$InitialADHDMedication defines only start of Medication :
"Medication, Dispensed: ADHD Medications" <= 60 day(s) starts after start of "Measurement Period"
"Medication, Dispensed: ADHD Medications" <= 90 day(s) starts before or concurrent with start of "Measurement Period"
However Denominator Exclusion criteria requires End date validation of ADHD Medication dispensed :
"Encounter, Performed: Inpatient Encounter (principal diagnosis: Mental Health Diagnoses)" <= 30 day(s) starts after end of $InitialADHDMedication
"Encounter, Performed: Inpatient Encounter (principal diagnosis: Substance Abuse)" <= 30 day(s) starts after end of $InitialADHDMedication
Please let us know if startdate validation can also be used for fetching medication enddate, or how should it be defined?