The calculation of a measure utilizing the ‘FIRST’ sub operator and the ‘count’ function can be affected when the start date/time is identical for a concept coded with more than one vocabulary.

For example the logic for CMS 61v5 contains several ‘count’ functions such as the “Count = 1 of: $FraminghamCADRiskfactors”. The provider organization codes "hypertension" using SM-CT, ICD-10, and ICD-9 codes. Since the start date/time is identical for each vocabularies hypertension code, each code is considered equal when the line of logic, listed below (see example) is evaluated. The net result returns a count = ‘3’ rather than the expected count of ‘1’.

CQM-1397 discusses this same issue in relation to encounters. The solution acknowledges this issue and states: “while we recognize this issue, it is not the intent of our specification or the intent of our measure – the expectation is that to satisfy the requirement of ‘COUNT >= 2’, the patient will have at least two unique encounters/interactions”.

The QDM alludes to this issue in relation to ‘sub operators’ such as ‘FIRST’. According to the QDM 4.2 guide, pg 15, footnote 8 states:
“In cases where two or more events have the same exact date/times for comparison, they will hold equal status (i.e., in rare cases, it is possible for subset operators like FIRST and MOST RECENT to return more than one event).”

The QDM guide acknowledges this could be an issue but does not offer any guidance regarding calculating of the measure under these circumstances. Similarly, CQM-1397 indicates the ‘expectation’ is to report at least two unique encounters but does not offer any additional guidance for reporting. Should the QRDA file include the three codes referenced above or should only one code be reported as ‘intended’?