Etat des lieux de l'homéopathie en Belgique - KCE

KCE Reports 154 Homeopathy 19
2.3.3.3 Vaccine uptake
There is conflicting evidence regarding the relationship between CAM (complementary
& alternative medicine) use and vaccine uptake and the role of different CAM providers
in this.
Jones et al found that, overall, there were no statistically significant odds ratios between
use of any of the CAM therapies (including homeopathy) and receiving either flu,
pneumococcal, or both vaccines but could not exclude it either 55, 56 . Zuzak et al found a
significant relation between CAM use and vaccine refusal but found that this was mainly
due to patient preferences and not induced by the CAM provider. He found that 43 %
of users of homeopathy refused at least some basic vaccines but numbers specific for
homeopathy were too small to find statistically significant results. Schonberger et al
found that parental belief in homeopathy was a risk factor for non uptake of measles
vaccination 57 . On the other hand, Stokley et al 58 found that CAM users had a higher
vaccination coverage, even after adjusting for education and income level.
2.3.4 Discussion and conclusions
2.3.4.1 Main findings
We did not find compelling evidence that homeopathy works for any single condition.
Shang et al 59 pooled 110 studies on homeopathy and came to the similar conclusion that
the findings are compatible with the notion that the clinical effects of homeopathy are
placebo effects. We did not include this study however because we consider it
inappropriate to pool all treatments for all conditions, given the very diverse nature of
the conditions that are treated, with a diverse range of symptoms in which placebo
effects may play a role to a varying degree. The study was in contradiction with a study
by Linde et al 60 doing a similar pooling and who found a pooled effect incompatible with
placebo but where no proof for any single condition could be found.
We did not find evidence of side effects and only anecdotal evidence for patient delay
caused by homeopaths. Also the relationship between CAM use and vaccine uptake
seems complex and we did not find compelling evidence for the accusation that
homeopaths have a harmful influence on the health seeking behavior of the patient. It is
possible that homeopathy has a beneficial effect on drug consumption of the patient.
More research on these issues would be useful here.
The quality of the reviews was variable but in general acceptable. A lot of the studies
included in the reviews were of low quality. The well conducted large trials did not
show an effect.
2.3.4.2 Placebo effect.
The question of placebo effects is complex and one can ask if making the distinction
placebo-‘real’ effects is always that useful in practice.
The power of placebo effects and what is sometimes called ‘enhanced placebo effects’ is
amongst others demonstrated for acupuncture and spinal manipulations 61 .
There is an increased attention in the medical literature for the usefulness and
importance of placebo effects in clinical practice, and the role it plays when addressing
pain, like its role in enhancing the effect of analgesics that have a proven effect beyond
placebo, the role of provider knowledge and beliefs when administering pain killers. 62 .
Hróbjartsson A & Gøtzsche 63 did a meta-analysis and meta-regression to measure the
effect of placebos and found that it was heterogeneous and that the effect depended on
the type and credibility of the placebo. For instance, placebos involving a form of
physical contact were more effective when used for pain relief.
However, measuring the effect of placebo is complicated due to differential drop out,
poor acceptability of ‘waiting list type’ control groups and coping mechanism of suffering
patients such as self medication or other forms of health seeking behavior.