Peer Review is universally used to ensure the quality of scientific research, but the process may not be as reliable as people assume. A new study in PLoS One suggests that the recommendations reviewers may not be much more reliable than a coin toss.

"Peer review provides an important filtering function with the goal of insuring that only the highest quality research is published," said William Tierney, M.D., a Regenstrief Institute investigator and study co-author. "Yet the results of our analysis suggest that reviewers agree on the disposition of manuscripts – accept or reject – at a rate barely exceeding what would be expected by chance. Nevertheless, editors' decisions appear to be significantly influenced by reviewer recommendations."

A total of 2,264 manuscripts submitted to the Journal of General Internal Medicine (JGIM) were sent by the editors for external review to two or three reviewers each during the study period. These manuscripts received a total of 5,881 reviews provided by 2,916 reviewers. Twenty-eight percent of all reviews recommended rejection.

However, the journal's overall rejection rate was much higher -- 48 percent overall and 88 percent when all reviewers for a manuscript agreed on rejection (which occurred with only 7 percent of manuscripts). The rejection rate was 20 percent even when all reviewers agreed that the manuscript should be accepted (which occurred with 48 percent of manuscripts).

"We need to better understand and improve the reliability of the peer-review process while helping editors, who make the ultimate publish or not publish decision, recognize the limitations of reviewers' recommendations," said Dr. Tierney, who served as JGIM co-editor-in-chief from 2004-2009.

"Published research is becoming a more and more significant factor in scientific dialogue. Physicians and other researchers are no longer the only readers of medical studies. Patients and their families and friends now regularly access medical literature. This makes the review process even more important."

Citation: Kravitz et al., 'Editorial Peer Reviewers' Recommendations at a General Medical Journal:
Are They Reliable and Do Editors Care?', PLoS ONE 5(4): e10072;