@kbell - in the UK, a committee called NICE (National Institue for Clinical Excellence) decides that.
The rough rule of thumb is that the national health service in the UK will pay 30 thousand pounds a year (50 thousand dollars) for every year of comfortable life you get as a result.
When the costs are higher than that, or when the treatment will still leave you in pain - things get complicated. And new drugs and treatments have to be judged on a case by case basis. This can lead to a lot of controversy in the media - eg a breast cancer drug which costs 100 thousand pounds a year - but gives only patients an extra 6 months of life.
The rough rule of thumb is that the national health service in the UK will pay 30 thousand pounds a year (50 thousand dollars) for every year of comfortable life you get as a result.
When the costs are higher than that, or when the treatment will still leave you in pain - things get complicated. And new drugs and treatments have to be judged on a case by case basis. This can lead to a lot of controversy in the media - eg a breast cancer drug which costs 100 thousand pounds a year - but gives only patients an extra 6 months of life.