Basics of research (Part 2): Reviewing the literature.

Air Medical Journal 14:2 April-June 1995 In the first part of the Basics of Research series, you learned how to get started in research and how to formulate an appropriate research question. The next step in the process of developing a research project is to perform a comprehensive re view of the literature. The fundamental premise of the research question and subsequent selection of an appropriate study design depends on what gaps exist in our current understanding. These deficiencies must be assessed accurately to prevent wasting time, energy and resources in addressing a question that has been answered already. Thus, you become an expert on the current state of knowledge for the subject area. There are multiple ways to obtain a collection of articles in the area of interest. These include references from text chapters, article files from colleagues with knowledge or interest in the subject, references from articles and, finally, the formal literature search. While an author, in all probability, will use all of these methods, no research review is complete without a literature search. The literature search is an organized method of reviewing scientific information concerning a particular topic. Its fo cus is on journals. Journals are regarded as the principal vehicle for the communication of information in the medical community and have significant advantages over other information sources, such as texts. Their frequency of publication and shorter preparation time makes them a source for the most recent information, an extremely important point considering the rapidity with which health-care research generates new data.1 In addition, journals are the primary channel of communication between medical researchers and are the vehicle for the introduction of new ideas, concepts, proce dures, etc.2 In some journals, articles also are peer reviewed, which means after the paper is submitted individuals with either knowledge or experience concerning the topic of interest critique the study. This serves two basic functions. First, poorly designed, executed or written material is rejected and kept out of print. In actuality this works better as a concept than in practice, but it does mean that the paper must have cleared at least one hurdle prior to publication. Second, the reviewer may make suggestions to the authors to help improve the manuscript, such as clarifying certain sections, reorganizing, adding or deleting data or making other changes designed to improve the project. Thus, for all of these reasons, the journal remains the primary source of background information for any research effort. Searching the literature is much easier today than it was five to 10 years ago and can be accomplished through a variety of approaches. Previously, finding literature of interest required a slow search through large books such as the Index Medicus or Cumulative Index of Nursing and Allied Health Literature (CINAHL) that indexes health-care related literature by subject heading. If you were looking for research not covered by one of the Medical Subject Headings (MeSH) terms, your chances of finding resources were minimal. In the past, few individuals had knowledge of proper search techniques. Frequently, the assistance of a librarian was sought. A medical librarian is familiar with health-care terminology and the process for searching through this sub-