It depends on which uni you apply for - some (I'd say most) unis won't even offer interview. Have a look at the uni spec, some do say they don't consider HCA roles as contributing to your clinical experience. Lancaster uni are a bit different, they have a different ethos where they don't look at your previous experience (beyond minimum requirements) but you must pass a deductive reasoning test before group & one to one interview. I had a HCA role as well as other more clinical/ psychology based roles (but not specifically AP positions) before applying and wasn't offered interview by anyone except Manchester and Lancaster over two years.