The processes of making clinical decisions are complex indeed. In seeking the evidence on which to base clinical practice, clinicians and researchers are faced with a myriad of published papers and web-based sites often offering unclear or conflicting information regarding the choice of intervention approaches, expectations of outcomes or use of measurement tools.
Given these challenges, the emergence of the systematic review has been timely, providing a structured approach to analyzing available information to aid in making important clinical decisions. Although the term systematic review has been used for more than 30 years, its current use has become standardized through the efforts of an international organization called the Cochrane Collaboration (see Box 16.1). Systematic review refers to a rigorous process of searching, appraising and summarizing existing information on a selected topic. Reviews are most commonly focused on the effectiveness of interventions, but may also address the accuracy of diagnostic tools or identification of prognostic factors.
The key word "systematic" differentiates this process from the classical "review" article. Traditional narrative literature reviews have been and continue to be a good source of information, particularly on the background of a specific topic. The traditional review, however, does not include a detailed description of the methods and criteria used to select and evaluate articles that are included. Authors may approach their topics with a bias from their clinical perspective that may not represent the breadth of information. The procedures for conducting a systematic review, on the other hand, are formulated to be inclusive of the body of research evidence at the time the review is undertaken.
BOX 16.1 The Cochrane Collaboration
The impetus for developing the current procedures for systematic review can be traced to a 1979 letter written by Archie Cochrane (1908-1988), a British physician, who suggested that a critical summary of randomized clinical trials was needed in medical specialties to provide a reliable source of evidence for medical care.1
In 1993, The Cochrane Collaboration was initiated in his honor, creating an international not-for-profit organization, dedicated to promotion of clinical trials evidence and development and dissemination of systematic reviews of healthcare interventions.2 The principles of the Collaboration include ensuring quality of evidence by being open and responsive to criticism, applying advances in methodology, and developing systems for quality improvement.3 Twelve Cochrane Centres, located in countries around the world, take responsibility for supporting members through training and coordinating review activities.
The primary product of the Collaboration is the Cochrane Database of Systematic Reviews (see Chapter 31), which is published electronically four times a year as part of The Cochrane Library. These systematic reviews are prepared and regularly updated by 51 Review Groups that are made up of individuals interested in particular topic areas.4 Examples of topics include movement disorders, wounds, stroke, neuromuscular disease, back problems, developmental and learning problems, bone and joint trauma, and HIV/AIDS. Rigorous standards ...