Current issues of ACP Journal Club are published in Annals of Internal Medicine


The Cochrane Collaboration

ACP J Club. 1994 May-June;120:A11. doi:10.7326/ACPJC-1994-120-3-A11

We live in exciting times in health care: rich in information, full of promise, blessed with powerful scientific methods, and beset with turmoil over which clinical and other health care maneuvers to provide and how to pay for them. The health of present and future generations depends, in important ways, on our collective ability to identify and apply the affordable maneuvers that do more good than harm. This issue contains several examples of attempts to identify such maneuvers, including a pair of high-quality overviews on the efficacy of selective decontamination of the digestive system (SDD) in patients requiring intensive care.

There is a science to the art of intervening in the health of persons and populations. It has its basis in the successful quest for interventions that produce huge changes in the structure and function of cells, tissues, organs, and entire organisms, including humans and their societies.

After the awful discovery that some of these interventions, developed and applied with the best of intentions, did more harm than good, health scientists developed powerful research methods for determining the efficacy and effectiveness of health interventions, culminating in the randomized controlled trial. The randomized trial is now the acknowledged gold standard for deciding whether a preventive, screening, diagnostic, therapeutic, rehabilitative, or even educational or administrative intervention does more good than harm; hence, the primacy of randomized trials in this journal.

Field by field, authoritarianism based on mere seniority is giving way to authoritativeness based on randomized trials. The commanding role of the randomized trial is seen in the striving of researchers to design them and granting bodies to support their execution, in the speed and prominence with which they appear in scientific journals and the lay press, in their incorporation into regulations of drug-licensing and other health care agencies, and in their currency at the bedside, in the boardroom, and in the corridors of health care institutions everywhere.

Too often, however, the results of randomized trials are ignored in providing health care; helpful maneuvers often are omitted, and useless or even harmful interventions often are applied. The reasons for these failures are several, and important among them are the simple unawareness of trial results and the confusion that arises when several trials of the same maneuver provide individually inconclusive or conflicting results.

To overcome this failure to provide evidence-based health care, a rapidly growing cadre of health care providers, consumers, and scientists have come together to engage in the unselfish, collaborative enterprise of preparing, maintaining, and disseminating systematic, up-to-date reviews, by specialty, of all relevant randomized controlled trials of health care (and, when they are not available, reviews of the most reliable evidence from other sources). We call ourselves the Cochrane Collaboration.

On the basis of shared interests and expertise in specific health problems, members are forming themselves into collaborative groups (called Health Problem Review Groups) that carry out exhaustive searches for all relevant trials, scrutinize these for their relevance and quality, assemble and analyze them, draw conclusions about how their net result should be applied in health care, and prepare structured reports for widespread dissemination to health care providers and planners. Indeed, members of the 2 teams that prepared the SDD overviews are coming together to continue following the emerging evidence in this field, thus fulfilling another objective of the Cochrane Collaboration: the avoidance of unnecessary duplication of effort.

These Health Problem Review Groups are assisted in each stage in their work by other elements of the Collaboration, coordinated by a worldwide network of Cochrane Centers. Through these centers, Health Problem Review Groups may be provided with extensive citations for potentially relevant trials (often assembled by teams of persons with special interests in a broad field of health care). They also are furnished a “tool kit” of scientific strategies and tactics for carrying out their reviews. Finally, they are provided with a wide array of multiple, coordinated approaches to the electronic and paper-based dissemination of their reports.

Despite this assistance, forming and working in a Health Problem Review Group are not for the faint-of-heart. These endeavors require an ego that is satisfied by unselfish collaboration and group, rather than individual, recognition; a career-long commitment to the continuing, exhaustive retrieval and analysis of all relevant trials; enormous numbers of hours of individual and group effort; and the subservience of personal convictions to scientific evidence.

But the rewards are great. The opportunity to remain at the cutting edge of one's field is unparalleled. The fun and learning that accompany working with a worldwide group of like-minded colleagues are exceptional. And in what other endeavor can you multiply your individual effectiveness a millionfold and contribute to the preservation and restoration of the health of countless persons around the world, in your own and subsequent generations?For further information about the Cochrane Collaboration, go to

David L. Sackett, MD, MSc EpidChair, Cochrane Collaboration Steering Group

Editor's Note

For further information about the Cochrane Collaboration, contact Judi Morrison care of the editorial office at McMaster University (905-525-9140, ext. 22255).