Evidence suggests that giving honey for up to three days probably relieves cough symptoms and cough duration to a greater extent than placebo or salbutamol, while salbutamol is more effective in relieving the impact of a cough on the quality of sleep of children and their parents. Moreover, honey is more effective in reducing cough frequency, cough severity, the bothersome cough, impact of a cough on sleep for both children and parents compared with no treatment or placebo when given for one day. The findings of this review appear reliable.
Overall summary Low risk of bias in the review
All domains were considered at low concern suggesting no limitations regarding the review process.
|A. Did the interpretation of findings address all of the concerns identified in Domains 1 to 4?||Yes|
|B. Was the relevance of identified studies to the review's research question appropriately considered?||Yes|
|C. Did the reviewers avoid emphasizing results on the basis of their statistical significance?||Yes|
|Risk of bias in the review||Low|
|Number of studies||6|
|Number of participants||899|
|Last search date||12 February 2018|
|Objective||To evaluate the effectiveness of honey for acute cough in children in ambulatory settings.|
|Population||Children (aged 12 months to 18 years) with a cough caused by acute viral or bacterial upper respiratory tract infection.
Studies that included participants with a chronic cough (lasting for more than three weeks) were excluded.
|Interventions||Honey only, honey plus antibiotics|
|Comparator||Honey-based cough syrup, non-honey cough syrup, placebo, no treatment, antibiotics alone, non-honey cough syrups plus antibiotics.|
|Outcome||Primary outcomes: Duration of cough, symptomatic relief of a cough (frequency of coughs, reduction in severity and less bothersome cough).
Secondary outcomes: Improvement in quality of sleep at night for children (cough impact on sleep score), improvement in quality of sleep at night for caregiver (cough impact on sleep score), improvement in quality of life (e.g. school attendance and playing), adverse effects, improvement in appetite, cost of honey alone compared with other cough syrups.
|Study design||Randomised controlled trials|
The pooled analysis reported no significant difference between honey and dextromethorphan in the mean reduction of frequency of cough (mean difference [MD] -0.07, 95% confidence interval [CI] -1.07 to 0.94, 2 studies, n = 149 children), severity of cough (MD -0.13, 95% CI -1.25 to 0.99, 2 studies, n = 149 children), cough impact on sleep score by children (MD 0.03, 95% CI -1.12 to 1.19, 2 studies, n = 149 children) and parents (MD -0.16, 95% CI -0.84 to 0.53, 2 studies), bothersome cough (MD 0.29, 95% CI -0.56 to 1.14, 1 study, n = 69 children) and combined cough score (MD 2.32, 95% CI -1.24 to 5.88, 1 study, n = 69 participants).
One study (n = 80 children) reported that honey significantly reduced the cough frequency (MD -0.57, 95% CI -0.90 to -0.24), severity of cough (MD -0.6, 95% CI -0.94 to -0.26), cough impact on sleep score by children (MD -0.55, 95% CI -0.87 to -0.23) and parents (MD -0.48, 95% CI -0.76 to -0.20) compared with diphenhydramine. Using a 7-point Likert scale, honey significantly reduced cough frequency compared with no treatment (MD -1.05, 95% CI -1.48 to -0.62, 2 studies, n = 154 children) or placebo (MD -1.62, 95% CI -3.02 to -0.22, 2 studies n = 402 children). Moreover, a significant reduction was found in the severity of a cough, children’s sleep score, parent’s sleep score and combined symptom score in the honey group compared to no treatment group.
Giving honey for up to three days or four days was more effective in relieving cough symptoms compared with placebo or salbutamol. Beyond four days honey had no advantage over placebo in reducing cough frequency, cough severity, bothersome cough, and impact of a cough on sleep for parents and children. Using a 5-point cough scale, there was no difference between the effects of honey and bromelin mixed with honey in reducing cough frequency and severity.
There was no significant difference between honey and dextromethorphan in the incidence of nervousness, insomnia and hyperactivity (risk ratio [RR] 2.94, 95% Cl 0.74 to 11.71, 2 studies, n = 149 children), in the incidence of stomachache, nausea and vomiting (RR 4.86, 95% CI 0.24 to 97.69, 1 study, n = 69 participants) and drowsiness (RR 2.92, 95% CI 0.12 to 69.20, 1 study, n = 69 participants). Similarly, there was no significant difference between honey and diphenhydramine groups in somnolence (RR 0.14, 95% Cl 0.01 to 2.68, 1 study, n = 80 children).
Studies reported that honey significantly increased the incidence of stomach ache, nausea and vomiting when compared with placebo (RR 1.91, 95% CI 1.12 to 3.24, 2 studies, n = 402 children) and salbutamol (RR 1.74, 95% CI 1.04 to 2.92, 1 study, n = 100 children), while no significant difference was found between the intervention and comparators in the incidence of diarrhea, tachycardia and rash. Moreover, honey significantly increased the incidence of nervousness, insomnia, hyperactivity than no treatment, while no significant difference was found between the two groups in the occurrence of stomach ache, nausea and vomiting and drowsiness.
The research objective was clearly stated and appropriate inclusion criteria were defined. Studies with sample sizes of fewer than 10 per intervention were excluded and it was considered appropriate. No restrictions were reported based on sources of information.
|1.1 Did the review adhere to pre-defined objectives and eligibility criteria?||Probably yes|
|1.2 Were the eligibility criteria appropriate for the review question?||Yes|
|1.3 Were eligibility criteria unambiguous?||Probably yes|
|1.4 Were all restrictions in eligibility criteria based on study characteristics appropriate (e.g. date, sample size, study quality, outcomes measured)?||Yes|
|1.5 Were any restrictions in eligibility criteria based on sources of information appropriate (e.g. publication status or format, language, availability of data)?||Yes|
|Concerns regarding specification of study eligibility criteria||Low|
The CENTRAL part of the Cochrane Library, which includes the Cochrane Acute Respiratory Infections Group’s Specialised Register, MEDLINE, Embase, CINAHL, Web of Science and LILACS were searched for relevant studies. Moreover, the World Health Organization International Clinical Trials Registry Platform, ClinicalTrials.gov and the reference lists of all retrieved studies were searched to identify additional articles and contacted the authors of studies for unpublished data. The searches were not restricted by date, publication format, or language. Two authors were independently involved in the study selection process. Any disagreements were resolved by consensus. A good range of databases were searched. The strategies were structured appropriately, combining relevant free-text and subject indexing terms.
|2.1 Did the search include an appropriate range of databases/electronic sources for published and unpublished reports?||Yes|
|2.2 Were methods additional to database searching used to identify relevant reports?||Yes|
|2.3 Were the terms and structure of the search strategy likely to retrieve as many eligible studies as possible?||Yes|
|2.4 Were restrictions based on date, publication format, or language appropriate?||Probably yes|
|2.5 Were efforts made to minimise error in selection of studies?||Yes|
|Concerns regarding methods used to identify and/or select studies||Low|
Data extraction was performed by one author and checked by another author for accuracy and completeness. Any disagreements were resolved by consensus. Sufficient study characteristics appear to have been extracted to allow interpretation of results. Relevant study results appear to have been extracted. The methodological quality of included studies was assessed using the Cochrane ’Risk of bias’ tool. Two authors were involved in the assessment of the risk of bias.
|3.1 Were efforts made to minimise error in data collection?||Probably yes|
|3.2 Were sufficient study characteristics considered for both review authors and readers to be able to interpret the results?||Yes|
|3.3 Were all relevant study results collected for use in the synthesis?||Probably yes|
|3.4 Was risk of bias (or methodological quality) formally assessed using appropriate criteria?||Yes|
|3.5 Were efforts made to minimise error in risk of bias assessment?||Yes|
|Concerns regarding methods used to collect data and appraise studies||Low|
The synthesis appeared to include all relevant studies. The method of analysis was explained and appeared appropriate. There was evidence of heterogeneity among the studies. However, appropriate attempts were not possible to explore the possible sources of heterogeneity due to the inclusion of a limited number of studies in each comparison (2-3 studies). Publication bias assessment or sensitivity analysis was also not possible due to the same reason. The quality of individual studies was considered in the synthesis.
|4.1 Did the synthesis include all studies that it should?||Probably yes|
|4.2 Were all pre-defined analyses reported or departures explained?||Probably yes|
|4.3 Was the synthesis appropriate given the degree of similarity in the research questions, study designs and outcomes across included studies?||Probably yes|
|4.4 Was between-study variation minimal or addressed in the synthesis?||Probably yes|
|4.5 Were the findings robust, e.g. as demonstrated through funnel plot or sensitivity analyses?||Probably yes|
|4.6 Were biases in primary studies minimal or addressed in the synthesis?||Yes|
|Concerns regarding synthesis and findings||Low|