We are a vendor creating QRDA files to submit to HARP/Cypress and TJC.   We have found a difference between the way that TJC interprets the initial population, and the way HARP (and Cypress) interpret the initial population.

It appears that TJC includes discharges from the ED if the discharge is the same date as the Inpatient admission date.

HARP/Cypress does not include that ED visit discharge into the Initial Population, only the Inpatient visit discharge is included.

Because of the conflicting results it is unclear if Initial Population should include ED visits