Clinical Focus

  • Emergency Medicine
  • Emergency Department operations
  • Digital Health
  • Quality Improvement
  • Patient safety
  • Health Care Management

Academic Appointments

Administrative Appointments

  • Patient Safety Officer, Stanford Health Care (2019 - Present)
  • Vice Chair, Clinical Operations & Quality, Stanford University School of Medicine (2017 - Present)
  • Fellowship Director, EM Administration Fellowship (2015 - Present)
  • Medical Director, Emergency Medicine (2014 - 2017)

Boards, Advisory Committees, Professional Organizations

  • Board Member, IHI Certification Board for Professionals in Patient Safety (2022 - Present)
  • Member, Society of Academic Emergency Medicine Fellowship Committee (2016 - Present)
  • Member, Society of Academic Emergency Medicine (2015 - Present)
  • Fellow, American College of Emergency Physicians (2008 - Present)
  • Board Certified, American Board of Emergency Medicine (2006 - Present)
  • Member, American College of Emergency Physicians (2006 - Present)

Professional Education

  • Residency: Beth Israel Deaconess Medical Center (2005) MA
  • Internship: Beth Israel Deaconess Medical Center (2003) MA
  • Medical Education: UCLA David Geffen School Of Medicine Registrar (2002) CA
  • MBA, Anderson School of Management at UCLA (2002)
  • BS, Stanford University, Biology, with Honors (1995)

Current Research and Scholarly Interests

Emergency Department process improvement
Digital Health
ED operations
ED innovations

2023-24 Courses

All Publications

  • Precision emergency medicine. Academic emergency medicine : official journal of the Society for Academic Emergency Medicine Strehlow, M., Alvarez, A., Blomkalns, A. L., Caretta-Wyer, H., Gharahbaghian, L., Imler, D., Khan, A., Lee, M., Lobo, V., Newberry, J. A., Riberia, R., Sebok-Syer, S., Shen, S., Gisondi, M. A. 2024


    Precision health is a burgeoning scientific discipline that aims to incorporate individual variability in biological, behavioral, and social factors to develop personalized health solutions. To date, emergency medicine has not deeply engaged in the precision health movement. However, rapid advances in health technology, data science, and medical informatics offer new opportunities for emergency medicine to realize the promises of precision health.In this article, we conceptualize precision emergency medicine as an emerging paradigm and identify key drivers of its implementation into current and future clinical practice. We acknowledge important obstacles to the specialty-wide adoption of precision emergency medicine and offer solutions that conceive a successful path forward.Precision emergency medicine is defined as the use of information and technology to deliver acute care effectively, efficiently, and authentically to individual patients and their communities. Key drivers and opportunities include leveraging human data, capitalizing on technology and digital tools, providing deliberate access to care, advancing population health, and reimagining provider education and roles. Overcoming challenges in equity, privacy, and cost is essential for success. We close with a call to action to proactively incorporate precision health into the clinical practice of emergency medicine, the training of future emergency physicians, and the research agenda of the specialty.Precision emergency medicine leverages new technology and data-driven artificial intelligence to advance diagnostic testing, individualize patient care plans and therapeutics, and strategically refine the convergence of the health system and the community.

    View details for DOI 10.1111/acem.14962

    View details for PubMedID 38940478

  • Stanford Emergency Medicine Partnership Program: a novel approach to streamlining the evaluation and implementation of emerging health technologies through academic-industry partnerships BMJ INNOVATIONS Dayton, J., Yiadom, M. B., Shen, S., Strehlow, M. C., Rose, C., Bunney, G., Ribeira, R. 2024
  • 2023 Society for Academic Emergency Medicine Consensus Conference on Precision Emergency Medicine: Development of a policy-relevant, patient-centered research agenda. Academic emergency medicine : official journal of the Society for Academic Emergency Medicine Strehlow, M., Gisondi, M. A., Caretta-Weyer, H., Ankel, F., Brackett, A., Brar, P., Chan, T. M., Garabedian, A., Gunn, B., Isaacs, E., von Isenburg, M., Jarman, A., Kuehl, D., Limkakeng, A. T., Lydston, M., McGregor, A., Pierce, A., Raven, M. C., Salhi, R. A., Stave, C., Tan, J., Taylor, R. A., Wong, H. N., Yiadom, M. Y., Zachrison, K. S., Vogel, J. 2024


    Precision medicine is data-driven health care tailored to individual patients based on their unique attributes, including biologic profiles, disease expressions, local environments, and socioeconomic conditions. Emergency medicine (EM) has been peripheral to the precision medicine discourse, lacking both a unified definition of precision medicine and a clear research agenda. We convened a national consensus conference to build a shared mental model and develop a research agenda for precision EM.We held a conference to (1) define precision EM, (2) develop an evidence-based research agenda, and (3) identify educational gaps for current and future EM clinicians. Nine preconference workgroups (biomedical ethics, data science, health professions education, health care delivery and access, informatics, omics, population health, sex and gender, and technology and digital tools), comprising 84 individuals, garnered expert opinion, reviewed relevant literature, engaged with patients, and developed key research questions. During the conference, each workgroup shared how they defined precision EM within their domain, presented relevant conceptual frameworks, and engaged a broad set of stakeholders to refine precision EM research questions using a multistage consensus-building process.A total of 217 individuals participated in this initiative, of whom 115 were conference-day attendees. Consensus-building activities yielded a definition of precision EM and key research questions that comprised a new 10-year precision EM research agenda. The consensus process revealed three themes: (1) preeminence of data, (2) interconnectedness of research questions across domains, and (3) promises and pitfalls of advances in health technology and data science/artificial intelligence. The Health Professions Education Workgroup identified educational gaps in precision EM and discussed a training roadmap for the specialty.A research agenda for precision EM, developed with extensive stakeholder input, recognizes the potential and challenges of precision EM. Comprehensive clinician training in this field is essential to advance EM in this domain.

    View details for DOI 10.1111/acem.14932

    View details for PubMedID 38779704

  • Changes in low-acuity patient volume in an emergency department after launching a walk-in clinic. Journal of the American College of Emergency Physicians open Kurian, D., Sundaram, V., Naidich, A. G., Shah, S. A., Ramberger, D., Khan, S., Ravi, S., Patel, S., Ribeira, R., Brown, I., Wagner, A., Gharahbhagian, L., Miller, K., Shen, S., Yiadom, M. Y. 2023; 4 (4): e13011


    Unscheduled low-acuity care options are on the rise and are often expected to reduce emergency department (ED) visits. We opened an ED-staffed walk-in clinic (WIC) as an alternative care location for low-acuity patients at a time when ED visits exceeded facility capacity and the impending flu season was anticipated to increase visits further, and we assessed whether low-acuity ED patient visits decreased after opening the WIC.In this retrospective cohort study, we compared patient and clinical visit characteristics of the ED and WIC patients and conducted interrupted time-series analyses to quantify the impact of the WIC on low-acuity ED patient visit volume and the trend.There were 27,211 low-acuity ED visits (22.7% of total ED visits), and 7,058 patients seen in the WIC from February 26, 2018, to November 17, 2019. Low-acuity patient visits in the ED reduced significantly immediately after the WIC opened (P = 0.01). In the subsequent months, however, patient volume trended back to pre-WIC volumes such that there was no significant impact at 6, 9, or 12 months (P = 0.07). Had WIC patients been seen in the main ED, low-acuity volume would have been 27% of the total volume rather than the 22.7% that was observed.The WIC did not result in a sustained reduction in low-acuity patients in the main ED. However, it enabled emergency staff to see low-acuity patients in a lower resource setting during times when ED capacity was limited.

    View details for DOI 10.1002/emp2.13011

    View details for PubMedID 37484497

    View details for PubMedCentralID PMC10361543

  • Effectiveness, safety, and efficiency of a drive-through care model as a response to the COVID-19 testing demand in the United States. Journal of the American College of Emergency Physicians open Ravi, S., Graber-Naidich, A., Sebok-Syer, S. S., Brown, I., Callagy, P., Stuart, K., Ribeira, R., Gharahbaghian, L., Shen, S., Sundaram, V., Yiadom, M. Y. 2022; 3 (6): e12867


    Objectives: Here we report the clinical performance of COVID-19 curbside screening with triage to a drive-through care pathway versus main emergency department (ED) care for ambulatory COVID-19 testing during a pandemic. Patients were evaluated from cars to prevent the demand for testing from spreading COVID-19 within the hospital.Methods: We examined the effectiveness of curbside screening to identify patients who would be tested during evaluation, patient flow from screening to care team evaluation and testing, and safety of drive-through care as 7-day ED revisits and 14-day hospital admissions. We also compared main ED efficiency versus drive-through care using ED length of stay (EDLOS). Standardized mean differences (SMD)>0.20 identify statistical significance.Results: Of 5931 ED patients seen, 2788 (47.0%) were walk-in patients. Of these patients, 1111 (39.8%) screened positive for potential COVID symptoms, of whom 708 (63.7%) were triaged to drive-through care (with 96.3% tested), and 403 (36.3%) triaged to the main ED (with 90.5% tested). The 1677 (60.2%) patients who screened negative were seen in the main ED, with 440 (26.2%) tested. Curbside screening sensitivity and specificity for predicting who ultimately received testing were 70.3% and 94.5%. Compared to the main ED, drive-through patients had fewer 7-day ED revisits (3.8%vs 12.5%, SMD=0.321), fewer 14-day hospital readmissions (4.5%vs 15.6%, SMD=0.37), and shorter EDLOS (0.56vs 5.12hours, SMD=1.48).Conclusion: Curbside screening had high sensitivity, permitting early respiratory isolation precautions for most patients tested. Low ED revisit, hospital readmissions, and EDLOS suggest drive-through care, with appropriate screening, is safe and efficient for future respiratory illness pandemics.

    View details for DOI 10.1002/emp2.12867

    View details for PubMedID 36570369

  • Telemedicine to Decrease Personal Protective Equipment Use and Protect Healthcare Workers. The western journal of emergency medicine Ribeira, R., Shen, S., Callagy, P., Newberry, J., Strehlow, M., Quinn, J. 2020

    View details for DOI 10.5811/westjem.2020.8.47802

    View details for PubMedID 33052823

  • Off the Shelf: Rapid Deployment of an Emergency Department Telemedicine Platform Using Readily Available Consumer Products. The Journal of emergency medicine Lowe, J. n., Shen, S. n. 2020


    For 20 years, telemedicine has been waiting in the wings for its time in the spotlight. The Coronavirus Disease 2019 (COVID-19) pandemic, with its emphasis on personal protective equipment (PPE) and reducing high-risk contacts, was the catalyst needed to bring telemedicine into mainstream consciousness and acceptance.We first review some of the key factors that precipitated this abrupt alteration of the perception of telemedicine. We then detail the creation of a department-wide telemedicine network using off-the-shelf consumer products. Our goal was to very rapidly install a system that was familiar to end-users for the purpose of reducing high-risk contacts and conserving PPE. Sourcing from the consumer realm proved to be advantageous over enterprise-level equipment when these goals were desired.After a rollout of 1.5 weeks from zero to fully operational, we showed an immediate decrease in high-risk contacts and PPE use. All 80 rooms plus all triage areas in our department were outfitted with Apple iPads running Zoom. User adoption was high and telemedicine use increased from ∼17 to ∼90 instances a day, a 429% increase. We saw a decrease in high-risk contacts of about 75%, with a concomitant cost savings in PPE.We propose that the use of consumer products sourced from local vendors is a viable solution for telemedicine systems focusing on speed, reducing costs, and ease of deployment. Future work will focus on studying its performance characteristics vs. other systems in an evolving landscape.

    View details for DOI 10.1016/j.jemermed.2020.09.026

    View details for PubMedID 33097352

  • Introduction of a Horizontal and Vertical Split Flow Model of Emergency Department Patients as a Response to Overcrowding. Journal of emergency nursing: JEN : official publication of the Emergency Department Nurses Association Wallingford, G. n., Joshi, N. n., Callagy, P. n., Stone, J. n., Brown, I. n., Shen, S. n. 2017


    ED overcrowding is an issue that is affecting every emergency department and every hospital. The inability to maintain patient flow into and out of the emergency department paralyzes the ability to provide effective and timely patient care. Many solutions have been proposed on how to mitigate the effects of ED overcrowding. Solutions involve either hospital-wide initiatives or ED-based solutions. In this article, the authors seek to describe and provide metrics for a patient flow methodology that targets ESI 3 patients in a vertical flow model.In the Stanford Emergency Department, a vertical flow model was created from existing ED space by removing fold-down horizontal stretchers and replacing them with multiple chairs that allowed for assessment and medical management in an upright sitting position. The model was launched and sustained through frequent interdisciplinary huddles, detailed inclusion and exclusion criteria, scripted text on how to promote the flow model to patients, and close analytics of metrics. Metrics for success included patient length of stay (LOS) for those triaged to the vertical flow area compared with ESI 3 patients triaged to the traditional emergency department as a comparison group. The secondary outcome is the total number of patients seen in the vertical flow area. This was a 6-month-September 2014, to February 2015-retrospective pre- and postintervention study that examined LOS as a marker for effective launch and implementation of a vertical patient workflow model.The patients triaged to the vertical flow area in the study period tended to be younger than in the control period (43 years versus 52 years, P = 0.00). There was a significant decrease in our primary end point: the total LOS for ESI 3 patients triaged to the vertical flow area (270 minutes versus 384 minutes, P = 0.00).Implementation of a vertical patient flow strategy can decrease LOS for the vertical ESI 3 patients based upon the inclusion and exclusion criteria. Furthermore, this is accomplished with minimal financial investment within the physical constraints of an existing emergency department.

    View details for DOI 10.1016/j.jen.2017.10.017

    View details for PubMedID 29169818

  • Observational study of organisational responses of 17 US hospitals over the first year of the COVID-19 pandemic. BMJ open Choo, E. K., Strehlow, M., Del Rios, M., Oral, E., Pobee, R., Nugent, A., Lim, S., Hext, C., Newhall, S., Ko, D., Chari, S. V., Wilson, A., Baugh, J. J., Callaway, D., Delgado, M. K., Glick, Z., Graulty, C. J., Hall, N., Jemal, A., Kc, M., Mahadevan, A., Mehta, M., Meltzer, A. C., Pozhidayeva, D., Resnick-Ault, D., Schulz, C., Shen, S., Southerland, L., Du Pont, D., McCarthy, D. M. 2023; 13 (5): e067986


    The COVID-19 pandemic has required significant modifications of hospital care. The objective of this study was to examine the operational approaches taken by US hospitals over time in response to the COVID-19 pandemic.This was a prospective observational study of 17 geographically diverse US hospitals from February 2020 to February 2021.We identified 42 potential pandemic-related strategies and obtained week-to-week data about their use. We calculated descriptive statistics for use of each strategy and plotted percent uptake and weeks used. We assessed the relationship between strategy use and hospital type, geographic region and phase of the pandemic using generalised estimating equations (GEEs), adjusting for weekly county case counts.We found heterogeneity in strategy uptake over time, some of which was associated with geographic region and phase of pandemic. We identified a body of strategies that were both commonly used and sustained over time, for example, limiting staff in COVID-19 rooms and increasing telehealth capacity, as well as those that were rarely used and/or not sustained, for example, increasing hospital bed capacity.Hospital strategies during the COVID-19 pandemic varied in resource intensity, uptake and duration of use. Such information may be valuable to health systems during the ongoing pandemic and future ones.

    View details for DOI 10.1136/bmjopen-2022-067986

    View details for PubMedID 37156578

  • A Body Bag Can Save Your Life: A Novel Method of Cold Water Immersion for Heat Stroke Treatment A Body Bag Can Save Your Life: A Novel Method of Cold Water Immersion for Heat Stroke Treatment Kim, D. A., Lindquist, B. D., Shen, S. H., Wagner, A. M., Lipman, G. S. 2020: 4

    View details for DOI 10.1002/emp2.12007

  • A predictive tool for identification of SARS-CoV-2 PCR-negative emergency department patients using routine test results. Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology Joshi, R. P., Pejaver, V. n., Hammarlund, N. E., Sung, H. n., Lee, S. K., Furmanchuk, A. n., Lee, H. Y., Scott, G. n., Gombar, S. n., Shah, N. n., Shen, S. n., Nassiri, A. n., Schneider, D. n., Ahmad, F. S., Liebovitz, D. n., Kho, A. n., Mooney, S. n., Pinsky, B. A., Banaei, N. n. 2020; 129: 104502


    Testing for COVID-19 remains limited in the United States and across the world. Poor allocation of limited testing resources leads to misutilization of health system resources, which complementary rapid testing tools could ameliorate.To predict SARS-CoV-2 PCR positivity based on complete blood count components and patient sex.A retrospective case-control design for collection of data and a logistic regression prediction model was used. Participants were emergency department patients > 18 years old who had concurrent complete blood counts and SARS-CoV-2 PCR testing. 33 confirmed SARS-CoV-2 PCR positive and 357 negative patients at Stanford Health Care were used for model training. Validation cohorts consisted of emergency department patients > 18 years old who had concurrent complete blood counts and SARS-CoV-2 PCR testing in Northern California (41 PCR positive, 495 PCR negative), Seattle, Washington (40 PCR positive, 306 PCR negative), Chicago, Illinois (245 PCR positive, 1015 PCR negative), and South Korea (9 PCR positive, 236 PCR negative).A decision support tool that utilizes components of complete blood count and patient sex for prediction of SARS-CoV-2 PCR positivity demonstrated a C-statistic of 78 %, an optimized sensitivity of 93 %, and generalizability to other emergency department populations. By restricting PCR testing to predicted positive patients in a hypothetical scenario of 1000 patients requiring testing but testing resources limited to 60 % of patients, this tool would allow a 33 % increase in properly allocated resources.A prediction tool based on complete blood count results can better allocate SARS-CoV-2 testing and other health care resources such as personal protective equipment during a pandemic surge.

    View details for DOI 10.1016/j.jcv.2020.104502

    View details for PubMedID 32544861

  • A body bag can save your life: a novel method of cold water immersion for heat stroke treatment. Journal of the American College of Emergency Physicians open Kim, D. A., Lindquist, B. D., Shen, S. H., Wagner, A. M., Lipman, G. S. 2020; 1 (1): 49–52


    Non-exertional heat stroke is a life-threatening condition characterized by passive exposure to high ambient heat, a core body temperature of 40°C (104°F) or greater, and central nervous system dysfunction. Rapid cooling is imperative to minimize mortality and morbidity. Although evaporative and convective measures are often used for cooling heat stroke patients, cold water immersion produces the fastest cooling. However, logistical difficulties make cold water immersion challenging to implement in the emergency department. To our knowledge, there is no documented case utilizing a body bag (ie, human remains pouch) as a cold water immersion tank for rapid resuscitation of heat stroke. During a regional heat wave an elderly woman was found unconscious in a parking lot with an oral temperature of 40°C (104°F) and altered mental status. She was cooled to 38.4°C (101.1°F) in 10 minutes by immersion in an ice- and water-filled body bag. The patient rapidly regained normal mentation and was discharged home from the ED. This case highlights a novel method for efficient and convenient cold water immersion for heat stroke treatment in the emergency department.

    View details for DOI 10.1002/emp2.12007

    View details for PubMedID 33000014

    View details for PubMedCentralID PMC7493529

  • Design and Implementation of a Novel Acute Stroke Code for the Extended Window of Endovascular Treatment Legault, C., Dujari, S., Shen, S. H., Wagner, A. M., Albers, G., Bernier, E., Callagy, P., Vora, N. LIPPINCOTT WILLIAMS & WILKINS. 2018
  • Lean Manufacturing Improves Emergency Department Throughput and Patient Satisfaction. journal of nursing administration Kane, M., Chui, K., Rimicci, J., Callagy, P., Hereford, J., Shen, S., Norris, R., Pickham, D. 2015; 45 (9): 429-434


    A multidisciplinary team led by nursing leadership and physicians developed a plan to meet increasing demand and improve the patient experience in the ED without expanding the department's current resources. The approach included Lean tools and engaged frontline staff and physicians. Applying Lean management principles resulted in quicker service, improved patient satisfaction, increased capacity, and reduced resource utilization. Incorporating continuous daily management is necessary for sustainment of continuous improvement activities.

    View details for DOI 10.1097/NNA.0000000000000228

    View details for PubMedID 26252725

  • Arthrocentesis of the Knee (Videos in Clinical Medicine) Arthrocentesis of the Knee Thomsen, T. W., Shen, S., et al 2006; e19: 354

    View details for DOI 10.1056/NEJMvcm051914