The literature is not restricted, however, to simple criticisms of homeopathy, but contains numerous studies and meta-analyses, including a repeat of the original 1997 infamous one published in The Lancet. The conclusions range from the simple "there isn't evidence to support any results are anything other than placebo" to more concerning findings. Specifically, the researchers publishing studies on the efficacy of alternative medicine don't just poorly construct their experiments, they also do not report (and perhaps actively deceive in doing so) important information relating to what they did and what their findings were:
"The use of complementary and alternative medicine (CAM) in Canada and the United States is prevalent. Parallel to this trend, there is a large body of rigorous literature on CAM ...But current research suggests that reporting quality of CAM trials is poor...These results suggest that a large proportion of CAM trials have poor reporting quality, resulting in difficulties in assessment of internal and external validity. Reporting quality may vary across different types of complementary therapies, with herbal medicine trials being somewhat better reported compared with homeopathy and acupuncture trials. However, some research states that trials of herbal medicine still fail to report information necessary to judge internal validity, external validity, and reproducibility Our results indicate that RCTs of herbal medicine interventions frequently do not report important characteristics of the intervention. Specifically, we found that these trials fail to report more than 60% of the information suggested in recently published reporting guidelines for RCTs [randomized controlled trials] of herbal interventions...The results of the present study suggest that RCTs of herbal medicine interventions fail to report important aspects of the intervention to a greater degree than has been found previously."
Gagnier, J. J., Moher, D., Boon, H., Beyene, J., & Bombardier, C. (2011). Randomized controlled trials of herbal interventions underreport important details of the intervention. Journal of clinical epidemiology, 64(7), 760-769.
"Based on the summary score of the checklist used in this work, we found that overall approximately two-thirds of the RCTs evaluated suffered from a number of major methodological problems that seriously limit their usefulness in determining the effect of the CAM intervention on the PRO [patient-reported outcomes] endpoints under investigation."
Efficace, F., Horneber, M., Lejeune, S., Van Dam, F., Leering, S., Rottmann, M., & Aaronson, N. K. (2006). Methodological quality of patient-reported outcome research was low in complementary and alternative medicine in oncology. Journal of clinical epidemiology, 59(12), 1257.
"We found that reports of RCTs of herbal medicine interventions reported less than half of the necessary information in their published reports...less than one third of trials adequately reported information regarding whether those administering the intervention were blind (28%); the methods for implementation (22%) and generation (21%) of the random allocation sequence; whether there were protocol deviations (18%), blinding of outcome assessors (14%), and any methods to determine the success of blinding (<2%). Not reporting this information leaves the reader guessing as to their completion. This information must be reported for the reader to adequately assess the influence of bias on the results of the trial."
Gagnier, J. J., DeMelo, J., Boon, H., Rochon, P., & Bombardier, C. (2006). Quality of reporting of randomized controlled trials of herbal medicine interventions. The American Journal of Medicine, 119(9), 800-e1.
"Four RCTs compared homeopathic medicines to placebo; one assessing individually-prescribed medicines and three assessing formulaic medicines. None demonstrated a statistically significant difference in outcomes between groups, although two showed a trend towards better outcomes in the homeopathy treatment groups. Three of the RCTs demonstrated significant improvements from baseline in measures of sleep quality in both the homeopathy and placebo groups. All four RCTs involved small patient numbers and were underpowered, and were poorly reported with high patient withdrawal rates. The use of a crossover design in one study made the results difficult to interpret. An uncontrolled cohort study was also identified; this reported statistically significant improvements from baseline for the group receiving formulaic homeopathic medicine...
A large number of case studies of treatment by a homeopath for insomnia were also identified. However, the lack of control groups, lack of consistent outcome measures, and tendency to report only positive results (reporting bias) means that it is not possible to definitively ascribe the reported improvements to the treatment."
Cooper, K. L., & Relton, C. (2010). Homeopathy for insomnia: a systematic review of research evidence. Sleep Medicine Reviews, 14(5), 329-337.
"Approximately 150 randomized clinical trials of homeopathy have been published to date, and their results are far from uniform....As new studies emerged, so did further (n=11) systematic reviews; collectively, their results fail to show that homeopathic remedies are more than placebos. The most recent systematic review in this area focuses on homeopathy for depression and concludes that the evidence is limited ‘due to lack of clinical trials of high quality’.
Systematic reviews are prone to publication bias and poor methodological quality of the primary data. It is conceivable that the homeopathic community does not publish all studies that generated negative findings. One early and spectacular (but little-known) example of this phenomenon is Nazi Germany's attempt to evaluate homeopathy on a grand scale. Leading German scientists of the time were charged with testing homeopathy at a basic science level in addition to through clinical research. The results, which survived the war but later seem to have disappeared in the hands of homeopaths, were apparently wholly negative. The frequently poor quality of clinical trials constitutes a further problem. Re-analyzing their own data, Linde et al. concluded that ‘there was clear evidence that studies with better methodological quality tended to yield less positive results’ "
Ernst, E. (2005). Is homeopathy a clinically valuable approach?. Trends in pharmacological sciences, 26(11), 547-548.
"Because CAM historically has lacked the established research infrastructure of conventional medicine, it has attracted relatively few high calibre researchers. As a consequence, the field suffers from a general lack of research expertise (potentiated and perpetuated by lack of funds). This, in turn, has resulted in a situation where many of the relatively few scientific investigations in CAM are methodologically weak, or outright flawed. Yet flawed science is unlikely to be ethical: expressed in the words of the BMA, “Studies which are unscientific are also unethical”.
Ernst, E., Cohen, M. H., & Stone, J. (2004). Ethical problems arising in evidence based complementary and alternative medicine. Journal of medical ethics, 30(2), 156-159.
"The use of complementary and alternative medicine (CAM) in Canada and the United States is prevalent. Parallel to this trend, there is a large body of rigorous literature on CAM ...But current research suggests that reporting quality of CAM trials is poor...These results suggest that a large proportion of CAM trials have poor reporting quality, resulting in difficulties in assessment of internal and external validity. Reporting quality may vary across different types of complementary therapies, with herbal medicine trials being somewhat better reported compared with homeopathy and acupuncture trials. However, some research states that trials of herbal medicine still fail to report information necessary to judge internal validity, external validity, and reproducibility Our results indicate that RCTs of herbal medicine interventions frequently do not report important characteristics of the intervention. Specifically, we found that these trials fail to report more than 60% of the information suggested in recently published reporting guidelines for RCTs [randomized controlled trials] of herbal interventions...The results of the present study suggest that RCTs of herbal medicine interventions fail to report important aspects of the intervention to a greater degree than has been found previously."
Gagnier, J. J., Moher, D., Boon, H., Beyene, J., & Bombardier, C. (2011). Randomized controlled trials of herbal interventions underreport important details of the intervention. Journal of clinical epidemiology, 64(7), 760-769.
"Based on the summary score of the checklist used in this work, we found that overall approximately two-thirds of the RCTs evaluated suffered from a number of major methodological problems that seriously limit their usefulness in determining the effect of the CAM intervention on the PRO [patient-reported outcomes] endpoints under investigation."
Efficace, F., Horneber, M., Lejeune, S., Van Dam, F., Leering, S., Rottmann, M., & Aaronson, N. K. (2006). Methodological quality of patient-reported outcome research was low in complementary and alternative medicine in oncology. Journal of clinical epidemiology, 59(12), 1257.
"We found that reports of RCTs of herbal medicine interventions reported less than half of the necessary information in their published reports...less than one third of trials adequately reported information regarding whether those administering the intervention were blind (28%); the methods for implementation (22%) and generation (21%) of the random allocation sequence; whether there were protocol deviations (18%), blinding of outcome assessors (14%), and any methods to determine the success of blinding (<2%). Not reporting this information leaves the reader guessing as to their completion. This information must be reported for the reader to adequately assess the influence of bias on the results of the trial."
Gagnier, J. J., DeMelo, J., Boon, H., Rochon, P., & Bombardier, C. (2006). Quality of reporting of randomized controlled trials of herbal medicine interventions. The American Journal of Medicine, 119(9), 800-e1.
"Four RCTs compared homeopathic medicines to placebo; one assessing individually-prescribed medicines and three assessing formulaic medicines. None demonstrated a statistically significant difference in outcomes between groups, although two showed a trend towards better outcomes in the homeopathy treatment groups. Three of the RCTs demonstrated significant improvements from baseline in measures of sleep quality in both the homeopathy and placebo groups. All four RCTs involved small patient numbers and were underpowered, and were poorly reported with high patient withdrawal rates. The use of a crossover design in one study made the results difficult to interpret. An uncontrolled cohort study was also identified; this reported statistically significant improvements from baseline for the group receiving formulaic homeopathic medicine...
A large number of case studies of treatment by a homeopath for insomnia were also identified. However, the lack of control groups, lack of consistent outcome measures, and tendency to report only positive results (reporting bias) means that it is not possible to definitively ascribe the reported improvements to the treatment."
Cooper, K. L., & Relton, C. (2010). Homeopathy for insomnia: a systematic review of research evidence. Sleep Medicine Reviews, 14(5), 329-337.
"Approximately 150 randomized clinical trials of homeopathy have been published to date, and their results are far from uniform....As new studies emerged, so did further (n=11) systematic reviews; collectively, their results fail to show that homeopathic remedies are more than placebos. The most recent systematic review in this area focuses on homeopathy for depression and concludes that the evidence is limited ‘due to lack of clinical trials of high quality’.
Systematic reviews are prone to publication bias and poor methodological quality of the primary data. It is conceivable that the homeopathic community does not publish all studies that generated negative findings. One early and spectacular (but little-known) example of this phenomenon is Nazi Germany's attempt to evaluate homeopathy on a grand scale. Leading German scientists of the time were charged with testing homeopathy at a basic science level in addition to through clinical research. The results, which survived the war but later seem to have disappeared in the hands of homeopaths, were apparently wholly negative. The frequently poor quality of clinical trials constitutes a further problem. Re-analyzing their own data, Linde et al. concluded that ‘there was clear evidence that studies with better methodological quality tended to yield less positive results’ "
Ernst, E. (2005). Is homeopathy a clinically valuable approach?. Trends in pharmacological sciences, 26(11), 547-548.
"Because CAM historically has lacked the established research infrastructure of conventional medicine, it has attracted relatively few high calibre researchers. As a consequence, the field suffers from a general lack of research expertise (potentiated and perpetuated by lack of funds). This, in turn, has resulted in a situation where many of the relatively few scientific investigations in CAM are methodologically weak, or outright flawed. Yet flawed science is unlikely to be ethical: expressed in the words of the BMA, “Studies which are unscientific are also unethical”.
Ernst, E., Cohen, M. H., & Stone, J. (2004). Ethical problems arising in evidence based complementary and alternative medicine. Journal of medical ethics, 30(2), 156-159.