Abstract
This paper explores the features of the references cited in clinical practice guidelines. Two guidelines “Diabetes Clinical Practice Guidelines” and “Ovarian Cancer Treatment Guidelines” were selected. They had been revised three or more times, and the timing of these revisions was similar between the guidelines. The references in each version of each guideline were analyzed from three viewpoints: 1) year of issue and citation age; 2) continuation, addition, and deletion; and 3) research design. As the guidelines were formulated with an emphasis on evidence, there was a tendency for the citation age to be higher than that of the medical textbooks. When comparing the versions of each guideline, some of the later versions had lower citation ages than before they were revised. In the later versions, also, new and old citations were added and deleted, respectively, rather than just adding the new citations to those from the previous version.
