This review addressed a clear question supported by appropriate inclusion criteria. A limited number of relevant electronic databases were searched, it did not appear that attempts were made to identify unpublished studies and the inclusion of only English-language studies may mean that important information was missed. Data on publication bias was not reported. Appropriate methods were used to minimise reviewer errors and bias in the extraction of data, but it was unclear whether similar steps were taken in study selection.
The included studies were either cohort design of case series, and these are subject to various potential biases. The authors claimed that included studies were of moderate to good quality, but did not appear to consider the validity of included studies (without which it was not possible to know whether the quality of included trials was adequate). The authors reported that most caregivers reported improvement in symptoms following adenoidectomy although two included studies reported that less than 50% of patients improved following adenoidectomy. The forest plot presented was difficult to interpret as there was no scale and the summary estimate appeared to sit in the middle of the success line (this was not defined). Heterogeneity appeared not to have been reported or investigated. Pooling of studies in a meta-analysis may not have been appropriate given that the authors reported differences between studies in terms of study design and patient population.
Overall, this review may have been vulnerable to multiple important sources of bias and error, therefore, the authors conclusions should not be regarded as reliable.