Transcript hsw – homeopathy

How Science Works
Homeopathy
Structure
1.
2.
3.
4.
5.
Choosing Treatments
Medical Trials
Homeopathy
How Science Works
Ethics (optional)
Choosing Treatments
• Take a few minutes to discuss with your
neighbours what treatments you have used,
or those you have seen on TV or read about,
for poor health
Choosing Treatments
• Three ‘volunteers’ with lab coats to spread out
in the room.
• Students are to take a ‘condition’ card and
take turns asking the ‘doctor’ what treatment
they would suggest.
Choosing Treatments
• Students, in small groups, match the
‘conditions’ with ‘treatments’.
• There may be disagreement – the aim is to
promote discussion.
• Summarise with idea that in each case,
treatments are chosen for greatest
effectiveness.
Choosing Treatments - Extension
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Which treatments should be offered (if any) in
these cases:
Facial scarring
Mild diabetes which the sufferer fails to
control by diet and exercise
Chronic back pain that is not life-threatening
A condition which we cannot cure but where
life expectancy can be extended
Medical Trials
• New drugs may be based on traditional herbs,
newly discovered compounds or be
modifications of current treatments.
• New drugs are tested for safety and their
effects on animals before humans try them.
• This provides hints towards safe, effective
dosage for us.
Medical Trials
• We could simply give a patient a drug, record
if they get better and then decide if it works or
not.
• How well would this work?
• What are the problems?
Medical Trials
• For a fair test (and valid results) we need to
make sure only one factor – the drug or
treatment itself – changes.
• In practice, this means that we assign patients
randomly to one of two or three groups andm
if at all possible, keep their treatment secret
until after the trial.
Medical Trials
• One group will receive the treatment being
tested, for example a new drug.
• Another group receive a ‘placebo’ which does
not contain the drug but appears identical.
• Often a third group will receive the ‘next best’
drug or the current recommended treatment.
Medical Trials
• Patients do not know if they are receiving the
tested treatment because the placebo effect
can produce a result when someone thinks
they are receiving treatment.
• Medical staff should not know which
treatment particular patients are receiving to
avoid any deliberate or accidental bias.
Medical Trials
• Sometimes there is no placebo group because
it would be unethical to withhold treatment
for a medical condition.
• Sometimes trials are cut short if it becomes
clear that the treatment is much better or
worse than expected. (This happened with
AZT, used to treat HIV and AIDS, in the ’80s)
Medical Trials
Randomised (patients are randomly assigned
to different treatments) Control (treatments
are compared to something else) trials or RCTs
which are double-blind (neither patients nor
doctors know what they are receiving until
after) are the best way we have found to see
the true effects of a treatment.
Medical Trials
• The more patients there are in the study, the
more reliable the results are.
• If we measure the dependant variable (e.g.
blood pressure) more carefully or in more
detail, we say results are more precise.
• The more things we measure, the more likely
it is that one of them will appear to show a
change that is in fact random.
Homeopathy
• The Law of Similars
– A chemical which causes a symptom will also cure
that symptom
• The Law of Infinitesimals
– Diluting the chemical makes it more effective
• The Law of Succussion
– Shaking the diluted liquid increases effectiveness
Experiment and Observe
Hypothesis
Analyse and Discuss
Data
How Science Works
“It doesn’t matter how beautiful your theory
is, it doesn’t matter how smart you are. If it
doesn’t agree with experiment, it’s wrong”
Richard Feynman
How Science Works
• Scientists have collected a lot of data over
centuries of observation.
• We use the words accurate, precise, valid and
reliable (among others) to describe the data.
They are relative, not absolute terms.
• Scientists publish their data and methods in
detail. Other scientists suggest improvements
or carry out their own experiments.