Ensuring Scientific Rigour in Literature Review

Abstract

Literature reviews are an important method of summarising scientific data. However, many reviews are not themselves scientific. This has lead to some being inaccurate, on occasion dangerously so. Systematic literature reviews should involve six key elements: a clearly focused question; a thorough search for relevant studies; explicit criteria for including studies in the review; explicit criteria for judging the validity of the studies; an appropriate method of data synthesis; and suitable interpretation of the data presented. These ensure that the review is replicable and that reasons for the author's conclusions are explicit. Systematic reviews require considerable skills and resources. It is unlikely that all future reviews published in complementary medicine journals will constitute methodologically sound systematic reviews. It is suggested that authors of non-systematic reviews reflect on the possible shortcomings of their work and avoid making strong recommendations. Researchers should learn the skills of literature searching and critical appraisal.