Hi Bonnie team, we have an issue with CMS349.

The logic calls for the start of a diagnosis's prevalence period to start before the Measurement Period. The snippet of logic in question is at the end of this ticket.

The issue we're facing is when the prevalencePeriod is missing a start time, but has an end time, the measure still passes (see screenshot). The logic should only be assessing the start of the prevalence period, but when the end of the period is present without a start period, Bonnie appears to be imputing a value. With a missing value, we would expect the measure to fail. 

Please also note that when we add a start time, the measure passes and fails edge cases as expected. It is only when the value is missing entirely that we see odd results. 

 
{{define "Denominator Exclusions":
exists ( ["Diagnosis": "Indicators of Human Immunodeficiency Virus (HIV)"] HIVIndicators
where start of HIVIndicators.prevalencePeriod before start of "Measurement Period" )}}