The Variability of Patient Preferences

Wide variation in procedure utilization suggests that surgical indications might not be rigorously defined. An alternative explanation is that surgical outcomes are valued differently across groups. When a patient, using the information provided by the surgeon, places high value on successful results or is indifferent to the costs of ineffective treatment, the treatment threshold is lower and more surgery will be chosen. Is there a high variation in patients' preferences and, therefore, high variation in treatment thresholds? Do people poorly estimate their own treatment thresholds? I presented a hypothetical scenario describing a diagnostically uncertain meniscus injury to 100 college students, asking them to rate the value of the four end points based on treatment choice (arthroscopy chosen/declined) and post hoc knowledge of the true diagnosis (tear present/absent). From those data, I calculated treatment thresholds. Subjects also estimated their treatment threshold directly. The calculated treatment thresholds ranged from 4% to 88%. A discrepancy of at least 20% between the calculated and subject-estimated thresholds was present in 61 subjects. There is great variance in the treatment threshold reported; additionally, many subjects poorly predicted their own calculated treatment thresholds. Variability in patient preferences for outcome is an important, but perhaps underestimated, clinical parameter. Meaningful assessment of patient preferences when recommending treatment or creating clinical practice guidelines will lead to better shared decision making.