Considerations for understanding systematic reviews and network meta-analyses in neurological applications: a review and critique in chronic migraine

Network meta-analysis (NMA) is an evidence synthesis approach that combines direct and indirect evidence to estimate the relative effects of multiple treatments, including comparisons for which head-to-head clinical trial evidence is unavailable. Although methodological and reporting guidelines for NMAs and their accompanying systematic reviews are well established, we posit that such guidelines are not always followed in practice. In this narrative perspective, we provide a concise overview of key guidelines for conducting and reporting systematic reviews and NMAs and critically appraise two recent NMAs in chronic migraine that deviate from these recommendations. While a broader systematic review was not undertaken and the identified shortcomings of these two NMAs may not be representative of the wider NMA landscape in the neurology literature, we nevertheless encourage readers of published systematic reviews and NMAs to carefully evaluate the underlying data and methods used in evidence synthesis and to interpret findings with appropriate caution, favoring analyses conducted in accordance with rigorous best practice standards.