. The goals of this project were to characterize the ED presentation of HIV-related conditions, to develop a clinical decision rule to triage HIV-infected patients, and to validate the rule in clinical practice.
Methods: The study population consisted of ambulatory patients with self-reported HIV infection who presented for care to the ED of a 553-bed public hospital that serves a medically indigent, minority population. An Illness Severity Instrument was developed by an expert panel to serve as the criterion standard for defining medical urgency for HIV-infected patients presenting to the ED for care. Two phases of the study were conducted. Data from the first phase, a noninterventional cohort study, were used to develop a clinical decision rule for the ED triage of HIV-infected patients. The second phase was a prospective validation of the clinical decision rule.
Results: During phase I, data from 542 patient visits were collected. Data from 441 (81%) patient visits were used in a classification and regression tree (CART) analysis to produce a decision rule, the Clinical Triage Instrument. During phase II, the prospective validation of the Clinical Triage Instrument, 156 patient visits occurred. Of these, 88 (56%) patient visits were triaged using the Clinical Triage Instrument and could be scored using the Illness Severity Instrument. The Clinical Triage Instrument accurately triaged 45 [51%; 95% confidence interval (95% CI) = 40% to 62%] patient visits, undertriaged 11 (13%; 95% CI = 6% to 21%) patient visits, and overtriaged 32 (36%; 95% CI = 26% to 47%) patient visits. Sensitivities and specificities for determining emergent, urgent, and nonurgent medical conditions by the Clinical Triage Instrument were 56% (95% CI = 31% to 75%) and 84% (95% CI = 74% to 92%), 71% (95% CI = 55% to 84%) and 39% (95% CI = 25% to 55%), and 18% (95% CI = 6% to 37%) and 93% (95% CI = 84% to 98%), respectively. The positive and negative predictive values for determining an emergent medical condition using the Clinical Triage Instrument were 48% (95% CI = 26% to 70%) and 88% (95% CI = 78% to 95%), respectively. The positive and negative predictive values for determining a nonurgent medical condition using the Clinical Triage Instrument were 56% (95% CI = 21% to 86%) and 71% (95% CI = 60% to 81%), respectively.
Conclusions: The Clinical Triage Instrument was not sufficiently accurate for clinical use. Until accurate and reliable triage methods are developed, all patients infected with HIV who present to the ED for care should receive timely evaluation and care.