For a patient who has been on overlap therapy for 5 days, the difference between the overlap therapy start date and the last parenteral anticoagulant administration date is actually 4 days, since the subtraction doesn’t take into account one of the dates. For example, for a patient started on overlap therapy on 01/01/2015 who was last administered a parenteral anticoagulant on 01/05/2015, the difference between the dates is 4 days, but the number of days the patient was on overlap therapy was 5.

CQM-73 has differing guidance regarding the INR and Overlap therapy information. The Numerator guidance states "Five or more days with an INR greater than or equal to 2 prior to discontinuation of parenteral therapy, or Five or more days with an INR less than 2 and discharged on overlap therapy, or less than five days and discharged on overlap therapy". The numerator criteria, however, provides logic that states "greater than or equal to 4 days". It is unclear which of the two pieces of guidance is correct for this measure.