THE prospect of closer ties between Trump's America and the UK's health service in a post-Brexit trade deal has generated fear, alarm - and promises by Nicola Sturgeon of an NHS Protection Bill.

Despite vows from Tory leader Boris Johnson that the NHS would be "off the table" in any negotiations with the US, a pledge strenuously reiterated by UK Health Secretary Matt Hancock, the unease remains.

READ MORE: Tories call on Health Secretary to resign over infection death

Scotland's former Chief Medical Officer, Professor Sir Harry Burns, told the Herald on Sunday that the greatest danger would emerge if a Brexit deal was abandoned in favour of a no-deal exit where the UK simply adopted World Trade Organisation rules - the so-called "true Brexit" favoured by some of the Tory right.

Burns said: "Politicians have already started saying there's no way we'd ever let the American bid to run the NHS.

"In fact, if you're a member of the WTO and you have at some point contracted with private companies to deliver healthcare, you are absolutely obliged to open up your system to bids from other members.

"So I think this statement that 'we'll never allow Americans in' - I don't think we could stop it if we were governed by WTO rules.

"I don't think having a devolved healthcare system, as we do in Scotland, would help because of course Scotland has contracted with private providers as well over the past 20-30 years.

"Deals were done with private hospitals to take NHS patients and get the waiting lists down, which was fine then. But it means US involvement would be difficult to stop under a WTO deal."

Burns, a supporter of Scottish independence, said his concerns were crystallised some 17 years ago when he attended a conference at Stanford University in California.

The topic was the future of the American healthcare system, but Burns said he came away convinced that the goal of the American healthcare companies in attendance was to "come up with ways to persuade the WTO to de-regulate its members' healthcare systems so that American healthcare companies could go and run them".

READ MORE: Royal College of Surgeons chief ousted in vote of no confidence

Such a move would be disastrous for patients and taxpayers, said Burns. Despite its private insurance system, the US spends a higher percentage of its GDP on healthcare than any other OECD nation, but is rated poorly for efficiency and cost-effectiveness.

A hip replacement in the US costs around £37,000 compared to £7,500, largely driven by the disproportionately high remuneration for physicians.

Burns said the system is also prone to over-treating patients.

"The classic example is prostate surgery," he said. "When a few years ago these robots were introduced suddenly the number of people getting prostate surgery went up enormously.

"But many prostate cancers are harmless; they never grown, never spread, or cause any trouble.

"But in America suddenly everyone was getting operated on by these robots because you could charge them a lot of money."

Others, however, caution against conflating a UK-US trade deal with a move towards an American-style healthcare system, and are sceptical that the US would ever secure the influence it might seek.

Mark Dayan, trade policy analyst and Brexit programme lead at the health think tank, Nuffield, believes the warnings about the NHS in relation to a US trade deal have been "overblown".

He said: "A trade deal is not going to switch the fundamental model of the NHS that exists in all UK countries away from one that's based on tax funding and free care for people".

READ MORE: Two people in Lothian treated for potentially deadly diphtheria infection

However, a recent episode of Channel 4 investigative documentary, 'Dispatches', claimed that the real risk would come if the US pharmaceutical industry succeeded in removing the UK's ability to bargain down drug pricing - something done routinely for the NHS, but banned in the American system.

As a result, a single diazepam (Valium) pill costs the NHS around two pence, but £3.05 in the US. Viagra varies from £4 per pill on the NHS to £61 per pill in the US.

Medicines are already the second largest cost to the health service - the bill in Scotland was £1.8 billion last year - but Dispatches warned that if we lost our ability to prescribe cheaper, non-branded drugs or to bargain over their cost, the bill for medicines across the UK NHS would rocket £27 billion, wiping out any 'Brexit dividend'.

Dayan believes such an outcome is unlikely, however.

"You wouldn't expect the UK government to just say yes to all of this," he said. "If you look at other recent US trade deals like South Korea and Australia, it's quite clear that they've already tried this stuff - but they haven't been able to get very major changes through.

"With those countries, as in the UK, medicines are largely paid for from the public purse, so they do have quite a strong incentive not to give an infinite amount of ground on that."

In the UK, pharmaceutical companies are voluntarily signed up to a five-year agreement known as the Pharmaceutical Price Regulation Scheme(PPRS) which caps how much the NHS will pay for branded, on-patent medicines.

It is then up to the Scottish Medicines Consortium - or NICE south of the Border - to gauge on the basis of cost-effectiveness which drugs should be provided on the NHS.

Jonathan Burton, chair of the Scottish board of the Royal Pharmaceutical Society, said they could see no benefit from a UK-US trade deal that includes any aspect of medicine supply.

He said: "We have a competitive system which means that we have some of the lowest priced generic medicines in the western world.

"We would see that any interference in the supply and the pricing of medicines really has the potential to turn a lot of those robust good arrangements on their head.

"Without wanting to get too political about it, when you have a Trump administration that makes no attempt to pretend that it's not 'America First', whenever you have a trade deal things are going to have to move both ways. And the only way our medicine prices are going to go - as we see it - is up.

"[Medicines] are already huge cost and, if you start to multiply that cost, what that means is less money for staff, less money for health professionals, potentially longer waiting times, and an impact on facilities. It's huge.

"If you want a practical example, take adrenaline pens. The humble EpiPen used for allergic reactions. In the UK, our NHS system pays £25 for an EpiPen. In the US, that costs something in the region of $150 per pen.

"A question sometimes put back to me is: are there US medicines that we can't get in the UK that we really need? The answer is there are some medicines made and licensed in the US which UK patients do need, but it's a very small number and we already have a very efficient import system for those medicines.

"They are still very expensive but it's a small number and there's a system in place for that and we do not have any great desire or need to tap into anything that we can't already access."

Brexit is already deeply unpopular with the medical profession. The Royal College of Radiologists warned that any disruption to the supply of radioisotopes used in cancer diagnosis and treatment - the vast majority of which are imported from the EU and cannot be stockpiled - would put patients lives at risk.

The Royal College of GPs said that Brexit also posed a risk of driving out at least some of Scotland's 226 GPs from other EU countries at a time of record vacancies.

Lewis Morrison, chair of doctors' trade union, BMA Scotland, said if Brexit itself cannot be avoided then a US trade deal that encompassed the NHS definitely should be.

He said: "The BMA are absolutely clear that our NHS must not be included in any such negotiations. This is for numerous reasons, ranging from the threat of opening up of our NHS to competition to potentially blocking public health measures.

“There is a considerable consensus in Scotland around the principle that NHS care in Scotland should be completely free from market forces. We absolutely must not let any trade deal threaten that – it cannot even be on the table in the first place.

“Equally Scotland has taken some bold steps on public health over recent years. We have also outlined serious concerns that the rush to sign trade agreements may mean they include clauses or mechanisms that strengthen the rights of investors to oppose potential public health measures or demand reimbursement from the Government as a result of such policies.

"Any trade deals the UK enters into after Brexit must not sacrifice the ability of UK or Scottish Governments to bring forward legitimate measures to improve public health.

“There are also clearly complex issues to do with drug pricing and the power of pharmaceuticals companies that could impact on the UK and Scotland as a result of reaching an agreement with the US.

“All these issues are extremely serious, which is why the BMA has repeatedly called for the NHS to be excluded from any future trade agreements. Our unequivocal message is simply: profit should never take priority over the protection of the health service and the health of citizens.”