[Indicates that the decision to substitute or to not substitute was driven by a desire to maintain consistency with a pre-existing therapy. I.e. The performer provided the same item/service as had been previously provided rather than providing exactly what was ordered, or rather than substituting with a lower-cost equivalent. ( HL7V3.0 )]
UMLS (HL7) C1553904 Relation/PAR: SubstanceAdminSubstitutionReason