Bibliometric analysis of research on spinal tuberculosis in last 5 years

Abstract

BACKGROUND

Spinal tuberculosis (TB), also known as Pott’s spine, remains a significant global health issue, particularly in regions with a high TB burden. The disease presents complex challenges in diagnosis, management, and treatment, prompting a growing interest in research over recent years. The advancements in imaging, diagnostics, and treatment strategies have driven an increased focus on publishing clinical outcomes, review articles, and case series related to spinal TB (STB).

AIM

To perform a bibliometric analysis of STB research published over the last 5 years (2019-2023) to identify trends in publication volume, contributions by country, and the nature of the research being conducted.

METHODS

A comprehensive bibliometric analysis was conducted using the PubMed database, focusing on research articles published between 2019 and 2023. Keywords such as “spine tuberculosis,” “spinal TB,” “TB spine,” and “Pott’s spine” were utilized to capture relevant publications. Articles were analyzed based on the type of research (e.g., case reports, review articles, cohort studies, randomized controlled trials [RCTs]), number of citations, and country of origin based on the corresponding author's details. Further subgroup analysis was performed according to the TB burden in various countries to assess research trends in high-burden regions.

RESULTS

A total of 528 articles met the inclusion criteria for this bibliometric analysis. The majority of articles were published between 2020 and 2023 (440/528; 83.3%), while the lowest number was published in 2019 (88/528; 16.7%). India led the global contributions with 25.8% of the total publications, followed by China (19.9%) and the United States (10.4%). Combined, African countries contributed 6.8% of the research on STB. Regarding the type of articles, case reports and case series dominated the literature (353/528; 66.9%), followed by review articles (120/528; 22.7%) and cohort studies (45/528; 8.5%). Only 1.9% (10/528) of the studies were RCTs. Countries such as the United States, Germany, the United Kingdom, and Japan have pioneered the use of artificial intelligence (AI) in the diagnostic processes for STB, while India, China, South Africa, and other countries have been pivotal in conducting clinical trials and improving clinical management strategies.

CONCLUSION

This bibliometric analysis revealed a significant increase in STB research over the last 5 years, with India and China being the leading contributors. However, most publications are case reports or case series, with a limited number of RCTs. The results highlighted the need for more high-quality research, especially in terms of RCTs and innovations in diagnostic technologies. Additionally, the application of AI to STB diagnostics shows promise in developed countries, while high-burden countries are focusing on clinical trials and management strategies.

Key Words: Spinal Tuberculosis; Pott’s spine; Research trends; Artificial intelligence diagnostics; Bibliometric analysis

Core Tip: This bibliometric analysis provides an overview of global research trends in spinal tuberculosis (STB) from 2019 to 2023, highlighting a significant increase in publications, with Asia leading research contributions. Despite the high global burden of STB, there is a disparity in research output between high-burden, low-income countries and more developed regions, where advanced diagnostic tools like artificial intelligence are being explored. Case reports and case series dominate the literature, while randomized controlled trials remain scarce. These findings emphasize the need for more collaborative efforts, especially in resource-limited settings, to bridge the research gap and advance global strategies for TB elimination.

INTRODUCTION

Tuberculosis (TB) remains the leading infectious disease contributing to global mortality and morbidity, despite significant advancements in diagnostic and therapeutic interventions. According to the Global TB Report 2023, over 10.3 million people developed TB, reflecting a 3.9% rise in incidence between 2020 and 2022. Of this global TB burden, 87% was concentrated in 30 high-burden countries, with South-East Asia and Africa contributing over 65% of the cases[1,2]. TB manifests in two major forms: Pulmonary TB (PTB) and extrapulmonary TB (EPTB), the latter being particularly challenging to diagnose and manage due to its paucibacillary nature and atypical clinical presentations.

Osteoarticular TB accounts for 1%-2% of all TB cases and 10% of EPTB cases, with spinal TB (STB) comprising half of the osteoarticular TB burden[3]. STB poses unique challenges due to its varied clinical presentation and the risk of catastrophic complications, including neurological impairment. The burden of STB is exacerbated in regions with high prevalence of malnutrition, poverty, and limited healthcare resources[4]. These challenges are further compounded by the lack of advanced diagnostic facilities, insufficient expertise in managing STB, and poor patient compliance, which hinder efforts toward global TB elimination[5-7].

In response to the rising burden of STB, there has been a global push to expand research on the disease, with a focus on improving diagnosis, management, and treatment outcomes. However, there is a perception that countries with high TB burdens may prioritize clinical management over research efforts. Nevertheless, strong leadership and policies that encourage investment in research are critical to advancing the global TB elimination agenda[8]. Each year, new literature emerges addressing the challenges and advances in diagnosing and managing STB.

Bibliometrics is a comprehensive approach combining quantitative and qualitative analyses to reveal various features of publications and helpful in understanding the problem statements in health-related issues areas like other subtypes of TB or chronic diseases such as atherosclerosis, hypertension etc. [9-12]. This approach plays a key role in shaping policy, clinical guidelines, and research trends[10,11]. Additionally, bibliometric analysis offers researchers a comprehensive understanding of the progress and scope of a specific field of study[12].

This study identified publication trends, analyzed geographical research contributions, and evaluated the types of studies conducted in STB research from 2019 to 2023. Special focus is given to the application of artificial intelligence (AI) and multiomics in diagnostics in high-burden regions.

MATERIALS AND METHODS

Bibliometric analysis was conducted on research papers published over the past 5 years (2019-2023) related to STB and indexed in the PubMed database. Ethics approval was obtained from our institution before commencing the study. The PubMed database was chosen due to its extensive collection of over 37 million abstracts and citations related to biomedical research. The following search keywords were used: ((Spin* AND Tuberculosis) OR (Spin* AND TB) OR (Pott* AND Disease) OR (Pott’s Paraplegia) OR (vertebr* AND Tuberculosis)).

Inclusion criteria for the study encompassed research focusing on the diagnosis, treatment, and management of STB, including all age groups and various article types. Exclusion criteria consisted of non-English studies, articles unrelated to STB, and duplicate entries, which were systematically removed. Abstracts were independently screened by two reviewers to ensure inclusion of relevant studies on STB while eliminating duplicates. The collected data was categorized based on the type of research paper (e.g., case reports/series, original research articles, reviews, cohort studies, and randomized controlled trials [RCTs]), the country of origin (determined by the corresponding author), and the number of citations received by each article. Additionally, global contributions were analyzed in the context of high- and low-burden TB regions.

The evaluation focused on identifying the country contributing the highest number of articles, the types of papers published, and the research trends observed across different countries. These aspects were assessed based on the data obtained from the bibliometric analysis, providing insights into the global distribution of research efforts and the prevailing focus areas in STB studies.

Statistical analyses

The collected data were organized in an Excel sheet and analyzed using SPSS version 21. Categorical variables are presented as percentages. The χ² test was employed for statistical comparisons. All statistical tests were two-tailed, and P < 0.05 was considered statistically significant.

RESULTS

Of the total PubMed-indexed research articles on STB published between 2019 and 2023, 528 articles were shortlisted based on the study’s criteria and analyzed. The majority of these articles were published between 2020 and 2023 (440/528; 83.3%), with the fewest published in 2019 (88/528; 16.7%), as illustrated in Figure 1. Figure 2 shows the continent-wise contribution to STB publications, indicating that over 66% of the research originated from Asia, followed by Europe (13.8%) and North America (11.2%). India was the top contributor, accounting for 25.7% of the publications, followed by China (19.9%) and the United States (10.4%). Collectively, African countries contributed 6.8% of the published data. In terms of citations, research from India had the highest total (877), followed by China (498) and the United States (453), as shown in Table 1.

Figure 1  Year-wise distribution of publications.

Figure 2  Continent-wise distribution of studies.

Table 1 List of country-wise distribution of published studies and citations, n (%).

Name of the country	Number of studies (n = 528)	Name of the continent	Total citation
United States	55 (10.4)	North America	453
India	136 (25.8)	Asia	877
Australia	3 (0.6)	Australia	21
West Africa	1 (0.2)	Africa	4
Dominican Republic	1 (0.2)	Africa	7
Albania	1 (0.2)	Europe	0
Argentina	1 (0.2)	South America	0
Greece	4 (0.7)	Europe	9
Thailand	5 (0.9)	Asia	26
Germany	6 (1.1)	Europe	184
Brazil	5 (0.9)	South America	39
Canada	3 (0.6)	North America	42
China	105 (19.9)	Asia	498
Columbia	1 (0.2)	South America	1
Egypt	1 (0.2)	Africa	53
United Kingdom	12 (2.3)	Europe	198
Ethiopia	1 (0.2)	Africa	5
Europe	1 (0.2)	Europe	0
France	8 (1.5)	Europe	47
Hungary	3 (0.6)	Europe	10
Indonesia	31 (5.9)	Asia	77
Iran	4 (0.7)	Asia	14
Italy	13 (2.5)	Europe	227
Ivory coast, West Africa	1 (0.2)	Africa	1
Japan	11 (2.1)	Asia	11
South Korea	13 (2.5)	Asia	63
Kosovo	1 (0.2)	Europe	1
Malaysia	9 (1.7)	Asia	39
Mexico	1 (0.2)	North America	3
Morocco	6 (1.1)	Africa	5
Namibia	2 (0.4)	Africa	8
Nepal	2 (0.5)	Asia	6
Netherlands	1 (0.2)	Europe	1
Nigeria	4 (0.8)	Africa	3
Pakistan	5 (0.9)	Asia	10
Philippines	2 (0.4)	Asia	1
Poland	5 (0.9)	Europe	13
Portugal	6 (1.1)	Europe	6
Qatar	4 (0.8)	Asia	12
Romania	2 (0.4)	Europe	3
Russia	1 (0.2)	Europe	13
Saudi Arabia	11 (2.1)	Asia	19
Singapore	3 (0.6)	Asia	3
South Africa	10 (1.9)	Africa	71
Spain	4 (0.8)	Europe	8
Sri Lanka	2 (0.4)	Asia	5
Switzerland	5 (0.9)	Europe	17
Syria	2 (0.4)	Asia	1
Taiwan	4 (0.8)	Asia	31
Tanzania	1 (0.2)	Africa	0
Tunisia	4 (0.8)	Africa	15
Uganda	1 (0.2)	Africa	0
Venezuela	1 (0.2)	South America	0
Vietnam	1 (0.2)	Asia	0
West Africa	1 (0.2)	Africa	1
Algeria	1 (0.2)	Africa	1

In terms of the types of publications, most were case reports or case series (353/528; 66.9%), followed by review articles (120/528; 22.7%) and cohort studies (45/528; 8.5%). Only 10 RCTs (1.9%) were published during this period (Table 2). When comparing the research output from high TB-burden areas with that of other regions, the difference was statistically significant (P < 0.0001), as displayed in Table 3.

Table 2 Types of studies, n (%).

Study type	Number of published study (n = 528)
Case report	353 (66.9)
Cohort	45 (8.5)
Randomized control trial	10 (1.9)
Review article	120 (22.7)

Table 3 Comparison of research contribution between high-burden areas and the rest of the geographic area.

Geographical areas	Contribution to tuberculosis burden	Contribution to research related to spinal tuberculosis	χ² and P value
High burden areas	87%	44.4%	40.912 (with 1 degree of freedom) and P value < 0.0001
Rest of the globe	13%	55.6%

Countries such as the United States, Germany, the United Kingdom, and Japan have been pioneering the use of AI technology for the diagnosis of STB, while countries such as India, China, and South Africa have focused on clinical trials and the clinical management of the disease. Table 4 presents the top 20 journals that contributed the most to STB-related publications.

Table 4 List of top 20 journals contributing the highest number of spinal tuberculosis-related publications, n (%).

S/L number	Name of the journal	No. of publication (n = 528)
1	Cureus Journal of Medical Science	48 (9.1)
2	BMJ Case Reports	20 (3.8)
3	World Neurosurgery	19 (3.6)
4	Journal of Orthopaedics of Case Reports	16 (3.1)
5	Indian Journal of Tuberculosis	14 (2.7)
6	World Journal of Clinical Cases	9 (1.7)
7	Medicine (Baltimore)	8 (1.5)
8	The Pan African Medical Journal	8 (1.5)
9	Asian Spine Journal	5 (0.9)
10	European Spine Journal	5 (0.9)
11	Global Spine Journal	5 (0.9)
12	Indian Journal of Orthopaedics	5 (0.9)
13	Journal of Clinical Orthopaedics and Trauma	5 (0.9)
14	Neurology India	5 (0.9)
15	Asian Journal of Neurosurgery	4 (0.8)
16	BMC Musculoskeletal Disorders	4 (0.8)
17	Spinal Cord Series and Cases	4 (0.8)
18	Spine Deformity	4 (0.8)
19	Journal of Orthopaedic Surgery and Research	3 (0.6)
20	Orthopaedic Surgery	3 (0.6)

DISCUSSION

STB is a subset of EPTB that is often difficult to diagnose due to the disparate clinical presentations, paucibacillary nature of the disease leading to delay in diagnosis, and limited treatment options. This study highlights the research progress in STB over the past 5 years, aligning with the global objective to eliminate TB by 2030[13].

Publication trends

There has been a notable increase in the number of research articles on STB published between 2019 and 2023, with over 80% of publications occurring between 2020 and 2023. This consistent upward trend, particularly in recent years, underscores the ongoing relevance of STB as a significant health issue that continues to challenge healthcare systems. The increasing number of published articles related to STB may be due to advancements in diagnostic tools like Gene Xpert or increased global health funding for TB-related research. While there was a decline in reported TB cases during the coronavirus disease 2019 (COVID-19) pandemic, this reduction was largely attributed to the reallocation of diagnostic resources for COVID-19 testing and disruptions in reporting[14].

Ekenoğlu Merdan et al[15], in their bibliometric study on TB-related research from 1840 to 2020, observed a similar gradual rise in TB publications, with 26.91% of the articles published in the last decade alone. A separate report by Garrido-Cardenas et al[16] further confirmed this trend, showing a steady increase in TB-related research since 1990.

These findings indicate that, despite the disruptions caused by the COVID-19 pandemic, TB—particularly EPTB and STB—remains a critical area of investigation for mitigating TB-related morbidity and mortality worldwide.

Geographical location

The current study reveals that 65.9% of the STB-related publications originated from the Asian continent, with the primary contributing countries being India (25.8%), China (19.9%), and the United States (10.4%)[15,16]. Collectively, African countries contributed only 6.5% to the research output. Previous studies conducted in different time frames have similarly shown that India, the United States, and the United Kingdom were the major contributors to published research work. Analyses by Held et al[17] in 2018 and Sathish et al[11] in 2020, focusing on the top 100 and 250 cited articles on STB, also confirmed that India, the United States, and China were the top three contributors[11,17]. Notably, Asia accounted for nearly double the research output (48.6%) compared to North America (23.5%). This is unlike other bibliometric studies, which show United States as the top contributor[18-21]. Comparing our findings with these previous studies, we observe a slight shift in the ranking of research-contributing countries, although India and the United States continue to dominate the list. Both India and China are classified as high-burden TB countries, with significant challenges related to multidrug-resistant TB and human immunodeficiency virus-TB coinfections[17]. Importantly, analysis by Sathish et al[11] highlights the resourcefulness of Indian and Chinese scholars, who were responsible for 17 of 31 prospective studies (54.8% of the total)[11]. China's significant progress in research has been bolstered by funding projects, especially from the National Natural Science Foundation of China, which supported 7.7% of the studies[21,22]. China’s emergence as a research spear leader is also reiterated by Rui et al[23], who found China leading worldwide in research trends in bone metastasis following lung cancer.

By contrast, African countries have lagged in research output, likely due to the overwhelming clinical load faced by low-income nations. Held et al[17] noted that many research centers in these regions struggle with insufficient funding and inadequate laboratory support, hindering their ability to contribute to the global research landscape[17]. We concur with these observations and emphasize the need for more research opportunities and support in these regions in form of technology transfer or international collaborations in the future could address these gaps. However, even simple studies are contributing valuable insights, which can be further expanded upon in future research. Tokur et al[20] also note in their in their bibliometric analysis on research related to lung transplantation, that the majority of cutting-edge research findings are focused on only a few developed nations, and exchanges with emerging nations are still in their infancy[20]. Islam et al[24] also did a bibliometric study on antibiotic-resistant pulmonary TB and the authors determine that the outcomes of antibiotic-resistant TB research would be more productive and translational if researchers from low- or middle-income countries (especially from Africa, South America, and Asia) with high research productivity and TB burden could be in collaboration with high-income countries exhibiting low TB burden.

Journals

The top three journals for publishing STB research in this study were Cureus Journal of Medical Science, BMJ Case Reports, and World Neurosurgery. Similarly, Yilmaz et al[22] study identified European Spine Journal, International Orthopaedics, and World Neurosurgery as the most preferred journals for STB-related publications[21]. Additionally, Yilmaz et al[22] noted an interesting trend of articles being published in native languages alongside English[21]. Held et al[17], in their analysis of the top 100 influential articles on STB, found that the Journal of Bone and Joint Surgery, British edition had the highest number of citations, contributing 20% of the total publications[11]. This was followed by the Journal Spine with 14 publications (14%), The American Volume of the Journal of Bone and Joint Surgery with 9 publications (9%), and Clinical Orthopaedics and Related Research with eight publications (8%)[17].

Numerous journals have transitioned to online formats, either in hybrid or open access models. The open-access movement has enhanced the dissemination of research, especially in resource-constrained environments that may lack. Few journals also offer discounts or full waivers for submissions from low-income countries, particularly for open-access publishing. This initiative could explain the recent shift in journal preferences, as it facilitates broader participation from researchers in resource-limited settings.

Citations

This study reveals that articles from India, the United States, and China received the highest number of citations, indicating that researchers from these countries are actively engaged in various aspects of STB and frequently share their findings through publication. Other notable contributors to STB-related publications include Indonesia, the United Kingdom, South Korea, Italy, Japan, Saudi Arabia, and South Africa. Our results align with those of Ekenoğlu Merdan et al[15], although their study focused more broadly on TB in general, whereas our analysis is specific to STB. Regardless of the geographic focus, the significance of TB, in both PTB and EPTB forms, has remained critical in global research over the years.

Type of articles

In evaluating the types of studies published on STB, case reports and case series accounted for the majority (66.4%), while RCTs were the least common, making up only 1.9% of the total. Conducting RCTs in STB is complicated as sometimes there can ethical concerns especially when randomizing patients to surgical vs non-surgical treatments particularly when one treatment has been proved to be superior based on current evidence or clinical judgment. Moreover, randomization to a conservative treatment arm may delay surgery for patients who could benefit, potentially worsening outcomes. But regional collaborations or funding incentives may definitely foster higher-quality research and even RCTs in domain where it is feasible.

Sathish et al[11] observed that among the top 250 most cited articles, the majority were retrospective studies (73.3%), with a smaller proportion being prospective (12.4%) and even fewer RCTs (4.8%). This trend was further supported by findings from Held et al[17]. Additionally, there has been a noticeable increase in diagnostic research, particularly with the use of advanced molecular tests such as Gene Xpert and other similar technologies[25-26].

TB burden and publications

Our analysis reveals a significant difference (P < 0.0001) in the scientific contributions to STB research between countries with the highest burden of TB (44.4%) and those from the rest of the world (55.6%). Additionally, advanced technology-driven research, such as studies utilizing AI, is more prevalent in high output countries like China[27]. Several African nations, face a disproportionate impact of STB cases and fall into the low socioeconomic groups. These populations often experience greater economic hardship, delays in treatment initiation, and poor adherence to treatment and follow-up. Consequently, it is essential to intensify research and international efforts in these resource-limited regions to combat TB more effectively and work toward global elimination. AI can accelerate innovation and make research processes more efficient and impactful by addressing few of the challenges such as limited access to funding, infrastructure, and expertise. Moreover, the study of multi-omics is crucial for understanding STB, as it provides a comprehensive view of the molecular mechanisms underlying the disease. By integrating genomics, transcriptomics, proteomics, and metabolomics, multi-omics approaches can unravel host-pathogen interactions, identify biomarkers for early diagnosis, and uncover potential therapeutic targets. This holistic perspective is essential for advancing precision medicine in the management of STB[28].

Strengths and limitations

This study had several limitations. While bibliometric analysis provides a comprehensive snapshot of the existing literature at a specific point in time, research is dynamic and continuously evolving. Our study relied solely on the PubMed database, excluding other databases that may have relevant research. Additionally, only articles published in English were included, potentially overlooking valuable contributions in other languages. Exploration of other databases such as Scopus and incorporation of multilingual analysis would provide a more holistic view of global research output. To bridge the research gap, it is crucial to foster collaboration between centers in low-income, high-burden countries and those with high research output to enhance global understanding and advancements in STB research.

CONCLUSION

This bibliometric analysis revealed a significant rise in STB-related research publications over the past 5 years, with Asia, particularly India and China, leading the global output. Despite this progress, there is a disproportionate contribution from high-burden countries, particularly in low-income regions like Africa. The majority of published research remains in the form of case reports and case series, with a paucity of RCTs. These findings highlight the need for more collaborative, high-quality research efforts, especially in resource-poor settings, to address the global challenge of STB. Enhanced international collaboration and investment in research infrastructure are crucial for advancing diagnostic and treatment innovations and for achieving the global goal of TB elimination by 2030.