Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I Tool)

Sterne, J., Hernán, M., Reeves, B., Savović, J., Berkman, N., Viswanathan, M., et al. ROBINS-I: a tool for assessing risk of bias in non-randomized studies of interventions. BMJ 2016; 355; i4919; doi: 10.1136/bmj.i4919.

Template available Evaluated/validated


This tool evaluates the risk of bias (RoB) in the results of non-randomized intervention studies. It can be used to evaluate quantitative observational trials, including cohort and case-control studies, controlled before-and-after studies, interrupted-time-series studies and quasi-randomized studies.

Steps for Using Method/Tool

The tool guides users through a series of signalling questions for each of the seven domains through which bias may be introduced:

  1. Bias due to confounding
  2. Bias in selection of participants into the study
  3. Bias in classification of interventions
  4. Bias due to deviations from intended interventions
  5. Bias due to missing data
  6. Bias in measurement of outcomes
  7. Bias in selection of the reported result

At the end of each section, an algorithm is provided to make a final judgement on the risk of bias. Each component is weighed equally to provide an overall risk of bias judgement.


Sterne, J. A., Hernán, M. A., Reeves, B. C., Savović, J., Berkman, N. D., Viswanathan, M., et al. (2016). ROBINS-I: A tool for assessing risk of bias in non-randomised studies of interventions. BMJ (Clinical research ed.), 355, i4919. https://doi.org/10.1136/bmj.i4919

These summaries are written by the NCCMT to condense and to provide an overview of the resources listed in the Registry of Methods and Tools and to give suggestions for their use in a public health context. For more information on individual methods and tools included in the review, please consult the authors/developers of the original resources.

We have provided the resources and links as a convenience and for informational purposes only; they do not constitute an endorsement or an approval by McMaster University of any of the products, services or opinions of the external organizations, nor have the external organizations endorsed their resources and links as provided by McMaster University. McMaster University bears no responsibility for the accuracy, legality or content of the external sites.

Have you used this resource? Share your story!