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The importance of randomization in clinical research

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Abstract

Studies evaluating average treatment effects (ATE) of an intervention could broadly be classified into those with observational and randomized designs. Observational studies are limited by confounding, in addition to selection and information bias, making the evaluation of ATE hypothesis generating and not hypothesis testing. Randomization attempts to reduce the systemic error introduced by observational studies by ensuring equal distribution of prognostic factors between the treatment and control groups, thereby confirming that any difference in outcomes observed between the two groups is attributable to the treatment. While randomized controlled trials (RCT) remain the gold standard in estimating ATE of therapeutic interventions, they do have inherent limitations due to uncertain external validity. Observational studies can have a complementary role in enhancing RCTs’ ability to inform routine clinical practice. In this review, we focus on the limitations of observational studies, the need for randomization, interpretation, and the limitations of RCTs.

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Authors and Affiliations

  1. Louis Stokes Veteran Affairs Medical Center, Cleveland, OH, 44106, USA

    Varun Sundaram, Padmini Selvaganesan, Salil Deo & Mohamad Karnib

  2. Harrington Heart and Vascular Institute, University Hospitals Cleveland Medical Center, Cleveland, OH, USA

    Varun Sundaram & Mohamad Karnib

  3. Case Western Reserve University, Cleveland, OH, USA

    Varun Sundaram, Padmini Selvaganesan, Salil Deo & Mohamad Karnib

Authors
  1. Varun Sundaram
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  2. Padmini Selvaganesan
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  3. Salil Deo
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  4. Mohamad Karnib
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Correspondence to Varun Sundaram.

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Sundaram, V., Selvaganesan, P., Deo, S. et al. The importance of randomization in clinical research. Indian J Thorac Cardiovasc Surg 38, 562–565 (2022). https://doi.org/10.1007/s12055-022-01401-7

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  • DOI: https://doi.org/10.1007/s12055-022-01401-7

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