Cold and Flu Symptoms

H J Hamre et al. (2023) · Systematic reviews

This systematic review examined six earlier meta-analyses (statistical pooling studies) of placebo-controlled randomized trials of homeopathy for any health condition in humans, asking whether homeopathy shows an effect beyond placebo. Homeopathy is built on drug provings (recording symptoms in healthy people), the principle that a substance causing a symptom pattern is used to treat a similar one, and potentization, which means serial dilution with vigorous shaking. Because the six meta-analyses, published between 1997 and 2017, used different methods and reached different conclusions, the authors reviewed them together under a published protocol and judged their risk of bias and the certainty of the overall evidence. The authors searched eight databases plus a private collection and contacted experts, identifying 16 reports covering six meta-analyses, with searches running to December 2020 and an update to April 2023. Two reviewers screened and extracted data independently. The meta-analyses together covered 310 trials or trial comparisons (182 distinct trials published between 1943 and 2014), most often on respiratory conditions such as allergic rhinitis and influenza. Each meta-analysis was rated for risk of bias with ROBIS, and the combined evidence was graded with a GRADE-based approach. All five meta-analyses with reported pooled estimates found a significant effect favouring homeopathy across all trials, for example an odds ratio of 2.45 (95% CI 2.05-2.93) across 89 trials in the 1997 analysis and a standardized mean difference of 0.33 (0.21-0.44) across 54 non-individualised trials in 2017. When only high-quality trials were kept, three of four analyses stayed significant, but the 2017 analysis did not (SMD 0.18, -0.09 to 0.46, 3 trials). Only 6-29% of trials met each analysis's high-quality criteria. Three analyses showed significant heterogeneity and funnel plot asymmetry, a pattern that can signal publication or small-study bias; individualised homeopathy showed neither. Two analyses that combined quality and trial-size restrictions found no significant difference from placebo. Three meta-analyses were rated low and three high risk of bias. The authors rated evidence certainty as high for individualised homeopathy and moderate for the other categories. The authors conclude that the data do not support the hypothesis of no difference from placebo and that placebo-controlled evidence gives no justification for regulatory action against homeopathy. The review only covers trials already in six meta-analyses, so trials after 2011 (individualised) and 2014 (non-individualised) are missing. It also reports no indication-specific results, and its use of GRADE tested whether any effect exists rather than how large it is. The authors recommend updating the individualised homeopathy analysis and studying specific non-individualised treatments for specific conditions.

Monira Alwhaibi et al. (2017) · Evidence-based complementary and alternative medicine : eCAM

This cross-sectional survey of 178 mothers of young children in the Central Appalachian Region of the United States explored how many use herbal remedies and which factors are linked to that use. Herbal remedies are plant-based products taken for health purposes, and they are the most common form of complementary and alternative medicine (CAM, health approaches used alongside or instead of conventional care) among American adults. The authors framed the work with the Comprehensive Model of Information Seeking, which holds that a person's background, past experiences, mood and beliefs shape where information is sought and, in turn, whether action follows, here the use of herbal remedies. The participants were women aged 18 or older with at least one child under three years of age, living in Central Appalachia and mostly in West Virginia, with a mean age of 31.3 years. They were recruited through social media groups, listserv emails, daycares and physician's offices, and completed an online survey. One item asked whether any herbal remedy had been used in the past six months, with follow-ups on which remedy and which condition. Two new five-point scales captured how often six information sources were used and how strongly herbal remedies were believed to be safe and effective. One-third of the women (33.5%) reported using herbal remedies in the past six months. Fenugreek was the most widely used remedy (35.1%), followed by honey (8.8%), chamomile (5.3%) and ginger (5.3%). The main reasons were stimulating or increasing breast milk production (38.6%) and treating cold or flu symptoms (26.3%). Women with the highest information seeking scores had 3.61 times the odds of using herbal remedies compared with those with the lowest (95% CI 1.433-9.77), meaning that more active information seeking went with more use. Women with the highest belief in herbal safety and efficacy had 4.02 times the odds (95% CI 1.468-9.57). Part-time or unemployed women had 2.98 times the odds of full-time employed women (95% CI 1.05-8.47), while education, income and Appalachian identity showed no association. The internet was the most frequently used information source (mean 3.2 out of 5). The authors conclude that herbal remedy use is common in this region and propose that public health efforts and communication from health care providers could raise awareness of the safety and efficacy of herbal remedies. The survey recorded use and beliefs only; it did not test whether any remedy worked, and safety was not assessed. Limitations include a sample drawn mostly from West Virginia, self-selection in an internet-based survey, self-reported answers open to recall bias, and no data on whether use was regular or occasional. The authors call for further research, including qualitative work, on what health information women seek.