Cohort Definition Guideline

Cohort Definition

Broadly, the cohort categories can be described as a sequence of categorizations based on age => gender => risk factors => COVID-19 status, ideally with equal representation amongst all the different combinations, with category definitions as follows:

Age

We match typical CMS reporting age groups with the following categories:

• 0-18: Youth
• 19-44: Young Adults
• 45-64: Middle Aged
• 65-84: Elderly
• 85+: Elderly 2

Gender

Is based on gender assigned at birth

Risk Factors

Is based on an aggregate score

• If age 65-84, add +1 to score
• If age 85+, add +2 to score For presence of each of the risk factors as defined in https://github.com/OHNLP/N3C-NLP-Documentation/wiki/Risk-Factors Add +1 to score for presence of each distinct factor.

Categorization is as follows

• Risk score 0: Low Risk
• Risk score 1,2: Moderate Risk
• Risk score 3+: High Risk

COVID-19 Status

Divide into lab-confirmed positive, lab-confirmed negative, suspected positive, and possible positive cases. Definitions for these categories can be found at https://github.com/National-COVID-Cohort-Collaborative/Phenotype_Data_Acquisition/wiki/Latest-Phenotype (note, weak positive mentions may be supplemented with NLP definitions as found elsewhere in this documentation, particularly with reference to fever, dyspnea, and pneumonia). Additionally, add a category for never tested by laboratory as defined by those excluded by the N3C phenotype guideline.