Add words in the Missing Data section to use $care-gaps to determine if data is missing: Use the following text: The $care-gaps report indicates instances in which information does not support the occurrence of an expected action. The report indicates absence of evidence; it cannot differentiate between activity that happened yet is missing from the record or from activities that did not occur. However, both of these situations result in the $care-gaps and the provider is notified in that report.  Missing data may be identified in a GuidanceResponse resource as shown in http://build.fhir.org/ig/HL7/davinci-deqm/StructureDefinition-gaps-detectedissue-deqm.html .