Update: This blog post and the resources mentioned in it are now combined and organised as two files to download: hsw – homeopathy (scheme and resources as pdf) and hsw – homeopathy (accompanying powerpoint). Hope they’re useful – if so please let me know!
How Science Works: Homeopathy
In the UK – and worldwide – there are many competing interests in the field of healthcare. Hopefully students would agree that people should choose – or have provided for them, for example by the NHS – treatments that work. Considering how scientists find out which treatments work well and which ones don’t seems to me to be both interesting and relevant. This post has been inspired by the recent 10:23 campaign and is intended mainly for 14-16 year old students. It seems particularly relevant as it is apparently World Homeopathy Awareness Week. It’s vaguely matched to the GCSE syllabus my school uses, AQA A Core Science, specifically section 11.3 of B1a: Human Biology. I’ve produced a powerpoint which may be useful, in whole or in part: hsw – homeopathy (saved as pptx)
1 Choosing Treatments (mainly discussion-based lesson)
Starter: Students to produce bullet point list of medical treatments (perhaps linked to examples of specific conditions). Treatment card sort could be used here for inspiration, or role play where six students are issued white coats and others are given cards of medical conditions and have to ask what treatments might be suggested.
- When there is a choice of treatments, who chooses and why?
- Can students explain what is involved in therapies listed on treatment card sort? They could be divided into categories, possibly including ‘medical’ or ‘conventional’ vs ‘alternative’.
- How could we test which are effective and which are not? What do we mean by effective?
Plenary: Summarise that we want effective treatments and for an organisation like the NHS we want the most cost-effective ones. This provides an opportunity to consider that a limited amount of money is available and so some treatments will not be considered ‘cost-effective’. QALYs could feature here (explanation at NICE) for able/older students. This also could be a great opportunity to discuss the wide variety of careers in healthcare that are not doctors and pharmacists.
2 Medical Trials (content-based)
Starter: How do we find out if a treatment is effective? Hopefully students will make suggestions showing they are aware that to be scientific, we want:
- valid data in a fair trial (only one factor affects results)
- accurate results (reflects true situation)
- precise numbers (how much better? how many people are helped? how many lives saved/years added to life expectancy?)
- reliable, repeatable results (large number in trial, to account for random variables, spontaneous remission etc)
Main: Scientific trials compare the treatment being tested with, usually, the closest alternative and a placebo or sham treatment. Explain why patients may benefit from a placebo treatment for some conditions. Challenge students to explain why this needs to be (1) randomly allocated and (2) double-blinded. Discuss the difficulty in providing a convincing placebo to, for example, physiotherapy or acupuncture. Provide notes on useful clinical trials, which include the different stages of testing before patients are asked to volunteer.
Plenary: If it has been shown to be effective, it should no longer be considered ‘alternative’ medicine. Give examples of herbal treatments which have ‘inspired’ drugs and how, in reverse, trials and results showing dangers or ineffectiveness have caused drugs and treatments to be discontinued.
3 Homeopathy (research lesson)
Starter: State ‘three laws’ of homeopathy (listed at: http://www.1023.org.uk/what-is-homeopathy.php and on my powerpoint) and leave on board.
Main: Ask students, singly or in pairs, to investigate the scientific evidence for or against one of the laws. Ideally there should be duplication and they should be able to add their comments, evidence and so on to one of three posters or boards spread around the room (Post-it notes work well for this as they must be brief, but can write at their desk/from text book/in front of computer screen and then transfer it to a central point). Those investigating the ‘law of infinitessimals/dilutions should be encouraged to do the maths regarding Avagadro’s number. A brief series of questions for each law might help to direct students’ thinking.
Printable: homeopathy laws prompts as pdf
Plenary: Gather around board(s) or posters – what does the evidence say and where does it come from?
4 How Science Works (content/explanation)
Starter: Feynman quote and hypothesis/experiment/data/explanation cycle (both on powerpoint).
Main: Science should be about evidence, not reputations. Scientific ideas do change and are refined over time. However, we would need very convincing evidence for homeopathy working better than placebo before we could claim it contradicted so much of modern science. The problem is not, as homeopaths claim, a lack of evidence, but plentiful evidence of a lack of effect. Systematic reviews e.g. Cochrane could be discussed here. Set of ‘research’ cards could be issued and students asked to discuss them. (This will be here as soon as I can get it sorted – contributions welcome.)
Plenary: Ethical questions to answer (this could easily be a separate lesson).
- Homeopathy shows benefits consistent with the placebo effect for some conditions. Should it be available and if so, who should pay?
- Homeopathy has been shown to offer no help in conditions not influenced by placebo effect, e.g. infectious diseases such as HIV and malaria. How should we deal with homeopaths who claim to be able to treat these conditions?
- People treated by homeopaths tend to delay seeking medical advice, which may in some conditions be dangerous. Some homeopaths also advise their clients against treatments shown to be very effective such as childhood immunisations. How can this risk to public health be managed?
These four – or five – lessons offer, I think, a fairly interesting mini-project which could reinforce the ‘How Science Works’ aspect of GCSE as well as fitting in to Biology. It would be easy to modify this for other alternative treatments, or indeed other interventions (Omega-3 and Brain Gym spring to mind, as I have been a fan of Ben’s Bad Science column for some years) which students could research themselves. A few years back a school student in the USA, for example, investigated therapeutic touch quite convincingly.