I used the service a few times, and discovered that it was mostly a waste of time. If I have to call a service, spend a few minutes on the phone only to then go to hospital, then it's cost more than me just going to hospital.
I get the impression that the whole idea was that it was some management consultant wheeze that the government liked the look of because it made them look all 21st century, like all the banks with call centres.
The big difference is that a business generally has the facts at their fingertips about your account, or can ask you questions to solve most problems. With medical diagnosis you often need to examine a patient, check blood pressure and so forth. Can't be done over the phone.
This resulted in a paradox with NHS Direct. They employed fully qualified nurses, yet because of the limitations of diagnosis, were limited in what they could actually deal with.
So, the new 111 service actually makes a lot more sense. Don't employ highly trained nurses, put them into wards where they should be, and hire some people off the streets, train them in 60% of problems that are very routine and get them to tell patients to go to A&E for anything else. That's how ISPs work - put monkeys on 1st line support and put skilled people on 2nd and 3rd line.