Abstract
Background This study focuses on randomised controlled trials (RCTs) of individualised homeopathic
treatment (IHT) in which the control (comparator) group was other than placebo (OTP).
Aims To determine the comparative effectiveness of IHT on health-related outcomes in adults
and children for any clinical condition that has been the subject of at least one
OTP-controlled trial. For each study, to assess the 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 2015, 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 they examined IHT as an alternative treatment (study
design Ia), adjunctively with another intervention (design Ib), or compared with a
no-intervention group (design II). For each RCT, we identified a ‘main outcome measure’
to use in meta-analysis: ‘relative effect size’ was reported as odds ratio (OR; values
>1 favouring homeopathy) or standardised mean difference (SMD; values < 0 favouring
homeopathy).
Results Eleven RCTs, representing 11 different medical conditions, were eligible for study.
Five of the RCTs (four of which in design Ib) were judged to have pragmatic study
attitude, two were explanatory, and four were equally pragmatic and explanatory. Ten
trials were rated ‘high risk of bias’ overall: one of these, a pragmatic study with
design Ib, had high risk of bias solely regarding participant blinding (a bias that
is intrinsic to such trials); the other trial was rated ‘uncertain risk of bias’ overall.
Eight trials had data that were extractable for analysis: for four heterogeneous trials
with design Ia, the pooled OR was statistically non-significant; collectively for
three clinically heterogeneous trials with design Ib, there was a statistically significant
SMD favouring adjunctive IHT; in the remaining trial of design 1a, IHT was non-inferior
to fluoxetine in the treatment of depression.
Conclusions Due to the low quality, the small number and the heterogeneity of studies, the current
data preclude a decisive conclusion about the comparative effectiveness of IHT. Generalisability
of findings is limited by the variable external validity identified overall; the most
pragmatic study attitude was associated with RCTs of adjunctive IHT. Future OTP-controlled
trials in homeopathy should aim, as far as possible, to promote both internal validity
and external validity.
Keywords
comparative effectiveness - explanatory trial - individualised homeopathic treatment
- meta-analysis - pragmatic trial - randomised controlled trial - risk of bias - systematic
review
