The QUADAS-C (Quality Assessment of Diagnostic Accuracy Studies–Comparative) tool was developed to assess risk of bias in studies that compare the accuracy of diagnostic tests with one another. Thi... Comparative diagnostic test accuracy studies assess and compare the accuracy of 2 or more tests in the same study. Although these studies have the potential to yield reliable evidence regarding com...

Background: Conduct problems are common, disabling and costly. The prognosis for children with conduct problems is poor, with outcomes in adulthood including criminal behaviour, alcoholism, drug abuse, domestic violence, child abuse and a range of psychiatric disorders. There has been a rapid expansion of group based parent-training programmes for the treatment of children with conduct problems in a number of countries over the past 10 years. Existing reviews of parent training have methodological limitations such as inclusion of non-randomised studies, the absence of investigation for heterogeneity prior to meta-analysis or failure to report confidence intervals. The objective of the current study was to systematically review randomised controlled trials of parenting programmes for the treatment of children with conduct problems. Methods: Standard systematic review methods were followed including duplicate inclusion decisions, data extraction and quality assessment. Twenty electronic databases from the fields of medicine, psychology, social science and education were comprehensively searched for RCTs and systematic reviews to February 2006. Inclusion criteria were: randomised controlled trial; of structured, repeatable parenting programmes; for parents/carers of children up to the age of 18 with a conduct problem; and at least one measure of child behaviour. Meta-analysis and qualitative synthesis were used to summarise included studies. Results: 57 RCTs were included. Studies were small with an average group size of 21. Meta-analyses using both parent (SMD -0.67; 95% CI: -0.91, -0.42) and independent (SMD -0.44; 95% CI: -0.66, -0.23) reports of outcome showed significant differences favouring the intervention group. There was insufficient evidence to determine the relative effectiveness of different approaches to delivering parenting programmes. Conclusion: Parenting programmes are an effective treatment for children with conduct problems. The relative effectiveness of different parenting programmes requires further research.

Assessing risk of bias and applicability is critical in diagnostic test accuracy reviews to ensure valid, relevant findings that can inform decision making and policy. This article introduces QUADAS-3, an updated version of the widely used QUADAS-2 tool that was developed in response to the latest evidence, feedback from users of QUADAS-2, and comprehensive piloting. The QUADAS-3 tool comprises 6 phases: 1) define the systematic review synthesis question, 2) define the ideal test accuracy trial for each synthesis question, 3) draw a flow diagram, 4) identify estimates of accuracy for assessment, 5) assess risk of bias and applicability, and 6) make an overall judgment. Risk of bias is assessed across 4 domains: Participants, Index Test, Target Condition, and Analysis. The first 3 domains are also assessed in terms of concerns regarding applicability to the synthesis question. Signaling questions are included to help judge risk of bias. The QUADAS-3 tool incorporates several changes compared with the previous version (QUADAS-2) which will ideally improve its validity, usability, and usefulness. Key changes from QUADAS-2 include introduction of the concept of an ideal test accuracy trial, assessment at the estimate level rather than the study level, replacement of the "Flow and Timing" domain with a new "Analysis" domain, introduction of sections on the rationale for judgments, and formal introduction of overall judgment of risk of bias and concerns regarding applicability. Some changes to domains and signaling questions have also been made.

Quality assessment tools for primary studies of test accuracy are relatively well developed, although only one is validated (QUADAS), but very little work has been done to develop tools to quality-assess studies evaluating the impact of diagnostic testing on management of patients (diagnostic or therapeutic yield). The recent draft NICE Guide to the Methods of Technology Appraisal (2007) suggests QUADAS "as a useful starting point for appraising studies that evaluate the sensitivity and specificity of a test" but does not mention how to quality assess diagnostic or therapeutic yield studies, in particular diagnostic before-after studies. In the context of undertaking a rapid systematic review of structural neuroimaging in psychosis for NICE, we describe the modifications that we made to QUADAS, our experience of this in practice and in relation to published theory on diagnostic or therapeutic yield studies.