quantityOffset
A quantity-based offset used in before/after interval operator phrases to express a temporal distance. May be inclusive (quantity with or more/or less) or exclusive (less than/more than quantity).
Examples
Exactly 30 days offset
MedStart 30 days before start of Encounter.period
At least 30 days offset (inclusive)
MedStart 30 days or more before start of Encounter.period
Strictly less than 7 days offset
FollowUp less than 7 days after end of Encounter.period
EBNF
quantityOffset : (quantity offsetRelativeQualifier?) | (exclusiveRelativeQualifier quantity) ;