The addition of a search parameter to search SDC-QuestionnaireResponses based on the human readable name of the questionnaire filled would be very helpful. Especially since the canoncial reference to Questionnaire doesn't allow for chained searches. 

I suggest adding a search parameter to allow e.g. /QuestionnaireResponse?display=healthsurvey in order to retrieve all QuestionanireResponses where a Questionnaire of such title has been filled.

name = display
type = string
expression = QuestionnaireResponse.questionnaire.extension(
http://hl7.org/fhir/StructureDefinition/display)