General information
A total of 924 publications on the health of and interventions for family dementia caregivers published from 1988 to 2018 were identified through our search strategy in the WOS. A total of 722 titles were excluded, including 143 titles were unrelated to the study, 53 titles that did not primarily discuss this theme, and six duplicate titles. In addition, 180 articles were excluded, including 42 for which abstracts were not accessible and 138 for which the abstracts did not mainly discuss the health of and interventions for family dementia caregivers (Figure 1).Thus, the final number of full-length articles was 542. The papers were published by 2,328 authors in 177 journals and used 3232 keywords. The total number of citations was 11,289. The number of articles fluctuated during 1988–2005 and then began growing steadily in 2006. Of the included articles, 464 were published between 2006 and 2018, accounting for 85.6% (Figure 2A).
Country
The 542 articles were published in 43 countries, and the top 10 countries are shown in Figure 2B. The USA is the clear leader in terms of publication quantity (196, 36.2%), followed by the UK (70, 12.9%), and Australia (61, 11.3%). Figure S1A shows the changes in the number of publications over time and the national distribution characteristics, and Figure S1B shows the international cooperation. The USA is not only a major producer in this research field but also has more collaborations, primarily with China.
Institutions
The publications in this field were from 941 institutions. The top 10 institutions ranked by the number of articles published 141 articles, approximately 26.0% of the total (Table 1). The leading institutions that were most productive in terms of published articles were University College London, which published the greatest number (27, 5.0%), followed by Vrije University Amsterdam (19, 3.5%), and New York University (15, 2.8%). Among the top 10 institutions, four are in the USA, two are in the UK, two are in the Netherlands, and the other two are in China and Australia.
The top 30 institutions ranked by number of publications were subjected to a co-author analysis (Figure S2). The network map shows which institutions have close cooperation, such as University College London and King’s College London; University College London and the University of Nottingham; the University of Pittsburgh and the University of Miami; New York University and Columbia University; Vrije University Amsterdam and the University of Queensland; and the Chinese University of Hong Kong and Hong Kong Polytechnic University.
Journals
A total of 177 journals have published articles in this field. Nearly half of the publications were published in the top 10 journals (229, 43.7%) (Table 2). The International Journal of Geriatric Psychiatry, International Psychogeriatrics, and Aging & Mental Health published the most manuscripts. The Journal of the American Geriatrics Society shows the highest citation frequency per publication (64 times). The International Journal of Geriatric Psychiatry ranks second, with 27 citations per publication. This information, combined with the IF, indicates that the Journal of the American Geriatrics Society can be considered the most influential journal in the field of health intervention for dementia caregivers.
Authors, articles and references
The top 10 authors contributed a total of 105 papers related to health interventions for dementia caregivers, accounting for 19.3% of all the relevant published literature. Orrell M from the University of Nottingham in the UK published the most papers in this field (14 papers), followed by Gitlin LN from Drexel University in the USA (13 papers), and Mittelman MS from New York University (11 papers). The most-cited article was written by Mittelman MS, at 862 citations (Table 3). All articles were subjected to a bibliographic coupling analysis (bibliographic couplings exceeded five) to produce the network map shown in Figure S3. The connection between two nodes indicates that the articles have a common reference, and the weighting reflects the coupling strength of the two nodes. Thick connections indicate numerous common references between the two authors, that is, their study subjects are similar.
The ten most-cited articles in this field are presented in Table S2. The paper entitled "Meta-analysis of psychosocial interventions for caregivers of people with dementia” (2010), published in the Journal of the American Geriatrics Society by Brodaty H et al., was the most frequently cited, with 497 citations.
Twenty-four references with a citation frequency greater than 30 were selected to create the co-occurrence map, as shown in Figure S4, where each node represents a highly cited article. A large node indicates that the article has a high citation frequency. The connection between two nodes indicates co-citation, the thickness of the connection line reflects the intensity, and the Euclidean distance of the two nodes indicates the articles’ similarity. The reference titled “A Practical Method for Grading the Cognitive State of Patients for the Clinician”, published by Folstein MF in 1973, was the most frequently cited article.
Hotspots
The keywords of the 542 papers were analyzed using VOSviewer. As shown in Figure 3A, the 71 keywords (those used more than 10 times within abstracts of all the articles) were classified into five clusters: "Burden-related research“, “Depression- and stress-related research”, "Quality-of-life-related research“, “Methods and symptoms” and "Description and prevalence“.
In the “Burden-related research” cluster, the most commonly used keywords were “burden” (104 times), “health” (105 times), and “intervention” (46 times). In the cluster “Depression- and stress-related research”, the most commonly used keywords were “depression” (112 times), “stress” (36 times), and “impact” (35 times). In the cluster “Quality-of-life-related research”, the most commonly used keywords were “meta-analysis” (65 times), “quality of life” (48 times), and “psychosocial interventions” (29 times). In the cluster “Methods and symptoms“, the most commonly used keywords were “symptoms” (42 times), “randomized controlled trial” (37 times), and “validation” (23 times). In the cluster “Description and prevalence”, the most commonly used keywords were “Alzheimer’s disease/dementia” (282 times), “prevalence” (56 times), and “scale” (38 times).
We further analyzed the research hotspots in this field in 2017 and 2018, and VOSviewer applied colors to the keywords based on the year (2017 or 2018) that they appeared in the literature (Figure 3B). The results show that the keywords “psychosocial intervention” (6 times), “long-term” (5 times), “e-learning/online” (5 times), “communication" (5 times), “qualitative research” (5 times), “cognitive behavioral therapy” (4 times), “interaction/mixed methods” (3 times), and “music therapy” (3 times) may indicate the main research hotspots in recent years.