The influence of staffing on diagnostic yield of EMU admissions: a comparison study between two institutions

Patients with recurrent, stereotyped neurological events of unclear etiology often warrant admission for continuous video-EEG monitoring in an epilepsy monitoring unit (EMU) for diagnosis. Epilepsy monitoring unit admission duration has been reported to range from days to weeks. To date, there are limited data on the average duration of admission for patients admitted to the EMU for spell classification. Many EMUs are forced to limit the overall duration of admission for numerous reasons including limited resources. It is unclear if a time-limited EMU stay reduces the event capture rate and, therefore, diagnostic yield of event classification admissions. The goal of this study was to determine how a time-limited length of stay strategy impacted event capture in patients admitted for spell classification. A retrospective chart review was performed at two comparable adult epilepsy monitoring units, Mayo Clinic Hospital (MCH) in Phoenix, Arizona, and Banner Good Samaritan Medical Center (BGSMC) in Phoenix, Arizona. Banner Good Samaritan Medical Center is only staffed Monday through Friday, thereby limiting the total possible duration of admission to five days. The goal was to determine if the rate of event capture differed between two institutions employing a time-limited EMU admission (BGSMC) when compared with the nonlimited admission (MCH). A total of 300 patient admissions at MCH and 260 patient admissions at BGSMC were reviewed over a comparable time period. The event capture rates at MCH and BGSMC were 74% and 72%, respectively. There was a greater percentage of patients with nonepileptic events (NEEs) at MCH than at BGSMC (62.7% vs. 47.3%). The mean duration until first event was 31h at MCH and 38 h at BGSMC. The mean length of stay was greater at MCH (4.5 days) when compared with BGSMC (3.3 days). The overall diagnostic yield of a time-limited EMU admission was similar to that of a nonlimited admission for the purpose of spell classification. There was a statistically significant difference when comparing the time until first event at both institutions; however, this still fell within the 5-day duration that the time-restricted admission was limited to. These results may be important in optimizing an EMU practice in patients requiring admission for spell classification.