Bibliometric and visual analysis of overlooked fatigue in kidney transplantation: a narrative review

Abstract

Background:

Fatigue significantly influences and predicts quality of life, social function, and graft survival after kidney transplantation. Accurate assessment and management of fatigue in kidney transplant recipients are vital, especially when planning treatment strategies and potential rehabilitation programs. However, there is no bibliometric report in this area.

Methods:

The Web of Science Core Collection for all original articles and reviews published in English on this topic was searched up from 1 January 1978 to 31 December 2023. A total of 719 articles meeting inclusion criteria were analyzed using bibliometric approaches.

Results:

The United States is the most influential country in this research area, with the Pennsylvania Commonwealth System of Higher Education being the most prolific institution. The Transplantation and American Journal of Transplantation emerged as the foremost in publishing articles in this field. The highest-frequency keywords were quality of life, kidney transplantation, chronic kidney disease, dialysis, and fatigue. Besides, important research topics included kidney transplantation, quality of life, dialysis, fatigue, and depression.

Conclusions:

Kidney transplant-related fatigue has been gradually concerned by scholars, with research focusing on its impact on quality of life, chronic kidney disease, dialysis, and depression. However, the current body of research remains largely descriptive, with limited studies on effective prevention and intervention strategies. Future research should prioritize the development of targeted interventions to address fatigue in kidney transplant recipients, incorporating multidisciplinary approaches involving clinical medicine, psychology, and rehabilitation. Promising strategies may include psychological therapies such as cognitive behavioral therapies, personalized exercise programs, and optimized medication management.

Introduction

Kidney transplantation (KT) is the most effective treatment for end-stage kidney disease worldwide, while the health status and reported quality of life (QoL) of kidney transplant recipients (KTRs) after transplantation depend largely on individual’s characteristics and comorbidities, rather than graft alone^[1]. Upper to 48.3% KTRs experience varying degrees of fatigue, making it an important clinical outcome measure, particularly in the context of therapies that extend graft survival and patient longevity^[2]. Fatigue is a complex physiological and psychological phenomenon that encompasses various aspects of an individual’s well-being^[3]. It not only impairs performance in professional, social, and daily functioning but also substantially reduces therapeutic engagement and QoL in populations^[4]. In KTRs, fatigue may arise from a distinct constellation of factors not typically observed in the general population, including prolonged immunosuppressive therapy^[5], and psychological burdens such as sleep disruption and depressive symptoms^[2,6]. For example, immunosuppressive agents like calcineurin inhibitors have been linked to neurotoxicity and mitochondrial dysfunction^[7,8], both of which are implicated in the pathogenesis of central fatigue^[9–11]. Additionally, disturbances in sleep and mood can disrupt circadian rhythms and alter inflammatory cytokine levels, further contributing to fatigue development^[12]. Notably, this persistent fatigue is often independent of graft function or renal pathology and is more likely driven by behavioral and psychosocial factors^[13], underscoring the need for context-specific assessment tools and management strategies.

HIGHLIGHTS

• Summarizes research trends and emerging themes in kidney transplant-related fatigue.

• Maps key contributors, leading institutions, and influential journals in this field.

• Reveals gaps in collaboration, contribution, and international impact.

• Calls for interdisciplinary approaches to enhance health, quality of life, and research.

Recognizing its importance, KDIGO 2024 advises using standardized tools at follow-up^[14], and NICE recommends 150 minutes of moderate-intensity exercise weekly for KTRs and non-dialysis CKD patients^[15]. Post-KT fatigue has emerged as a critical issue with complex causes, including poor sleep^[16] and immunosuppressive therapy^[8,17]. It can impair social functioning and increase the risk of social isolation and the loss of social networks^[18]. Importantly, fatigue can reduce treatment adherence and increase the risk of graft rejection and infection^[19]. Social support and adherence to medical recommendations are crucial in protecting vulnerable patients from pathological fatigue^[20]. Therefore, accurately assessing and managing fatigue in KTRs is vital, particularly when planning consultations, decision-making, and potential rehabilitation programs.

Bibliometric analysis differs from traditional systematic reviews or meta-analyses by focusing on mapping research trends, knowledge structures, and collaboration networks rather than evaluating individual study outcomes. It emphasizes broad coverage and reproducibility, revealing patterns and emerging hotspots that traditional reviews may overlook^[21,22]. Due to these advantages, bibliometric methods have emerged as a powerful tool for investigating large-scale research patterns in medicine, as exemplified by recent studies on phase separation in cancer^[23], immunotherapy^[24], and thrombopoietin receptor agonist studies^[25]. In the field of KT, bibliometric analysis has proven valuable for identifying emerging research trends and guiding future inquiry. For instance, Chun-Lian Huang et al^[26] utilized bibliometrics to explore the role of the immune microenvironment in KTR prognosis. A recent study has also explored non-invasive detection strategies, such as plasma and urine, as promising approaches in monitoring antibody-mediated rejection in KTRs^[27]. Given that medical scientists and medical health workers face a burgeoning number of publications daily, it is crucial to synthesise a clear knowledge map of each study topic^[25]. However, there is a lack of bibliometric reports focusing on fatigue as a rehabilitation indicator for KTRs. This study aims to analyze the current state of research and emerging trends concerning the relationship between KT and fatigue, helping clinicians better understand and address the fatigue issue in KTRs, ultimately improving patients’ overall health and QoL^[28]. This study complies with the TITAN Guidelines 2025, and no AI was used during any stage of the research or manuscript preparation.

Materials and methods

Data sources

Data were sourced from the Web of Science Core Collection (WOSCC), a comprehensive database encompassing high-quality scientific publications suitable for citation analysis^[29]. (date of data retrieval and download: 5 November 2024).

Search strategy

We collected extensive relevant studies published from 1 January 1978 to 31 December 2023. The accuracy search was detailed in the supplementary material (Data Collection). After screening, 719 publications were included (Supplemental Digital Content Figure S1, available at: http://links.lww.com/MS9/A893).

Data analysis

Using the “Bibliometrix” package in R 4.1.0, CiteSpace (v5.7.R3), and Microsoft Excel (2021), data were analyzed and visualized to assess research hotspots and collaboration networks in the field of KT-related fatigue. The specific processing steps were detailed in the supplementary material (Data Analysis).

Results

Descriptive analysis

Supplementary Digital content Table S1, available at: http://links.lww.com/MS9/A893, details the main information, which consists of 719 articles published in 338 journals.

Annual publication analysis

Figure 1 displays the annual publication trends. Annual publications stayed below 10 until 1997, increased with fluctuations between 1998 and 2010 and surged post-2011(R² = 0.9612), projecting 95 publications this year.

Countries and institution analysis

Collaborative networks

Figure 2 shows co-authorship relationships among nations. The strongest connection, with 18 collaborations, is between the USA and Canada. The USA and China have 6 collaborations.

Figure 2.

Map of keyword co-occurrence network in KT and fatigue.

Figure 1.

Trend analysis of publications on KT and fatigue between 1978 and 2023.

Geographic and institutional contributions

Supplementary Digital Content Figure S2, available at: http://links.lww.com/MS9/A893, shows the countries and affiliations of corresponding authors.

Supplemental Digital Content Figure S2A, available at: http://links.lww.com/MS9/A893, presents the top 10 contributing countries. The USA leads with 207 publications, followed by Germany (41) and the Netherlands (40). The USA also recorded the highest number of single-country publications (180) as well as multiple-country publications (27). Australia has the highest proportion of multi-country publications at over 53%.

Supplemental Digital Content Figure S2B, available at: http://links.lww.com/MS9/A893, presents the top 10 contributing institutions. The Pennsylvania Commonwealth System of Higher Education leads with 63 publications.

Journal analysis

Top 10 journals

The H-index measures academic impact by counting the number of papers with at least h citations each, reflecting a researcher’s or journal’s contribution.

Supplementary Digital Content Table S2, available at: http://links.lww.com/MS9/A893, lists the top 10 journals with the highest H-index. Transplantation has the highest H-index of 22 and has published 32 articles about KT-related fatigue, which have been cited 1300 times. American Journal of Transplantation and Nephrology Dialysis Transplantation ranked second, each with an H-index of 14, publishing 19 and 17 papers, respectively, which have been cited 889 and 796 times.

Core journals

Bradford’s law states that articles on a specific topic are distributed across journals, which can be divided into a core set and subsequent zones based on the number of relevant articles^[30].

Supplemental Digital Content Figure S3, available at: http://links.lww.com/MS9/A893, presents the core zone consists of 16 high-quality journals with 251 articles published, notably Transplantation Proceedings, Transplantation, and Clinical Transplantation.

Articles analysis

Table 1 lists the top 10 articles on KT-related fatigue, providing various bibliometric indicators, with a focus on local citations (LCs), global citations (GCs), the ratio of local citations to global citations (LC/GC ratio (%), and normalized GC.

Table 1.

The top 10 article ranked by local citations

No.	Document	DOI	LCa	GCb	LC/GC Ratio (%)	Normalized GC
1	GOEDENDORP MM, 2013, TRANSPL INT	10.1111/tri.12166	22	33	66.67	1.54
2	RODRIGUE JR, 2011, CLIN TRANSPLANT	10.1111/j.1399-0012.2010.01326.x	21	51	41.18	1.1
3	CHAN W, 2013, TRANSPLANTATION	10.1097/TP.0b013e3182a2e88b	19	37	51.35	1.73
4	VAN SANDWIJK MS, 2019, NEPHROL DIAL TRANSPL	10.1093/ndt/gfy103	13	55	23.64	2.98
5	KOVACS AZ, 2011, NEPHROL DIAL TRANSPL	10.1093/ndt/gfq476	11	79	13.92	1.7
6	ARTOM M, 2014, KIDNEY INT	10.1038/ki.2014.86	10	136	7.35	3.67
7	BOSSOLA M, 2016, CLIN TRANSPLANT	10.1111/ctr.12846	10	19	52.63	0.73
8	MCADAMS-DEMARCO MA, 2017, TRANSPLANTATION	10.1097/TP.0000000000001546	10	113	8.85	4.16
9	MCADAMS-DEMARCO MA, 2015, TRANSPLANTATION	10.1097/TP.0000000000000444	9	105	8.57	2.48
10	LAUPACIS A, 1993, NEPHRON	10.1159/000187318	8	71	11.27	0.64

^aLC, local Citations.

^bGC, Global Citations.

LCs reflect regional or community-specific recognition, GCs quantify the worldwide impact of research, an LC/GC ratio (%) indicates the balance of local versus global influence, and normalized GCs adjust citation counts for fair comparison across different contexts and times^[31].

Reference analysis

Supplemental Digital Content Table S3, available at: http://links.lww.com/MS9/A893, indicates the top 10 most referenced articles. “Severe Fatigue After Kidney Transplantation: A Highly Prevalent, Disabling, and Multifactorial Symptom” published by Goedendorp MM in Transplantation International in 2013^[13] is the most cited article. This indicates a strong interest in the post-transplant outcomes and the various factors affecting transplant populations, focusing on severe fatigue, psychological well-being, and physical recovery.

“Development of the Kidney Disease Quality of Life Instrument” published by Hays RD in Health Qual Life Outcomes in 1994 ranks as the second most cited article and provides vital methodologies for assessing quality of life among kidney disease patients^[32], essential for evaluating treatment outcomes and guiding clinical decision-making.

“A Cross-Sectional Study of Fatigue and Sleep Quality Before and After Kidney Transplantation” published by Rodrigue JR in Clinical Transplantation in 2011 holds the third position^[16], further underscores the growing awareness of psychosocial factors in transplantation success and patients’ QoL.

Author analysis

Supplemental Digital Content Table S4, available at: http://links.lww.com/MS9/A893, shows the most prolific author is Bakker, Stephan J L from the Netherlands with 9 publications, yet his centrality is 0.00, indicating limited collaboration within the research network. Nodes with high centrality are pivotal points in a particular field^[33], and Knobbe, Tim J collaborated more extensively with other authors. The most cited author is Segev DL from Israel, with 32 citations, but his centrality remains at 0.00, suggesting his work is widely cited without much interconnectedness in the research network. Notably, Harper L has the highest centrality among the cited authors (0.44), indicating stronger collaboration with other authors.

Keyword analysis

Keywords represent the main content of publications and are essential for retrieving literature on specific topics. High-frequency keywords indicate emerging or hot topics in a given field, while keywords with high centrality reflect influential research within that field.

Supplemental Digital Content Figure S4, available at: http://links.lww.com/MS9/A893, presents a keyword network graph for articles on KT-related fatigue, featuring 188 nodes and 677 links. The size of each circle corresponds to keyword frequency, emphasizing their significance. The lines connecting the circles represents co-occurrence between keywords, showing how often terms appear together. The purple rings highlight keywords with higher centrality or importance, suggesting their strong connections and core role in the research. The color bar in the legend quantifies measures like centrality or frequency, with warmer colors indicating higher values.

Notably, depression is a high-frequency keyword, indicated by its large node size and close spatial proximity to fatigue. These two terms are directly connected by co-occurrence lines, forming a dense cluster that reflects their frequent co-mention in KT-related fatigue studies. This highlights depression’s central role in this field and underscores the need to address psychological distress when managing fatigue in KTRs.

Supplemental Digital Content Table S5, available at: http://links.lww.com/MS9/A893, shows the top 10 high-frequency keywords and the top 10 keywords with the highest centrality

Thematic evolution analysis

The map of thematic evolution is presented in Figure 3, illustrating the flow and evolution of keywords, concepts, or research topics over time, highlighting the varying levels of attention received by different keywords during each period, identifying potential hotspots across various stages.

The thematic map of keywords is created for each time slice and divided into 1978–2000 and 2001–2023, with dimensions of centrality (topic relevance in the research field) and density (topic development maturity), where higher density indicates greater development and higher centrality indicates greater relevance^[34]. Supplemental Digital Content Figure S5A-B, available at: http://links.lww.com/MS9/A893, delineates four quadrants of the map (counterclockwise), which represent motor themes (first quadrant), highly specialized themes (second), emerging themes (third), and fundamental themes (fourth).

From 1978 to 2000 (Supplemental Digital Content Figure S5A, available at: http://links.lww.com/MS9/A893), dominant themes focused on therapy efficacy, leukemia, mortality, multiple myeloma, and non-Hodgkin’s lymphoma. However, from 2001 to 2023 (Supplemental Digital Content Figure S5B, available at: http://links.lww.com/MS9/A893), themes such as QoL and fatigue emerged and even gained attention comparable to that of mortality.

Beyond psychological influences, the thematic evolution analysis also highlights immune-related mechanisms as an emerging focus within the KT- related fatigue. In the thematic evolution map (Supplemental Digital Content Figure S5B, available at: http://links.lww.com/MS9/A893), the keywords expression, activation, and extrusion are clustered in the upper-right quadrant, reflecting their recent development and centrality within KT-related fatigue research. These terms are closely linked with immune-related mechanisms^[35–37], suggesting that immunological regulation constitutes a prominent theme in the field. However, terms directly referring to immunosuppressive therapy do not appear as central keywords in either Supplemental Digital Content Figure S4, available at: http://links.lww.com/MS9/A893, or Supplemental Digital Content Figure S5B, available at: http://links.lww.com/MS9/A893, indicating that while immune signaling pathways are well represented, the specific role of immunosuppressive drugs in fatigue research remains underexplored.

Discussion

This study analyzed trends and hot topics in KT-related fatigue research through 719 publications in English from 1978 to 2023. Annual outputs averaged below 10 until 1997, reflecting the early post-KT (first performed in 1954) focus on survival over symptoms rather than accompanying symptoms. Publications rose post-1998, surging after 2010 to peak at 88 in 2023. This surge in scholarly attention highlights a shift from focusing solely on survival to broader health assessments, driven by medical advancements and improved treatment methods^[38]. With people’s increased willingness to donate organs, rapid advancements in KT, and significant improvements in graft survival rates, researchers have started focusing on post-transplantation sequelae, with fatigue being a primary concern. Publications on KT-associated QoL, especially fatigue, are projected to grow, reaching 95 this year.

Among the top 10 publishing countries, only China ranked fourth with 37 articles as the sole developing country, the rest are developed nations. Co-authorship networks predominantly linked developed countries, likely influenced by geographic proximity, economic ties, and cultural and personnel similarities^[39]. Importantly, compared to developing countries, developed nations generally excel in transplantation maturity and advanced medical technology, providing them with a stronger foundation and richer clinical experience for research in this field. For instance, in 2020, the United States performed approximately 39 000 organ transplants, nearly 20 000 of which were kidney transplants^[40], whereas China performed fewer than 20 000 transplants of all types^[41]. Additionally, developed countries lead in cutting-edge technologies such as gene editing, stem cell research, and 3D printing in transplantation, making their research more influential and innovative, with a focus that has expanded from transplant survival to improving post-surgery QoL. These findings highlight the urgency to strengthen international collaborations, particularly with developing countries, to enhance the understanding and treatment of KT-related fatigue.

Key journals such as Transplantation, American Journal of Transplantation, and Nephrology Dialysis Transplantation dominate the field. Transplantation leads with the highest H-index and the most publications, asserting its dominance in terms of citations and impact. Recognized as one of the foremost international academic journals in organ transplantation, it covers the latest advances in both basic and clinical research related to organ transplantation. Bradford’s law further highlights this oligopoly that a limited core journals account for the majority of articles. This indicates that these journals are vital resources for researchers, steering both publishing and information-seeking activities in the field of KT-related fatigue, thereby shaping the trajectory of future research and developments in this specialized area.

The top 10 most locally cited articles reveal variations in local and global citation counts, shedding light on the regional and international influences. The 2017 article by McAdams-DeMarco MA in Transplantation boasts the highest GC count of 113 and a normalized global citation count of 4.16, showcasing its broad international acceptance. This study, “Individual Frailty Components and Mortality in Kidney Transplant Recipients,” longitudinally assessed pre-transplant fatigue and its postoperative changes, identifying risk factors such as sleep disorders, suggesting a significant global influence in research on longitudinal changes in KT-related fatigue^[42]. These differences in citation metrics underline the dynamic interplay between regional focus and global appeal in research dissemination. Such insights are crucial for researchers aiming to align their studies with both local needs and global discussions.

The impact factor (IF) quantifies a journal’s international prestige by measuring average citations per article. Higher IF indicates greater academic influence. The most prolific author in this area is Bakker, Stephan J L from the Netherlands, whose research focuses on CKD, cardiovascular diseases, and the impacts of fatigue in KTRs^[43]. In 2021, he published an article entitled “Machine Learning-based Sleep Staging in Patients with Sleep Apnea Using a Single Mandibular Movement Signal” in the American Journal of perspiratory and Critical Care Medicine (IF = 19.3), which showed that the incidence of airflow restriction was higher in KTRs and was strongly associated with fatigue and reduced physical health-related QoL^[44]. Notably, addressing the intersection of fatigue with other post-transplant complications, such as cardiovascular disease, could improve patient outcomes^[45]. Bakker’s expertise in nephrology and his leadership in the fields of CKD and KT have positioned him at the forefront of this critical area of research. Knobbe, Tim J from the USA demonstrates a high degree of centrality within the research community, underscoring his strategic position at a collaborative nexus. This is illustrated by his significant publication in 2023 entitled “health-related quality of life is linked to the gut microbiome in kidney transplant recipients” in the Journal of Nature Communications (IF = 14.7), which emphasized the critical relationship between the gut microbiome and QoL in KTRs^[46]. His involvement in high-impact journals and central role in collaborative networks highlight his leadership in enhancing the QoL for KTRs. This centrality not only amplifies the reach and impact of his research but also underscores the importance of collaborative networks in driving scientific innovation and application in clinical settings^[47].

Keyword co-occurrence and bursts highlight research hotspots over time^[48]. The 20 most frequent keywords illuminate critical areas in the KT-related fatigue relationship, revealing emerging trends with a focus on QoL, dialysis, and fatigue, which underscore vital aspects of patient care and research. QoL is the most frequent, suggesting that alongside advancements in immunology, transplantation technology, and personalized treatment, research increasingly prioritizes overall health. Dialysis is crucial for transplant preparation and managing post-transplant complications, with ongoing improvements directly impacting QoL and fatigue. Fatigue, commonly experienced by recipients, links to both QoL and dialysis, highlights interconnected patient challenges. These keywords reflect nephrology research’s evolving focus on enhancing holistic health of KTRs, emphasizing the critical interplay between clinical practices and patient well-being. Particularly noteworthy is the recurrent appearance of QoL and fatigue in both the frequency and centrality aspects within the research, underscoring their significance. This focus reflects a broader trend in medical research towards patient-centered outcomes, emphasizing not only survival and traditional clinical measures of health but also how patients feel and function in their daily lives.

Beyond keyword frequency, our co-occurrence network analysis (Supplemental Digital Content Figure S5A, available at: http://links.lww.com/MS9/A893) reveals that depression forms a close cluster with fatigue, indicating a strong thematic association despite not ranking among the top 10 most frequent terms. This finding aligns with prior evidence linking KT-related fatigue to psychological conditions such as depression, anxiety, and insomnia^[4,6,13,49]. Importantly, our results suggest the need to address depression not only as a secondary symptom but also as a core therapeutic target in fatigue management. Cognitive behavioral therapy (CBT) has emerged as a promising treatment for complex physiological and psychological symptoms such as depression and insomnia^[50–52]. Notably, CBT has demonstrated efficacy in alleviating fatigue among patients receiving hemodialysis^[53,54], where such symptoms may impair adherence and survival of KTRs^[4,55]. Future studies should explore strategies to alleviate fatigue through psychological rehabilitation, with a particular focus on targeting depression, while avoiding additional pharmacological burden. Interventions such as CBT and structured exercise programs warrant further investigation for their potential to enhance quality of life in KTRs.

Emerging literature highlights immunosuppressive therapy as a significant contributor to fatigue and related symptoms, such as headache and insomnia^[4,5], which are frequently reported with agents like bortezomib^[56], monoclonal antibodies^[57], everolimus, and intravenous immunoglobulin^[58]. However, although our thematic evolution analysis (Supplemental Digital Content Figure S5B, available at: http://links.lww.com/MS9/A893) places immune-related terms (expression, activation, and extrusion) indicating both centrality and maturity, immunosuppressive therapy is notably absent. This reveals a critical gap in the literature: while immune signaling is a prominent focus, the fatigue-related toxicity of immunosuppressive agents remains insufficiently explored. This gap is especially urgent with the emergence of immune checkpoint inhibitors^[23,59] and may alter KT-related fatigue in ways that differ from differs from traditional therapies. Accordingly, pharmacovigilance studies are needed to clarify the long-term effects of these agents^[23], unravel underlying fatigue mechanisms, and inform the development of targeted, low-toxicity immunosuppressive strategies for KTRs.

Evidence from CKD and dialysis populations indicates that structured aerobic and resistance training can reduce fatigue by improving cardiorespiratory fitness, muscle metabolism, and urea clearance^[60]. Similarly, psychosocial interventions such as CBT have shown sustained benefits for fatigue, mood, and sleep^[53]. Hence, personalized immunosuppressive strategies should incorporate regular drug monitoring and reduced-toxicity regimens, along with moderate aerobic exercise and psychological support to alleviate fatigue and improve QoL. These integrated, patient-centered approaches may help reduce fatigue, maintain immune stability, and enhance long-term outcomes.

While bibliometric analysis provides insights into trends and hotspots, this study has limitations that can be improved in future research. First, we only retrieved the literature from the WoSCC, excluding others like PubMed and Scopus. Second, focusing on English articles may overlook high-quality research in other languages. Finally, potential improvement measures were not discussed in depth and should be considered in future studies.

Moreover, current evidence remains limited regarding whether KTRs exhibit distinct biological alterations or unique fatigue patterns compared to the general population. Future research should aim to include larger and more diverse cohorts, well-defined subgroups, and comprehensive assessments that integrate biological, psychological, and behavioral dimensions to better understand the underlying mechanisms and clinical characteristics of fatigue in KTRs.

Conclusion

This bibliometric analysis of 719 publications spanning 45 years maps global KT-related fatigue research trends, highlighting current status and emerging trends to guide nephrology and nursing care in improving KTRs’ health. Notably, post-2010 research transitioned from survival metrics to patient-centered holistic outcomes, reflecting transplantation care advancements and the critical role of fatigue. Future research should prioritize the interplay across psychological distress, immunosuppressive toxicity, and fatigue pathophysiology, while exploring targeted interventions such as CBT, exercise programs, and low-toxicity immunosuppressive regimens to mitigate fatigue and enhance QoL in KTRs.

Ethical approval

Ethics approval was not required for this review as it did not involve human participants or identifiable personal data.

Consent

Informed consent was not required for this review article as it did not involve human participants or identifiable personal data.

Sources of funding

None.

Author contributions

All co-authors reviewed the draft and gave final approval.

Conflicts of interest disclosure

None.

Guarantor

Shaohui Ma.

Research registration unique identifying number (UIN)

Not applicable.

Guarantor

Shaohui Ma.

Provenance and peer review

None.

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Assistance with the study

None.

Presentation

None.