CEC-UW Project Highlights

2020

April to June: Project Initiation

• Obtained University of Wisconsin (UW) IRB Exemption approval for project
• Identified discrete EHR data elements of interest (about 250 elements), all of which are HIPAA-compliant and de-identified (per HIPAA requirements)
• Provided a 64-digit unique de-identified patient identifier for each patient included in the cohort. The unique identifier allows for tracking of additional treatments provided by the same health system after the initial COVID-19 diagnosis
• Completed data transfer and use agreements with each of the 21 participating health systems
• Contracted with BlueTree to consult on use of EHR data

July to September: Initiated Data Extraction

• Corrected and refined EHR coding across the 21 health systems
• For the first time, processed, merged, optimized, and harmonized data from all 21 health systems

October to December: Produced first Analyzable Data Set Findings

• February 1, 2020 – December 31, 2020 total sample size – approximately 620,000 discrete patients meeting the COVID-19 case definition

2021

January to April: Data Transformed to Limited Data Set; Vaccines Included in Extract Code; Additional Analyzable Data Set Findings

• Received IRB approval to transform data from deidentified data set to a limited data set
• Updated data transfer and use agreements with each of the 21 participating health system
• Added COVID-19 vaccine table to patient information file
• February 1, 2020 – April 30, 2021 total sample size – approximately 875,000 discrete patients meeting the COVID-19 case definition

May to September: Added Diagnosis Extract; Additional Analyzable Data Set Findings

• Diagnosis-based medical history added to data elements in patient EHR extracts cohort
• Changed code logic to use ICD10 COVID-19 diagnosis codes U07.1 and J12.82 for inclusion into patient cohort
• February 1, 2020 – September 30, 2021 total sample size – approximately 1.1 million discrete patients meeting the COVID-19 case definition

October 2021 to January 2022: Final Data Pull Completed

• Added booster/third shot to COVID-19 vaccine table in patient information file
• February 1, 2020 – January 31, 2022 final sample size of CEC-UW cohort collected – approximately 1.8 million discrete patients meeting the COVID-19 case definition