Diagnostic test accuracy network meta-analysis methods: a scoping review and empirical assessment

Objectives: To (a) identify methodological and application papers reporting a model developed specifically for diagnostic test accuracy network meta-analysis (DTA-NMA) or a hierarchical meta-regression method for comparing at least three index tests; (b) review and summarize the characteristics of the methods and the application papers; and (c) compare DTA-NMA and hierarchical meta-regression methods empirically. Study Design and Setting: We performed a scoping review and searched major databases until March 3rd, 2021. We assessed the characteristics of the identified methods, conducted a descriptive analysis of characteristics of the application articles, and applied the DTA-NMA and meta-regression methods to the available data. Results: We included 49 articles (plus one companion report), of which nine were methodological (describing 11 DTA-NMA methods) and 40 were application papers (data available for 32 DTA-NMAs). Our results showed a steep increase in recent years in DTA-NMA publications. DTA-NMA models may lead to different results. Although sensitivity estimates were comparable between meta-regression and DTA-NMA models, specificity estimates were higher in meta-regression. Conclusion: The choice of a DTA-NMA model will depend on the available data, including the use of different thresholds for test positivity, different study designs, and software familiarity. Selection between the methods may impact on the NMA results, especially for specificity.