Abstract
Introduction This study focuses on randomised controlled trials (RCTs) of non-individualised homeopathic
treatment (NIHT) in which the control (comparator) group was other than placebo (OTP).
Objectives To determine the comparative effectiveness of NIHT on health-related outcomes in
adults and children for any given condition that has been the subject of at least
one OTP-controlled trial. For each study, to assess its risk of bias and to determine
whether its study attitude was predominantly ‘pragmatic’ or ‘explanatory’.
Methods Systematic review. For each eligible trial, published in the peer-reviewed literature
up to the end of 2016, we assessed its risk of bias (internal validity) using the
seven-domain Cochrane tool, and its relative pragmatic or explanatory attitude (external
validity) using the 10-domain PRECIS tool. We grouped RCTs by whether these examined IHT as alternative treatment (study
design 1a), adjunctively with another intervention (design 1b), or compared with no
intervention (design 2). RCTs were sub-categorised as superiority trials or equivalence/non-inferiority
trials. For each RCT, we designated a single ‘main outcome measure’ to use in meta-analysis:
‘effect size’ was reported as odds ratio (OR; values > 1 favouring homeopathy) or
standardised mean difference (SMD; values < 0 favouring homeopathy).
Results Seventeen RCTs, representing 15 different medical conditions, were eligible for study.
Three of the trials were more pragmatic than explanatory, two were more explanatory
than pragmatic, and 12 were equally pragmatic and explanatory. Fourteen trials were
rated ‘high risk of bias’ overall; the other three trials were rated ‘uncertain risk
of bias’ overall. Ten trials had data that were extractable for analysis. Significant
heterogeneity undermined the planned meta-analyses or their meaningful interpretation.
For the three equivalence or non-inferiority trials with extractable data, the small,
non-significant, pooled effect size (SMD = 0.08; p = 0.46) was consistent with a conclusion that NIHT did not differ from treatment
by a comparator (Ginkgo biloba or betahistine) for vertigo or (cromolyn sodium) for seasonal allergic rhinitis.
Conclusions The current data preclude a decisive conclusion about the comparative effectiveness
of NIHT. Generalisability of findings is restricted by the limited external validity
identified overall. The highest intrinsic quality was observed in the equivalence
and non-inferiority trials of NIHT.
Keywords
comparative effectiveness - explanatory trial - non-individualised homeopathic treatment
- meta-analysis - pragmatic trial - randomised controlled trial - risk of bias - systematic
review
