I think we can pretty safely put Scotty and Trip at the bottom of the pile. They've never shown any specific aptitude for medical work and I think 24th century Starfleet basic medical training and technology helps everyone else. Of the remaining three, Geordi seems like he would be very nice and try to be as helpful as possible about your injuries, but I'm ranking him 3rd overall. I don't recall O'Brien ever doing anything on screen to indicate his medical competence, but we can guess that maybe he's seen enough combat to have picked up some of the basics, so second place to Miles. Torres, with her extensive knowledge of programming and reprogramming the Doctor (enough to suggest a DNA re-sequencing of her own baby to the Doctor [Lineage, Voy]) and the fact that her year at the academy may have been a double major in engineering and medical [Extreme Risk, Voy] makes me put her in first place.