Dr. Bernadette Carr:

With regard to supply and demand, it is not like people are dragged into hospital. Instead of having an inexpensive X-ray, a person may have an MRI or CT scan, which would be more expensive. That would not be done if the scanner was not there. Many people with bad hip arthritis would not have had a hip replacement 40 years ago but as it becomes more available, the procedure is done much earlier. If a sporting person has a hip replacement earlier - at 50, for example - the person would remain fitter and there would be a better quality of life. Nevertheless, there is a cost. That is supplier-induced demand.