The Effect of Laboratory Testing on Emergency Department Length of Stay: A Multihospital Longitudinal Study Applying a Cross‐classified Random‐effect Modeling Approach

Abstract

Objectives: The objective was to examine the relationship between laboratory testing (including test volume and turnaround time [TAT]) and emergency department (ED) length of stay (LOS), using linked patient-level data from four hospitals across 4 years.Methods: This was a retrospective, multisite cohort study of patients presenting to any one of four EDs in New South Wales, Australia, during a 2-month period (August and September) in 2008, 2009, 2010, and 2011. Data from ED information systems were linked to laboratory test data. A cross-classified random-effect modeling approach was applied to identify factors affecting ED LOS, taking into account the correlation between patients' presentations at the same hospital and/or in the same calendar year. Number of test order episodes (tests ordered at one point in time during the ED stay) and TAT (time from laboratory order receipt to result available) were examined.Results: As the number of test order episodes increased, so did the duration of patient ED LOS (p < 0.0001). For every five additional tests ordered per test order episode, the median ED LOS increased by 10 minutes (2.9%, p < 0.0001); each 30-minute increase in TAT was, on average, associated with a 5.1% (17 minutes; p < 0.0001) increase in ED LOS, after adjustment for other factors. Patients presenting to the ED at night (7 p.m. to 7 a.m.) had longer stays than those presenting during the daytime, although the median TATs at nights were shorter than those during the daytime.Conclusions: Laboratory testing has a direct effect on patients' LOS in ED. Laboratory TAT, number of testing episodes, and test volume influence ED LOS. Targeted increases of ED resources and staffing after-hours may also contribute to reductions in ED LOS.ACADEMIC EMERGENCY MEDICINE 2015;22:38-46

Overcrowding in the Emergency Department and Patient Safety

“…for lab tests which has been shown to directly decrease ED length of stay (a 17-min increase in ED LOS per 30 min increase in lab TAT) [47]. Additionally, performing labs from triage could potentially identify patients requiring more immediate atention if there is a way to lag critical values to a responsible provider [48].…”

Laboratory testing in the emergency department: an Italian Society of Clinical Biochemistry and Clinical Molecular Biology (SIBioC) and Academy of Emergency Medicine and Care (AcEMC) consensus report

“…abnormalities detected by coincidence, without clinical symptoms or suspicion) [2]. Notably, it was also shown that the median length of stay (LOS) in the emergency department (ED), even in a very developed setting, may increase by up to 10 min for every five additional tests ordered, and by up to 17 min for each 30-min increase in turnaround time [3].…”

Laboratory testing in the emergency department: An Italian Society of Clinical Biochemistry and Clinical Molecular Biology (SIBioC) and Academy of Emergency Medicine and Care (AcEMC) consensus report

“…2 Notably, it was also shown that the median length of stay (LOS) in the emergency department (ED), even in a very developed setting, may increase by up to 10 minutes for every five additional tests ordered, and by up to 17 minutes for each 30-minute increase in turnaround time. 3 Reliable evidence attests that urgent testing represents a large part of laboratory activity, with median percentage of stat analyses approximating 33% of all tests performed in clinical laboratories. 4 Additional evidence suggests that the panels of tests made available to the emergency physicians are extremely heterogeneous and variegated worldwide, so highlighting a rather poorly standardized scenario.…”