Update on the placebo effect
In my recent exchange with Elaine regarding homeopathy, the subject of placebo effects predictably arose.
I say ‘predictably’ because it seems to be that once proponents of ‘alternative therapies’ are backed into a corner, and finally realise that their treatments are no better than placebo, the next line of defense (or is it attack?) is: “well, the placebo achieved by our modality is very valuable and shouldn’t be under-estimated”. Elaine made that very claim.
To summarise even further, here are the two critical graphs which tell the story.
In this first graph (Figure 4), we have a subjective assessment of 4 different interventions by patients suffering asthma . Notice that the placebo inhaler and sham acupunctureare just as highly rated as the ‘real’ treatment. Wow, nice work Mr. Placebo.
Now look at Figure 3. In this case, instead of asking the subjects how they assess the improvement, we measure the lung function of each – a much more objective assessment of the treatment.
Hey presto, all of as sudden, the ‘real’ intervention is dramatically better.
The clear outcome is that treatment with placebo is barely better than no treatment at all. And, as a bonus, this also shows that the placebo inhaler is better than the fake acupuncture – so the charade of magical modalities is unnecessary.
As another bonus, this study also addresses another claim made by Elaine in the dog study she cited, and also all the hoo-ha regarding Elmore Oil (too many articles to which to link – do a search on Elmore, here at rationalbrain). Even though she claims that dogs are not subject to placebo effects (an assumption which I questioned), it clearly shows the folly of relying on subjective assessments – and is the reason I suggested some sort of objective measure of whether there was any improvement in the condition.
Clearly, subjective assessments are notoriously unreliable in predicting real physiological effects, and simply ‘feeling better’ doesn’t cut it with significant illnesses.