Background In the Netherlands, the General Practitioner (GP) is generally not involved in treatment decisions in cancer. However, the GP often has a long history with patients and can help to explore patients’ values, especially in older patients. This can help the patient prepare for shared decision making with the oncologist. The aim of this randomised controlled trial is to study the effect of a conversation about treatment goals between GPs and patients on self-efficacy just after the diagnosis of non-curable cancer.

Methods We included patients aged ≥60 years with a diagnosis of non-curable cancer, who have heard the treatment options from their oncologists. In the intervention group, patients consulted their GP using an Outcome Prioritisation Tool (OPT) to discuss the prioritisation of treatment goals (staying alive, maintaining independence, reduce pain, reduce other symptoms). The control group received care as usual. Primary outcome was the score on a decision self-efficacy scale after the decision-making consultation with the oncologist.

Results Inclusion ends on 1 January 2019. Results are not yet available but we will present the first results during the conference.

Conclusion The OPTion-study provides information about the effect of a consultation, about preferred treatment goals, between GPs and older patients with non-curable cancer on self-efficacy.