Evaluating Medical Studies (cont.)
The study was seriously flawed and it made me wonder why a newspaper would report on such a study. Perhaps just as important, the newspaper article did not provide either a critical evaluation of the study or enough information about the study so that the reader could critically evaluate it. Then, I began to wonder if people understood what is involved in a critical evaluation of a medical study. Careful physicians always critically review new information so that they can decide whether or not a study's findings should be used in caring for patients. I decided that it might be useful to describe how I review a medical study.
A published medical study usually has several parts. There is a title, which tells what the study is about and a list of the study's authors, the researchers who did the study. These are followed by a brief summary, or abstract, of the entire published study. The body of the published study includes an introduction, which presents background information to put the study into scientific perspective, and also provides a purpose or aim for the study. What follows next is a description of the methods used in the study, a presentation of the study's results, and finally a discussion of the results.
The first thing I do is look at the title of the article. If the title suggests that the study will be of interest to me, I will read the abstract. If not, I'll move on to the next study. If, after reading the abstract, I feel that the study may be a good one, I then look at the list of authors. If I recognize the authors as experts in the area of the study's research, it suggests to me that the study is likely to be well-done. Then I read the methods. If the methods used in the study are not good, there is no point in reading further. Bad methods always yield bad results. If the methods seem sound, I'll then read the introduction, results, and the discussion. You may notice, I don't get to the "meat" of the study until I have determined that the results are likely to be valid.
How did the study reported by the newspaper stack up? First of all, the study appeared in a second-tier journal, that is, a journal that does not usually publish the best studies. Despite the fact that many research studies are published, only a minority of them are well-done. The first-tier journals are very careful about the studies they publish. In these journals, studies are chosen for publication only after two or more scientists who know the area of research have critically reviewed the study. The reviewers can accept the study, reject it, or ask the authors to clarify or modify it. Only studies that hold up under critical, expert scrutiny and present new information are chosen. Second-tier journals also have expert reviewers for the studies they publish, but the first-tier journals usually receive the best studies first, and the standards of the second-tier journals therefore tend to be lower. Nevertheless, good studies do appear in second-tier journals. For example, they may present studies that hold up under critical review but do not report new information.
Medically Reviewed by a Doctor on 12/1/2014