Table 1.
The systematic review by Linde et al.[3] and its subsequent re-analyses.
| Reference | Included trials (number) | Total patient number | Assessment of methodological quality | Meta-analysis | Overall conclusion* | Comment |
|---|---|---|---|---|---|---|
| Linde (1997) [3] | All double-blind and/or randomized placebo-controlled trials of any clinical condition (n = 186) | 2588 | Yes | Of 89 trials which could be submitted to meta-analysis: OR = 2.45; of 26 ‘good quality trials’: OR = 1.66 (both in favour of homeopathy) | Clinical effects of homeopathy are not completely due to placebo | Review was criticised for 1) including different remedies 2) including different conditions 3) including nonrandomized trials |
| Ernst (1998) [4] | All studies from Linde et al.[3] which received 90 (of 100) points in at least 1 of the 2 quality ratings, using highly dilute remedies, following the principles of ‘classical’° homeopathy (n = 5) | 587 | Yes | OR = 1.0 (no evidence in favour of homeopathy) | Homeopathic remedies are associated with the same clinical effects as placebo | This analysis specifically tested the efficacy of highly diluted remedies (other remedies could still work via conventional pharmaceutical effects) |
| Linde (1998) [5] | All trials from Linde et al.[3] which tested ‘classical’° homeopathic remedies against placebo, no treatment or another treatment (n = 32) | 1778 | Yes | 19 placebo-controlled trials were submitted to meta-analysis; OR = 1.62; however, when this analysis was restricted to the methodologically best trials the effect was no longer significant | Individualized homeopathy has an effect over placebo; the evidence, however, is not convincing | Not all of the included trials were randomized and many had other serious methodological weaknesses |
| Linde (1999) [6] | All trials from Linde et al.[3] which could be submitted to meta-analysis (n = 89) | n.d.p. | Yes | The mean OR of the best studies was not in favour of homeopathy | There was clear evidence that studies with better methodological quality tended to yield less positive results | The authors felt that these results ‘weaken the findings of [their] original meta-analysis’ |
| Morrison (2000) [7] | 26 trials classified by Linde et al.[3] as high quality (n = 26) | n.d.p. | Yes | None | No significant trend was seen when correlating security of randomization and trial result | Large multicentre trials were recommended |
| Ernst (2000) [8] | All trials from Linde et al.[3] that received quality ratings between 1 and 4 on the Jadad score (n = 77) | n.d.p. | Yes | None | There is a . . . strong linear correlation between OR and Jadad score (n = 0.97, P < 0.05); homeopathic remedies are, in fact, placebos | Extrapolation from this correlation implies that the most rigorous studies yield an effect size of zero |
| Sterne (2001) [9] | 89 trials of Linde et al.[3] review compared with 89 trials of allopathic medicines | n.d.p. | Yes | Strong evidence for publication bias causing a false positive result in favour of homeopathy | When adjusting high quality trials [of homeopathy] for publication bias, the OR changed from 0.52 to 1.19 but remained unchanged for allopathy | Paper probably not peer-reviewed, adjusting for bias nullified the effect of homeopathy but not for allopathy |
RCT = randomized clinical trial, OR = odds ratio,
*
= verbatim quotes, n.d.p. = no details provided.
°
Classical homeopathy = approach where remedies are individualized according to patient characteristics deemed important by homeopaths.