About Leaf

Leaf is a drag-and-drop, self-service query application used to directly query de-identified patient data in the Mount Sinai Data Warehouse. Historically, Leaf has been successfully implemented at the University of Washington through the support of UW Medicine, the Institute of Translational Health Sciences, and the National Center for Data to Health. Leaf source code has been released into the public domain at https://github.com/uwrit/leaf.The Mount Sinai Health System implementation of Leaf went live in September 2021.

Leaf is currently in software version 1 at Mount Sinai and is occasionally updated. Click here to see Leaf’s Status and Roadmap.

Leaf is supported by grant UL1TR004419 from the National Center for Advancing Translational Sciences, National Institutes of Health.


Leaf Accounts

Leaf is free to use and is available to all Mount Sinai School and Hospital users. All Leaf users must have their own accounts. Users can log in to https://leaf.mssm.edu using Mount Sinai School or Hospital credentials. (As of August 2022, Mount Sinai users do not need to request account access through the service desk ticket system.)

Questions about Leaf accounts or Leaf access may be submitted as a service desk ticket.


Leaf Support Materials

The Mount Sinai Data Warehouse team encourages users to utilize the training and support materials publicly available:


Leaf Data & Features

Leaf utilizes ICD-10 codes to query de-identified patient data in the Mount Sinai Data Warehouse.

  • Search de-identified patient data from the Mount Sinai Health System (click here for more)
  • Search metadata from Imaging Research Warehouse 1.0 (click here for more)
  • Search de-identified cohorts from the Cancer Institute Biorepository

Leaf data types include:

  • Conditions: coded and descriptive diagnoses
  • Procedures: procedure, service and events
  • Demographics, further broken down into: AgeEthnicityGenderRace, and Vital Status
  • Encounters: patient visit criteria
  • Vitals: baseline patient health criteria
  • Lab Results: clinical, laboratory, and survey measurements
  • Medications: medications prescribed and administered

Query turnaround time takes seconds and results can visualize demographic details of cohorts in charts and diagrams in addition to a downloadable file. Leaf contains de-identified patient data only. To see how Leaf features compare to other MSDW query tools, click here for Services.


Leaf vs ATLAS

Compare Leaf to our other self-service query tool, ATLAS:

Development Nic Dobbins, University of Washington
Open-source collaborators (including Mount Sinai)
OHDSI Community

Open-source software
Extensive use by academic researchers
Specify cohort inclusion criteria
Visualize cohort characteristics

Ease of Use User Friendly Learning curve
Cohort Inclusion Criteria Easy drag-and-drop Complex rules, temporal dependencies
Data Export  Export cohort patient list (de-identified) Export cohort definition critera
Analytics Capabilities Minimal Built-in
For Data Marts Extensive setup Easy Setup



Leaf Quick Links