In this Friday’s edition of “It’s Science!”, we cover this recent publication demonstrating, essentially, what we already knew: throughput suffers when test turnaround times are longer!
To do so, however, requires (apparently) cross-classified random-effect modeling, linking Emergency Department information systems to laboratory test data. These authors evaluated a retrospective, multi-site cohort consisting of 27,656 linked ED and laboratory encounters and modeled the attributable effect of test turnaround time on ED length-of-stay. They discovered, rather obviously, patients receiving more tests had longer ED LOS. Working backwards, furthermore, they found for every 30 minute increase in laboratory test turnaround time, there was an approximately 17 minute increase in median ED length-of-stay. It’s not a 1:1 relationship – as you can imagine situations where the ED LOS is dictated rather by radiography, procedures, or consultations, rather than laboratory testing – but increases in a relatively linear fashion.
So, depending on the structure and flow of your Emergency Department, there may be substantial benefits to focusing on improved laboratory turnaround times. And, likewise, you can probably improve all your times by simply ordering fewer tests!
“The Effect of Laboratory Testing on Emergency Department Length of Stay: A Multihospital Longitudinal Study Applying a Cross-classified Random-effect Modeling Approach”
http://www.ncbi.nlm.nih.gov/pubmed/25565488
This paper shows an association. It does not show causality.
It is likely that sicker patients spend more time in ED AND have more blood tests eg thumb nail injury vs severe sepsis.
I don't think we can conclude anything about lab turn around times, or the need to reduce the number of tests from this article … unfortunately
I think this analysis only tries to show increased turnaround times -> increased ED LOS, controlling for the number of tests order on each patient, for precisely the obvious reasons you state. That's where the advanced statistics was required.
The other suppositions are my own hyperbole!