77) in the disciplines of health services research, health care evaluation , policy, health economics, quality improvement, management and clinical research focused on the quality of care and patient safety. For every paper, its keywords play a vital part for dissemination of its findings. These keywords are freely available to all users and get sent to many online sources, from which users und...

Authors are requested to select key words from the following list. You may use plurals and adjectives for combinations like absolute pupillary response, centrifugal optic nerve, inter blobs, etc. If key words are needed which do not appear in this list, please underline them. For animal classification the Latin nomenclature should be used. p-mechanism A-scan a-wave aberration absolute absorptio...

In this paper, choosing highly frequent keywords from core journals in the field of 1992-2013 national knowledge discovery in CNKI database, counting the number of two frequent keywords co-occurrences in the same journal, then constructing the highly frequent keywords matrix, and transforming the highly frequent keywords matrix into a correlation matrix and a dissimilarity matrix, we analyze th...