Use of implicit persuasion in decision making about adjuvant cancer treatment: A potential barrier to shared decision...

Shared decision making (SDM) is widely advocated, especially for preference-sensitive decisions like those on adjuvant treatment for early-stage cancer. Here, decision making involves a subjective trade-off between benefits and side-effects, and therefore, patients' informed preferences should be taken into account. If clinicians consciously or unconsciously steer patients towards the option they think is in their patients' best interest (i.e. implicit persuasion), they may be unwittingly subverting their own efforts to implement SDM. We assessed the frequency of use of implicit persuasion during consultations and whether the use of implicit persuasion was associated with expected treatment benefit and/or decision making.

Observational study design in which consecutive consultations about adjuvant systemic therapy with stage I-II breast cancer patients treated at oncology outpatient clinics of general teaching hospitals and university medical centres were audiotaped, transcribed and coded by two researchers independently.

In total, 105 patients (median age = 59; range: 35-87 years) were included. A median of five (range: 2-10) implicitly persuasive behaviours were employed per consultation. The number of behaviours used did not differ by disease stage (P = 0.07), but did differ by treatment option presented (P = 0.002) and nodal status (P = 0.01). About 50% of patients with stage I or node-negative disease were steered towards undergoing chemotherapy, whereas 96% of patients were steered towards undergoing endocrine therapy, irrespective of expected treatment benefit. Decisions were less often postponed if more implicit persuasion was used (P = 0.03).

Oncologists frequently use implicit persuasion, steering patients towards the treatment option that they think is in their patients' best interest. Expected treatment benefit does not always seem to be the driving force behind implicit persuasion. Awareness of one's use of these steering behaviours during decision making is a first step to help overcome the performance gap between advocating and implementing SDM.