Homeopathic medicinal products for preventing and treating acute respiratory tract infections in children.

BACKGROUND: 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.

OBJECTIVES: To assess the effectiveness and safety of oral homeopathic medicinal products compared with placebo or conventional therapy to prevent and treat ARTIs in children.

SEARCH METHODS: 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.

SELECTION CRITERIA: 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.

DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane.

MAIN RESULTS: 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).

AUTHORS' CONCLUSIONS: 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.