Impact of Mandatory HIV Screening in the Emergency Department: A Queuing Study

Abstract

To improve HIV screening rates, New York State in 2010 mandated that all persons 13-64 years receiving health care services, including care in emergency departments (EDs), be offered HIV testing. Little attention has been paid to the effect of screening on patient flow. Time-stamped ED visit data from patients eligible for HIV screening, 7,844 of whom were seen by providers and 767 who left before being seen by providers, were retrieved from electronic health records in one adult ED. During day shifts, 10% of patients left without being seen, and during evening shifts, 5% left without being seen. All patients seen by providers were offered testing, and 6% were tested for HIV. Queuing models were developed to evaluate the effect of HIV screening on ED length of stay, patient waiting time, and rate of leaving without being seen. Base case analysis was conducted using actual testing rates, and sensitivity analyses were conducted to evaluate the impact of increasing the testing rate. Length of ED stay of patients who received HIV tests was 24 minutes longer on day shifts and 104 minutes longer on evening shifts than for patients not tested for HIV. Increases in HIV testing rate were estimated to increase waiting time for all patients, including those who left without being seen. Our simulation suggested that incorporating HIV testing into ED patient visits not only adds to practitioner workload but also increases patient waiting time significantly during busy shifts, which may increase the rate of leaving without being seen.

Keywords: HIV testing; emergency department; health care utilization; queuing theory; waiting times.

FIGURE 1.

Queuing model for emergency department (ED) waiting times for service, in which patients are the customers in the system, patients in the ED awaiting beds are in the queue, and ED beds are the servers for patient care.