The High-Quality Randomised Controlled Trials of Homeopathic Treatment, as Defined by Systematic Review and Meta-Analysis

Background: In our programme of systematic reviews, assessment of internal validity (IV) and model validity (MV) of randomised controlled trials (RCTs) of individualised and non-individualised homeopathic treatment (IHT and NIHT respectively) has enabled us to rate placebo-controlled RCTs as high, moderate or low study quality. Assessments of IV and external validity (degree of pragmatic or explanatory study attitude) have recently been achieved for other-than-placebo (OTP)-controlled RCTs of IHT and NIHT.

Aims: To examine the totality of clinical evidence in homeopathic treatment across the four RCT designs, with particular focus on high-quality studies and their meta-analysis.

Methods: The 90 RCTs that were included in our four prior meta-analyses comprised the data-set. A study was rated ‘high quality’ if it had high IV and acceptable MV (placebo-controlled trials) or if it had high IV and suitable pragmatic or explanatory attitude (OTP-controlled trials). One main outcome measure per RCT was identified and used in sensitivity analysis based on high study quality.

Results: The quality rating was ‘high’ for 5 RCTs, ‘moderate’ for 31, and ‘low’ for 54. Four of the high-quality trials were placebo-controlled (3 IHT, 1 NIHT): Jacobs et al (Pediatrics 1994; childhood diarrhoea); Jacobs et al (Pediatr Infect Dis J 2001; otitis media); Bell et al (Rheumatology 2004; fibromyalgia); Colau et al (Drugs RD 2012; menopausal syndrome). One was OTP-controlled (a pragmatic study of IHT): Peckham et al (Homeopathy 2014; irritable bowel syndrome, IBS). Analysis of the high-quality trials identified a treatment effect favouring homeopathy over placebo (odds ratio = 2.05; 95% confidence interval, 1.33 to 3.15; n = 4; p = 0.001); there was no significant difference between homeopathy and usual care for IBS.

Conclusions: There are 5 high-quality RCTs of homeopathic treatment, containing evidence of a distinct effect of homeopathic medicines compared with placebo. Additional high-quality RCT research in homeopathy is necessary to enable more complete and decisive data interpretation.

Keywords: Individualised, non-individualised, randomised controlled trials, systematic review, meta-analysis