Intended for healthcare professionals

Practice Practice Pointer

Using a clinical process map to identify prescribing cascades in your patient

BMJ 2020; 368 doi: (Published 19 February 2020) Cite this as: BMJ 2020;368:m261
  1. Katrina L Piggott, geriatrician and general internist, Mount Sinai Hospital; clinical associate, University of Toronto; MSc candidate, Quality Improvement and Patient Safety, Institute of Health Policy, Management and Evaluation1 4,
  2. Nishila Mehta, medical student, University of Toronto; research assistant, Women’s College Research Institute2 4,
  3. Camilla L Wong, geriatrician, St Michael’s Hospital; associate professor, University of Toronto; project investigator, Li Ka Shing Knowledge Institute3,
  4. Paula A Rochon, vice-president, Research, Women’s College Hospital; senior scientist, Women’s College Research Institute; professor, Department of Medicine and Institute for Health Policy, Management and Evaluation, University of Toronto1 4
  1. 1Department of Medicine and the Institute for Health Policy, Management and Evaluation (IHPME), University of Toronto, Toronto, Canada
  2. 2Undergraduate Medicine, Faculty of Medicine, University of Toronto, Toronto, Canada
  3. 3Division of Geriatric Medicine, St Michael’s Hospital, University of Toronto, Toronto, Canada
  4. 4Women’s College Research Institute, Women’s College Hospital, University of Toronto, Toronto, Canada
  1. Correspondence to: P Rochon paula.rochon{at}

What you need to know

  • Prescribing cascades are a type of problematic polypharmacy that occur when an adverse drug event is misinterpreted as a new medical condition, and a second medication is prescribed or a diagnostic test is ordered

  • Older adults are at higher risk of experiencing prescribing cascades due to the higher incidence of polypharmacy and drug side effects than in younger patients

  • Prescribing cascades increase the pill burden for patients, raise healthcare costs, and cause preventable adverse events

  • One way to identify and reverse prescribing cascades is by creating a clinical process map, a tool designed to illustrate a patient’s presentation, symptoms, medications, possible side effects, and interventions

  • Ask yourself: “Could my patient’s new symptom be caused by a drug they are taking rather than a new medical condition?”

The adverse effects of a drug may “hide” behind common presenting symptoms.1 Prescribing cascades occur when a healthcare provider misinterprets an adverse drug event as a new medical condition and provides a second drug to address the side effect, as described in 1997 by Rochon and Gurwitz in the BMJ.2 The concept has also been expanded to include unnecessary diagnostic tests, medical devices, and over-the-counter therapies,3 which may expose the patient to risk and harm. There is no universally accepted approach to identifying whether a drug is responsible for a symptom, but by identifying prescribing cascades, clinicians can reduce the number of unnecessary medications, investigations, consultations, and harms.

To date, more than 20 prescribing cascades have been identified by cohort and population studies4 (see fig 1 for examples). These prescribing cascades are the result of medications for common conditions such as heart disease, hypertension, obstructive lung disease, diabetes, dementia, and chronic pain.356

Fig 1

Simple clinical process maps of three common prescribing cascades

While prescribing cascades are well …

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