Introducing presumed consent or opt-out system may increase organ donation rates, suggests a new systematic review published in the BMJ (British Medical Journal).

There is currently insufficient supply of donor organs to meet the demand for organ transplantations in the UK but the number of patients registered for a transplant continues to increase. In March 2008, 7,655 patients were on the active transplant list and 506 died in the years 2007-2008 while waiting for their transplant.

At present the UK has an informed consent legislative system where individuals opt-in if they are willing for their organs to be used after death. However, only a quarter of the UK population are on the NHS donor register. 

The review, carried out at the Centre for Reviews and Dissemination (CRD), University of York, combines 26 previous studies and public opinion surveys and represents the most comprehensive review to date examining the impact of having a presumed consent or opt-out system.

The existing evidence, albeit somewhat methodologically limited, suggests that presumed consent legislation is associated with an increase in organ donation rates, though the size of the association varied between studies. 

The evidence also suggests that presumed consent alone is unlikely to explain the variation in organ donation rates between different countries. A number of other factors appear to be associated with organ donation rates, though their relative importance is unclear. These factors include deaths from causes most likely to provide organ donors, the transplant co-ordination infrastructure, the wealth and health expenditure of a country, religion, education, and the legislative system. 

Underlying public attitudes about organ donation and systems of consent are also likely to be important and the review assessed public and professional attitudes to presumed consent. 

Dr Catriona McDaid said: “The survey evidence is incomplete and the variation in attitudes between surveys may reflect differences in methods and the phrasing of questions. Some surveys suggest a lack of public support both in the UK and elsewhere, though the more recent UK surveys do suggest public support for presumed consent.”

Article: Amber Rithalia, Catriona McDaid, Sara Suekarran, Lindsey Myers, Amanda Sowden. 'The impact of presumed consent for organ donation on donation rates: a systematic review', BMJ 2009;338:a3162 doi:10.1136/bmj.a3162