title: Meta-analysis of diagnostic accuracy studies in mental health.
abstract: OBJECTIVE
  To explain methods for data synthesis of evidence from diagnostic test accuracy (DTA) studies, and to illustrate different types of analyses that may be performed in a DTA systematic review.
  
  
  METHODS
  We described properties of meta-analytic methods for quantitative synthesis of evidence. We used a DTA review comparing the accuracy of three screening questionnaires for bipolar disorder to illustrate application of the methods for each type of analysis.
  
  
  RESULTS
  The discriminatory ability of a test is commonly expressed in terms of sensitivity (proportion of those with the condition who test positive) and specificity (proportion of those without the condition who test negative). There is a trade-off between sensitivity and specificity, as an increasing threshold for defining test positivity will decrease sensitivity and increase specificity. Methods recommended for meta-analysis of DTA studies --such as the bivariate or hierarchical summary receiver operating characteristic (HSROC) model --jointly summarise sensitivity and specificity while taking into account this threshold effect, as well as allowing for between study differences in test performance beyond what would be expected by chance. The bivariate model focuses on estimation of a summary sensitivity and specificity at a common threshold while the HSROC model focuses on the estimation of a summary curve from studies that have used different thresholds.
  
  
  CONCLUSIONS
  Meta-analyses of diagnostic accuracy studies can provide answers to important clinical questions. We hope this article will provide clinicians with sufficient understanding of the terminology and methods to aid interpretation of systematic reviews and facilitate better patient care.
authors.affiliation: Public Health, Epidemiology and Biostatistics, University of Birmingham, Birmingham, UK.
authors.forename: Yemisi
authors.initials: Y
authors.lastname: Takwoingi
authors.affiliation: Research Institute for Primary Care and Health Sciences, Keele University, Staffordshire, UK.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Riley
authors.affiliation: Public Health, Epidemiology and Biostatistics, University of Birmingham, Birmingham, UK.
authors.forename: Jonathan J
authors.initials: JJ
authors.lastname: Deeks
mesh_terms: D001714:Bipolar Disorder / Q000175:diagnosis; D006801:Humans; D001523:Mental Disorders / Q000175:diagnosis*; D015201:Meta-Analysis as Topic; D011581:Psychological Tests; D012107:Research Design / Q000706:statistics & numerical data*; D012196:Review Literature as Topic; D012680:Sensitivity and Specificity; D009626:Terminology as Topic