After a major heart op my elderly mother needed an oxygen cylinder. She was house bound and couldn't lift anything very heavy. I offered to collect this for her and was surprised to learn the I couldn't. There were several reasons given, such as control of the whereabouts of these cylinders, health and safety of transporting the cylinders, patient care etc. The cylinders started off being delivered by an ambulance, then the visiting nurse delivered it. Finally it was dlivered by a private contractor. This was fine until, it ran out at the weekend and she was told she couldn't get a replacement until Monday morning. Fortunately the nurse brought one round. The answer from the NHS was that it is more cost effective to use private contractors for deliveries as they free up the (presumably more expensive?) time for the ambulances and nurses.