title: Performance of methods for meta-analysis of diagnostic test accuracy with few studies or sparse data.
abstract: Hierarchical models such as the bivariate and hierarchical summary receiver operating characteristic (HSROC) models are recommended for meta-analysis of test accuracy studies. These models are challenging to fit when there are few studies and/or sparse data (for example zero cells in contingency tables due to studies reporting 100% sensitivity or specificity); the models may not converge, or give unreliable parameter estimates. Using simulation, we investigated the performance of seven hierarchical models incorporating increasing simplifications in scenarios designed to replicate realistic situations for meta-analysis of test accuracy studies. Performance of the models was assessed in terms of estimability (percentage of meta-analyses that successfully converged and percentage where the between study correlation was estimable), bias, mean square error and coverage of the 95% confidence intervals. Our results indicate that simpler hierarchical models are valid in situations with few studies or sparse data. For synthesis of sensitivity and specificity, univariate random effects logistic regression models are appropriate when a bivariate model cannot be fitted. Alternatively, an HSROC model that assumes a symmetric SROC curve (by excluding the shape parameter) can be used if the HSROC model is the chosen meta-analytic approach. In the absence of heterogeneity, fixed effect equivalent of the models can be applied.
authors.affiliation: 1 Public Health, Epidemiology and Biostatistics, University of Birmingham, Edgbaston, Birmingham, UK.
authors.forename: Yemisi
authors.initials: Y
authors.lastname: Takwoingi
authors.affiliation: 2 School of Medicine, University of Nottingham, Nottingham, UK.
authors.forename: Boliang
authors.initials: B
authors.lastname: Guo
authors.affiliation: 3 Research Institute of Primary Care and Health Sciences, Keele University, Staffordshire, UK.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Riley
authors.affiliation: 1 Public Health, Epidemiology and Biostatistics, University of Birmingham, Edgbaston, Birmingham, UK.
authors.forename: Jonathan J
authors.initials: JJ
authors.lastname: Deeks
mesh_terms: D001064:Appendicitis / Q000000981:diagnostic imaging; D003955:Diagnostic Tests, Routine / Q000379:methods* / Q000592:standards*; D050723:Fractures, Bone / Q000000981:diagnostic imaging; D006801:Humans; D016015:Logistic Models; D015201:Meta-Analysis as Topic; D012372:ROC Curve; D021361:Scaphoid Bone / Q000000981:diagnostic imaging; D012680:Sensitivity and Specificity
keywords: Diagnostic accuracy; HSROC model; bivariate model; diagnostic odds ratio; hierarchical models; meta-analysis; random effects; sensitivity; sparse data; specificity