Data, Systems, Society, and Healthcare
I'm an Assistant Professor at the Johns Hopkins' Center for Data Science in Emergency Medicine. I'm also a member of the Malone Center for Engineering in Healthcare, and I serve as a Data Scientist at the Johns Hopkins Medical Institutions. I graduated from South Florida in 2015 with a PhD in industrial engineering, working under the guidance of Jose Zayas-Castro in applications of operations research to healthcare delivery and health policy. From 2015 to 2017, I was a postdoctoral research fellow within Scott Levin's systems engineering group at the Johns Hopkins School of Medicine. I joined the Johns Hopkins faculty in 2017.

Current

***COVID-19*** Extracting meaning from large and sparse data, and creating real-time decision support systems
  • Emergency Department Triage (with Scott Levin). Investigating the potential for machine learning decision support systems to improve via the exchange of information with knowledgeable users. With the support of the NSF and AHRQ
  • ​Acute Kidney Injury Prediction (with Jeremiah Hinson). Predicting the onset of acute kidney injury during hospitalization at ED presentation, and build an electronic tool embedded into the electronic medical records to support ED disposition and medication administration decision-making. With the support of the EMF
Understanding how parts of a system interact to become a whole
  • Optimizing Waiting List Management (with Jose Zayas and Felipe Feijoo). Investigating the effects of prolonged waiting for patients waiting for medical attention in countries with universal healthcare, and developing data-driven waiting list management models. With the support of the AHW
  • Epidemics on Networks (with Eili Klein). Investigating the epidemic processes by which infectious diseases spread over networks of contact between humans. In particular, we are using Bayesian MCMC modeling to determine the effectiveness of contact precautions in preventing transmission of antibiotic-bacteria. With the support of the CDC​

2019

Sep 2019 (JMIR)
Jiang, Siddiqui, Barnes, Barouch, Korley, Martinez, Toerper, Cabral, Hamrock, Levin
We developed a dynamic readmission risk prediction model that yields daily predictions for patients hospitalized with heart failure
Sep 2019 (IIE Healthcare Systems Engineering)
Martinez, Jalalpour, Efron, Levin
We explained how to assess the impact of process improvement interventions with routinely collected longitudinal hospital data
Jan 2019 (BMC Public Health)
Martinez, Zhang, Bastias, Feijoo, Hinson, Martinez, Dunstan, Levin, Prieto
We measured a possible link between lengthy waits to access health care with an increased risk of mortality in waiting lists not prioritized by universal healthcare (Plan AUGE) in Chile
Jan2019 (Emergency Nurses Association)
Whalen, Gardner, Martinez, Henry, McKenzie, Hinson, Levin
We quantify and qualify our evolution from traditional ESI triage system to machine-learning-based system as an exemplar of transition from research to practice and nursing integration

2018

Nov 2018 (Joint Commission Journal on Quality and Patient Safety)
Kane, Scheulen, Puttgen, Martinez, Levin, Bush, Huffman, Jacobs, Rupani, Efron
We designed and implemented a command center to manage patient flow at a large urban academic hospital using systems engineering principles
Nov 2018 (AHRQ Research Grant)
Levin (PI), Hinson (PI), Martinez (Co-Inv)
To improve decision-making by emergency clinicians that relates to diagnosis, treatment, and disposition of patients with respiratory tract infections in the emergency department
Nov 2018 (PUCV, Chile)
Pontifical Catholic University of Valparaiso Data Science Seminar
Diego Martinez
Invited talk. Valparaiso, Chile
Nov 2018 (Annals of Emergency Medicine)
Hinson, Martinez, Cabral, George, Whalen, Hansoti, Levin
We synthesized what is known about the performance of emergency department triage systems
Jun 2018 (Journal of Medical Systems)
Martinez, Kane, Jalapour, Scheulen, Rupani, Toteja, Barbara, Bush, Levin
We created and implemented an electronic dashboard to monitor hospital patient flow
May 2018 (Applied Physics Lab)
Johns Hopkins Applied Physics Lab Network Science Seminar
Diego Martinez
Invited talk. Laurel, MA
Jan 2018 (Int J Emergency Medicine)
Hinson, Martinez, Schmitz, Toerper, Radu, Scheulen, Levin, Stewart de Ramirez
We measured the extent to which patient characteristics contribute to inaccurate emergency department triage
Jan 2018 (Geisinger Health System)
Geisinger Health Operations Research Seminar
Diego Martinez
Invited talk. Danville, PA
Jan 2018 (JHU Research Grant)
Prieto (PI), Martinez (Co-PI)
To reduce waiting lists in a health delivery network for low income patients in Chile
Jan 2018 (Annals of Emergency Medicine)
Hinson, Martinez, Grams, Levin
We use electronic health records and machine learning to develop a predictive model for acute kidney injury (AKI) with capacity for identifying patients at high risk of developing AKI within 7 days of their emergency department visit

2017

Dec 2017 (Annals of Emergency Medicine)
Mistry, Steward de Ramirez, Kelen, Schmitz, Levin, Martinez, Psoter, Anton, Hinson
We performed an accuracy and reliability evaluation of the emergency severity index for emergency department triage
Aug 2017 (CDC Research Grant)
Klein (PI), Martinez (Co-Inv)
To improve understanding of how biological factors associated with the transmission of multidrug-resistant organisms impact interventions to reduce hospital-associated infections
May 2017 (IIE Healthcare Systems Engineering)
Wan, Zhang, Witz, Musselman, Yi, Mullen, Benneyan, Zayas-Castro, Rico, Cure, Martinez
We synthesized what is known about preventable hospital readmissions in the US
Feb 2017 (JAMA Pediatrics)
Woods-Hill, Fackler, McMillan, Ascenzi, Voskertchian, Colantuoni, Martinez, Toerper, Levin, Milstone
We created a new clinical practice guideline to reduce unnecessary testing in a tertiary pediatric ICU, which reduced blood sample collections without increasing missed sepsis cases

2016

Feb 2016 (Trials)
Martinez, Tsalatsanis, Yalcin, Zayas-Castro, Djulvegovic
We model and optimize the opening of clinical trials at an academic medical center
Sep 2016 (Health Care Management Science)
Martinez, Feijoo, Zayas-Castro, Das, Levin
We mathematically model the tension between market incentives and federal regulations in hospital markets
May 2016 (Journal for Healthcare Quality)
Rico, Liu, Martinez, Huang, Zayas-Castro, Fabri
We measured the extent to which patient and hospital characteristics increase the ​risk of preventable hospital readmissions

2015

October 2015 (BMC Medical Informatics and Decision Making)
Strauss, Martinez, Garcia, Taylor, Mateja, Fabri, Zayas-Castro
We identified design features for interoperable electronic medical records from a physician perspective
Nov 2015 (Applied Clinical Informatics)
Martinez, Mora, Gemmani, Zayas-Castro
​We uncover information needs of physicians from outside hospitals while managing patients in the hospitalist service
Disclaimer: Any opinions, findings, conclusions, or recommendations expressed herein are those of the author and do not necessarily reflect the views of Johns Hopkins University or any other organization supporting our research.