CALYPSO (Criteria Assessment Logic for Your Population Study in Observational data) is a web user interface to define, instantiate and evaluate a study population and the implications of inclusion criteria
As I was creating my cohort, I wanted all events that matched the criteria and I thought I had done that when I specified 'Limit primary events to all events person'. I did not change the cohort expression drop-down choice because it sits under the 'Additional Filters' button. Since I did not have any additional filters, I did think that the cohort expression drop-down applied to my cohort. After investigation, I realized that both choices need to be made in order to return the cohort I was interested in. The logic behind the tool was working correctly, but the UI was confusing.
As I was creating my cohort, I wanted all events that matched the criteria and I thought I had done that when I specified 'Limit primary events to all events person'. I did not change the cohort expression drop-down choice because it sits under the 'Additional Filters' button. Since I did not have any additional filters, I did think that the cohort expression drop-down applied to my cohort. After investigation, I realized that both choices need to be made in order to return the cohort I was interested in. The logic behind the tool was working correctly, but the UI was confusing.