‘The Archers’ and Health Economics – Mini Mental State Exam
This post is a bit outside of my usual areas of interest, so there’s bits of background that I’d really appreciate comments on. It does give the chance for a nice introduction to some interesting areas of psychological testing & health economics, and it’s even somewhat topical, so here goes.
I’m a regular listener to ‘The Archers’, a long-running radio soap opera on BBC Radio 4 ‘An everyday tale of simple country folk’. I’m maybe 40 years younger than most of the demographic, but blame that one on Mum.
An ongoing storyline is that one of the characters, ‘Jack Woolley’, has dementia, probably Alzheimer’s. In Monday’s episode, he was given what appears to be the Mini Mental State Exam ( http://www.patient.co.uk/showdoc/40000152/ ), a psychological test used to measure the progress of dementia. The examining doctor also talked about his medication, though without specifying what Jack was taking. Episode here if you are interested: http://www.bbc.co.uk/radio4/archers/catch/this_week.shtml?mon
Obviously, the full 10-minute test wasn’t on air in a 12-minute episode, but parts were. Now, I’m not trained to work clinically with patients, or to administer the MMSE, but I’ve had a go at scoring what there is.
Orientation – Jack needed a bit of prompting to say where he was, but he eventually came out with ‘Hospital, in Borchester, England’ – 3 points of 5?
Registration – here Jack had to remember 3 words (‘Apple, picture, table). This took him 2 attempts, first managing two words, then all three. 3 points of 3?
Attention & calculation – Jack had to spell ‘WORLD’ backwards (a working memory task – more on that in my next post), but he only got as far as ‘D’ – is this 1 point of 5?
I’m not too sure on the scoring for these tasks, & we didn’t get an overall numerical score, only ‘in line with what we would expect’. But messing around with percentages, and assuming that Jack did equally well on all areas of the test, Jack would have scored 16 out of 30. This would put him just over the border from ‘moderate’ into ‘severe impairment’.
Whilst throughout the episode Jack is somewhat confused & disorientated at times, rather obviously has problems, and is ‘wandering’ problematically at times, he is able to talk, interact with people, do basic self-care for himself, & isn’t nearly at the worst dementia can do to people. I have worked in a few elderly care homes and watched my grandfather go steadily downhill, and at the worst dementia can leave people completely unable to communicate, having no idea where they are, not recognising close family, doubly incontinent, etc. It’s horrible. The problem with using the Mini Mental State Exam alone to score the progress of dementia is that there’s a long way to get worse from a score of ‘severe impairment’, and even a score of 0 can cover a fair range of problems. It doesn’t adequately differentiate between people who aren’t ‘in the middle’.
This effect of not adequately differentiating between people at the bottom of a measuring scale is called by psychologists a ‘floor effect’. Imagine if you wanted to test the fitness of a group of ‘couch potatoes’, and did so by making them all run a mile. Now imagine you stopped timing after 7 minutes. Most of the group would not have got to the end in that time. Even though there would be an important difference in fitness between those who took 10 mins & those who took 30, your test would group them all together as having the lowest possible score – this is a ‘floor effect’, because the test is too hard.
You can also get ‘ceiling effects’ – for this imagine you have a group of PhD physicists, and gave them all a lower tier GCSE Maths paper. Even though some of the physicists would be cleverer than others, they would probably all still get the highest possible score of a C, because the test is too easy. The MMSE also has ceiling effects, because most people will need to loose a fair bit of function before they start having problems with the simple tasks on it.
NICE (National Institute for Health and Clinical Excellence) basically decide whether new treatments provide enough benefit for their costs to be prescribed on the NHS (oversimplifying massively here, sorry). They look at Quality Adjusted Life Years, QALYs, which are a measure of years of life gained from a treatment, adjusted by the quality of the life gained – so if with one intervention you live for an extra 10 years in severe pain, it might be more worthwhile to have an intervention which will give you an extra 8 years of pain-free life. The way they do the adjustments is fascinating, but perhaps for a different post. More on QALYs here: http://www.library.nhs.uk/healthmanagement/ViewResource.aspx?resID=123545 [there’s a brilliant BMJ article somewhere written by someone from NICE explaining this in more detail, but I can’t seem to find it – anyone?]
QALYs are rationing, although the government don’t really like to say so. NICE decide how much a QALY is worth, and (at least in theory) try to spend the same amount per QALY across every illness. Last I heard, a year of good quality life was worth ~£30-35 0000, though that’s probably a bit out of date & an oversimplification. More than that, and the money could be better spent elsewhere – which is why all the fuss about prescribing things like Herceptin, ‘cos they cost too much per QALY. (I’ll scrimp on the general ethical debates around QALYs – try here: http://www.ethics-network.org.uk/ethical-issues/resource-allocation/ethical-considerations for some points).
Alzheimer’s disease isn’t curable. There are some drugs which might be able to slow its progress. I’ll skip the details though again they are rather cool (see here for starters: http://www.alzheimers.org.uk/site/scripts/documents_info.php?documentID=147 ). However, there has been a lot of argument over whether they can be prescribed on the NHS, as they cost a lot per QALY. NICE decided that only those with ‘moderate’ dementia should get acetylcholinesterase inhibitors. This is because people with moderate dementia show the biggest change on the MMSE when given the drugs. This could be because the drugs work best in moderate dementia, or it could be because of the floor & ceiling effects in the MMSE – people who have ‘mild’ dementia quickly get up to the top score and can’t go further, or people with severe dementia get a lot better but still don’t manage to score much more than bottom on the MMSE.
There’s two big issues here really. Firstly, is the MMSE really measuring improvements properly, or is lack of measurable improvement just a task artefact? That’s the sort of thing which make psychologists very interested. Is the MMSE a valid measure of changes in early & severe dementia?
The other issue is much bigger and more complicated, and it’s around what & how we pay for healthcare. Dementia is a complicated one. Because people with dementia will eventually need very expensive residential care, it might be worth spending more on drugs to save on care. But then you get into arguments about who pays for care – in England then ‘social’ care, help with things like eating & toileting, is means-tested so does not always come from NHS budgets. There’s also issues around how much we should pay for health overall, the balance between preventative measures and treatments, how worthwhile is it to develop expensive new drugs when most people can’t access the ones we’ve got – it’s a lot to think about.
Anyway, I’m surprised & slightly disappointed that Jack is still getting his medication on the NHS, & despite being rather well-off seems to be coming up for social help too. ‘The Archers’ has a special place in British life, and I suspect that were Jack not to be getting help then questions would be asked in Parliament. At least it would get people thinking and talking about this sort of thing – it’s an uncomfortable thing to think about but too important to be swept under the carpet because of that.
Comments welcome, I’m sure some of you will know much more about this than me.