Sources of bias in a DTA review

This lesson is part of an introductory series developed by Cochrane Screening & Diagnostic Test Methods Group to support authors in the production of DTA reviews. A full list of currently available or planned lessons is available here.

Assessing the methodological quality of the included studies is a crucial part of the review process. Within the Cochrane DTA Reviews, methodological quality is defined as low risk of bias and low concerns regarding the applicability of the study findings. This lesson describes the sources of bias that need to be considered in a diagnostic test accuracy review.

After using this resource, you should be able to...
  • Identify methodological flaws and explain how they may lead to bias in diagnostic accuracy studies

6.1 Sources of bias

Author information: 
Leeflang, Mariska; Davenport, Clare; Takwoingi, Yemisi; Deeks, Jon

Cite as: Leeflang MM, Davenport CF, Takwoingi Y, Deeks JJ. Sources of bias. Lesson 6.1: Cochrane Collaboration DTA Online Learning Materials. The Cochrane Collaboration, October 2014. Videocast (32 slides, 26 minutes, sound, colour). Available at <>.

Session compiled and narrated by Mariska Leeflang with technical support from Anne Walker and Paul Good, University of Birmingham. With grateful acknowledgement of the many members of the Cochrane DTA Reviews Working Group upon which the materials, in part, are based. Funded by the UK NIHR and the Cochrane Collaboration, with support from the University of Birmingham and the University of Amsterdam.