Mapping the knowledge structure of frailty in journal articles by text network analysis.

BACKGROUNDS: This study was to understand the trends of frailty research and networking features of keywords from the academic articles focusing on frailty in the last four decades.

METHOD: Keywords were extracted from articles (n = 6,424) retrieved from Web of Science, from 1981 to April 2016, using Bibexcel, and a social network analysis was conducted using Net Miner.

RESULTS: The core-keywords of research on frailty are constantly changing over the last 40 years. The keywords were tended to focus on impact in the 1980s, and moved to the determinants (i.e., malnutrition) in the 1990s and the 2000s, and in the 2010s, most of keywords were about determinants and measurement of frailty. In the early stages of frailty research, individual behaviour modifications were emphasized as intervention. Keywords with the highest degree centralities were 'impact' (1980s), 'frailty' (1990s), 'home care' (2000s), and 'dementia' (2010s). Keywords with the highest betweenness centralities were 'model' (1980s), 'frailty' (1990s), 'chronic disease' (2000s), and 'malnutrition' (2010s).

DISCUSSION: This study provides a systematic overview of frailty knowledge development. 'Dementia' was found to be the keyword with the highest degree centrality, showing that studies on cognitive function are those being most actively conducted in recent decade. In the 2000s frailty research, sub-themes were sarcopenia, dementia and disability, indicating that frailty was investigated from the view of disease. In the 2010s, obesity, nutrition, prevention, evaluation, and ADL (activities of daily living) were sub-themes of the research network that focused on frailty prevention.