Article Text

Download PDFPDF
‘Depletion of the susceptibles’ taught through a story, a table and basic arithmetic
  1. Steven D Stovitz1,
  2. Hailey R Banack2,
  3. Jay S Kaufman3
  1. 1 Family Medicine and Community Health, University of Minnesota System, Minneapolis, Minnesota, USA
  2. 2 Epidemiology and Environmental Health, University at Buffalo–The State University of New York, Buffalo, New York, USA
  3. 3 Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Quebec, Canada
  1. Correspondence to Dr Steven D Stovitz, Department of Family Medicine and Community Health, University of Minnesota, Minneapolis, MN 55455, USA; stovitz{at}

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

‘Depletion of the susceptibles’ is a phrase occasionally used to describe a form of selection bias where harmful exposures can appear protective.1 2 This bias, which affects evidence interpretation, may be difficult for clinicians to recognise, because study participants may represent a random sample of people similar to a clinician’s patients. In this letter, we explain the bias through a story, a table and basic arithmetic to help those unfamiliar with other explanations using hazard ratios,3 inverse probability weighting4 or directed acyclic graphs conditioning on survival.5

Imagine a …

View Full Text


  • Contributors All authors conceived the concept and contributed to the final manuscript.

  • Competing interests None declared.

  • Patient consent Not required.

  • Provenance and peer review Not commissioned; internally peer reviewed.