A Comprehensive Bibliometric Analysis of Biomedical Research Waste: Current Situation, Development, and Trends

Introduction

Research waste has become an increasingly recognized issue in scientific research, primarily referring to the inefficient use of research resources due to flaws in research design, execution, reporting, and other stages. The problem was first highlighted by D.G. Altman in 1994, who exposed the issue of poor medical research, thereby attracting considerable attention from the scientific community [1]. It is estimated that over $100 billion is allocated annually to support biomedical research worldwide; however, approximately 85% of this funding is squandered due to inefficiencies in the research process [2]. A significant milestone in research waste came in 2009, with a series of reviews published in The Lancet. These reviews addressed various aspects of avoidable waste, including issues related to study design and analysis [3], the definition of research priorities [4], laboratory implementation [5], systematic review [6], supervision and management [7], and experimental reporting [8], thereby drawing growing attention from researchers in the field. However, despite this progress, the current trends in biomedical research waste remain insufficiently understood.

Bibliometrics offers a quantitative approach to studying research hotspots and development trends within a specific field. It provides valuable insights into key factors such as authors, journals, institutions, and countries, which can guide the allocation of scientific research resources [9], inform policy and decision making [10], and facilitate scientific collaboration and network building [11]. Therefore, bibliometrics has become an indispensable tool in scientific research evaluation.

In recent years, various efforts to mitigate biomedical research waste have emerged through multiple strategies [12,13]. However, there is a notable lack of comprehensive investigations and bibliometric analyses within the broader field of research waste. Most existing bibliometric studies on research waste focus on specific diseases[14,15]. To address this gap, our study provides a comprehensive analysis of all biomedical research waste-related articles published over the past 2 decades. For this purpose, we utilized CiteSpace and VOSviewer to conduct an in-depth visual analysis of the relevant literature. We also explored the relationships among countries, institutions, authors, journals, and keywords. Furthermore, we investigated which stages of the clinical trial process are most prone to research waste and in which disciplines it is most likely to occur. We anticipate that our findings will play a pivotal role in enhancing the quality of scientific research, fostering academic collaboration, and advancing the principles of open science.

Material and Methods

DATA COLLECTION:

The literature for this study was comprehensively sourced from the WoS database, which offers standardized and extensive data. The search query used was: “TS=(‘clinical trials’ AND (‘research waste’ OR ‘unnecessary research’ OR ‘inefficiency’ OR ‘ethics in research’ OR ‘resource allocation’)) AND TS=(‘clinical trials’ AND (‘noncompletion’ OR ‘nonpublication’ OR ‘publication bias’ OR ‘trial failure’ OR ‘underreporting’))”. This search strategy was specifically designed to comprehensively capture literature related to biomedical research waste in clinical trials. It considers that issues such as non-publication, publication bias, and underreporting also contribute to research waste; therefore, these factors were incorporated into the query. The search was restricted to publications from January 1, 2004, to December 31, 2024, and only the literature categorized as either “articles” or “reviews” were included. This method resulted in the retrieval of 1118 eligible publications. After screening, 79 articles or reviews published outside the specified period (2004–2024) were excluded, along with 163 other types, such as book chapters, letters, news articles, and corrections. Consequently, a total of 876 valid articles were selected for further analysis. The bibliometric data were exported in plain text and CSV formats for subsequent analysis (Figure 1).

DATA ANALYSIS AND VISUALIZATION:

This study analyzed 876 articles retrieved from the WoS using 3 bibliometric analysis tools – CiteSpace, VOSviewer, and R-bibliometrix – to explore academic trends, research topics, and collaborative networks through visualization techniques. First, a literature co-occurrence analysis was conducted using CiteSpace 6.1.R2 to examine key themes within the research field and the interconnections between the literature, with a particular focus on the sudden emergence of literature. The co-occurrence analysis of keywords revealed the thematic evolution of the literature, while the burst analysis function helped identify high-frequency terms and emerging research hotspots. The resulting keyword co-occurrence network, generated by CiteSpace, effectively illustrated core topics, research trends, and pivotal articles in the domain of clinical trial research waste. Next, VOSviewer 1.6.18 was used to further analyze the literature’s keywords, highlighting their interrelationships through co-occurrence network analysis. The network map produced by VOSviewer visually represents the significance and relevance of keywords, as indicated by the size, color, and strength of the connections between nodes. This analysis also facilitated the identification of major research institutions and collaborative authors. In addition, R-bibliometrix 3.2.0 was employed for a comprehensive examination of publication trends and provided insights into the distribution of research across countries, journals, and institutions. The visualization capabilities of R-bibliometrix were leveraged to generate figures depicting publication trends and collaborative networks, which further enhanced our understanding of the dynamic changes and development trajectories in the field of research waste. Furthermore, R-bibliometrix facilitated a quantitative analysis of academic influence through indicators such as the H-index and citation counts, offering valuable insights into the impact of the literature (Figure 1).

Results

TRENDS IN THE NUMBER OF PUBLICATIONS AND CITATIONS:

The earliest literature related to research waste was published in 1995, but the number of publications remained relatively low until 2004. Since then, there has been a marked increase in the volume of publications, as shown in Figure 2A, which illustrates the annual publication trends of literature on research waste from 2004 to 2024. The data reveal a steady rise in publications, with a sharp uptick in recent years, suggesting a growing awareness and increasing focus on this issue. The cumulative number of publications demonstrates a strong fitting relationship, and a quadratic polynomial fitting curve, y=1.5629x2+9.1766x+5.4451, was applied to model and predict future trends in literature accumulation. The model achieved an R2=0.9987, indicating an excellent fit. This quadratic growth pattern emphasizes the increasing attention that research waste is receiving, partly due to heightened recognition of inefficiencies and resource waste in scientific research.

According to data from WoS, the 876 publications collected were cited a cumulative total of 39 768 times, yielding an average citation frequency of 45.4 citations per article. Figure 2B presents the annual citation trends and key milestones of research waste articles from 2004 to 2024. Notably, although the foundational concepts introduced in 1995 and 2009 helped clarify the issue of research waste in biomedical research, the most significant increase in citations occurred after 2014, with a particularly sharp rise in 2014. This surge in citations may be attributed to the increased emphasis on research process improvement in The Lancet in 2014, which motivated academics and research institutions to focus more on strategies to enhance research quality.

COUNTRY/REGION AND INSTITUTIONAL DISTRIBUTION:

Figure 3A illustrates the number of publications on research waste by country from 2004 to 2024. Table 1 presents the centrality, total citations, and average citations per article for the top 10 countries in terms of publication volume. The data reveal that the United States and England lead in the number of articles, total citations, and article share, with the United States publishing 136 articles and receiving 8884 citations, followed closely by England. Despite a relatively smaller volume of publications, Canada has the highest citations per article (80.95), indicating its significant impact on the field. Regarding centrality, Scotland has the highest value (0.2), reflecting its dominant influence within the research network, while countries like Germany and France have lower centrality values, suggesting a comparatively smaller influence.

Figure 3B highlights international collaboration within the field, where the size of each node represents a country’s influence in research waste. England is positioned as central nodes, indicating robust collaboration. Canada and Australia also demonstrate significant influence and maintain strong collaborative ties with the United States and England. Although China and Switzerland have relatively lower influence, they actively engage in research partnerships. Conversely, Brazil is represented by a smaller node, implying limited cooperation within the global network. In summary, research on this area is predominantly concentrated in a few developed countries with high publication output and extensive collaboration networks, such as the United States, England, Canada, and Australia, likely due to their earlier establishment of clinical research infrastructures. Additionally, the advantages of developed countries in terms of research resources, management, and international partnerships have played a key role in advancing the field of research waste.

Figure 4, generated using VOS viewer, illustrates the collaborative network and potential linkages between various countries and research institutions in the field of research waste. The University of Oxford and the University of Ottawa are positioned as central nodes in this network, with strong links between them, indicating their leading roles in advancing research on this topic. The University College London and the University of Liverpool have also established strong partnerships with Oxford, further facilitating academic collaboration in the field of research waste. Notably, the collaborative network reveals a clear trend of geographic concentration, with European and North American universities dominating the landscape. Institutions from these regions tend to have closer collaborative relationships with one another. In contrast, institutions from Asia and other regions, such as universities in New Zealand and Switzerland, while also participating in global collaboration, exhibit relatively more independent networks. These institutions are more singularly connected to mainstream academic circles, rather than forming densely interconnected partnerships. Overall, while cooperation in the field of research waste is extensive, regional differences are evident, particularly in developed countries and regions where academic institutions are more actively promoting collaboration and exchange in this area of research.

AUTHOR DISTRIBUTION:

Figure 5 illustrates author collaborations in the field of research waste. The figure clearly delineates cooperation among authors, represented by 9 distinct colors, each corresponding to a separate group. Douglas G. Altman stands out as one of the important nodes in the network, demonstrating extensive collaborations with numerous scholars. Altman has made significant contributions to study design and statistical analysis in medicine, establishing himself as a key figure in the field. He has closely worked with scholars, such as Jamie J. Kirkham and Carrol Gamble, focusing on areas like methodology and research quality improvement. Notably, these partnerships extend beyond authors from similar academic backgrounds, as evidenced by Altman’s collaborations with An-wen Chan and David Moher, which span diverse disciplines, including statistics, epidemiology, and public health.

According to Table 2, the top 10 most cited research articles are listed, with a total of 11 551 citations. The article by Marcus R. Munafo, published in Nature Human Behaviour in 2017, ranks first, with a cumulative total of 1851 citations and an average annual citation rate of 264.4 citations. Interestingly, all the authors of these highly cited articles are from the UK, United States, and Canada, with 5 out of the 10 authors based in the UK. Additionally, the top 4 most cited articles are all authored by UK researchers. The Lancet was early to focus on the problem of research waste and published articles with extremely high citation rates. The overarching themes of these publications focus on critical issues such as study design, data transparency, bias control, and enhancing the reliability and efficiency of research. This trend indicates that the academic community is increasingly addressing research waste and promoting more efficient research practices through improved methodologies and greater transparency.

JOURNAL ANALYSIS:

The double mapping overlay of journals is a tool used to visualize citation and publication relationships among academic journals. It can be used to analyze the relevance of journals, uncover research trends, identify key journals, and foster interdisciplinary collaboration. Figure 6 demonstrates that in the field of research waste, the citing journals predominantly belong to disciplines such as mathematics, clinical medicine, ecology, molecular biology, and immunology. In contrast, the cited journals are primarily from fields such as systematics, environmental science, toxicology, nutrition, chemistry, physics, nursing, and psychology.

The top 10 journals in terms of the number of publications contributed a total of 239 articles, accumulating 12 944 citations (Table 3). Among them, The Lancet ranked first with 48 publications, accounting for 5.49% of the total publications. The journal with the highest impact factor (93.7) was Medical Journal, which also had the highest total number of citations (3589) and the highest average number of citations per article (123.76). Furthermore, 8 of these 10 journals are ranked within the top 25% of journals, suggesting that research waste has become a prominent academic focus and that substantial progress has been made in this field.

KEYWORDS ANALYSIS:

Keywords are fundamental elements that reflect the central topics and content of research articles. Figure 7A illustrates the distribution of various keywords in the field of research waste, with the size and color of the keywords indicating their frequency of occurrence in the relevant literature. In this heatmap, “clinical trial” occupies a prominent position, underscoring its centrality to the field of research waste. Other frequently occurring keywords, such as “reducing waste”, “publication bias”, and “quality”, further highlight the ongoing emphasis on improving research efficiency and minimizing bias.

A deeper analysis of these keywords was conducted using CiteSpace, revealing 14 closely related clusters, as shown in Figure 7B. These clusters can be categorized into 3 main groups: one pertaining to the domains where research waste occurs (clinical trials), another addressing the factors associated with research waste in clinical trials, and a third focused on strategies to reduce research waste. As illustrated in Figure 7B, a detailed analysis of the data distribution and category aggregation enables a deeper understanding of the key characteristics of research waste in clinical trials. Keywords such as “#0 clinical trials,” “#9 drug research,” “#11 evidence-based research,” and “#14 randomized controlled trials” form a distinct cluster, indicating that research waste is particularly prevalent within the clinical trial domain, especially in drug research, randomized controlled trials (RCTs), and evidence-based medicine. This highlights the significant role that issues in study design, sample selection, and drug effects play in contributing to research waste. In clinical trials, many studies fail to produce valid conclusions due to inadequate sample rigor, flawed design, or inability to achieve expected outcomes. Another cluster, which includes keywords like “#5 association” and “#6 trial protocol,” points to influential factors within clinical trials. These factors such as financial support, research methodology selection, and patient participation are strongly correlated with clinical trial results and directly impact the efficiency and success of trials. Finally, clusters associated with keywords such as “#4 patient-reported outcomes,” “#7 clinical trial registry,” “#6 reducing waste,” “#10 intervention sequence (IVS),” and “#13 intervention development” suggest potential strategies for minimizing research waste. Patient-reported outcomes (PROs) are an essential tool for capturing the true needs and experiences of patients, enhancing trial reliability and helping mitigate inefficiencies. The position of PROs in the clustering analysis indicates that this approach has been widely adopted and has yielded substantial results. Furthermore, intervention development has emerged as an effective strategy to reduce clinical trial waste. Scoping reviews, a widely recognized form of evidence synthesis, provide a scientific foundation for intervention development by offering a comprehensive summary of existing evidence, eliminating redundant studies, and informing policy formulation [16]. In summary, the trends observed in keyword clustering and clinical trial findings are interconnected, offering valuable insights that can guide the design and implementation of future clinical trials, ultimately reducing waste and improving the quality of research.

To visualize the start and end times of keywords in the research waste domain, we extracted the citation bursts of all keywords using CiteSpace software and listed the top 20 keywords with the earliest citation bursts. As shown in Figure 8, the keyword “confidence intervals” experienced the first citation burst in the field of research waste, with the burst period lasting from 2010 to 2013. The most prominent keywords during the outbreak were “quality” and “design”, with burst intensities of 3.28 and 3.3, respectively. This indicates that significant attention was given to how to effectively reduce waste in research quality improvement and clinical research design. Since 2020, the focus in the field of research waste has shifted towards keywords such as “bias”, “association”, “barriers”, and “outcome”, suggesting potential research trends in the field for the coming years.

CATEGORIES ANALYSIS:

A comprehensive clinical study typically includes registration, research design, termination, results reporting, publication, and citation, among other stages. We categorized the collected articles on research waste according to these segments. Figure 9A illustrates the trends in the research waste domain across each segment of clinical research between 2004 and 2024. By dividing the timeline into 4-year cycles, we observe a significant increase in the number of articles in the registration, research design, and publication segments, particularly between 2013 and 2020. This indicates that these areas have garnered more attention in efforts to reduce research waste. In contrast, the citation segment has seen a slower growth in publication numbers, suggesting that it has received relatively less focus in the context of research waste. Meanwhile, the number of articles related to termination and results reporting has not fluctuated significantly, implying that the discussion surrounding these areas remains relatively limited and may still be in its preliminary stages. Overall, the focus within the research waste domain has progressively shifted towards registration, research design, and enhancing the transparency and efficiency of study publication, reflecting the growing emphasis on improving research quality and minimizing waste.

As shown in Figure 9A, research design is one of the most significant contributors to research waste in the clinical research process. We further extracted the 4 research design types that most frequently lead to research waste (Figure 9B), summarized their causes, and proposed corresponding solutions.

DISCIPLINES ANALYSIS:

To further investigate the distribution of research waste across clinical disciplines, we categorized research waste articles by clinical discipline for the period 2004 to 2024. After excluding 392 articles without discipline attribution, a total of 484 articles were included in the analysis. As shown in Figure 10A, internal medicine accounted for the largest share, comprising 36.38% of the research waste articles, followed by surgery (14.84%), pediatrics, pharmacology, and psychiatry, with relatively fewer articles from other disciplines.

Figure 10B reveals that within internal medicine, oncology (71 articles) represented the largest proportion, indicating a high prevalence of research waste in oncology clinical trials. This is likely due to the large number and complexity of clinical trials in oncology, which are often prematurely discontinued or left unpublished due to poor trial design, insufficient recruitment, and lack of external funding [17,18]. Additionally, the assessment of publication bias is not commonly utilized in systematic reviews within oncology, leading to exaggerated treatment effects and contributing to publication bias [19]. Neurology (25 articles) also shows a significant percentage of research waste within internal medicine, which may be attributed to the complexity and heterogeneity of the patient population, as well as the challenges in diagnosis and efficacy assessment.

As shown in Figure 10C, orthopedics (31 articles) accounted for the largest proportion of research waste in surgery, with a significant portion resulting from early discontinuation and non-publication of trials [20–22]. Other specialties, including plastic surgery, neurosurgery, urology, and burn care, accounted for smaller proportions of research waste.

During our categorization of disciplines, we identified several articles that quantified research waste within specific fields. To further examine the characteristics of research waste quantification, we focused on articles quantifying research waste in oncology and orthopedics. As shown in Table 4, the majority of research waste quantification in oncology was found in clinical trials involving early-stage tumors and gastrointestinal cancers, particularly gastric cancer. Of the 137 RCTs on gastric cancer conducted between 2009 and 2019, only 81 (59.1%) were published. Among the 81 published RCTs, 63 (77.8%) exhibited avoidable design flaws [15]. In Table 5, we observe that osteoarthritis and spinal cord disorders represented areas with relatively high levels of research waste quantification in orthopedics. Of the 173 trials on bone and joint disorders, only 243 studies were completed, and 67 (27.6%) of these trials have yet to be published [23]. Overall, the quantified research waste predominantly occurred in the publication, discontinuation, and results reporting stages, while research design-related waste was less frequently quantified. This may be due to the challenges of measuring study design waste using standardized metrics. Additionally, this finding highlights the critical role that publication plays in the dissemination of research findings, the transparency of research, and the efficient use of resources. Unpublished research represents the most significant waste in the research process.

Discussion

STRENGTHS AND LIMITATIONS OF THE RESEARCH:

In this study, we utilized the WoS to comprehensively collect literature on research waste in the field of clinical trials, combining bibliometric analysis and visual representations to provide readers with a clear understanding of the current status and trends in this area. However, there are some limitations to this study. First, bibliometric metrics, such as the H-index, may inherently favor more experienced scholars, as they account for the researchers’ publication history. Although younger scholars may have made significant academic contributions, they may not be sufficiently highlighted in such evaluations [47]. Second, bibliometric indicators primarily rely on citation data, overlooking other important factors such as social impact, public perception, and researchers’ innovation capacity, which complicates the ability to fully capture the multidimensional nature of academic impact. Lastly, the WoS predominantly includes English-language publications, with limited coverage of non-English scholarly works, which introduces certain constraints.

Conclusions

We carried out the first comprehensive bibliometric analysis of all research waste literature from the past 20 years, examining the various processes and disciplinary distributions in clinical trials. The findings of this analysis not only provide a solid foundation for future research on research waste but also offer a valuable reference for researchers worldwide seeking to mitigate research waste in clinical trials.