Assessing the Usability of the Risk Of Bias in Non-randomized Studies – of Interventions (ROBINS-I) Tool for Studies of Exposure and Intervention in Environmental Health Research

Abstract

Introduction: The Risk Of Bias in Non-randomized Studies – of Interventions (ROBINS-I) tool evaluates internal validity (risk of bias) in non-randomized studies of interventions in comparison to an ideal (hypothetical) randomized trial. The use of ROBINS-I in studies dealing with exposures or interventions in environmental health has not yet been explored. This study evaluated the usability and applicability of ROBINS-I in studies of environmental health (EH) exposure. Methods: Three researchers in sequential rounds applied ROBINS-I to three systematic reviews of EH exposures: bisphenol-A and obesity; perfluorooctanoic acid and birth weight; and polybrominated diphenyl ethers and thyroid function. We began by providing instructions for application of ROBINS-I to EH studies, including possible confounders and co-exposures specific to the exposures considered in the three reviews. For the first two rounds of testing, two reviewers independently applied ROBINS-I and provided feedback on usability of the tool. Barriers and facilitators to the appropriateness of ROBINS-I for environmental health were identified and modifications made to the tool, as necessary. For the third round of testing, three reviewers independently applied the tool and came to consensus on item-level and overall study risk of bias. Results: Suggested modifications ranged from syntax and wording to conceptual changes to the tool. The term “intervention” was replaced with “exposure” throughout the document. Additional instructions were provided to address assessment of cross-sectional studies. Fields to collect information on measurement of exposures and outcomes of interest was added to the project protocol. Additional granularity was added to the measurement of interventions/exposure domain. Conclusion: Modifications made to the risk of bias tool to tailor it to studies of EH exposure increased understanding and application of the tool, as well as consistency in responses.