A Bibliometric Analysis of Older Adult Population Research Published in Biological Research for Nursing

Abstract

The global increase in older adults places greater demands on understanding how body tissues change structurally and physiologically with age. Given this demographic trend and Biological Research for Nursing’s focus on biological or biobehavioral outcomes, we analyzed the scientific production and impact, including citation count, of 87 relevant research papers published in this journal between 2002 and 2024. Using the OpenAlex database and VOSviewer, we found that the five papers published in 2018 accrued the highest citation count of 227. Among 81 articles, 12 research fronts were identified, with physical activity, frailty, sleep, and/or cognition included in several of them. A co-occurrence network of 102 authors’ terms/keywords generated five clusters, where the three terms with the largest nodes were medicine, internal medicine, and physical therapy. Terms associated with more current research papers included inflammation, quality of life, economics, and grip strength. Regarding location, the United States dominated the country network but showed strong collaborative links with European and Asian nations. The author network consisted of 398 authors; however, less than 10% demonstrated strong collaborations. Therefore, Biological Research for Nursing, with its focus on nursing perspectives regarding aging-related biological and behavioral dimensions of health, serves as a key platform for evidence-based, holistic gerontological health care.

According to He et al. (2016), we live in an aging world. Current assessments indicate that by 2050, the number of individuals aged 65 or older will increase by 2.5-fold, and those aged 80 or older by 3.5-fold (He et al., 2016); additionally, approximately two thirds of older adults will live in Asia (He et al., 2016). By 2060, the Centers for Disease Control and Prevention (2024) estimates that nearly 25% of the U.S. population will be 65 years or older.

As part of aging, body tissues change structurally and physiologically. For instance, human muscle mass loss, which can lead to sarcopenia, often begins as early as the mid-20s (Lexell et al., 1988; Ceyhan et al., 2025). Older adults, likewise, frequently develop insulin resistance, substantially increasing their risk for metabolic conditions like diabetes mellitus and atherosclerosis (Hao et al., 2025). The decline in estrogen levels in older women also predisposes them to serious health concerns, including cardiovascular problems (Fasero & Coronado, 2025) and osteoporosis (Stokes et al., 2025). Aging can also affect intellectual or cognitive functioning (Fernández-Rubio et al., 2025; Sánchez-Izquierdo & Fernández-Ballesteros, 2021). Underlying many of these body tissue changes is inflammaging and/or senescence (Fetarayani et al., 2025; Moscucci et al., 2025; Pellegrini et al., 2024; Wang et al., 2025). Therefore, biological or biobehavioral nursing research intersects with aging by addressing these changes or mechanisms to promote the healthy aging and living of older adults.

Biological Research for Nursing (BRN) is dedicated to disseminating research on biological or biobehavioral outcomes across a wide range of conditions and ages. With the growing older adult population and BRN’s focus on such outcomes, we used bibliometric methods to map and analyze the older adult research papers published in the journal.

Bibliometrics (Pritchard, 1969) and science mapping (Börner et al., 2005) can aid in guiding journal strategic development, strengthening a journal’s position in the global research landscape, and enhancing collaboration among investigators.

Nursing journals are frequently the subject of bibliometric analysis, covering topics ranging from specific nursing subject matter (e.g., nursing theory; Zhu et al., 2024) to broad, clinically related research (e.g., geriatric nursing research; Ghamgosar et al., 2021). In the late 2010s/early 2020s, several journals published bibliometric analyses, including Clinical Simulation in Nursing (Kokol et al., 2017), Journal of Advanced Nursing (Železnik et al., 2017), The Canadian Nurse (Marcellus, 2019), and Journal of Nursing Management (Yanbing et al., 2020). These analyses identified publication themes inherent to each journal, suggesting that the articles published aligned with its aims, scope, and/or subject matter of importance. This analysis also provided insight into the journal and its readership regarding growth and decline in scientific production, publication quality indicators (e.g., average author number, impact factor), and investigators’ characteristics (Kokol et al., 2017; Marcellus, 2019; Yanbing et al., 2020; Železnik et al., 2017). Expanding beyond one journal and specialty journals, Giménez-Espert and Prado-Gascó (2019) conducted a bibliometric analysis of six nursing journals with a high Science Citation Index impact factor (>1.1 from 2012 to 2016), which included International Journal of Nursing Studies, Journal of Advanced Nursing, Journal of Nursing Scholarship, Nurse Education Today, Nursing Outlook, and Worldviews on Evidence-Based Nursing. In their keyword co-occurrence analysis, Giménez-Espert and Prado-Gascó (2019) found that patient was a predominant term, indicating that clinical nursing research is a common focus of papers published in high-impact, non-specialty nursing journals. Collectively, these bibliometric analyses involving distinct journals establish the scope and/or core subject matter of these journals.

Given the patient as a focus in high-impact nursing journals (Giménez-Espert & Prado-Gascó, 2019), another bibliometric approach is to analyze papers based on specific patient populations in non-specialty journals, such as older adults in BRN. To our knowledge, older adult population research emphasizing nursing-related biological and biobehavioral outcomes has not been examined from a bibliometric perspective.

The main purpose of this study was to conduct a bibliometric analysis of biological and biobehavioral BRN research papers involving older adults using the OpenAlex (n.d.) database. The specific aims were to (a) analyze BRN publication trends related to older adult population research, including the annual publications and citation patterns; (b) map the pattern of collaborating authors, institutions, and countries; and (c) explore keyword co-occurrence networks and research fronts (Shibata et al., 2008; Small & Griffith, 1974). This evidence could inform editorial decisions that strengthen BRN’s position as a leading outlet for interdisciplinary, evidence-based research on the biological and behavioral dimensions of aging.

Methods

Search Strategy and Dataset

We initially searched the Sage database from January 1, 1999, to December 31, 2024, for original research reports published in BRN that included older subjects (≥50 years), yielding 90 published articles as of March 6, 2025. However, the Sage database proved limited for bibliometric analysis because it lacks the large-scale, standardized metadata needed for mapping trends, collaborations, and citations (van Bellen et al., 2025). (During our search, we observed that the Sage database may list the Epub year as the date of publication. Therefore, this analysis is based on the Sage database listed publication date). To overcome this metadata limitation, we used OpenAlex, PubMed, and the Web of Science to examine the scope of older adult population research published in BRN. OpenAlex (n.d.) yielded the most complete number of papers in this field. This is likely because the platform has broad disciplinary coverage and is considered an appropriate source for bibliometric studies, making it valuable for analyzing biological and biobehavioral nursing research (Thelwall & Jiang, 2025).

OpenAlex (n.d.) allowed us to search by the journal’s full title, Biological Research for Nursing, then refine the search by the digital object identifier of the 90 published articles, resulting in a final set of 87 original papers by July 25, 2025. The last step involved using the OpenAlex IDs of the 87 articles to construct the OpenAlex API link and integrate it into VOSviewer (van Eck & Waltman, 2010), facilitating the construction of bibliometric networks.

Paths of Analysis

We used VOSviewer v.1.6.20 to visualize bibliometric networks (van Eck & Waltman, 2010), enabling us to explore the intellectual structure of this field, identify key themes, and uncover collaboration and citation patterns. Using this science-mapping tool’s capability to implement graph-theoretical approaches in the context of bibliometric networks (Börner et al., 2020; Boyack et al., 2005), we used bibliographic coupling (Kessler, 1963) to explore the underlying research fronts (Shibata et al., 2008; Small & Griffith, 1974) and used frequently cited works to identify the most influential points in the older adult population knowledge structure published in BRN. The software also facilitated the discovery of country- and institutional-level collaborations through its network and overlay visualizations (van Eck & Waltman, 2010).

Additionally, we used—Lin/Log Modularity method and Bibliometrix tool—for data visualization. Lin/Log Modularity (clustering method) supplied a clustered visualization of the networks, where each color represents a group of related items (Du et al., 2024). This method helped to reveal a network with more structured clusters of nodes, such as the groups of keywords that often co-occur in this discipline. Bibliometrix (Aria & Cuccurullo, 2017), an RStudio library, facilitated the creation of the three-field plot (authors–author’s keywords–institutions) to show how research themes in BRN are distributed across leading scholars and their affiliated institutions.

The evolution of the normalized impact of research on the older adult population, as published in BRN, was analyzed using the Median Field-Weighted Citation Impact (FWCI; Purkayastha et al., 2019). The Median FWCI offers insight into the typical paper’s performance and is a more robust measure of citation performance because it is less influenced by outliers.

Results

Descriptive Analysis

The earliest paper that met the inclusion criteria was published in 2002. Figure 1 presents the annual distribution of publications and the citations per year, on older adult population research papers published in BRN between 2002 and 2024. Over this period, 87 papers were published, generating 1,536 citations, for an average of 17.65 citations per paper (CPP). The annual growth rate of publication output during this period was 6.5%, indicating a steady, sustained increase in research productivity related to this population.

Figure 1.

Evolution of scientific production and citation patterns in BRN (2002–2024)

There were notable fluctuations in both scientific production and citation impact (Figure 1). Early output was modest, with one or two papers per year from 2002 to 2005, followed by a surge of three papers in 2006 that coincided with a peak of 196 citations. Another major citation spike occurred in 2018, when five papers were published and received 227 citations, marking the highest single-year citation impact in the dataset. In contrast, the highest publication volume was observed in 2022, with 11 papers, though these achieved a moderate citation count of 70.

Overall, the trend suggests that while publication output gradually increased in recent years (particularly from 2018 onward), citation impact was uneven, often concentrated in specific years or in individual papers that received a high number of citations.

Figure 2 compares the Median FWCI with the global baseline Median FWCI set at 0.4 (Elsevier, n.d.). The Median FWCI of these papers shows yearly variability, reflecting fluctuations in the normalized citation performance across different cohorts.

Figure 2.

Normalized citation performance using Median Field-Weighted Citation Impact (Median FWCI)

Early years (2002–2007) exhibited inconsistent performance, with values ranging from 0.17 (2002) to 2.95 (2006), suggesting occasional, normalized high-impact article values. From 2010 to 2014, the Median FWCI gradually increased, peaking at 2.35 in 2014, indicating stronger alignment with impactful global research.

The most notable peaks occurred in 2016 (3.34) and 2018 (3.42), where the median citation impact was more than three times the world average, underscoring periods of exceptional influence and visibility. However, the sharp drop to 0.00 in 2015 and low points in 2012 (0.26) and 2021–2022 (0.72–0.77) revealed vulnerabilities in which the journal’s papers had below-average impact relative to the global standard.

In more recent years (2023–2024), BRN’s Median FWCI stabilized above the global Median FWCI (1.68 in 2023 and 1.30 in 2024). These values suggest improved and sustained visibility for work in this journal for this domain.

The long citation trend showed repeated instances in which BRN outperformed the world baseline. The years 2013, 2016, 2018, and 2024 demonstrated the journal’s capacity to publish highly influential contributions centered on integrating physical activity, lifestyle interventions, and mind-body practices to improve biological and functional outcomes in older adults, with evidence spanning mental health, metabolic health, cancer survivorship, physical function, and chronic disease management.

A three-field plot (authors–author’s keywords–institutions) provides a clear visualization of how research themes in BRN are distributed across leading scholars and their affiliated institutions (Figure 3). On the left, authors such as Maria Yefimova, Diana Lynn Woods, Kathleen C. Insel, and Barbara Resnick appear as central contributors (Supplemental File Table 1). In the middle, the dominant keywords—such as quantitative sensory testing, sleep, cognitive decline, depression, cross-sectional study, and cortisol awakening response—highlight the main categories of the older adult population. On the right, institutions such as the University of Maryland School of Nursing, University of Valencia, University of California, University of Arizona, and University of Washington reflect hubs of productivity (Supplemental File Table 2). The visualization thus illustrates the alignment between influential authors, their key research topics, and the institutions driving these studies, offering insight into the intellectual and collaborative landscape of older adult–focused nursing research.

Figure 3.

A three-field plot of authors (left), author’s keywords (middle), and institutions (right)

Main Research Fronts

A thematic overview of biological and biobehavioral research focused on older adults was created using the classic bibliometric method of bibliographic coupling (Kessler, 1963) to identify the main research fronts organized in clusters (Figure 4). The main component of the bibliographic coupling network revealed 12 thematic clusters, encompassing 81 of the 87 analyzed articles. In this mapping, three papers were excluded because they did not meet the minimum threshold of one shared citation required to establish a connection with other research papers; these papers remained isolated, showing no bibliographic coupling links within the network. Bibliometric coupling showed that most publications were interrelated through shared references, reflecting a well-connected intellectual structure. However, a small portion of the papers lay at the periphery of the network.

Figure 4.

Visualization of research fronts using a bibliographic coupling network

Each cluster represents a distinct research front—that is, a group of studies sharing references (Figure 4). This network provides scientific knowledge based on older adult papers published in BRN. Central clusters (mapped in the center of the network) are represented by clusters 1 (red), 2 (green), 3 (blue), 4 (yellow), 5 (purple), 6 (aqua), 7 (orange), and 11 (light green). The peripheral clusters (mapped away from the network’s center) are 8 (brown), 9 (pink), 10 (salmon), and 12 (light blue).

Physical activity as a self-regulation strategy is the major research front that describes cluster 1 (red). The authors highlight the importance of promoting movement and fitness to counteract aging-related health decline (Ibrahim et al., 2023; Jessup et al., 2003) and reinforce nursing science’s contribution to behavioral health promotion and chronic disease prevention among older adults (Wallmann et al., 2008; Wu et al., 2016).

Interactions between physical activity and health mechanisms is another relevant research front (cluster 2; green). These papers focus on integrative models linking lifestyle behaviors and physiological outcomes (Wang et al., 2020; Winkelman et al., 2018).

Frailty, functional status, and/or body mass is the research front of cluster 3 (blue). One study focuses on identifying biological and functional parameters to distinguish frailty among long-term care residents (Arrieta et al., 2022), whereas another examines the relationship between allostatic load and frailty (Szanton et al., 2008). The scope of these papers indicates a deep level of investigation into frailty and overall functioning.

Cluster 4 (yellow) addresses aging-related behavioral issues or serious health conditions based on gene polymorphisms or protein levels. These studies include variables such as depression, sleep quality, and cognitive decline (Lee et al., 2022; Merriman et al., 2013; Tang et al., 2019).

Testing cognitive or physical activity interventions or outcomes related to brain health describes cluster 5 (purple). Studies test exercise, mindfulness, or behavioral strategies to maintain brain and body health (Halloway et al., 2017; Lengacher et al., 2018; Newland et al., 2021; Starkweather, 2007).

Sleepiness–awakeness–brain health with or without cortisol levels is cluster 6 (aqua). Most papers in this research front are authored by the same research team (Woods et al., 2010, 2011; Woods & Martin, 2007; Woods & Yefimova, 2012), and these papers explore the biological pathways linked to sleep and cognitive performance. Another study shows how sleepiness, circadian rhythm, and brain activation affect cognitive aging and dementia risk (Kim et al., 2022).

The research front, Detecting brain health and biomarkers (cluster 7, orange), includes papers on detecting and monitoring biomarkers or other assessments associated with brain health. For example, two of the studies investigated salivary cortisol (Davis et al., 2004) or a urinary oxidative stress marker (Insel et al., 2011). Cole et al. (2011) used a computerized test administered in the home environment to evaluate attention in persons with dementia.

Cluster 8 (brown) analyzes the importance of functional health management in older adults living with multimorbidity (Ahn et al., 2019; Klinedinst et al., 2022; Ogai et al., 2020). This multimorbidity includes chronic conditions such as osteoarthritis and restricted mobility, along with pain or skin breakdown.

Several papers in cluster 9 (pink) address traumatic brain injury and its biological and behavioral consequences in older adults (Bouferguène et al., 2019; Bouferguène et al., 2020; Martha et al., 2020). Cluster 9 is one of the emerging fronts, reflecting the journal’s growing responsiveness to new scientific developments and its potential to strengthen leadership in gerontological and behavioral health research.

Physical activity/function and/or cognition in relation to inflammation or gene polymorphisms is the research front for cluster 10 (salmon). For example, Park et al. (2021) explored the genetic underpinnings of healthy cognitive aging.

The final two research fronts are smaller clusters. Cluster 11 (light green) includes one paper focused on type 2 diabetes and its relationships with biobehavioral factors such as lifestyle, metabolic regulation, and cognitive function (Gatlin & Insel, 2014). Cluster 12 (light blue) addresses negative symptoms that affect quality of life in older adults with mental or cognitive disorders (Binford et al., 2017; Leutwyler et al., 2013).

Keyword Co-Occurrence Analysis

To identify the main research themes, evolving focus areas, and conceptual structure, we performed a keyword co-occurrence analysis using the keywords from papers published in BRN involving the older adult population. We grouped keywords into color-coded clusters, each representing a thematic area or research topic (Figure 5). The size of each node represents the frequency of keyword occurrence in the dataset. The Supplemental File Figure shows the evolution of these clusters over time.

Figure 5.

Network of co-occurring keywords in BRN publications including older adults

Broader terms (e.g., medicine, psychology, and internal medicine) are main concepts in this research field. The keyword co-occurrence cluster map reveals the multidisciplinary structure of research in this domain, with several distinct yet interconnected thematic clusters.

The red cluster (Figure 5) dominated by medicine, internal medicine, physical therapy, and pathology, represents the clinical and physiological foundations of biobehavioral nursing research. This cluster highlights BRN’s emphasis from 2014 to 2016 on rehabilitation, chronic disease management, and physiological outcomes, including studies addressing type 2 diabetes and other metabolic disorders (Supplemental File Figure). The prominence of these topics reflects nursing science’s enduring contribution to clinical practice through promoting healthy living and managing age-related physiological decline.

Another major cluster (green, Figure 5), anchored by psychology, psychiatry, cognition, and clinical psychology, reflects the biobehavioral and cognitive dimensions of aging that gained momentum between 2016 and 2018 (Supplemental File Figure). Those keywords integrate mental health, cognition, and emotional regulation with biological processes, including work on genomics and oncology. This cluster illustrates the journal’s evolution toward integrating molecular and psychological approaches to understand the mind–body relationship in older adults.

Cluster 3 (blue, Figure 5) groups terms such as population, environmental health, economics, and statistics, pointing to a broader epidemiological and systems-level perspective on aging research. The inclusion of inflammation, C-reactive protein, and systemic inflammation means a growing focus on biochemical and molecular markers, linking environmental and social determinants with biological mechanisms. This cluster represents BRN’s more recent phase, from 2020 to 2024, marked by a transition toward integrative and multidisciplinary frameworks that connect biochemistry, genetics, and neuropsychology (Supplemental File Figure).

Cluster 4 (yellow), centered around dementia, physiology, circadian rhythm, and sleep, captures the journal’s sustained interest in neurodegeneration and biological rhythms. Research in this domain links physiological regulation to cognitive decline, emphasizing the relevance of sleep and circadian processes in geriatric health and cognitive aging.

Cluster 5 (purple) stresses terms such as computer science, polysomnography, and neuroscience, underscoring the technological and methodological innovation underpinning recent BRN research. These studies leverage advanced measurement techniques and computational tools to explore biobehavioral mechanisms, reflecting the journal’s increasing engagement with technological and methodological innovations to advance health and behavior.

Collaboration Analysis

This section primarily focuses on descriptive and exploratory analyses to outline co-authorship as a central driver of scientific advancement in this topic. A total of 18 countries were represented in the published papers on older adult populations. Figure 6 illustrates the country’s collaboration network. Each node represents a country, with node size indicating research output, and links showing international co-authorships. The network consists of nine countries.

Figure 6.

Mapping of the nine-country collaboration network in older adult population publications

The United States dominates the network as the central hub, reflecting its leading role in both publication volume and international collaboration. Strong connections link the United States with China, Taiwan, South Korea, and Hong Kong SAR, underscoring active partnerships across East Asia. Additional collaborations are evident with academic institutions from Sweden, the Netherlands, Spain, and Chile.

Figure 7 displays 157 institutions in collaboration focused on older adult research published in BRN (2002–2024). Each node represents an institution, and the node size corresponds to its productivity, while the connecting lines (edges) indicate co-authorship links across institutions.

Figure 7.

Mapping the institutional collaboration network

The red cluster includes a total of 13 academic institutions, such as the University of Washington, Oregon Health & Science University, and Washington State University. Institutions in the red cluster are connected to those in the blue cluster, such as the University of Pittsburgh and the University of Pennsylvania, indicating strong collaborations in public health and clinical research.

The green cluster is the second-largest cluster in the network, with 12 institutions from Europe. This cluster of institutions connects INSERM, Université Paris Sciences et Lettres, Normandie Université, Trinity College Dublin, and other European institutions.

The University of Florida, the University of Texas Health Science Center at Houston, and Emory University are part of a tightly linked U.S.-based cluster (pink) that includes healthcare-focused institutions like Methodist Hospital.

Overall, the network shows both nationally concentrated partnerships within the United States and international collaborations linking North America, Europe, and Asia. The structure highlights how geriatric-focused nursing research is anchored in a small number of U.S. universities while also extending into global partnerships that diversify the research base.

The author’s collaboration network (Figure 8) visualizes the connections among 398 researchers who have published in BRN on topics related to the older adult population. Each node represents an author, and the node size reflects the number of publications; the links indicate co-authorship relationships. The color-coded clusters represent different collaboration communities or research groups.

Figure 8.

Mapping of the author collaboration network

The map reveals a collaborative structure with several distinct interconnected clusters, suggesting both disciplinary diversity and thematic specialization within BRN. Central nodes such as Kathleen C. Insel, Diana Lynn Woods, Rose Ann DiMaria-Ghalili, Barbara W. Carlson, and Thomas P. McCoy act as important collaboration hubs, linking multiple research groups and fostering interdisciplinary connections. These clusters illustrate collaborations across areas such as clinical nursing, gerontology, cognitive health, biobehavioral research, and physiological studies (Figure 8).

The densest clusters are represented by a total of 32 authors (Figure 9). With multiple links between Drs. Merriman and Conley, we explored this connection using internet resources. We determined that Dr. Conley, at the time of this investigation, served as Dr. Merriman’s postdoctoral mentor at the University of Pittsburgh. This connection exemplifies how the postdoctoral mentor-mentee relationship can lead to a high degree of enriched new scientific production (Figure 9).

Figure 9.

Mapping of the densest author collaboration network

Discussion

Although bibliometric analyses have been conducted in the field of gerontology or geriatics (Ang & Kwan, 2017; Ch’ng et al., 2017; Chen et al., 2025; Ghamgosar et al., 2021; Gonzalez-Alcaide et al., 2021; Han et al., 2025; Lund & Wang, 2020; Müller et al., 2016), to our knowledge, the current bibliometric study is novel in emphasizing nursing-related biological and biobehavioral outcomes in the older adult population research. Across the 23-year period examined in this study, one major finding is that approximately 80% of the years have a Median FWCI value above the global Median FCWI value. A second significant finding was the identification of well-established research fronts of papers published in BRN (e.g., physical activity as a self-practice or self-management and ecosystem preservation and interactions among physical activity, sleep, inflammation, cognition, and/or cardiovascular conditions). Finally, we identified new research fronts that may reflect a widening of the biological and biobehavioral scope of the journal, focusing on brain health, cognition, and behavior.

Normalized citation-based indicators, such as FWCI (Elsevier, n.d.), can aid in illustrating a research paper’s and a journal’s visibility and impact. Simply, the higher the FWCI value, the more visible and impactful the research (Purkayastha et al., 2019). In this dataset of papers related to the older adult population, the five years with the highest Median FWCI were 2006, 2013, 2014, 2016, and 2018. In scanning the titles of these research papers, approximately one third focused on physical activity or functional status. For the researchers, this may mean that BRN is an effective dissemination channel for reaching the appropriate consumers of this research. For BRN, this may mean the journal attracts both authors and readers interested in these older adult topics. As such, these topics may be important to the journal’s visibility and its contribution to nursing science.

Although nurse researchers who study biological or biobehavioral phenomena are limited (Kang et al., 2010; Roberts & D'Errico, 2023; Schaffer & Yucha, 2005), the landscape of biological phenomena, especially related to aging, is abundant (Bartolomucci et al., 2024; Ceyhan et al., 2025; Fasero & Coronado, 2025; Fernández-Rubio et al., 2025; Hao et al., 2025; Lexell et al., 1988; Sánchez-Izquierdo & Fernández-Ballesteros, 2021; Stokes et al., 2025). We used bibliographic coupling (Kessler, 1963) to uncover the foci or research fronts studied by researchers focusing on the older adult population and publishing in BRN. Two well-established research fronts that we found are (a) physical activity as a self-practice or self-management and ecosystem preservation and (b) interactions among physical activity, sleep, inflammation, cognition, and/or cardiovascular conditions. While physical activity is well-known for its healthful effects, its distinction as a research front in this journal is surprising as it is not typical core curricular content in nursing research-focused programs (American Association of Colleges of Nursing, n.d.). Although, McEwen and Bechtel (2000) identified that exercise physiology is one research focus of the Johns Hopkins University doctoral nursing program, and Dieckmann et al. (2022) reported that exercise and weight management was 1 of 24 topics found while examining publicly accessible PhD dissertation abstracts from 2015 to 2019. However, if physical activity is viewed as self-practice or as a non-pharmacological management strategy, then this topic aligns well with the discipline and profession of nursing. The roots of the discipline and profession of nursing are centered on finding non-pharmacological interventions or coaching patients or healthy individuals to engage in these kinds of practices to manage chronic illness or maintain healthy aging, respectively.

This visibility of physical activity as wholly or partly identified as a research front in geriatric-related research is consistent with other bibliometric analyses. For example, Müller et al. (2016) reported that the majority of highly-cited physical activity publications involving older adults were focused on physical activity effects on health or the relations between health and physical activity. In their bibliometric cluster analysis of keywords, Ding et al. (2024) identified physical activity as a top keyword in older-adult-subjective-cognitive-decline studies. Recently, Han et al. (2025) conducted a bibliometric analysis of research focused on digital health technologies, physical activity, and cognition in older adults and found that the number of publications increased from 2 in 2011 to 37 in 2024. These findings indicate that BRN older-adult physical activity research contributes to the knowledge domain of physical activity and older adults similar to other journals, such as the Journal of Aging and Physical Activity (Müller et al., 2016), Neurology (Ding et al., 2024), and Frontiers in Aging Neuroscience (Han et al., 2025).

For more recent years, the bibliometric network analysis based on bibliographic coupling revealed emerging research fronts (clusters 5 and 7) focused on brain health, cognition, and behavior. Although cognition, mental health, and other brain-related issues have always been a concern for nursing, recent national developments may have spurred greater nursing research interest in these areas. From 2001 to 2014, three Middle East conflicts (Enduring Freedom, Iraqi Freedom, and New Dawn) involved U.S. service members (Defense Manpower Data Center, n.d.), and traumatic brain injury was a common blast-related casualty (Agimi et al., 2019). This health problem led the U.S. Congress, starting in fiscal year 2007, to fund traumatic brain injury and psychological health research (Congressionally Directed Medical Research Programs, 2025). In 2013, the National Institutes of Health (2025) established The Brain Research Through Advancing Innovative Neurotechnologies® Initiative (The BRAIN Initiative®). In addition to the national level, brain health research initiatives may be present at the state level. For example, in 2025, Texas voters approved a constitutional amendment to create the Dementia Prevention Research Institute of Texas (Langford, 2025).

A surge in nursing research related to the brain is also evident in the PubMed database. A quick search (November 2025) of the keywords brain and “nursing research” generates 895 results from 1974 to 2026, and 92% of these results occur between 2007 and 2026. In addition, modifying the PubMed search to “older adults” generates an initial publication in 2013, with 96% of the publications between 2018 and 2025. Therefore, the Middle East conflicts, national initiatives, and publication trends may explain the emergence of nursing research fronts focused on brain health, cognition, and behavior.

As shown by this and other bibliometric analyses, keywords, which are single or multiple terms, are important elements in demonstrating scientific production and impact. With the rise in bibliometric analyses, keywords become even more important for a scientist or research team’s visibility (Pottier et al., 2024). Keywords identified in the study network include both single and multiple terms as well as specific (e.g., cortisol, C-reactive protein, and grip strength) and broad (e.g., genetics and physical therapy) terms. Interestingly, in the network, the terms medicine and internal medicine exhibit the largest nodes and outsize the term nursing. However, as shown in the Supplemental File Figure, these terms may reflect keywords used in earlier papers.

Another value of bibliometric analysis is that it shows collaborations among countries, authors, and institutions (Duan, 2024). Generally, research collaborations, or team science, are critical to today’s scientific productivity, funding, and impact (National Academies of Sciences, Engineering, and Medicine, 2025). In addition, cross-country collaborations are important for addressing global health problems. Country, author, and institutional collaborations were evident in the papers on the older adult population published in BRN. Overall, the country–author collaborations seemed limited. Less than 10% of the authors were present in dense clusters, and the United States was the only hub country. Other bibliometric analyses of geriatric-related research have found this prominence of the United States (Chen et al., 2025; Ghamgosar et al., 2021; Gonzalez-Alcaide et al., 2021; Lund & Wang, 2020). The activity among institutions appeared stronger. Approximately five institutions composed each institutional cluster (157 institutions divided into 34 clusters), although at least three clusters had more than 10 institutions. One growth area could be links between the European institutional cluster (green) and the American-Asian institutional clusters.

This study has limitations. Because our focus was on original papers published in BRN on the older adult population, this bibliometric analysis did not examine productivity and impact indicators for papers related to other populations (e.g., maternal-child and young adult). We also did not benchmark these indicators across the different populations. Therefore, we cannot address whether these indicator values associated with the older adult population papers represent the strongest values of BRN. For example, although we observed high Median FWCI values during the study period, we do not know their ranking relative to other population-specific papers published in BRN.

Another limitation of this study is the exclusion of data from the Web of Science Core Collection. Although the Web of Science is a commonly used database for geriatric-related bibliometric analyses (Chen et al., 2025; Ghamgosar et al., 2021; Gonzalez-Alcaide et al., 2021; Lund & Wang, 2020), we could not use it because BRN papers before 2006 are not indexed, even though the journal began publishing papers in 1999. Nonetheless, this limitation was mitigated by using OpenAlex, an openly accessible and comprehensive database that provides broad disciplinary coverage and transparent metadata. The use of OpenAlex enhances the reproducibility and inclusivity of the analysis, supporting the reliability of the findings despite the absence of Web of Science data.

Conclusions, Future Nursing Research Directions, and Nursing Practice Implications

This bibliometric analysis of research on older adults published in BRN over the past two decades provides a comprehensive overview of the journal’s intellectual structure, thematic analysis, and collaborative landscape related to this population. By applying field-normalized indicators such as the FWCI, we demonstrate that BRN has consistently disseminated research with citation performance above the global average for comparable disciplines, underscoring the journal’s visibility and scientific influence. In addition, the results indicate that BRN serves as a key scientific communication channel for advancing biobehavioral approaches to aging. The identified research fronts—particularly those centered on self-management through physical activity and the interactions among sleep, inflammation, cognition, and cardiovascular function—illustrate the journal’s commitment to evidence-based, holistic gerontological health care.

Emerging aging-associated research directions, including brain health, cognition, and behavior, highlight the journal’s expanding intellectual scope and responsiveness to new scientific developments in gerontology and health behavior. These trends suggest strategic opportunities for BRN to further position itself as a leader in publishing research that bridges brain-biological processes, behavioral interventions, and patient-centered brain-outcomes in older adults.

Finally, the collaboration analysis indicated international participation, with developed (e.g., United States and European countries) and developing countries (e.g., Chile and Egypt). Expanding cross-national collaborations could enhance the journal’s global reach, diversify its evidence base, and support nursing science in addressing the complex biological and behavioral dimensions of aging worldwide.

Although many of this study’s findings suggest future directions for the journal, one major takeaway for nursing research teams concerns keyword selection. As explained above, keyword selection now has implications for establishing the intellectual base of a discipline or field. Many journal publishers offer suggestions regarding keyword selection, but peer or editorial feedback regarding keywords seems rare. Pottier et al. (2024) offer advice about author keyword selection to ensure studies are discoverable through search engines. This advice is also applicable to ensuring that studies are incorporated into a scientific field’s intellectual base: Select (a) “[p]recise and familiar terms” (Pottier et al., 2024, p. 3), (b) “terms or phrases that are directly related to your research” (Pottier et al., 2024, p. 5), and (c), if necessary, broad terms without distancing the primary research audience (Pottier et al., 2024).

The visibility of physical activity within the research fronts aligns with the visibility of physical activity in nursing practice. In interactions with patients, nurse clinicians around the world discuss, educate, assess, and/or counsel about physical activity to promote healthy living or manage chronic diseases (Lehtomäki et al., 2025; Levi et al., 2025; McCormick et al., 2023; Pellerine et al., 2022). Although nurse clinicians recognize the health-related benefits of physical activity, the extent that these nurses are aware of physical activity’s biological mechanisms is unclear because studies do not address this specific topic (Lehtomäki et al., 2025; Levi et al., 2025; McCormick et al., 2023; Pellerine et al., 2022). However, these investigations involving nurse clinicians address (a) their perspectives on recommending physical activity (Pellerine et al., 2022) or counseling on physical activity (Lehtomäki et al., 2025), (b) an evaluation of their own physical activity (Levi et al., 2025; McCormick et al., 2023), and/or (c) the nature or frequency of educating, assessing, or counseling patients about physical activity (Lehtomäki et al., 2025; Levi et al., 2025; McCormick et al., 2023). Perhaps nurse scientists can identify opportunities to inform nurse clinicians regarding physical activity’s biological mechanisms, and nurse clinicians can seek the research papers or nurse scientists to learn more about these biological mechanisms.

Supplemental Material

Supplemental material - A bibliometric analysis of older adult population research published in Biological Research for Nursing

Supplemental material for A bibliometric analysis of older adult population research published in Biological Research for Nursing by Ibis A. Moreno-Lozano, PhD and Barbara St. Pierre Schneider, PhD, RN, FAAN in Biological Research For Nursing.