Health experts reject proposals reportedly being considered by the government to assess a patient's benefit to society when deciding to pay for new drugs.
The National Institute for Health and Care Excellence (Nice) has dismissed plans by ministers that could see patients who are seen to contribute more to the economy being given priority, the Times has reported.
Sir Andrew Dillon, head of Nice, told the newspaper that this would leave the old at risk as younger patients would be given priority for treatment as they could give more back.
Under proposals reportedly being considered by the government, drugs that help older people live longer could be seen as having a "negative" value for society as elderly patients take more than they can give back.
The Department of Health has reportedly instructed Nice to look at how it assesses cost-effectiveness of medication, taking into account the benefits successful treatments could have for the economy - such as allowing people to return to work.
A Nice assessment of the plans found that this would "inevitably take age into account to some degree".
Sir Andrew said: "This wider societal impact is such a sensitive issue. You can do it in a hard-nosed economic way, which is the department's calculation, but our sense is the wider public see wider societal impact as being more subtle than that.
"We're really concerned that we don't send out the message that we value life less when you're 70 than we do when you're 20."
Nice approves drugs costing less than £20,000 to give a year of good-quality life and Sir Andrew wants a similar formula to assess how a patient's quality of life is affected by illness.
He said: "What we don't want to say is those 10 years you have between 70 and 80, although clearly you are not going to be working, are not going to be valuable to somebody.
"You might be doing all sorts of very useful things for your family or local society. That's what we are worried about and that's the problem with the Department of Health's calculation.
"There are lots of people who adopt the fair-innings approach; 'you've had 70 years of life you've got to accept that society is going to bias its investments in younger people'. There are people who subscribe to that but it's not something we feel comfortable (with)."
Ministers insist they would not allow the elderly to be discriminated against.
A Department of Health spokesman said: "We want to make sure we get the best possible results for all NHS patients with the resources we have, which means using taxpayers' money responsibly and getting good value for money.
"That's why we have asked Nice to look at the way drugs are assessed so that patients can get the treatments they need at the best value for the NHS and the price the NHS pays is more closely linked to the value a medicine brings.
"We understand that it's an important and complex issue on which many people will have views and Nice will be consulting widely on the proposals."