To what extent was the NHS a complete success in the years 1946-1979? (20 marks)

To understand the extent to which the NHS was a complete success, you need to understand some of the circumstances surrounding healthcare in England before it was implemented in July of 1948. Prior to then, healthcare was a luxury few could afford. Workers could see a general practitioner for free, but their families could not.  Hospitals had disparate admission policies and practices. Mentally ill and handicapped people were sent away to institutions with horrible conditions, often causing their health to become worse. Seniors who couldn't support themselves did very poorly, and many died in workhouses known as Public Assistance Institutions.
The NHS immediately resolved the problem of patient cost by ensuring the organization was financed almost entirely by taxes. Treatment standards quickly improved as better drugs were introduced and spread through the NHS. These were the years a polio vaccine was created, dialysis allowed people with liver failure to continue living, and chemotherapy began saving cancer patients. All of these new developments were excellent for patients, but they also drove up the cost of the NHS.
By the second decade of the NHS, doctor's low pay became a contentious issue. Negotiations between the government and general practitioners lead to the GP Charter, a new contract that helped provide financial incentives to practice medicine. This lead to better staffed hospitals and doctors joining together in what today is known as group practice.
An oil embargo in 1967 caused the NHS to financially struggle. But while its expansion stalled, meaningful developments continued from within the organization. Transplant surgery became more successful, intensive care units and non-steroidal anti-inflammatory drugs were made available. The NHS began to emphasize care for seniors, the mentally ill, and children. 
Finally, in 1974, the NHS was reorganized, changing many of the relationships between regional healthcare authorities. New authorities were created to intermediate between district authorities and hospitals. This allowed area health authorities to unite into a tripartite service , providing better service in conjunction with local providers. 
Stephen Hawking has said "I wouldn't be here today if it were not for the NHS, I have received a large amount of high-quality treatment without which I would not have survived." His sentiment reflects the extent to which the NHS has been successful through its early years. While the NHS has faced problems, it's a complete success relative to the challenges it's been tasked with solving.
http://www.nhshistory.net/shorthistory.htm

https://www.kingsfund.org.uk/projects/nhs-in-a-nutshell/how-nhs-funded

https://www.telegraph.co.uk/news/worldnews/northamerica/usa/6017878/Stephen-Hawking-I-would-not-be-alive-without-the-NHS.html