Citation

LaKind JS, Burns CJ, Mattison DR. Glob. Epidemiol. 2022; 4: e100088.

Copyright

(Copyright © 2022, Elsevier Publishing)

DOI

10.1016/j.gloepi.2022.100088

PMID

unavailable

Abstract

As Sir Austin Bradford Hill noted in a now-famous 1965 speech, "many an environmental association may be thrown up" [1]. At issue is how we assess those reported associations, make determinations regarding exposure-related health risks, and set limits on exposure. These assessments begin (and sometimes end) with a review of the literature, yet the completeness, robustness, and reliability of reviews as a foundation for decision-making vary widely [2]. To move us towards a more coherent method for examining causality, formal systematic review protocols have been designed with transparency and reproducibility in mind. For example, a recent paper by Goodman et al. [3] uses a systematic review approach to evaluate the weight of evidence for a causal association between exposure to perchloroethylene (PCE) and non-Hodgkin lymphoma (NHL).

With the advent of the use of systematic review in environmental research, it is now easy to be overwhelmed by the plethora of approaches. The reader merely needs to visit sites such as the EQUATOR Network (Enhancing the QUAlity and Transparency Of health Research) or the GRADE site (Grading of Recommendations Assessment, Development and Evaluation) to get a sense of the array of approaches now available and in use [4,5]. Adhering to the many recommendations for a systematic review is time- and resource-intensive. Issues around costs and complications associated with conducting systematic reviews of observational epidemiology research have been described [[6], [7], [8]].

In this commentary, we discuss three main steps in the systematic review paradigm (evidence identification, evaluation, and synthesis). We then consider the following question: has there been sufficient improvement in the ability of reviews to inform decision-making to warrant the added necessary time and resources necessary for the process? We offer a spoiler alert: We do not believe that this question has been sufficiently explored and acknowledge that this commentary introduces more questions than answers. Before a unified systematic review approach becomes set in stone, we believe this is a propitious time for reflection on the questions raised in this commentary...

Language: en

Keywords

Bradford Hill; Evidence synthesis; Literature search; Matrix; Systematic review