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Gastrointest Endosc. 2014 Nov;80(5):762-73. doi: 10.1016/j.gie.2014.02.1032. Epub 2014 May 3.

Optimizing efficiency and operations at a California safety-net endoscopy center: a modeling and simulation approach.

Author information

Division of Gastroenterology, San Francisco General Hospital and Trauma Center, San Francisco, California, USA; GI Health Outcomes, Policy and Economics (HOPE) Research Program and Center for Innovation in Access and Quality (CIAQ), Department of Medicine, University of California, San Francisco, California, USA.
Daniel J. Epstein Department of Industrial and Systems Engineering, University of Southern California, Los Angeles, California, USA.



Improvements in endoscopy center efficiency are needed, but scant data are available.


To identify opportunities to improve patient throughput while balancing resource use and patient wait times in a safety-net endoscopy center.


Safety-net endoscopy center.


Outpatients undergoing endoscopy.


A time and motion study was performed and a discrete event simulation model constructed to evaluate multiple scenarios aimed at improving endoscopy center efficiency.


Procedure volume and patient wait time.


Data were collected on 278 patients. Time and motion study revealed that 53.8 procedures were performed per week, with patients spending 2.3 hours at the endoscopy center. By using discrete event simulation modeling, a number of proposed changes to the endoscopy center were assessed. Decreasing scheduled endoscopy appointment times from 60 to 45 minutes led to a 26.4% increase in the number of procedures performed per week, but also increased patient wait time. Increasing the number of endoscopists by 1 each half day resulted in increased procedure volume, but there was a concomitant increase in patient wait time and nurse utilization exceeding capacity. By combining several proposed scenarios together in the simulation model, the greatest improvement in performance metrics was created by moving patient endoscopy appointments from the afternoon to the morning. In this simulation at 45- and 40-minute appointment times, procedure volume increased by 30.5% and 52.0% and patient time spent in the endoscopy center decreased by 17.4% and 13.0%, respectively. The predictions of the simulation model were found to be accurate when compared with actual changes implemented in the endoscopy center.


Findings may not be generalizable to non-safety-net endoscopy centers.


The combination of minor, cost-effective changes such as reducing appointment times, minimizing and standardizing recovery time, and making small increases in preprocedure ancillary staff maximized endoscopy center efficiency across a number of performance metrics.

[Indexed for MEDLINE]

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