Screen test

January 12th, 2008 by Ben Goldacre in regulating research, statistics | 38 Comments »

Ben Goldacre
The Guardian,
Saturday January 12 2008

So we’re all going to get screened for our health problems, by some geezers who’ve bought a CT scanner and put an advert in the paper maybe, or perhaps off Gordon Brown: because screening saves lives, and it’s always good to do something rather than nothing. I think you’ll find – and I fancy having this on a t-shirt – that it’s a tiny bit more complicated than that.

Screening is a fascinating area, mainly because of the maths of rare events, but also because of the ethics. Screening isn’t harmless, because the tests aren’t perfect. You might get a false alarm, causing stress and anxiety (“the worst time in my life” said women in one survey on breast screening), or have to endure more invasive medical investigations, like maybe biopsies. Or you might get false reassurance from a false negative result, which can delay diagnosis of a genuine problem.

And here’s an interesting ethical issue. One of the proposed screening programmes is to catch “abdominal aortic aneurysms” earlier. An AAA is a swelling of the main blood vessel trunk in your belly: they can rupture, and when they do, people can die both quickly and frighteningly. But if you do the repair operation at your leisure, before they rupture, survival is far better. Screening and repairing has been shown to reduce mortality by around 40%, looking at the whole population, so it is a good thing.

But remember, you will operate on some people – as a preventive measure, because you picked up their aneurysm on screening – who would never have died from their aneurysm: it would have just ticked away, quietly, not rupturing. And some of the people you operate on unnecessarily (and remember there’s no crystal ball to identify these guys) will die of complications on the operating table. They only died because of your screening programme: it saves lives overall, but Fred Bloggs, loving husband of Winona Bloggs, who would have lived, remains dead, thanks to you.

That’s Vegas, you could say. But it’s tricky, and the sums are often close. For example, mammogram screening for breast cancer every two years has been estimated to prevent two deaths in 1000 women aged 50-59 over 10 years: that is good. But to do that takes 5000 screens, 242 recalls, and 64 women to have at least one biopsy. Five women will have cancer detected and treated. Again, this isn’t an argument against screening, we’re just walking through some example numbers.

Although interestingly that’s not something everybody is keen to do with screening. Researchers have studied the invitation letters sent out for screening programmes, along with the websites and pamphlets, and they have repeatedly been shown to be biased in favour of participation, and lacking in information

Where figures are given, they generally use the most dramatic and uninformative way of expressing the benefits: the “relative risk reduction” is given, the same statistical form that journalists prefer, like “a 30% reduction in deaths from breast cancer”, rather than a more informative figure like the “number needed to screen”, say, “two lives saved for every 1,000 women scanned”. Sometimes the leaflets even contain some borderline porkies, like this one from Ontario: “There has been a 26% increase in breast cancer cases in the last ten years” it said, in scary and misleading tones. This was roughly the level of overdiagnosis caused by screening, over the preceeding ten years that the screening programme itself had been operating.

These problems with clear information raise interesting questions around informed consent, although seductive letters do increase uptake, and so save lives. It’s tricky: on the one hand, you end up sounding like a red-neck who doesn’t trust the gub’mint, because screening programmes are often valuable. On the other hand, you want to be thinking this through.

And the amazing thing is, in at least one large survey of 500 people, even when presented with the harsh realities of the tests, people made what many would still think are the right decisions. 38% had experienced at least one false-positive screening test; more than 40% of these individuals described the experience as “very scary” or the “scariest time of my life.” But looking back, 98% were glad they were screened. Most wanted to know about cancer, regardless of the implications. Two thirds said they would be tested for cancer even if nothing could be done. Chin up.



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38 Responses



  1. ulysses2031 said,

    January 12, 2008 at 10:12 am

    Who the hell subbed this in the Guardian today? I read it before going to bed last night and the edited version of the last paragraph makes no sense – the second sentence has been sliced in half, losing the bit before the semicolon, which alters the meaning (and the stats) entirely.

  2. neilcam2001 said,

    January 12, 2008 at 11:45 am

    ulysses2031 – I agree. A crime has been committed. Do you think the cause may have been terminal boredom or something similar?

  3. kingshiner said,

    January 12, 2008 at 1:06 pm

    The recall letters are also unnecessarily scary for most women. According to the mammographic diagnostic criteria there are two grades of positive, one has about a 5% chance of being cancer, and the other probably is cancer. But the recall letters are usually the same. The whole risk communication literature has been ignored.

    Maybe it’s because the proportion of recalled women who show up for review is one of the common performance measures of screening programmes. Weighting this at 100% and recall anxiety among healthy women at 0% leads logically to scaring women into coming back.

    More broadly it’s often been noted that a marketing approach has been taken to promoting breast screening, rather than a health-educational one, or a public health one, and that we are turning healthy women into anxious patients-to-be

  4. greatunknown1 said,

    January 12, 2008 at 2:12 pm

    You seem to have missed out the potentially dangerous effects of ct scans in terms of allergic reactions and radiation.

    Is the radiation dose considerably lower for these specific scans than for full body scans? According to this article the risks are significant. www.cbsnews.com/stories/2004/08/31/health/webmd/main639707.shtml
    I didn’t have time to look up the relevant journal article.

  5. wheels5894 said,

    January 12, 2008 at 5:56 pm

    Of course this is ignoring one of the pressing cancers, prostate, for which we don’t have a test that is reliable are necessarily a treatment of preference either.

  6. Dr Aust said,

    January 12, 2008 at 10:15 pm

    As I understand it most radiologists – see e.g. Dr Ray’s UK radiology blog – are thoroughly opposed to no-reason-to-do-it-except-a- look-see (plus cash) screening by CT, as advertised to rich dingbats with fancy private health plans and occasionally talked up in thinly disguised “advertorials” in the media. They are anti for a range of reasons, including both the “incidentalomas” (things that turns out to be nothing but which once seen have to be investigated), and the fact that whole body CT scans deliver a dose of radiation that carries finite risks.

    In other words, not something to have unless there is a sensible reason to need one.

    Screening which can be done by far cheaper methods like ultrasound, which is how the AAA screening would be done – you can currently have the test privately for as cheap as £ 50 – and with less downside obviously has different cost-benefit calculations.

    But as Ben says, the whole issue is much more complicated than at first appears, and far less clear-cut than the silly way politicians, journalists, and some of the pressure groups play it. “Screening” sounds really good, but the upshot of talking it up incessantly may be what happens in the States, where loads of men aged 50+ have an annual PSA test (which supposedly “screens for prostate cancer”, but probably doesn’t, see last comment) and where there is something of an epidemic of older people getting regular invasive “surveillance colonoscopies” (yes, with a tube – ouch) to look for bowel cancer. Sigh. More medicalising for profit.

    Personally I shall be trying to stave off cancer, furred arteries and the rest of the nasties in 2008 by eating more fruit and veg and bicycling to work to try and lose some weight. Crikey, almost sounds like a new year’s resolution…. or possibly something an Alt therapist would charge £ 50 for “prescribing”.

  7. Robert Carnegie said,

    January 13, 2008 at 1:53 am

    As for cost, the argument seemed to be that the NHS will provide prevention for everyone and cures where necessary, but the curing will be reduced because of the prevention – surgeons probably don’t say “a stitch in time saves nine” but they could. They’ll save money when people don’t get awfully sick in the first place.

    I hope it works like that! But if it was only for economics then they shouldn’t be testing for conditions where you suddenly drop dead, because surely that’s almost the cheapest way to go in terms of NHS costs? But then if it was only economics then we wouldn’t have a public health service at all.

    It also comes to mind that screening will give everyone regular contact with the NHS, which probably is politically valuable in presenting a positive view of it… if -that- works.

    Incidentally, how long do you have to spend in an aeroplane, or in Aberdeen, to get radiation equivalent to the proposed scanning?

  8. mjs said,

    January 13, 2008 at 3:09 am

    Adding to Dr. Aust’s comment above, “no-reason-to-do-it-except-a-look-see (plus cash),” is the even more ridiculous is the suggestion of a biopsy when radiology comes back negative.

    Talk about profiteering. :P

  9. Dr Aust said,

    January 13, 2008 at 2:10 pm

    Things where you drop dead suddenly while still at a possibly working age have a potential economic cost. Given the possibility that men will soon have to be working to 67-70, then AAA screening at 65 might have some economic value. Plus we don’t know what fraction of people with AAA reach hospital and undergo emergency surgery, or perhaps end up permanently disabled and thus needing long-term care.

    It is an unpalatable fact that costs are a consideration for health strategies and treatments, especially new ones, and most topically for expensive new drugs. Modern monoclonal antibody drugs, notably the ones that prolong survival a bit in terminal disease, are the obvious battleground for this argument. An example is Avastin, at £ 20 K for a year’s treatment to prolong survival by some months in terminal cancer, esp colon cancer. It also relates to screening in a way, since it is sometimes argued that the money that would be spent on these treatments (if NICE were to approve them) would do more good put into screening (e.g. for colon cancer in the over-50s). But that argument, uderstandably, is little comfort to the person with terminal cancer and their family.

  10. Dr Syninys said,

    January 14, 2008 at 12:32 am

    “Incidentally, how long do you have to spend in an aeroplane, or in Aberdeen, to get radiation equivalent to the proposed scanning?”

    National background radiation amounts to 3 mSv a year. Aberdeen is about double that. An intercontinental flight looks like about 0.06 mSv (but varies – depends on altitude and duration).

    An abdominal CT scan is about 10 mSv.

    So, that’s 3 years up in the granite, or a whole lot of flying… 150 flights or so.

  11. Martin said,

    January 14, 2008 at 3:30 am

    Richard,

    Are you suggesting that annual CAT scans could be used by the government as justification for the building of more nuclear power stations? That’s so cynical, I’m impressed.

  12. ACH said,

    January 14, 2008 at 10:17 am

    As the current waiting times for diagnostics CT scans can exceed 18 weeks, and many hospitals have “scanner appeals” to try to buy their scanners through charitable donations, is Mr Brown now committing to a scanner for every surgery so GPs can implement screening programmes?

    /Removes tongue from cheek

  13. Dr Aust said,

    January 14, 2008 at 4:58 pm

    For AAA screening by ultrasound, you can find detailed cost-benefit calculations fairly easily online, e.g. here (NB – PDF).

    An interesting excerpt:

    The MASS (AAA screening) Trial, Cost Effectiveness.

    Professor Martin Buxton, Health Economics Research Group, Brunel University.

    Analysis of cost effectiveness was analysed at four years based on observed
    patient data and at ten years based on conservative modelling. An invitation
    and an initial screen cost £20.39p. An elective AAA operation cost £6909 and an emergency one cost £11176. After four years the screened group cost
    £98.42p per patient compared to £35.03 per patient in the control group. The
    cost per life year gained by the screening programme after four years was
    £28389. The survival advantage will continue to improve with time: the 47
    fewer AAA related death patients should return to a normal life expectancy
    after surgery, and additional deaths should be averted. After 10 years the cost
    per life year gained falls to £8000 or around £10000 per QALY (quality adjusted
    life year) gained. In comparison, NICE uses a benchmark figure of around
    £30000 per QALY as an indicator of what is likely to be acceptable to the NHS.
    Thus even at the 4 year analysis, cost effectiveness is already at or close to the
    margin of acceptability. Modelling shows that costs per QALY will fall
    considerably over time, supporting the cost effectiveness of screening and
    providing an (unusually) strong evidence base on which to recommend a
    national screening programme.

    BTW, another contribution gives the “mortality in elective (non emergency) endovascular AAA repair surgery” as 2.2% (1 in 45), see Ben’s discussion in the original article.

    The actual (ultrasound) screening test for AAA is cheaper than the breast or cervical cancer screening. The argument has been explicitly about the cost-effectiveness of the whole screening programme in terms of “cost per life gained”. The Chairman of NICE sets this out in another of the meeting papers. Interestingly the meeting, which was in March 2004, was apparently attended by “the Prime Minister’s [TB at the time, of course] …personal advisor on Health at No 10,
    Simon Stevens.”

    Given that the trials for AAA screening were completed in 2002, and the meeting discussing it was nearly 4 yrs ago, one wonders why the sudden decision to institute AAA screening now… hmmm.

    Back to the idea of sceening for anything by CT, for which there clearly seems to be no good evidence, there is an interesting comment here which quotes some useful figures.

    This last one is nice and clear on the reasons why (e.g.) screening for heart disease with CT was not actually useful. Which brings one back again to Ben’s central point – why is the discussion of this screening by politicians and the media so dim, when the real issues are repeatedly laid out in clear and reasonably simple language in the specialist press? Can they not read? Or are they just “not bothered”?

  14. CelticLeopard said,

    January 14, 2008 at 8:45 pm

    Benjamin Goldacre said,

    “Sometimes the leaflets even contain some borderline porkies, like this one from Ontario: “There has been a 26% increase in breast cancer cases in the last ten years” it said, in scary and misleading tones.”

    Dr Ben really does write a tedious load of old cobblers. It seems he has to shuffle off to Ontario to find a statement that might be a little less than kosher – or might not really be a porkie at all.

    The cancer stats website tells us that in the UK, in the last 20 years, the incidence of breast cancer has risen by 50% or so – so possibly a rise of 26% in a decade is not that far wide of the mark – for Canada. I think you’re tone is just a tad misleading Dr Ben.

  15. Fralen said,

    January 14, 2008 at 9:23 pm

    @CelticLeopard

    That quote is just one of many from a review of “borderline porkies” in screening leaflets and invitations, and the reference is even given in the text above, if you’d bothered to research the area before your tantrum.

    This slavish adherence to the nostrum of screening, and the vilification of anyone who points out a chink, is striking. No wonder people are so reluctant to speak out against the medical hegemony on it.

    www.bmj.com/cgi/content/full/332/7540/538

    BMJ 2006;332:538-541 (4 March), doi:10.1136/bmj.332.7540.538
    Content of invitations for publicly funded screening mammography

    Karsten Juhl Jørgensen, Peter C Gøtzsche,

    Pamphlets

    “There has been a 26% increase in breast cancer cases in the last ten years” [scaring and misleading—this is the level of overdiagnosis expected with screening over the 10 years this programme had been operating]—Ontario

    “Research has shown that regular screening mammograms can lower deaths in women 50 to 69 years of age by 1/3″ [the risk of dying (total mortality) is reduced by 0.1% at most]—Manitoba

  16. CelticLeopard said,

    January 15, 2008 at 7:45 am

    @Fraulein Fralen

    “That quote is just one of many from a review of “borderline porkies” in screening leaflets and invitations, and the reference is even given in the text above, if you’d bothered to research the area before your tantrum.”

    Printed in the BMJ! So that’s all right then! And yet just this week a medical editor let slip that lack of Vitamin D caused osteoporosis. (see ‘News’ section)

    “This slavish adherence to the nostrum of screening, and the vilification of anyone who points out a chink, is striking. No wonder people are so reluctant to speak out against the medical hegemony on it.”

    Wot was that all about?

    To be or not to be, that is the question. Is Dr Ben a medical hegemonist or is he not? Is he a porkie? Or is he … not very honest?

  17. BellaDonna said,

    January 15, 2008 at 12:16 pm

    i dont see how such an immensley intelligent discussion of rare event statistics could ever be described as tedious or boring and i and a group of other students are using it as a tutorial topic in the coming month with the young females among us obviousley being greatley intrested in the apparent misleading pamphlets about breast screening which we hope will be a topic to be followed up by the time we face such a choice!

  18. CelticLeopard said,

    January 15, 2008 at 12:38 pm

    @Fraulein Fralen

    “This slavish adherence to the nostrum of screening, and the vilification of anyone who points out a chink, is striking. No wonder people are so reluctant to speak out against the medical hegemony on it.”

    Wot was that pomposity about? Wot is a medical hegemonist? Is Dr Ben one?

    PS. My response to F. Fralen seems to have been frittered – the forces of censorship are in rabid response mode – or perhaps the spam fritterer is in trigger happy mood. I feel sure that Dr Ben will soon hook it out of the boiling fat.

  19. CelticLeopard said,

    January 15, 2008 at 12:46 pm

    “i dont see how such an immensley intelligent discussion of rare event statistics could ever be described as tedious or boring”

    If you’re not already snorting the belladonna … then you should be.

  20. Dr Aust said,

    January 15, 2008 at 1:59 pm

    One good way to show that the screening calculations are actually complicated – certainly useful for explaining it to students – is to say:

    “Let’s imagine we start with two groups of 1000 patients (or 10,000, depending on the prevalence – occurrence – of the underlying condition, e.g. AAA). One group will all get screened, the other group won’t. Can you work out how many deaths the stats say there will be in each group (i.e. deaths from AAA w no screening vs. peri-operative deaths if we screen and then operate). So how many lives are saved? And what does it cost roughly per live saved if we assume the following costs?”

    And so on.

    Makes a useful exercise in stats , maths and reality.

    It is a widespread view among scientists who use maths and stats, but who are not mathematicians or statisticians, that you have to put some “real” numbers in equations and calculations (even if they are example / hypothetical numbers) to make the whole thing comprehensible for the “consumer”. So with screening, seeing estimates from a mathematical model is better than no numbers at all, but trying a back-of-the-envelope calculation yourself is better still as it shows you in basic terms how the models will have been constructed.

  21. BellaDonna said,

    January 15, 2008 at 4:44 pm

    thanks for your suggestion and your insight into model-making dr oast and i will definateley be reading the discusions on this website again as they are fascinating even if some comments like those by mr leopold are a bit obscure to say the least since bella donna is a spanish phrase for beautiful woman, referring to my spanish side and absoluteley nothing to do with illicit substances!!! and i’ve got no idea what hooking people out of boiling water refers to especialley in relation to spam fritters!

  22. SamB said,

    January 15, 2008 at 5:50 pm

    I’m usually impressed with Dr Ben’s columns, but as this is an area I work in I’m a little disappointed. His evidence regarding breast screening cites three papers – all from the BMJ. Not quite “repeatedly” showing anything! There are many sources of information on screening and awareness of screening out there, from more than one journal and more than one research group. It would have been great to see a more evidence based opinion published.

  23. Ben Goldacre said,

    January 15, 2008 at 6:17 pm

    i realise that screening is a massively cherished shiny thing for a large part of the medical and political professions and that even daring to question it (or explain it) does seem to involve a threat to the, er, hegemony.

    let’s be clear. i wrote a piece explaining that screening is not always definitely a good thing, and it often involves close risk benefit analyses; and secondly that the risks and benefits of screening can be misrepresented or brushed over by those running the programs.

    i’m always very eager to hear critical discussion and if you disagree it would be great if could say something useful on those points rather than “i dont trust the organ from which your references come”.

    the discussions here have generally been very interesting in the past, i think it’s a function of more traffic that they’re going a bit downhill. it’s hard to know what to do about it, but i guess i’ll do something. the trouble is if you spam/delete dreary and distracting abuse from people like “CelticLeopard” then they get all huffy about the fact that you CENSORED their REALLY IMPORTANT point. in fact i see he has already expressed that exciting thought. even re-reading his posts to check that bored me.

  24. CelticLeopard said,

    January 15, 2008 at 6:49 pm

    “since bella donna is a spanish phrase for beautiful woman …”

    And belladonna is also the poisonous … deadly nightshade … and not such a pretty flower as you!

  25. Dr Aust said,

    January 15, 2008 at 8:22 pm

    Hate to be a killjoy, Belladonna, but “bella donna” is actually Italian, not Spanish. Woman in Spanish is “mujer”, or more politely “senora” for “lady”… although women in the aristocracy would be addressed as e.g. “Dona Elisabeta” (Dona here is a term of respect).

    BTW, in case anyone doesn’t know already, the standard line (which appears in all pharmacology textbooks) as to how deadly nightshade got the name Belladonna is as follows.

    Deadly nightshade contains a chemical called atropine, which is a blocker of receptors (and hence of nerve signals being received) in some kinds of nerve endings. This includes the nerve endings in the eye controlling the muscles that determine the diameter of your pupils. Deadly Nightshade thus became an early cosmetic, since dropping a tincture of the plant in your eye would widen your pupils, which was supposed to make a woman look more attractive… hence “bella donna”. The scientific name of the plant is Atropa belladonna.

    Sorry, I’m getting like the guys in Private Eye’s pedant’s corner… occupational hazard of spending too much time working in a University, I fear.

  26. gadgeezer said,

    January 16, 2008 at 12:18 pm

    Off-topic for NHS scanning or screening but Holford Watch has some useful comments on the advisability of home tests for diagnosing conditions such as Coeliac Disease.

    More recently, Biocard has been promoted as a form of rapid-testing for Coeliac Disease; however, although these tests have been validated, and are comparatively easy for an expert to interpret, it is not necessarily straightforward for the general consumer (see also, Update 2). It is possible for a test to have very high specificity and sensitivity when used by appropriately trained and experienced personnel but to have very different accuracy when used by the general consumer who is (presumably) seeing and using the test for the first time.

    I hadn’t realised that a home test could be approved without extensive consumer testing to establish whether or not it has the same reliability as it does when used by trained personnel. What does the MHRA do?

  27. superburger said,

    January 16, 2008 at 12:55 pm

    what’d be really interesting would be to study what would happen if all screening for breast cancer was stopped (and X number of women present with with later stages of breast cancer) but in return the money saved was spent on any combination of newer drugs, healthy living advice, more cancer research. Presumably all these increase the number of people who survive cancer.

    It would be an interesting debate if one could show that the money is better spent elsewhere and that those women who present with breast cancer that would have been picked up by screening have more chance of surviving due to the better care, or fewer women get cancer due to improved education / advice.

  28. jodyaberdein said,

    January 16, 2008 at 2:21 pm

    Re: superburger

    Although it was my understanding that the aetiology of breast cancer is somewhat a can of worms. Interestingly for example it is one of the very few illnesses that don’t obey the usual social class distribution.

  29. CelticLeopard said,

    January 16, 2008 at 3:40 pm

    “…what’d be really interesting would be to study what would happen if all screening for breast cancer was stopped … but in return the money saved was spent on any combination of newer drugs …”

    Interesting thoughts – they certainly don’t call you superburger for nothing!

    I can smell ‘bonanza’ in the air: I expect a clever (and good) scientist (like Dr Ben) will discover that a newer drug – a novel variant on the statin theme – will prevent millions of lives being lost to breast cancer – as well as that concrete cardiovascular end point that we all so dread.

    I can smell a scam coming on – and I’ll bet Dr Ben can too.

  30. manigen said,

    January 16, 2008 at 6:15 pm

    Jodyaberdein:

    That’s interesting; I didn’t know that. Do you have a reference?

    (Look at me, asking for a reference like a real scientist and that.)

  31. sideshowjim said,

    January 16, 2008 at 7:03 pm

    Re: Would a CT scan of the aorta be less radiation dose than a full body scan? Not really, cos to be effective the scan would have to be from the arch of the aorta (just below the top of the sternum) all the way to the bifurcation at L4 (just above the pelvis).

    (Guess who had their cardivascular radiography exam last week?).

    Another possible problem could be the use of contrast agent (an Iodine based goo injected into the body to help visualise blood vessels on x-ray) and allergic reactions/renal disease. Since the introduction of iso-osmolar agents, the rate of complications has dropped masively, but there’s still gonna be someone out there who doesn’t know they’re allergic to iodine, or develops CIN and ends up on dialasys or worse…

    And finally, most CT depts in big hospitals are manic production lines already, so where are the scans going to take place, and what poor sod is going to spend the rest of their life reporting thousands of near-identical C.A.P. scans???

    Me, I vote for doppler ultrasound if it’s gonna happen. And aortic aneurysm stenting is a pretty safe procedure (there’s risk in everything, yeah, but I reckon there’s less risk in a stent insertion than there is walking around with a bulging water balloon of an aorta constantly swelling in yer abdo…).

    Hope someone else can find the statistics and references for the above, cos at the moment, I’m far too knackered.

  32. jodyaberdein said,

    January 16, 2008 at 8:07 pm

    Re: 34

    ‘Breast Cancer Incidence Trends in Deprived and Affluent Scottish Women’, Brown SBF, Hole D, Cooke TG, Breast Cancer Research and Treatment, 2007, 103:233-238

    First 6 references of this paper are other studies showing the trend also. Not open access i’m afraid.

  33. Dr Aust said,

    January 16, 2008 at 9:19 pm

    I’m pretty sure all the discussions about NHS screening of 65 yo men for AAA (which is what Gordie Broun is talking about) are assuming screening by ultrasound – cost to the NHS probably around £ 25 per test.

    According to Dr Ray, who is a real radiologist and thus well clued up on these things, AAA screening and surgical repair broadly works out as “cost-viable” (i.e. cost is acceptable by comparison with other stuff NICE accepts as cost acceptable for the NHS) if mortality from AAA repair (by open surgery or stenting) is less than 5%-ish. As the mortality gets higher, the overall cost of screening per life-year saved increases, getting into the area where it is “too expensive to be cost-effective” in NICE terms.

    This therefore suggests that the viability of the screening strategy will also depend how hot-shot the UK’s vascular surgeons are (which clearly affects the peri-operative mortality)… and whether there are enough of them.

    The last figure I saw for mortality with endovascular graft AAA repair was 2-2.5%… which I guess you could say was safe-ish for a major operation usually on an older person, but still between 1 in 50 and 1 in 40 peri-operative deaths.

    A final snag with the graft (keyhole) repairs is that from what I have read all the people who have this need to get an abdominal CT scan yearly thereafter to check for leaks… so that might well add to the queue for the CT scanners, see sideshowjim’s comment above, not to mention giving people a good deal of radiation.

    So we’re back to “trade-off of different risks” again.

    Gah! All a bit too complicated really… which is why the NICE folk are important, for (at least theoretically) taking these decisions “out of the political arena” … if only it were true.

    PS For real tech-y surgery freaks with Athens passwords, more on repairing AAAs by endovascular graft here.

  34. manigen said,

    January 17, 2008 at 11:10 am

    Thanks jodyaberdein. I can’t access the article but I can at least read the abstract (tinyurl.com/284qsf).

  35. tomrees said,

    January 18, 2008 at 3:30 pm

    For a top example of how to help patients make an informed choice: statin choice

  36. tomrees said,

    January 18, 2008 at 3:31 pm

    Hmm that link again: mayoresearch.mayo.edu/mayo/research/ker_unit/upload/decision_aid_statin_generic_booklet.doc

  37. Dr Aust said,

    January 18, 2008 at 5:28 pm

    Good link there, Tom. I like the little “coloured smiley face” charts. My friends in Med Soc Sci tell me that the studies show these sort of charts are the “best performing” way of presenting risk.

    Talking of coloured dots, anyone apart from me remember the old Rail adverts with the red and black dots? “The red dosts are the trains that didn’t run on time. The black dots…”

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