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Decision making about screening:
What factors influence physicians’ risk communication and recommendations?
Dafina Petrova, MSc1 , Olga Kostopoulou, PhD2, Brendan Delaney, MD2,
Edward T. Cokely, PhD3,4, Rocio Garcia-Retamero, PhD1,4
1 Mind, Brain, and Behavior Research Center, University of Granada, Spain.
2 Department of Surgery and Cancer, Division of Surgery, Imperial College London, United Kingdom.
3 National Institute for Risk & Resilience, and Department of Psychology, University of Oklahoma, USA.
4 Max Planck Institute for Human Development, Germany.
Cancer screening can save lives but can also carry risks such as false positive results and the risk of unnecessary treatment. To achieve informed decision making, both potential benefits and potential harms should be communicated to patients. However, many patients have low numeracy, which impedes their understanding and poses challenges to informed decision making. We investigated how physicians adapt their risk communication to accommodate the needs of patients with low numeracy, and how physicians’ own numeracy influences their communication and decisions to recommend screening.
In an online experiment, UK family physicians (N=151) read a description of a patient seeking advice on cancer screening. In the description, we manipulated the numeracy of the patient (low vs. high vs. unspecified), the availability of a clinical guideline recommending screening (present vs. absent), and the effectiveness of the screening for reducing mortality (effective vs. not effective). We measured physicians’ risk communication, recommendation to the patient, understanding of screening statistics, and numeracy.
Consistent with best practices, family physicians generally preferred to use visual aids rather than numbers when communicating information to a patient with low (vs. high) numeracy. However, physicians who had high (vs. low) numeracy themselves offered more meaningful and complete risk information: they were more likely to mention mortality rates, OR=8.55 [95% CI 1.77, 41.41], p=.007, and harms from overdiagnosis, OR=8.82 [1.34, 60.25], p=.023. Physicians with high numeracy were also more likely to understand that increased survival rates do not imply screening effectiveness, OR=6.05 [1.27, 28.72], p=.026.
Screening patients for low numeracy could help physicians tailor risk communication appropriately. However, physicians who themselves have low numeracy are likely to misunderstand risks and unintentionally mislead patients by communicating incomplete information. High-quality risk communication and decision making can depend critically on factors that can improve the risk literacy of physicians (e.g., numeracy, visual aids).