• i wanted to link https://github.ibm.com/watson-health-fhir-server/fhir/issues/493 to it
  - https://gforge.hl7.org/gf/project/fhir/tracker/?action=TrackerItemEdit&tracker_item_id=5531&start=0
  - https://gforge.hl7.org/gf/project/fhir/tracker/?action=TrackerItemEdit&tracker_item_id=6630&start=0

Good day HL7 FHIR,

When searching for Patient with ?deceased=true, the SearchParameter `"code" : "deceased"` is used. From the search-parameters.json definitions file from http://hl7.org/fhir/definitions.json.zip, the key elements are:
"description" : "This patient has been marked as deceased, or as a death date entered",
"code" : "deceased",
"type" : "token",
"expression" : "Patient.deceased.exists() and Patient.deceased != false",
"xpath" : "f:Patient/f:deceasedBoolean | f:Patient/f:deceasedDateTime",

The docmentation (http://hl7.org/fhir/r4/patient.html#search) further describes deceased as:
deceased TU token This patient has been marked as deceased, or as a death date entered Patient.deceased.exists() and Patient.deceased != false

The XPath expression seems to return a multiple typed response, where as the FHIRPath expression returns a Boolean valued result, such that the following pattern results .
deceasedBoolean deceasedDateTime extracted token
null null null
false null false
true null true
null 2018 2018

Is the XPath expression correct? Or should the last row return a Boolean value?

Many thanks for your time.

Paul Bastide/IBM

\\P.S.
The nearest tracker items we found are:
- https://gforge.hl7.org/gf/project/fhir/tracker/?action=TrackerItemEdit&tracker_item_id=5531&start=0
- https://gforge.hl7.org/gf/project/fhir/tracker/?action=TrackerItemEdit&tracker_item_id=6630&start=0