Emergency Department Attendance after Telephone Triage: A Population-Based Data Linkage Study

Abstract

Objective: To investigate compliance with telephone helpline advice to attend an emergency department (ED) and the acuity of patients who presented to ED following a call.

Data sources/collection methods: In New South Wales (NSW), Australia, 2009-2012, all (1.04 million) calls to a telephone triage service, ED presentations, hospital admissions and death registrations, linked using probabilistic data linkage.

Study design: Population-based, observational cohort study measuring ED presentations within 24 hours of a call in patients (1) with dispositions to attend ED (compliance) and (2) low-urgency dispositions (self-referral), triage categories on ED presentation.

Principal findings: A total of 66.5 percent of patients were compliant with dispositions to attend an ED. A total of 6.2 percent of patients with low-urgency dispositions self-referred to the ED within 24 hours. After age adjustment, healthdirect compliant patients were significantly less likely (7.8 percent) to receive the least urgent ED triage category compared to the general NSW ED population (16.9 percent).

Conclusions: This large population-based data linkage study provides precise estimates of ED attendance following calls to a telephone triage service and details the predictors of ED attendance. Patients who attend an ED compliant with a healthdirect helpline disposition are significantly less likely than the general ED population to receive the lowest urgency triage category on arrival.

Keywords: Administrative data uses; epidemiology; hospitals; referrals, referral networks.

Figure 1

Flowchart of Call and Subject Exclusions Used for Descriptive Analysis and Compliance Rates [Color figure can be viewed at wileyonlinelibrary.com] Notes. *Calls given nonassessable dispositions included dispositions such as a transfer to Sexual Assault Referral Centre or the Poisons Information Service. ^†Calls identified as likely wrong linkages included records of a healthdirect helpline call record occurring after a death record. ^‡Subjects identified as “extremely frequent callers” were defined as callers with a series of 20 or more calls to the healthdirect helpline where the time between calls of the same series was less than or equal to 24 hours. ^§These 12,558 subjects had at least one call excluded due to an inconsistency between the caller–patient relationship and the patient's age. These included 3,743 subjects who had all their calls excluded. ^‖Calls with inconsistent information between the caller–patient relationship and the patient's age included patients below 10 years calling for “self,” “grandchildren” calling for patients below 25 years, and “grandparents” calling for patients aged 60 years and older. ^¶These were most likely the result of vulnerability in the data collection software and could be the result of a triage nurse attempting to triage two sets of symptoms in a single call (personal communication, Healthdirect Australia). ^#Note that calls dated between July 1, 2008, and December 31, 2008, were excluded from descriptive analysis and the calculation of compliance rates, but they were used to calculate the variable “calls to healthdirect in the last 6 months,” a covariate in regression models.