The review question and inclusion criteria were clear. Little information was provided about participants in the included studies, which made it difficult to assess how generalisable the results of the review were. A number of relevant databases were searched for studies in English, French, Dutch, German or Portuguese; therefore, language bias could not be ruled out. It was unclear whether efforts were made to locate unpublished studies; some studies may have been missed. All stages of the review process were undertaken in duplicate, which reduced potential for error and bias.
Seemingly appropriate criteria were used to assess the quality of included studies, but measures and criteria used were not reported in detail for each study. Appropriate methods were used for the meta-analyses. Heterogeneity was assessed. The findings of the meta-analyses that compared ibuprofen and paracetamol were driven by one large study; small numbers of studies were compared to placebo for either of the treatment regimens. A narrative synthesis was appropriate to use where it was inappropriate to pool studies.
This was generally a well-conducted review and the authors’ conclusions are likely to be reliable, although (as acknowledged by the authors) some caution may be merited based on comparisons with placebo from a few small studies.