Just to fill out the above comments a little.
HCAs exist in the Regular Force from the rank of Lt to Major. At the rank of Major they are eligible to complete for Voluntary Occupational Transfer to the Health Services Operations (HSO) Officer trade. In fact, most of the HSOs are ex-HCAs.
HCAs work in four main environments:
1) Clinics
2) Field Units
3) Training Establishments
4) HQ Staffs
In clinics they are the experts in health care administration as their name would imply. This includes working in junior leadership positions and dealing with human resources, business planning, finance, civilian labour relations, infrastructure, medical records, etc.
In field units (field ambulances / the Field Hospital) they often work as platoon commanders, company 2ICs, occasionally company commanders, operations officer, adjutant, admission & discharge officer, liaison officers, and command post watch officers. They lead the field force at the platoon and company level.
In the Training Establishments they work as instructors teaching most of the topics above, as standards officers, and as Training Establishment key staff such as the service support officer, operations officer, adjutant, and company 2ICs.
On HQ staffs they work in the field of medical regulating, operations and planning, research, administration & finance, desk officers, project officers, executive assistants / staff officers to Directors / Aide de Camp, and as general staff officers in all areas.
Lots of people around here with HCA experience / have worked with HCAs. It is an interesting field, much different than the Log O occupation, IMHO.
Cheers,
MC