Assessing risk of bias in non-randomized studies of interventions: introduction to the ROBINS-I tool
Julian Higgins, University of Bristol
Jelena Savovic, University of Bristol
Background: Non-randomized studies of interventions (NRSI) can provide information about effects of interventions that is not available from randomized trials, but their results may be affected by confounding, selection and information biases. Assessing the risk of bias in NRSIs included in systematic reviews is essential to ensure the robustness of review findings. The ROBINS-I (Risk of Bias in Non-randomized Studies – of Interventions) tool (BMJ 2016;355:i4919), which provides a structured approach to such assessments, has been updated since its publication.
Objectives: 1) To describe the ROBINS-I tool to assess risk of bias in NRSI. 2) To describe recent updates and improvements to ROBINS-I. 3) To provide participants with hands-on experience in ROBINS-I assessments.
Description: This workshop will describe key features of the ROBINS-I tool and improvements to the version published in 2016. - Specification of a hypothetical pragmatic randomized trial that is free of bias, as a basis for risk of bias assessments. - Preliminary considerations at review protocol stage. - Specification of the effect of interest (either the effect of assignment to intervention or the effect of adhering to intervention). - Assessments of risk of bias within seven domains (confounding; selection of participants into the study; classification of interventions; deviations from intended intervention; missing data; measurement of outcomes; selection of the reported result). - Signalling questions to inform judgements on risk of bias. - Use of algorithms to map answers to the signalling questions to suggested risk of bias judgements. - Overall risk of bias in the result. The workshop will include a guided practical session. Working in small groups, participants will complete parts of a risk of bias assessment for a selected non-randomized study. There will be opportunities for discussion of the tool and its role in systematic reviews. Participants are encouraged to bring their own portable computing device to access detailed guidance from the internet (www.riskofbias.info). The facilitators are unable to provide printed copies of the guidance document.