The process and importance of systematic reviews

The current emphasis within the NHS on clinical effectiveness involves the need to ensure that practice is based on knowledge derived from research rather than on strongly held tradition or personal experience. However, busy practitioners find it increasingly difficult to keep abreast of all available research. This is hardly surprising when one considers that there are over 20,000 biomedical journals which contain over two million articles each year ( 1 ). These articles vary greatly in quality and often are not well indexed. Practitioners involved in patient care rarely have the time, resources and skills to gather together and critically appraise relevant research in an effort to inform their practice. However, one way of pulling together unmanageable amounts of research is through a systematic review ( 2 ): 'A systematic- review is the process of systematically locating, appraising and synthesising evidence from scientific studies in order to obtain a reliable overview.'