Communicating risk and uncertainty to families

Overview & Definition

A mother reads online that a treatment "reduces harm by 50%". In your clinic she asks whether her child should have it. Before you answer a single clinical question, you face a communication problem: that 50% is a relative reduction, and she has no idea what it is relative to. Whether she consents well or badly now depends on how you handle the number. [1] [10]

Risk communication is the work of conveying the probability and magnitude of potential benefits and harms in a form a family can use to make decisions. In paediatrics the family is the unit of decision, and the child or young person is included developmentally, so the numbers must reach not only a parent but the right people in the right language. [14]

Uncertainty sits beside risk in every such conversation. It has two flavours. Aleatory uncertainty is irreducible chance — the run of luck in who is affected. Epistemic uncertainty is the gap in what we know, which better evidence can narrow but rarely close. Prognosis in a relapsing illness, the meaning of an incidental finding, and the long-term effects of a new treatment all carry epistemic uncertainty that families deserve to hear named. [4] [13]

This page owns the process and skills of presenting numbers and uncertainty. Cross-link the dedicated leaves for shared decision-making and assent, breaking bad news, vaccine-hesitancy counselling, consent frameworks, health literacy, and working with interpreters — do not rebuild their content here. [14]

References14Show ledgerHide ledger

1. [1]Gigerenzer G Helping Doctors and Patients Make Sense of Health Statistics. Psychological science in the public interest, 2007.PMID 26161749
2. [2]Fagerlin A Making numbers matter: present and future research in risk communication. American journal of health behavior, 2007.PMID 17931136
3. [3]Paling J Strategies to help patients understand risks. BMJ, 2003.PMID 14512489
4. [4]Zipkin DA Evidence-based risk communication: a systematic review. Annals of internal medicine, 2014.PMID 25133362
5. [5]Woloshin S Communicating data about the benefits and harms of treatment: a randomized trial. Annals of internal medicine, 2011.PMID 21768582
6. [6]Schwartz LM Using a drug facts box to communicate drug benefits and harms: two randomized trials. Annals of internal medicine, 2009.PMID 19221371
7. [7]Bonner C Current Best Practice for Presenting Probabilities in Patient Decision Aids: Fundamental Principles. Medical decision making, 2021.PMID 33660551
8. [8]Hoffrage U Natural frequencies improve Bayesian reasoning in simple and complex inference tasks. Frontiers in psychology, 2015.PMID 26528197
9. [9]Garcia-Retamero R Visual aids improve diagnostic inferences and metacognitive judgment calibration. Frontiers in psychology, 2015.PMID 26236247
10. [10]Moxey A Describing treatment effects to patients. Journal of general internal medicine, 2003.PMID 14687282
11. [11]Galesic M Graph literacy: a cross-cultural comparison. Medical decision making, 2011.PMID 20671213
12. [12]Galesic M Statistical numeracy for health: a cross-cultural comparison with probabilistic national samples. Archives of internal medicine, 2010.PMID 20212183
13. [13]Peters E Communicating Numeric Risk Information to Patients. Journal of general internal medicine, 2025.PMID 40301218
14. [14]Levetown M Communicating with children and families: from everyday interactions to skill in conveying distressing information. Pediatrics, 2008.PMID 18450887