The use of placebos rather than existing treatments as comparators in medical research involving humans should be confined to very limited circumstances in which patients given placebos will not suffer any serious or irreversible harm, specifies a revised version of the Declaration of Helsinki.

The amendments were adopted by the World Medical Association (WMA) at its annual General Assembly in Seoul, South Korea last week. The updated principles reaffirmed the WMA’s “controversial stand against practices that open the door to exploitation of research subjects, particularly in developing countries”, the association said, noting its refusal in this respect “to bow to pressure from industry and government regulatory agencies”.

The revised Declaration also re-affirms the right of participants to share in any benefits that may arise from research, such as access to interventions identified as beneficial in a study. New paragraphs address consent for research using human materials (e.g. blood, tissues, DNA) and human data. They call for clinical trials to be registered in a publicly accessible database.

According to Dr Eva Bågenholm, chair of the five-country working group that drafted the revisions, the extensive consultation on the proposed changes showed that the Declaration’s strict provisions for protecting research subjects were sound and firm. “The WMA now looks to other stakeholders, especially governments, to raise their standards to the Declaration’s level,” she commented.

The process of revision began with a recommendation by the WMA’s Medical Ethics Committee in May 2007 that a formal working group should be appointed to review the Declaration “with the goals of a) identifying gaps in the content but avoiding a complete re-opening of the document and b) using the review process to promote the Declaration of Helsinki”.

Regarded by many as the foundation document for medical research ethics worldwide, the Declaration was first adopted in 1964 and has been amended five times since, most recently in 2000. Notes of clarification dealing with the acceptability of placebo-controlled trials and with arrangements for post-trial access to procedures identified as beneficial by the research were added to paragraph 29 and paragraph 30 of the Declaration respectively in 2002 and 2004.

In May to August 2007, national medical associations and other stakeholders were asked to identify paragraphs in the Declaration that might need revising, to propose specific amendments and/or to identify new topics for inclusion.

According to the WMA, this initial consultation produced almost unanimous consent that the principles of the Declaration were sound. However, there was also a desire for clarification on how these principles should be applied and recognition that a number of new issues had arisen since the existing version of the Declaration of Helsinki was adopted.