Proposals to overhaul the approach to obtaining patient consent lack detail, contain advice that is non-specific, and might prevent doctors from making major changes to their practice warns an editorial in this week's BMJ.

Writing in response to the publication of the General Medical Council (GMC) guidance on patient consent to be implemented in June, Professor Glyn Elwyn argues that although the guidance appears radical and urges a change in the approach to informed consent, it fails to address how doctors will do this in busy clinical settings.

The process of obtaining consent from patients for procedures such as surgical operations often just involves patients signing a piece of paper declaring that they understand the nature of the procedure and its consequences, only a few hours before an operation. This rarely provides time for patients to read or consider the information about harms and benefits. In addition, evidence shows that patients want to be given more information about risks and consequences.

According to Elwyn, although the much needed GMC guidance encourages doctors and patients to discuss procedures and treatments to help patients make more informed decisions, it lacks important finer details. For example, the guidance provides no detail about suggested risk thresholds for specifying the problem of harm, or suggestions on how to achieve balance, to tailor information, or how to explore personal preferences.

Before the guidance is implemented more preparation needs to be done, he argues. Shared decision making needs to integrated into the way mutlidisciplinary teams are set up to provide care. Patients should receive information early and the process should have clearly defined steps at which information and patient preference should be considered and documented.

In addition, he says, new informative materials describing the intervention, likely outcomes and their probabilities, complete with guidance on how to clarify patients' preferences and deliberate about options should be made available.

Elwyn points out that although generating these materials will require considerable expertise and investment, there is a wealth of experience and decision support technologies and aids already available to produce such tools.

"As consent becomes increasingly regarded as a form of choice that involves a deliberate decision rather then just acceptance of professional advice, the shift to adopt decision support technologies as a means of achieving informed consent seems not only necessary, but inevitable", he concludes.