'The NHS must evolve - or face a painful death' is the title of perhaps the worst commentary I've recently seen by a supposedly serious commentator on the NHS. It is by Ian Birrell, a journalist and former speechwriter for David Cameron.

The issue is not a failure to understand the scale of the challenges the service faces. Birrell rightly cites the salience of the NHS as a public concern second only to immigration in Lord Ashcroft's recent polling. It's a pity that he doesn't mention that this is polling of the marginal seats that will decide next year's election.

He states that "The cold financial facts that confront the service are frightening. The NHS budget when launched in 1948 was about £9bn at today's value; today, it is more than 12 times bigger and rising 4% a year in real terms".

Oooh! Scary!

Or it would be scary, if the UK's economy hadn't grown in proportion. The data here covers 1955-date, and shows 1955 UK GDP of £85,937 million adjusted for inflation (£4,749 unadjusted, showing the importance of inflation!). In the latest quarter of 2013, the ONS source data shows an adjusted figure of £382,818.

Now obviously, the NHS started a few years earlier than that, so the true comparator would be bigger again. Equally, as any nation becomes richer (which we have, vastly), the government may well choose to spend more of its resources on healthcare and welfare if that is what people want.

More importantly, the most recent work on the NHS's economic future by John Appleby and colleagues at the Kings Fund shows that NHS spending as a percentage of GDP is projected on current plans and trends to go into a significant reverse by 2021, down to 6.1% from the peak of 8%. This would take it back to the 2003 level of spending, just part-way through the decade of economic catch-up permitted by economic growth and legitimised by the Wanless Reports.

Birrell then asserts that the NHS "has to evolve fast or face a painful death. Yet this debate remains trapped in the past, with the institution still pathetically over-sanctified despite a series of horrific care scandals showing the damage this myopic stance can cause vulnerable patients. Cancer survival rates remain comparatively poor, social care often grotesquely inadequate, and we spend more per head on healthcare than Iceland – yet have double its mortality rates for under-fives".

Oh dear. Where to start?

Let's start with the rate of evolution, as measured in Darwins. One Darwin is a 2.718-fold change in a trait over a million years, which probably shows that careful selection of metaphor is advisable.

He starts with the false opposition that the NHS "has to change fast", which any sensible NHS watcher will observe that it has always been doing.

Often, this change has been meaningless rearrangement of managerial deckchairs, most noticeably with the 2012 Act which reduced bureaucracy by replacing 151 statutory commissioning organisations with 211; creating a further 17 (today?) commissioning support units which never previously existed; and replacing 10 strategic regional bodies with 27 local area teams. Oh, and which also created the biggest quango in Europe (as measured by spending) in NHS England. Now that's how to reduce bureaucracy!

The NHS has always been changing, fast and slow. As Nigel Edwards has often observed, it's been shutting beds since 1948, and shutting mental asylums since Enoch Powell's water towers speech (albeit the latter not very fast). Yes, as Birrell notes, it introduced prescription charges and dentistry charges within a few years of its creation. It's decanted significant amounts of care out of hospital settings and into primary care (which is really showing the strain now).

Oh, and in the past decade it's made monumental improvements on waiting times (though this may now be creaking under pressure and again, there are severe problems here for mental health); centralising stroke care and productivity.

Is the NHS as good as it should and could be? No it isn't. It's got a severe cultural problem around openness and transparency, which we're starting to uncover and which runs deep. Nor does it steal good ideas quickly enough. The IT is in general a joke. There are some teams and wards whose practice is dangerous, abusive or mendacious: see Mid-Staffs or the Colchester fiddling of cancer waits.

It's still a bit too easy for the less-good bits of organisations to treat patients paternalistically and as if their time had no value, with dreadful attention to flow, overlaps and duplication. There is too much variation in the use of evidence-based care, as shown by the NHS Atlas of Variation. And it's at the beginning of being able to measure outcomes in a systematictè and timely way.

Birrell is also right that cancer outcomes are comparatively worse than our comparator European neighbours. There is, as Macmillan pointed out, a long way to go in cancer care. This may in part be a result of the fact we remain among the continent's comparably sized populations and comparably developed economies' lowest spenders on healthcare.

It's clearly reasonable to point out that as Birrell mentions care, the prominent care scandal of recent times took place in Winterborne View, a private care provider run by Castlebeck. Serco were guilty of fiddling the figures for their GP contract in Cornwall.

Oh, and social care isn't great, true. It wasn't quite helped by an immature debate at the last election over 'Labour's death tax' (who was writing David Cameron's speeches, remind us?), nor by the significant real-terms cuts in central government funding, which are hitting the poorest regions hardest.

The public health experts whose data provide Birrell with the figures which compare the UK (population 65 million) with Norway (population 5 million) suggest that our relatively high infant mortality is probably associated with the current government's changes in welfare, specifically the benefits cap.

Birrell idolises Hinchingbrooke, run by Circle. Maybe he hasn't looked at its unspectacular ratings on NHS Choices, nor its below-average results in the NHS staff survey. Its feedback on Patient Opinion is average-to-mixed once you go beyond the first page. Nor, I suspect, has he looked at Circle's long-run share price or ownership changes. Following their restructuring of debt, you can only define Circle as employee-owned if you include the staff of the major investor hedge funds as employees. (I wonder if they can get the NHS pension?)

Birrell cites approvingly Norman Warner's wonderfully silly intervention about £10 a month NHS 'membership': a homonyn for user charges, for which the positive evidence is non-existent.

He ends with a spectacular reverse-ferret, having started with a Jeremiad about the NHS's relentless decontextualised cost rise, by saying "we need to talk about tax. For if the health service really needs £30bn more in seven years' time, and charging is unacceptable, that is equal to a 7p rise in income tax at a time when whoever wins next year's election will be scrabbling around for public sector savings ... One idea that might sweeten it slightly came from Paul Kirby, former No 10 policy chief, who suggested converting national insurance – a relatively progressive tax – into a dedicated NHS tax. It raises just over £100bn, roughly the current cost of the health service. The Treasury would hate this hypothecated tax, but it might just focus minds enough to kickstart a rational debate over the cost, funding and provision of modern healthcare".

NI isn't progressive on earnings over £42,000, of course. As I pointed out, hypothecation has no magical powers to make things better.

Birrell's analysis should not be tossed aside lightly, but hurled with great force. There are a lot of sensible discussions to be having about the NHS. None of them were in his piece.