Homeopathy is a type of complementary and alternative medicine. It is based on two main ideas: that substances that may cause illness or symptoms in a healthy person can, in very small doses, treat those symptoms in a person who is unwell; and that molecules in highly diluted substances retain a memory of the original substance. Due to a lack of solid evidence, the benefits and risks of oral homeopathic medicines for preventing and treating acute respiratory tract infections (ARTIs) in children are unclear. Studies of lower quality in design and reporting often suggest a possible benefit for oral homeopathic medicines, but studies of higher quality do not find benefit.
What are respiratory tract infections?
Respiratory infections are commonly caused by viruses, especially colds and influenza, though some lung and ear infections are caused by bacteria. It may be difficult to tell these infections apart, and sometimes they occur together. Most such infections improve without treatment, but sometimes symptoms persist after the initial infection has gone. Treatment is therefore aimed at relieving symptoms.
Why is this important in children?
Children have on average three to six respiratory tract infections each year. Although most are mild and treatable, they are sometimes acute (serious, swift, or sudden onset) respiratory tract infections that may require hospital treatment, but very rarely result in death.
How are ARTIs treated?
Antibiotic medicines taken orally (by mouth/swallowed, usually in the form of a tablet, pill, lozenge, or liquid) are often prescribed for ARTIs, even though they are ineffective against viruses. Homeopathic medicines may treat ARTIs with few side effects, but their effectiveness and safety has not been well researched.
What did we want to find out?
We wanted to know whether homeopathic medicines help children with ARTIs. We were interested in the effect of homeopathic medicines compared to placebo (a 'dummy' treatment that does not contain any medicine but looks or tastes identical to the medicine being tested) or to usual care therapies for ARTIs.
We were also interested in the effect of homeopathic medicines on improvement in the severity or symptoms of infection, the need for antibiotics, duration of illness (that would affect days off school or days off work for parents), symptom reappearance, and any medicine adverse effects.
What did we do?
We searched for randomised controlled trials (studies where people are randomly assigned to one of two or more treatment groups) that investigated whether oral homeopathic medicines, compared to placebo or usual care ARTI therapies, were effective in the prevention or treatment of ARTIs in children aged up to 16 years. We compared and summarised the results of the studies, and rated our confidence in the evidence based on factors such as study methods and number of participants.
What did we find?
We found 11 studies involving 1813 children (5 studies for prevention and 6 studies for treatment of ARTIs). All studies investigated upper respiratory tract (from the nose to the windpipe (trachea)) infections, but one study combined reporting of upper and lower respiratory tract (from the windpipe to the lungs and pleura (membranes covering the lungs)) infections, so the numbers of children with upper or lower ARTIs is unknown.
In the treatment or prevention of ARTIs in children, homeopathic medicines showed little or no beneficial effects, whether individualised by a trained homeopath or a standard commercially available homeopathic therapy (11 studies, 1813 children).
Where results could be combined, there was little or no difference between groups for short-term cure (2 studies, 155 participants) or long-term cure (2 studies, 155 participants), but the evidence is very uncertain. There may be little or no difference between groups for prevention of ARTI (3 studies, 735 participants).
There was no important difference between homeopathy and placebo groups for parents' time off work, antibiotic use, or adverse events. We are unsure about the safety of homeopathic medicines because data on adverse events were poorly reported. Overall, the findings of this review do not support the use of homeopathic medicinal products for ARTIs in children.
What are the limitations of the evidence?
We have little confidence in the evidence because the studies involved only small numbers of children, used different types of homeopathic medicines for various ARTIs, contained numerous biases, and failed to report information about important outcomes. Further research could provide results that differ from the results of this review.
How up-to-date is this evidence?
The evidence is current to 16 March 2022.
Pooling of five prevention and six treatment studies did not show any consistent benefit of homeopathic medicinal products compared to placebo on ARTI recurrence or cure rates in children. We assessed the certainty of the evidence as low to very low for the majority of outcomes. We found no evidence to support the efficacy of homeopathic medicinal products for ARTIs in children. Adverse events were poorly reported, and we could not draw conclusions regarding safety.
Acute respiratory tract infections (ARTIs) are common and may lead to complications. Most children experience between three and six ARTIs annually. Although most infections are self-limiting, symptoms can be distressing. Many treatments are used to control symptoms and shorten illness duration. Most treatments have minimal benefit and may lead to adverse events. Oral homeopathic medicinal products could play a role in childhood ARTI management if evidence for their effectiveness is established. This is an update of a review first published in 2018.
To assess the effectiveness and safety of oral homeopathic medicinal products compared with placebo or conventional therapy to prevent and treat ARTIs in children.
We searched CENTRAL (2022, Issue 3), including the Cochrane Acute Respiratory Infections Specialised Register, MEDLINE (1946 to 16 March 2022), Embase (2010 to 16 March 2022), CINAHL (1981 to 16 March 2022), AMED (1985 to 16 March 2022), CAMbase (searched 16 March 2022), and British Homeopathic Library (searched 26 June 2013 - no longer operating). We also searched the WHO ICTRP and ClinicalTrials.gov (16 March 2022), checked references, and contacted study authors to identify additional studies.
We included double-blind randomised controlled trials (RCTs) or double-blind cluster-RCTs comparing oral homeopathy medicinal products with identical placebo or self-selected conventional treatments to prevent or treat ARTIs in children aged 0 to 16 years.
We used standard methodological procedures expected by Cochrane.
In this 2022 update, we identified three new RCTs involving 251 children, for a total of 11 included RCTs with 1813 children receiving oral homeopathic medicinal products or a control treatment (placebo or conventional treatment) for ARTIs. All studies focused on upper respiratory tract infections (URTIs), with only one study including some lower respiratory tract infections (LRTIs). Six treatment studies examined the effect on URTI recovery, and five studies investigated the effect on preventing URTIs after one to four months of treatment. Two treatment and three prevention studies involved homeopaths individualising treatment. The other studies used predetermined, non-individualised treatments. All studies involved highly diluted homeopathic medicinal products, with dilutions ranging from 1 x 10-4 to 1 x 10-200.
We identified several limitations to the included studies, in particular methodological inconsistencies and high attrition rates, failure to conduct intention-to-treat analysis, selective reporting, and apparent protocol deviations. We assessed three studies as at high risk of bias in at least one domain, and many studies had additional domains with unclear risk of bias. Four studies received funding from homeopathy manufacturers; one study support from a non-government organisation; two studies government support; one study was co-sponsored by a university; and three studies did not report funding support.
Methodological inconsistencies and significant clinical and statistical heterogeneity precluded robust quantitative meta-analysis. Only four outcomes were common to more than one study and could be combined for analysis. Odds ratios (OR) were generally small with wide confidence intervals (CI), and the contributing studies found conflicting effects, so there was little certainty that the efficacy of the intervention could be ascertained. All studies assessed as at low risk of bias showed no benefit from oral homeopathic medicinal products, whilst trials at unclear or high risk of bias reported beneficial effects.
For the comparison of individualised homeopathy versus placebo or usual care for the prevention of ARTIs, two trials reported on disease severity; due to heterogeneity the data were not combined, but neither study demonstrated a clinically significant difference. We combined data from two trials for the outcome need for antibiotics (OR 0.79, 95% CI 0.35 to 1.76; low-certainty evidence).
For the comparison of non-individualised homeopathy versus placebo or usual care for the prevention of ARTIs, only the outcome recurrence of ARTI was reported by more than one trial; data from three studies were combined for this outcome (OR 0.60, 95% CI 0.21 to 1.72; low-certainty evidence).
For the comparison of both individualised and non-individualised homeopathy versus placebo or usual care for the treatment of ARTIs, two studies provided data on short-term cure (OR 1.31, 95% CI 0.09 to 19.54) and long-term cure (OR 1.01, 95% CI 0.10 to 9.96; very low-certainty evidence). The studies demonstrated an opposite direction of effect for both outcomes.
Six studies reported on disease severity but were not combined as they used different scoring systems and scales. Three studies reported adverse events (OR 0.79, 95% CI 0.16 to 4.03; low-certainty evidence).