Angry Doctor

Monday, September 18, 2006

How NOT to argue for Alternative Medicine 2

Dr Han, in his comment in one of my previous posts, brought my attention to this BBC news article.

Well, the BBC has previously been acccused of 'misleading viewers in an attempt to exaggerate the power of alternative medicine', so let's look at the studies mentioned in the news article ourselves.

angry doc knows nothing about cost-effectiveness analysis, so he shall look only at the trial.

Also, angry doc doesn't have the BMJ, so he can only rely on the abstract to form his initial opinion. (He will try to get his hands on a copy of the article though.)

angry doc notes, for a start, that the study involved 289 patients with 'persistent non-specific low back pain' of whom 241 were randomised (why were the other 48 excluded from the study?).

Of the 241 included in the study, 160 were assigned to the acupuncture arm, and 81 to the 'usual care' arm. angry doc wonders why the split wasn't an even fifty-fifty.

Of these subjects, only 213 remained in the study at 12 months, and only 182 remained at 24 months. In other words, 11% of the subjects dropped out of the study after the first year, and 24% of the subjects have dropped out of the study after two years.

Did these 11% and 24% come predominantly from the acupuncture arm, or the 'usual care' arm?

Why *did* they drop out?


What does angry doc make of the study?

Well, for a start we have 289 people with 'persistent' back pain. This means that they are likely to have undergone 'usual care' to begin with and are unlikely to benefit from a further round of 'usual care'.

The study utilised the SF-36 pain scale, which is a subjective scoring system. Fair enough for a study studying pain and for double-blind trials, but given that the study involved patients who had gone through 'usual care', one would expect those in the 'usual care' arm to report a higher pain score. They were probably reporting a high pain score under 'usual care' to begin with, so why should they suddenly change their tune when they *know* they are being given more of the same? Wouldn't you feel like an idiot if you told them you felt better with the same treatment?

Of the initial 289 patients referred for the study, 17% were not included in the study. Of the 241 who were enrolled in the study, one out of four did not complete the study. In fact, of the 289 patients referred for the study, only 63% completed it. More than one in three did not complete the study.

angry doc suspects that the percentage of drop-out from the 'usual care' arm is higher than that from the acupuncture arm. After all, if you have been under 'usual care' for a long time, would you be happy to stay in a study where you have 'more of the same' for another two years? Given the choice, angry doc would prefer the acupuncture arm himself. Perhaps that accounts for the uneven split into the two arms?


The authors themselves concluded that '[w]eak evidence was found of an effect of acupuncture on persistent non-specific low back pain at 12 months, but stronger evidence of a small benefit at 24 months'.

Note also that the patients' '[f]unctional disability was not improved', so while they were said they were *feeling* better, they weren't *doing* better.

Given that the study seems to be loaded in favour of acupuncture, angry doc remains unimpressed with the results.

Added: Found this summary which gave more information on the paper:

1. The 2-to-1 ratio was to ensure sufficient number of subjects in the acupuncture arm.

2. Two patients dropped out from the acupuncture arm immediately. Sixteen others dropped out later.

This means 41 patients dropped out from the 'usual care' arm, or a 50% attrition rate.

Added 2: angry doc managed to read the study. Some further thoughts:

1. The subjects were a heterogenous group, with complaints of back pain ranging from 4 to 48 weeks. 4% of those referred actually got better even before being enrolled into the trial.

2. The study did not study acupuncture per se, but a 'package of care' which included 'individualising of treatment', 'practitioner's skills at developing good therapeutic relationships', and 'process benefits such as protected time and attention from the practitioner'.

One may argue that acupuncture in practice comes in a 'package of care', but that begs the question of whether acupuncture is a vital part of the care, and if so by what degree.

Can one, for example, have an individualised acupuncture treatment with a practitioner who is not skilled at developing good therapeutic relationship, and have good outcome?

Or with 'usual care' with a practitioner skilled at developing good therapeutic relationships, with the process benefits of protected time and attention from the practitioner?

Having read the paper, angry doc gets the feeling that the study was not a scientific inquiry into the efficacy of acupuncture as a mode of treatment, but an attempt to use the scientific method to argue for cost-effectiveness of acupuncture as a treatment, with the object that it will result in more funding from the NHS.

angry doc would once again like to thank Dr Han for bringing the study to his attention.

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3 Comments:

  • Hi, yes, I have just read the BMJ article:

    http://bmj.bmjjournals.com/cgi/content/abstract/bmj.38878.907361.7Cv1

    And note the conclusion:

    "Conclusions Weak evidence was found of an effect of acupuncture on persistent non-specific low back pain at 12 months, but stronger evidence of a small benefit at 24 months. Referral to a qualified traditional acupuncturist for a short course of treatment seems safe and acceptable to patients with low back pain."

    Hardly rapturous approval. I think this is saying no more than placebo in a polite sort of way.


    John

    By Blogger Dr John Crippen, At September 20, 2006 12:00 am  

  • I could download a pdf from the website, maybe due to not being in the UK.

    The imbalance in the treatment arm numbers was so they had enough patients to allow comparisons between acupuncturists. Withdrawals prior to randomisation were due mainly to refusal (28), back pain resolved (12), outside age range (5) and 3 others, all perfectly reasonable. Withdrawals during the trial were similar in each group.

    The main difficulty is blinding, as there was none. Thos with acupuncture must have known they were getting more treatment, and this is known to improve outcomes. A better design would give the non-acupunture group an ineffective treatment in addition to usual care, but this is not easy to achieve, especially in an ethical way.

    By Anonymous Anonymous, At September 20, 2006 6:38 pm  

  • Got it! Thanks.

    I'll post my further thoughts on the main post itself.

    By Blogger angry doc, At September 20, 2006 6:53 pm  

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