By Mohamed Ali Ag Ahmed, José Almirall, Patrice Ngangue, Marie-Eve Poitras, Martin Fortin

A bibliometric study published by our team in 2005 demonstrated that there was a large discrepancy between the prevalence of multimorbidity in the population and the number of research studies devoted to it at that time [1]. However, the interest in the topic has increased substantially and, thanks to the contributions of many researchers, our knowledge about multimorbidity is much better today than it was only a decade ago.

This time, we conducted a bibliometric analysis of publications on multimorbidity from 2005 to 2019 aiming to identify and analyze publications on the subject, including those that most influenced this field [2]. We searched for publications containing “multimorbidity” or “multi-morbidity” using the PubMed database, and identified them with the tool iCite (https://icite.od.nih.gov/). We analyzed the number of publications, total citations, the article-level metric Relative Citation Ratio (RCR), type of study, the country of the institutional affiliation of the authors, and journals with the most cited articles.

The number of publications using “multimorbidity” has continuously increased since 2005 (2005-2009: 138; 2010-2014: 823; 2015-2019: 3068). Articles with RCR at or above the 97th percentile (RCR = 7.43) were analyzed in detail (n = 104). In 34 publications of this subgroup (33%), the word multimorbidity was used but was not the subject of study. The remaining top 70 publications included 32 observational studies, 22 reviews, five guideline statements, three analysis papers, two randomized trials, three qualitative studies, two measurement development reports, and one conceptual framework development report. The publications were produced by authors from 32 countries. They were published in 37 different journals, ranging from one to four articles in the same journal.

This study showed the important progress made in accumulating knowledge on multimorbidity, with a continuous increase that included 76% of all publications only in the last quinquennium. Nonetheless, more high impact randomized trials and qualitative studies are needed in this field of research. Our study also suggests that these numbers should be taken with caution and considered a general trend because the analysis of a subgroup of publications showed that multimorbidity was not the subject of research in one third of the publications.

The article can be accessed at the following link:
https://journals.sagepub.com/doi/full/10.1177/2235042X20965283

1. Fortin M, Lapointe L, Hudon C , Vanasse A. Multimorbidity is common to family practice. Is it commonly researched? Can Fam Physician 2005;51:244-5.
2. Ag Ahmed MA, Almirall J, Ngangue P, Poitras M-E , Fortin M. A bibliometric analysis of multimorbidity from 2005 to 2019. Journal of Comorbidity 2020;10:1-7.