Despite research investment and a growing body of diverse evidence there has been no comprehensive review and grading of evidence for public health emergency preparedness and response practices comparable to those in medicine and other public health fields. The National Academies of Sciences, Engineering, and Medicine convened an ad hoc committee…

Qualitative comparative analysis (QCA) is a hybrid method designed to bridge the gap between qualitative and quantitative research in a case-sensitive approach that considers each case holistically as a complex configuration of conditions and outcomes. QCA allows for multiple conjunctural causation, implying that it is often a combination of…

Reviewing complex interventions is challenging because they include many elements that can interact dynamically in a nonlinear manner. A systems perspective offers a way of thinking to help understand complex issues, but its application in evidence synthesis is not established. The aim of this project was to understand how and why systems…

Systematic reviews and meta-analyses are essential for drawing conclusions regarding etiologic associations between exposures or interventions and health outcomes. Observational studies comprise a substantive source of the evidence base. One major threat to their validity is residual confounding, which may occur when component studies adjust for…

Contextual factors such as cultural values and traditions impact on implementation processes of healthcare interventions. It is one of the reasons why local stakeholders may decide to role out a programme differently from how it has originally been developed or described in scientific literature. This can result in different but most likely more…

In narrative synthesis of evidence, it can be the case that the only quantitative measures available concerning the efficacy of an intervention is the direction of the effect, that is, whether it is positive or negative. In such situations, the sign test has been proposed in the literature and in recent Cochrane guidelines as a way to test whether…

Background: Network meta-analysis (NMA) of survival data with a multidimensional treatment effect has been introduced as an alternative to NMA based on the proportional hazards assumption. However, these flexible models have some limitations, such as the use of an approximate likelihood based on discrete hazards, rather than a likelihood for…

Randomized clinical trials underpin evidence-based clinical practice, but flaws in their conduct may lead to biased estimates of intervention effects and hence invalid treatment recommendations. The main approach to the empirical study of bias is to collate a number of meta-analyses and, within each, compare the results of trials with and without…

Background: This study describes an approach for the use of a specific type of qualitative evidence synthesis in the matrix approach, a mixed studies reviewing method. The matrix approach compares quantitative and qualitative data on the review level by juxtaposing concrete recommendations from the qualitative evidence synthesis against…

Introduction: Rating the quality of a body of evidence is an increasingly common component of research syntheses on intervention effectiveness. This study sought to identify and examine existing systems for rating the quality of a body of evidence on the effectiveness of health and social interventions. Methods: We used a multicomponent search…

This paper critically explores how survey and routinely collected data could aid in assessing the generalisability of public health evidence. We propose developing approaches that could be employed in understanding the relevance of public health evidence, and investigate ways of producing meta-analytic estimates tailored to reflect local…

Qualitative comparative analysis (QCA) was originally developed as a tool for cross-national comparisons in macrosociology, but its use in evaluation and evidence synthesis of complex interventions is rapidly developing. QCA is theory-driven and relies on Boolean logic to identify pathways to an outcome (e.g., is the intervention effective or…

Clinical trial data are essential for assessments of the effectiveness of health care interventions. Information about ongoing or completed, but not yet formally published, trials has been more difficult to identify until the development of clinical trials registers and portals. This paper summarises research evidence on identifying sources of…

Realist review has increased in popularity as a methodology for complex intervention assessment. Our experience suggests that the process of designing a realist review requires its customization to areas under investigation. To elaborate on this idea, we first describe the logic underpinning realist review and then present critical reflections on…

Bayesian networks (BNs) are tools for representing expert knowledge or evidence. They are especially useful for synthesising evidence or belief concerning a complex intervention, assessing the sensitivity of outcomes to different situations or contextual frameworks and framing decision problems that involve alternative types of intervention.…