A tool for rapid assessment of Risk of Bias (raRoB) in observational epidemiological studies

To enable a rapid and transparent assessment of the risk of bias in observational epidemiological studies, the raRoB tool (rapid assessment of Risk of Bias) was developed by the German Federal Institute for Risk Assessment. The tool allows a quick and transparent assessment of the risk of bias in observational epidemiological studies, which is needed for instance in policy advice. The tool can be used by scientific experts without specific epidemiological knowledge for a rapid and handy assessment of the risk of bias, such as recently published publication of human epidemiological studies on health risks that need to be assessed in the short term. There are numerous instruments for assessing the evidence from individual epidemiological studies, mostly in the course of systematic reviews. Special attention is given to the assessment of systematic errors (bias). However, the available instruments are limited in their applicability, often focusing on interventional studies, which examine planned interventions in a controlled setting. In contrast, there are few established instruments for observational epidemiological studies, which address exposures under real-world conditions and thus are relevant in the field of risk assessment. In addition, most established instruments are complicated to use, require specialized training, and the application process is time-consuming due to the complexity of the assessment.
For the development of the tool, domains and items from 152 previously identified instruments were extracted, systematised and implemented into a dialog-oriented and user-friendly software tool. The tool was then tested and improved in a pilot study (among epidemiologists and statisticians) and two subsequent test phases (among scientists in the context of risk assessment).