@article{slocum_jones_fletcher_mcconnell_hodgson_taheri_wilson_2020, title={Improving chemotherapy infusion operations through the simulation of scheduling heuristics: a case study}, volume={2}, ISSN={2047-6965 2047-6973}, url={http://dx.doi.org/10.1080/20476965.2019.1709908}, DOI={10.1080/20476965.2019.1709908}, abstractNote={ABSTRACT Over the last decade, chemotherapy treatments have dramatically shifted to outpatient services such that nearly 90% of all infusions are now administered outpatient. This shift has challenged oncology clinics to make chemotherapy treatment as widely available as possible while attempting to treat all patients within a fixed period of time. Historical data from a Veterans Affairs chemotherapy clinic in the United States and staff input informed a discrete event simulation model of the clinic. The case study examines the impact of altering the current schedule, where all patients arrive at 8:00 AM, to a schedule that assigns patients to two or three different appointment times based on the expected length of their chemotherapy infusion. The results identify multiple scheduling policies that could be easily implemented with the best solutions reducing both average patient waiting time and average nurse overtime requirements.}, journal={Health Systems}, publisher={Informa UK Limited}, author={Slocum, Ryan F. and Jones, Herbert L. and Fletcher, Matthew T. and McConnell, Brandon M. and Hodgson, Thom J. and Taheri, Javad and Wilson, James R.}, year={2020}, month={Feb}, pages={1–16} }
 @article{finn_lloyd_patel_allen_cornejo_davis_mcintosh_ferguson_sims_sudaj_et al._2019, title={Decreasing Endoscopy No-Shows Using a Lean Improvement Framework}, volume={17}, ISSN={["1542-7714"]}, DOI={10.1016/j.cgh.2019.02.002}, abstractNote={Despite advances in care quality and technology, access to health care in the United States remains a significant problem. Although there are many potential capital-intensive ways to address issues with access that make sizable changes to practice operations (eg, hiring more physicians, hiring advanced practice clinicians, extending clinic hours, or shortening appointment times) an alternative solution is to address no-shows and late cancellations. No-shows and late cancellations in health care settings are associated with significant opportunity costs if left unfilled, both from an access and a financial standpoint.}, number={7}, journal={CLINICAL GASTROENTEROLOGY AND HEPATOLOGY}, author={Finn, Raymond T. and Lloyd, Benjamin and Patel, Yuval A. and Allen, James T. and Cornejo, Jennifer and Davis, Andrea and McIntosh, Thasha and Ferguson, Stephanie and Sims, Kellie and Sudaj, Shawn and et al.}, year={2019}, month={Jun}, pages={1224-+} }
 @article{gellad_chermak_brown_taheri_2015, title={Sa1491 Automating Endoscopy Unit Efficiency Metrics: Leveraging the Electronic Health Record for Process Improvement}, volume={81}, ISSN={0016-5107}, url={http://dx.doi.org/10.1016/J.GIE.2015.03.1328}, DOI={10.1016/J.GIE.2015.03.1328}, abstractNote={Improving efficiency in GI endoscopy is both a business mandate and a quality imperative. Meaningful endoscopy unit efficiency metrics have been published but access to reliable time data impedes use of these measures.}, number={5}, journal={Gastrointestinal Endoscopy}, publisher={Elsevier BV}, author={Gellad, Ziad and Chermak, David and Brown, Emmanuel and Taheri, Javad}, year={2015}, month={May}, pages={AB236} }
 @article{yaylali_ivy_taheri_2014, title={Systems Engineering Methods for Enhancing the Value Stream in Public Health Preparedness: The Role of Markov Models, Simulation, and Optimization}, volume={129}, ISSN={["0033-3549"]}, DOI={10.1177/00333549141296s419}, abstractNote={Objectives. Large-scale incidents such as the 2009 H1N1 outbreak, the 2011 European Escherichia coli outbreak, and Hurricane Sandy demonstrate the need for continuous improvement in emergency preparation, alert, and response systems globally. As questions relating to emergency preparedness and response continue to rise to the forefront, the field of industrial and systems engineering (ISE) emerges, as it provides sophisticated techniques that have the ability to model the system, simulate, and optimize complex systems, even under uncertainty. Methods. We applied three ISE techniques—Markov modeling, operations research (OR) or optimization, and computer simulation—to public health emergency preparedness. Results. We present three models developed through a four-year partnership with stakeholders from state and local public health for effectively, efficiently, and appropriately responding to potential public health threats: ( 1) an OR model for optimal alerting in response to a public health event, ( 2) simulation models developed to respond to communicable disease events from the perspective of public health, and ( 3) simulation models for implementing pandemic influenza vaccination clinics representative of clinics in operation for the 2009–2010 H1N1 vaccinations in North Carolina. Conclusions. The methods employed by the ISE discipline offer powerful new insights to understand and improve public health emergency preparedness and response systems. The models can be used by public health practitioners not only to inform their planning decisions but also to provide a quantitative argument to support public health decision making and investment. }, journal={PUBLIC HEALTH REPORTS}, author={Yaylali, Emine and Ivy, Julie Simmons and Taheri, Javad}, year={2014}, pages={145–153} }
 @article{gellad_thompson_taheri_2013, title={Endoscopy Unit Efficiency: Quality Redefined}, volume={11}, ISSN={1542-3565}, url={http://dx.doi.org/10.1016/J.CGH.2013.06.005}, DOI={10.1016/J.CGH.2013.06.005}, abstractNote={This month’s contribution by Gellad et al concerns efficiency within an endoscopy unit. There are over 5400 Medicare certified ambulatory surgical centers (ASC) in the United States providing a distributed network of high quality, accessible centers for patients in need of outpatient endoscopic procedures. Most of these units are running efficiently with little room for waste (or they would not be able to survive in the current environment). Dr Gellad and colleagues have developed a process to analyze effi ciency by defining performance metrics based on standard Dona bedian analysis. Their article relates mostly to units performing a mix of procedures usually within a hospital unit. These units, unlike ASCs, deserve our scrutiny since many are operated at efficiency levels that provide “opportunities.”}, number={9}, journal={Clinical Gastroenterology and Hepatology}, publisher={Elsevier BV}, author={Gellad, Ziad F. and Thompson, Cole P. and Taheri, Javad}, year={2013}, month={Sep}, pages={1046–1049.e1} }
 @article{gellad_taheri_2014, title={Reply}, volume={12}, ISSN={1542-3565}, url={http://dx.doi.org/10.1016/J.CGH.2013.12.003}, DOI={10.1016/J.CGH.2013.12.003}, abstractNote={We thank Dr Kisloff for his comments on our recent article describing efficiency metrics for endoscopy.1Gellad Z.F. et al.Clin Gastroenterol Hepatol. 2013; 11: 1046-1049Abstract Full Text Full Text PDF PubMed Scopus (17) Google Scholar We agree entirely with Dr Kisloff that an exploration of overuse in gastrointestinal endoscopy is important and would be a valuable contribution to the literature. Multiple studies have highlighted potential overuse in colonoscopy,2Schoen R.E. et al.Gastroenterology. 2010; 138: 73-81Abstract Full Text Full Text PDF PubMed Scopus (170) Google Scholar, 3Goodwin J.S. et al.Arch Intern Med. 2011; 171: 1335-1343Crossref PubMed Scopus (157) Google Scholar and recent practice guidelines from the American College of Physicians have noted risks of overuse of upper endoscopy in evaluating reflux.4Shaheen N.J. et al.Ann Intern Med. 2012; 157: 808-816Crossref PubMed Scopus (130) Google Scholar Unraveling the reasons for overuse and mechanisms to curb overuse are much more complex undertakings, but promising work has begun. We would point to the recent editorial by Naik et al5Naik A.D. et al.Clin Gastroenterol Hepatol. 2013; 11: 753-755Abstract Full Text Full Text PDF PubMed Scopus (17) Google Scholar in this journal as such an example. The importance of endoscopy utilization notwithstanding, we continue to believe that efficiency at the operational level remains an important and understudied area of health care quality. As Jim Kim, president of the World Bank, wrote in a recent editorial, the American health care system has an “inexplicably high tolerance for poor execution…that has compromised health care in the United States.”6Kim J.Y. Healthcare. 2013; 1: 3Crossref Scopus (2) Google Scholar Rather than being used for “fiscal legerdemain,” efficiency metrics should be used to support the delivery of high-value, patient-centered endoscopy services. As Dr Kisloff points out, however, we would be remiss if we did not also emphasize that efficiency metrics should not be used in isolation but rather in conjunction with similarly robust measures of quality such as post-discharge adverse outcomes. Finally, in regard to Dr Kisloff's frustration regarding the absence of detailed information on the Donabedian paradigm, we regret the difficulty in accessing referenced material. Donabedian is a classic conceptual model, and we chose to reference the original article. A more recent reprint is available.7Donabedian A. Milbank Quarterly. 2005; 83: 691-729Crossref PubMed Scopus (1276) Google Scholar We hope this provides easier access to additional information. Quality RedefinedClinical Gastroenterology and HepatologyVol. 12Issue 3PreviewIn perusing the contents of my September 2013 issue of Clinical Gastroenterology and Hepatology, I was immediately enticed by the prospect of learning about Donabedian analysis in your “Practice Management: The Road Ahead” section.1 One can only imagine my disappointment at discovering that I would need to go to a supplementary table in an almost half-century-old reference to familiarize myself with the intellectual underpinnings of this section. My frustration was further compounded when I learned from the article of “…the absence of measures that have been evaluated rigorously in the context of the AHRQ [Agency for Healthcare Research and Quality] criteria of scientific soundness…” Finally, as I read Table 1 of the section, I could not find any mention of post-discharge measures as regards “Endoscopy Unit Efficiency Measures.” The aforementioned table provides an ample roadmap to the expeditious dispatching of a patient, with seemingly no regard to possible post-discharge adverse outcomes. Full-Text PDF}, number={3}, journal={Clinical Gastroenterology and Hepatology}, publisher={Elsevier BV}, author={Gellad, Ziad F. and Taheri, Javad}, year={2014}, month={Mar}, pages={527} }
 @inproceedings{taheri_gellad_burchfield_cooper_2012, title={A simulation study to reduce nurse overtime and improve patient flow time at a hospital endoscopy unit}, DOI={10.1109/wsc.2012.6465136}, abstractNote={Increasing demand for endoscopic procedures, coupled with decreasing insurance reimbursement, has necessitated improvement in endoscopy unit operational performance measures, such as increasing throughput and reducing staff overtime without an increase in patient waiting time. In pursuit of improving these measurements, maintaining the nurse-to-patient ratio requirements in the recovery area throughout the clinic's operation time is a challenging problem for endoscopy units. To maintain compliance with this ratio, patients occasionally have to be held in the procedure rooms during the clinic's peak time. On the other hand, level loading could potentially increase the amount of overtime. In this paper, we describe our efforts to use discrete event simulation to investigate the impact of several strategies to address the minimum recovery nurse requirements in the endoscopy unit of Duke University Medical Center. Our objective was to minimize patient flow times and nurse overtime while sustaining the required nurse-patient staffing ratio in recovery.}, booktitle={2012 winter simulation conference (wsc)}, author={Taheri, J. and Gellad, Z. and Burchfield, D. and Cooper, K.}, year={2012} }
 @article{gellad_taheri_burchfield_cooper_lothrop_al-kawas_2012, title={Su1270 Discrete Event Simulation Modeling: A Valuable Tool to Optimize Endoscopy Unit Efficiency}, volume={75}, ISSN={0016-5107}, url={http://dx.doi.org/10.1016/j.gie.2012.03.695}, DOI={10.1016/j.gie.2012.03.695}, abstractNote={Increasing demand for endoscopic procedures, coupled with decreasing reimbursement, has necessitated improvement in endoscopy unit efficiency. Discrete event simulation is a modeling methodology which has been used to optimize manufacturing processes for several decades. Our aim for this pilot study was to demonstrate the value of discrete event simulation in optimizing endoscopy unit efficiency.}, number={4}, journal={Gastrointestinal Endoscopy}, publisher={Elsevier BV}, author={Gellad, Ziad F. and Taheri, Javad and Burchfield, Dariele and Cooper, Kevin and Lothrop, Sarah and AL-Kawas, Firas H.}, year={2012}, month={Apr}, pages={AB273–AB274} }
 @article{morgan_fathi_taheri_2004, title={Algorithms for the model configuration problem}, volume={36}, ISSN={["1545-8830"]}, DOI={10.1080/07408170490245469}, abstractNote={The model configuration problem is a combinatorial optimization problem that arises in the context of switching cabinet manufacturing in the telecommunication industry. We discuss the manufacturing environment and define the q-model problem in this context, for q ≥ 1. We then discuss the structural properties of the q-model problem, and propose an efficient procedure for solving the 1-model problem. We also propose several heuristic procedures for solving the 2-model problem, and present an evaluation of these procedures through an extensive computational experiment.}, number={2}, journal={IIE TRANSACTIONS}, author={Morgan, SD and Fathi, Y and Taheri, J}, year={2004}, month={Feb}, pages={169–180} }