Dear Bonnie Team,

I noticed an unexpected performance with "Coalesce" in the first "if then" statement of this function "MedicationOrderPeriod". The intent of the first "if then" statement is as such: if relevantPeriod.end is available, return an interval starting with relevantPeriod.start and ending with releavntPeriod.end; if relevantPeriod.start is null, use authorDatetime instead.

Please find test case set up and result below. I would appreciate your assistance in pinpointing whether this is a cql-execution or logic issue. Thank you in advance!

define function "MedicationOrderPeriod"(Order "Medication, Order"):
  if Global.HasEnd ( Order.relevantPeriod ) then Interval[Coalesce(start of Order.relevantPeriod, Order.authorDatetime), 
end of Order.relevantPeriod]
  else ( Coalesce(Order.daysSupplied, Order.supply /(Order.dosage * ToDaily(Order.frequency)))* ( 1 + Coalesce(Order.refills, 0)) ) durationInDays
  let startDatetime: Coalesce(start of Order.relevantPeriod, Order.authorDatetime)
  return if durationInDays is not null then Interval[startDatetime, startDatetime + System.Quantity { value: durationInDays.value, unit: 'days' }]
    else null                   

Test case:

• Medication, Order
• relevantPeriod.start: null
• relevantPeriod.end: 1/4/2012 8:15am
• authorDatetime: 1/2/2012 8:00am
• Refills: 1
• Dosage: 50 'mg'
• Supply: 150 'mg'
• Frequency: SNOMEDCT 229797004
• Days Supplied: 10

Expected output vs actual:

• Expected: 1/2/2012 8:00am - 1/14/2012 8:15am
• Actual: Invalid date - 1/14/2012 8:15am