A Decade of Post-Intensive Care Syndrome: A Bibliometric Network Analysis

Abstract

Background and Objectives: In 2012, the umbrella term post-intensive care syndrome (PICS) was introduced to capture functional long-term impairments of survivors of critical illness. We present a bibliometric network analysis of the PICS research field. Materials and Methods: The Web of Science core database was searched for articles published in 2012 or later using 'post-intensive care syndrome' and variant spellings. Using VOSviewer, we computed co-authorship networks of countries, institutions, and authors, as well as keyword co-occurrence networks. We determined each country's relative research effort and Category Normalized Citation Index over time and analyzed the 100 most-cited articles with respect to article type, country of origin, and publishing journal. Results: Our search yielded 379 articles, of which 373 were analyzed. Annual PICS research output increased from 11 (2012) to 95 articles (2020). Most PICS research originates from the US, followed by England, Australia, the Netherlands, and Germany. We found various collaborations between countries, institutions, and authors, with recent collaborative networks of English and Australian institutions. Article keywords cover aspects of cognitive, mental health, and physical impairments, and more recently, COVID-19. Only a few keywords and articles pertained to PICS prevention and treatment. Conclusions: Our analysis of Web of Science-indexed PICS articles highlights the stark increase in PICS research output in recent years, primarily originating from US- and Europe-based authors and institutions. Despite the research field's growth, knowledge gaps with respect to PICS prevention and treatment remain.

Keywords: PICS; bibliometric analysis; critical illness; intensive care unit; post-intensive care syndrome; research collaboration; research output; survivorship.

Figure 1

Study inclusion flowchart. ICU, intensive care unit; PICS, post-intensive care syndrome.

Figure 2

(A) Number of articles on post-intensive care syndrome, by year. Up to the Web of Science search on 7 September 2021, 78 articles were published in 2021. (B) Histogram of the number of citations per article (bin width of five citations). Eight articles with >100 citations (range: 125–939 citations) are not displayed.

Figure 3

Collaborations between countries among articles on post-intensive care syndrome. Co-authorship-based network. Lines between countries indicate direct links (i.e., co-authorships). Thicker lines are indicative of stronger links (i.e., more co-authorships). The further two countries are apart, the weaker is their relation. Colors indicate the average publication year of a country’s articles. A number of 26 countries with at least three publications were identified. Greece, Portugal, and South Korea were excluded as they did not have any connection to the network. Created using VOSviewer.

Figure 4

Collaborations between institutions among articles on post-intensive care syndrome. Co-authorship-based network. Lines between institutions indicate direct links (i.e., co-authorships). Thicker lines are indicative of stronger links (i.e., more co-authorships). The further two institutions are apart, the weaker is their relation. Colors indicate the average publication year of an institution’s articles. Institutions with at least four publications are shown. Five institutions were excluded as they did not show any connection with the network. Created using VOSviewer.

Figure 5

Keyword co-occurrence among articles on post-intensive care syndrome. Lines indicate direct keyword co-occurrences. Thicker lines are indicative for more direct keyword co-occurrences. The further two keywords are apart, the weaker is their relation. Colors indicate the average publication year of articles with the respective keyword. Keywords with at least five publications are shown. ^§ Abbreviation for the keyword ‘post-intensive care syndrome (pics)’. Created using VOSviewer.