The Influence of Objective Prognostic Information on the Likelihood of Informed Consent for Decompressive Craniectomy: A Study of Australian Anaesthetists

Abstract

The aim of this study was to assess the influence of detailed prognostic information on the likelihood of informed consent for decompressive craniectomy for severe traumatic brain injury. The study was a simulation exercise, asking anaesthetists to give opinions as if they themselves were the injured party. Anaesthetists were chosen as they represent a distinct group likely to be familiar with the procedure and the decision-making process, but not necessarily aware of the longer-term outcomes. A two-part structured interview was used. Seventy-five anaesthetists were shown three cases of differing severity of traumatic brain injury. A visual analogue scale (1 to 10) was used to assess the strengths of their opinion. Initially they were asked their opinion with no predictive outcome data. They were then shown the prediction of an unfavourable outcome (Glasgow Outcome Scale severely disabled, vegetative state or dead) and the observed outcome at 18-month follow-up from a cohort of 147 patients (who had had a decompressive craniectomy for severe traumatic brain injury in Perth, Western Australia between the years 2004 and 2008). The opinions of the participants before and after seeing the prediction outcome data were compared. The participants' preferences to consent to the procedure changed after being informed of the predicted risks of unfavourable outcomes (P values < 0.01). The changes in attitude appeared to be independent of age group, amount of experience in caring for similar patients and religious background. These findings suggest that access to objective information on risks of unfavourable outcomes may influence opinions in relation to consent for decompressive craniectomy for traumatic brain injury.