Ambulance Services: Standards Mike Penning To ask the Secretary of State for Health what guidance has been issued to NHS ambulance trusts on establishing criteria to use in setting target response times for Category C patients who require an ambulance response. Mr. Mike O'Brien Since 1 October 2004, local national health service organisations have had responsibility for managing and monitoring the ways in which local services respond to Category C calls (i.e. those presenting conditions that are not immediately serious or life threatening).