Decision-making for older patients by Australian and New Zealand doctors with Advance Care Directives: a vignette-based study.

Background: Little is known about doctors' decision-making patterns when using Advance Care Directives (ACDs), particularly for older patients in Australia and New Zealand.

Aims: To determine the level of agreement among Australian and New Zealand doctors' decisions when using ACDs to guide treatment decisions for older patients. To evaluate factors that may affect decision-making including doctors' demographics, vignette complexity and Advance Care Directive (ACD) content.