Introduction

The global health system is currently at a critical juncture marked by dual pressures: an increasing burden of chronic diseases and increasingly tight fiscal constraints. In the aftermath of the COVID-19 pandemic, these challenges have evolved into a crisis of resilience, where health facilities are required not only to survive medically, but also to remain financially stable amid rising healthcare costs and global economic uncertainty. As a strategic response, many countries are accelerating financing reforms by shifting from the traditional fee-for-service (FFS) model to a prospective case-based payment system known as Diagnosis-Related Groups (DRG) and Case-mix [1], [2]. Diagnosis-Related Groups are a classification of diseases or procedures based on clinical similarities and similar resource usage [3]. The use of the DRG system offers advantages in healthcare financing in healthcare facilities, such as providing certainty and transparency of service costs, motivating providers to provide efficient services while still providing quality services in accordance with applicable clinical standards [4]. Various obstacles arise in the transition from fee-for-service to DRG financing. Principal-agent theory explains that an information gap between regulators as principals and healthcare providers as agents can trigger opportunistic behavior. In the FFS payment system, providers can provide excessive services to patients (supplier-induced demand). Meanwhile, the potential for moral hazard in the DRG system may include attempts at up-coding to increase the value of financing claims or the selection of patients by health facilities in order to maximize hospital revenue [5], [6].

This momentum for reform reached its peak in the last decade (2016–2025), which was the most transformative period in the history of modern health policy. There were two major paradigm shifts that became the focus of global attention: first, technological leaps in Asia, particularly China, which integrated DRG with the Big Data Diagnosis-Intervention Packet (DIP) system to improve payment accuracy [1], [7]; Second, the emergence of a need for more adaptive and transparent payment models as a direct response to the hospital cash flow crisis caused by the pandemic [8]. The focus of global research is no longer limited to macro cost control aspects, but has shifted towards the use of DRG data for clinical quality monitoring and the implementation of Value-Based Healthcare (VBHC) [9], [10].Although there have been many studies on the impact of DRGs in various countries, there is a significant research gap in terms of macro intellectual mapping. To date, there has been no comprehensive study visualizing how the topics of DRGs and financing reform have evolved, how patterns of global inter-institutional collaboration have been formed, and where research trends are headed towards 2025. Bibliometric analysis is very important to provide a “road map” for policymakers and academics to understand the existing knowledge structure and identify areas that are still rarely researched.

This study aims to fill this gap by conducting a bibliometric analysis of the Scopus database for the period 2016–2025. Findings from this study are useful as a strategic reference in the formulation of more robust and accountable financing regulations. Specifically, this study will answer the following questions:

What is the descriptive profile of global scientific publications related to Diagnosis-Related Groups (DRG) systems and health financing reform in the period 2016–2025?

Who are the main intellectual actors (countries, institutions, and authors) that have had a major influence on research into health financing reform at the global level in the period 2016–2025?

What is the analysis of the intellectual structure and cluster grouping based on keywords related to DRG and health financing system reform in the period 2016–2025?

How has the topic and research trend on Diagnosis-Related Groups (DRG) and health financing reform evolved from 2016 to 2025 that can be used as a direction for future research development?

Method

This study uses a descriptive bibliometric approach and thematic analysis. The research method consists of data collection, data analysis, data visualization, and interpretation of results.

1. Data Collection

Figure 1. Flowchart of Data Collection, Screening, and Analysis Process

The complete stages of the bibliometric analysis, including data collection, screening, and analysis procedures, are illustrated in Figure 1. The literature search was conducted systematically using the Scopus database as the main data source. Scopus was chosen because of its strong reputation for managing high-quality scientific literature and its significant influence in the global publication map. The data search process was carried out in January 2026 to identify studies relevant to the topic of diagnosis-related groups and health financing reform. The search was conducted using a combination of specific keywords in the title, abstract, and keywords with the following search string:

(TITLE-ABS-KEY ("diagnosis related groups" OR "case-mix" OR "case based groups" OR "Prospective Payment") AND TITLE-ABS-KEY ("payment reform" OR "reimbursement reform" OR "health reform" OR "system change"))

In the initial search phase, 185 scientific papers were identified. Screening was conducted using strict inclusion and exclusion criteria to ensure data quality and relevance. The publication time frame was limited to the last decade, from 2016 to 2025, in order to capture the latest developments in financing systems. The types of documents were limited to journal articles to ensure that the data came from original research; other types of publications such as conference proceedings, reviews, abstracts, newspaper articles, and book chapters were excluded from the search engine. Only articles in the final publication stage were included to avoid potential future changes to the data, and the search was limited to English-language manuscripts to facilitate analysis in a global context. Based on this selection process, a total of 143 documents that met all inclusion criteria were obtained for further analysis.

2. Data Analysis

Bibliographic data from 143 selected documents were exported from Scopus in CSV and RIS formats. The analysis was conducted in two stages. Descriptive analysis was performed using Microsoft Excel to map annual publication trends and identify the most productive journals, countries, and institutions related to the topics of payment reform and DRG systems. Bibliometric mapping was performed using VOSviewer software (version 1.6.20). VOSviewer was used to visualize bibliometric networks in two main forms of analysis: Co-authorship to see patterns of collaboration between countries or researchers; and Co-occurrence of keywords to identify dominant research themes, topic clusters, and current research trends.

In the keyword co-occurrence analysis, a minimum threshold of 5 occurrences was set for each keyword. This threshold was set to filter out noise (rarely occurring keywords) and ensure that the visualization map only displayed concepts that had a significant intellectual influence on health financing reform.

Results and Discussion

The results of the screening found 143 journals from 29 countries, 160 authors, 86 journal sources, and 1,219 keywords. This diversity shows that discussions on health financing system reform around the world, particularly through the Diagnosis Related Groups (DRG) system, are a strategic issue that is multinational and multidisciplinary in nature. The distribution of research covering 29 countries shows that there are global efforts to implement an efficient health financing system to support the financial sustainability of health services. The involvement of 160 authors indicates the formation of an active intellectual community in the transformation of health financing systems across various disciplines. The findings of 1,219 keywords provide an overview of the complexity of financing patterns using the DRG system in health financing reform.

1. Descriptive Profile Global Publication Health Financing Reform and Diagnosis Related Groups

a. Development The Number of Publications in the Period from 2016 to 2025

Figure 2. Development of the number of publications by year (2016-2025)

The data shows that the productivity of articles related to DRG and financing reform in the last 10 years (2016–2025) totaled 143 documents, with an average of approximately 14.3 articles published per year, as illustrated in Figure 2. Throughout the period from 2016 to 2023, the volume of research tended to fluctuate but remained stable in the range of 7 to 18 documents per year. These fluctuations indicate that although health financing issues are always relevant, there are dynamics in research interest that may be influenced by policy cycles or health reforms in various countries during that period [3], [11].

A significant increase in publications began to appear in 2024 (18 documents) and peaked in 2025 with 28 documents. This sharp increase indicates that the topic of financing reform is becoming a current research trend. This is most likely triggered by post-pandemic evaluations of the financial resilience of hospitals and the urgent need for countries around the world to adopt more efficient payment systems [12], [13], [14].

b. Development of Publication Numbers Based on Publisher Country

An analysis of the geographical distribution of the 143 selected documents shows the dominance of two major countries, namely the United States and China. The United States published 61 documents over the past 10 years, reinforcing its position as a pioneer in the development of DRG systems since the 1980s. China showed rapid growth, producing 53 documents.

Figure 3. Ten Countries with the Highest Publication Contributions

The dominance of these two countries reflects two fundamentally different approaches to reform which is clearly visualized in Figure 3. The United States focuses on improving efficiency in a highly fragmented insurance market between Medicare, Medicaid, and the private sector [15]. In contrast, China has undertaken massive reforms with a massive top-down approach through the DRG and DIP systems to achieve Universal Health Coverage for its large population. This reflects the Chinese government's ambitious goal of undertaking massive reforms of the national healthcare system, particularly through the implementation of DRG and DIP in hundreds of cities in recent years [16], [17]. China's high productivity provides a highly relevant context for other developing countries undergoing similar transitions. European countries such as the United Kingdom, Germany, the Netherlands, and Switzerland have consistently published the results of evaluations of their established financing systems [3]. In the Asia-Pacific region, Singapore's presence shows that the issue of sustainable hospital financing is also an important priority in the healthcare systems of these countries [2].

c. Development of Publication Numbers Based on Publishing Institutions

Figure 4. Ten Institutions with the Highest Number of Publications

The distribution of the ten most productive institutions in terms of publication volume is presented in Figure 4 Analysis of the top 10 affiliations shows that research on payment reform and DRG systems is dominated by leading universities and medical centers in the United States and China. Duke University School of Medicine is the most affiliated with 9 documents, followed by the University of Michigan, Ann Arbor (8 documents) and Harvard Medical School (6 documents). The dominance of medical institutions in the United States shows that the evaluation of cost efficiency is not only carried out from an economic perspective, but is also closely related to clinical and hospital management [17]. Institutions from China also exerted significant influence through Peking University Health Science Center, Huazhong University of Science and Technology, and Wuhan University, each contributing 5 documents. The concentration of publications at these health science centers reflects the Chinese government's systematic push to explore the transition of national health financing reform [18]. Technische Universität Berlin (4 documents) from Germany represent the strong European tradition in Social Health Insurance thinking and the early development of the technically mature DRG system [3].

d. Development of Publication Numbers Based on Journals

Figure 5. Top Ten Journals with the Highest Number of Publications

Figure 5 displays the ten most influential journals based on the volume of scientific articles published between 2016 and 2025. Identification of the top 10 most productive journals shows that topics related to DRG systems and financing reform are published through various multidisciplinary platforms. Frontiers in Public Health ranks first with 14 documents, followed by BMC Health Services Research with 8 documents. Journals focusing on health policy and health management, such as Health Policy (7 documents) and Risk Management and Healthcare Policy (7 documents), show that the issue of payment reform is closely related to broad public health policy and the operational management of health services.

In addition to general journals, the emergence of specialist journals such as the Clinical Journal of the American Society of Nephrology (3 documents) shows that the impact of DRG system reform is also beginning to be studied at certain levels of clinical specialization (for example, in cases of kidney disease that require high costs) [19]. This provides an important perspective that payment system evaluations must consider cost variations across different types of clinical services [20].

2. Collaboration Network Analysis (Co-authorship)

a. Patterns of Global Scientific Collaboration Among Authors

Figure 6. Inter-author Collaboration Network (Co-authorship)

The mapping of the author network reveals patterns of global scientific collaboration displays in Figure 6. The network visualization shows two main clusters that conduct extensive research on payment system reform and DRGs. The red cluster is dominated by researchers from US institutions, such as Maciejewski Matthew L., Hirth, Richard A., and Wang, Virginia. The intellectual and social structure of the field is depicted through the co-authorship network, revealing prominent research clusters and international collaborations

The green cluster represents a group of researchers from Asia, particularly China, with central figures such as Ying, Xiaohua, Qian, Mengcen, and Tang, Shenglan. The emergence of this cluster separately but still close to the red cluster shows that despite differences in geographical context and national health systems, these researchers refer to a similar DRG theoretical framework. Maciejewski, Matthew L. appears to act as a central figure or intellectual bridge connecting Western cluster thinking with research trends in Asia. This reflects a global flow of knowledge that attempts to adapt the success of DRG systems in developed countries to health reforms in developing countries.

b. Research Articles With Global Influence

Table 1. Ten Articles with the Most Citations

Table 1 details the 10 articles with the most citations from the Scopus database for 2016-2025, based on the number of citations analyzed to identify journals that have a significant impact on the topics of Diagnosis-Related Groups and health financing reform. The document with the highest number of citations (229 citations) is titled The Role of Patient-Reported Outcome Measures in Value-Based Payment Reform written by Squitieri et al., 2017. This indicates a global paradigm shift in which the success of financing reforms is no longer measured solely in terms of cost savings, but also from the perspective of patient quality of life. These findings confirm that the implementation of the DRG payment system must be accompanied by the strengthening of the clinical service quality management system [4], [10], [21]. Articles discussing the impact of the DRG system in China (82 citations) and healthcare financing systems in Japan, Korea, and Thailand (50 citations) provide important insights into the DRG system transition process in Asia. Nearly all of the articles on this list were published in Q1 journals, indicating that the topic of healthcare financing reform has very high scientific standards.

c. Authors Productivity in Research

Figure 7. Ten Authors with the Highest Productivity in Research

igure 7 highlights the leading researchers contributing to the global body of knowledge during the 2016–2025 period based on their publication volume. Identification of the most productive researchers shows that Maciejewski, Matthew L. is the most central figure in the literature on health payment reform, with a total of 6 publications in the last decade. The consistency of Maciejewski's contributions confirms his role as a leading authority in evaluating the effectiveness of prospective payment systems. In the next position, Wang, V. contributed with 5 publications, followed by Coffman, C.J. and Sloan, C.E., who each produced 4 publications. The researchers who ranked in the top four (Maciejewski, Wang, Coffman, and Sloan) have very strong affiliations, particularly with Duke University and the Durham VA Health Care System.

The presence of researchers such as Busse, R. and Quentin, W. represents a strong European (German) research tradition, while Jian, W. and Qian, M. demonstrate the emergence of new expertise from Asia (China). The diversity of these productive researchers' profiles shows that discussions about health payment systems are no longer dominated by a single geographical perspective, but have become a cross-continental intellectual collaboration.

3. Visualization of DRG Networks Based on Keyword Co-occurrence

Figure 8. DRG Network Visualization based on Keyword Co-occurrence

Figure 8 shows a visualization of keyword occurrences related to the topics of Diagnosis Related Groups and healthcare financing reform. The various colors in the network indicate that there are clusters with different research focuses. Clusters are connected by lines of the same color. Stronger relationships are indicated by closer lines, while frequently discussed topics are indicated by larger nodes. The keyword visualization also maps topic trends based on the year of publication. With this visualization, readers can find research gaps that have not been widely studied or new trending topics to support future research development.

a. Co-Occurrence Analysis Based on Keywords

Table 2. Clusters found in Co-Occurrence Analysis

Co-occurrence analysis of keywords was used to dissect the intellectual structure of this field of study. Based on Table 2, the research results were divided into four major themes.

The Red Cluster, with the theme of hospital operational and economic efficiency, is the largest cluster (30 keywords). Keywords such as economics, length of stay, and cost control indicate that the main focus of the research is how the DRG system is used as a tool to control operational costs and shorten the duration of hospitalization without compromising medical procedures (for example, in cases of surgery or arthroplasty) [18], [22]. The Green Cluster (22 keywords) focuses more on the macro level, particularly the Medicare and Medicaid systems and the transition to a prospective payment system. The themes in this cluster concern public policy and health insurance. This cluster also covers chronic disease management (such as chronic kidney disease and hemodialysis), which presents particular challenges in implementing payment reforms for patients with long-term needs .

The Blue Cluster is known to cover topics related to system management and individual health. Consisting of 19 keywords, this cluster connects how payment reform affects the way organizations are managed and how medical personnel adapt to changes in the payment system for health services [23], [24]. The Yellow Cluster consists of 17 keywords highlighting the shift from fee-for-service to models that prioritize quality of healthcare and outcome assessment. The presence of the keyword covid-19 in this cluster, along with quality of care indicators, provides very interesting findings. This shows that the COVID-19 pandemic acted as a catalyst that forced many countries to accelerate the adoption of the DRG system. This system was used as a strict budget control tool when national healthcare spending skyrocketed due to the pandemic. This study proves that in the midst of a crisis, a prospective financing system is essential to keep hospitals operating without compromising patient safety standards [25].

b. Analysis Based on Keyword Occurrence

Table 3. Ten Keywords with the Highest Frequency of Appearance

Table 3 highlights the top ten keywords that serve as the primary thematic pillars in the discourse on DRG and healthcare payment reform. Based on the keyword data analyzed, the following data was obtained the high frequency of keywords such as “Economics,” “Health Care Cost,” and “Health Expenditures” in bibliometric literature proves that the implementation of Diagnosis-Related Groups (DRG) has become the country's main fiscal instrument for systematically controlling health expenditures. This reinforces that the shift in payment methods is not merely a change in medical administration, but rather a macroeconomic strategy designed to maintain fiscal sustainability amid increasing demand for health services [2], [3]. The emergence of the terms “Health Care Policy” and “Health Care Reform” consistently shows that the payment system is always within the corridor of dynamic and continuously transforming policies in order to respond to global challenges and the need for a more robust health insurance system [23], [26].

This reform of the financing system ultimately leads to increased operational efficiency through a global transition to a more predictive and transparent payment model. The frequent use of keywords such as “Prospective Payment” and “Reimbursement” reflects a paradigm shift from traditional systems to systems that encourage healthcare facilities to optimize their resources more efficiently [14], [27], [28].

4. Trends in Research Topic Evolution by Year (Overlay Visualization)

Figure 9. Research Topic Evolution Trends by Year (Overlay Visualization)

Figure 9 displays the overlay visualization of the keyword network, highlighting the transition from foundational concepts to emerging hot topics in recent years. Overlay visualization analysis is used to understand shifts in research focus from year to year. The color scale at the bottom of the image shows a gradation from dark blue (representing topics that emerged earlier, around 2018) to light yellow (representing the latest topics, around 2022 and above). In the early period, research focused heavily on established systems and chronic disease management. Keywords such as “medicare,” “prospective payment system,” “organization and management,” and specific clinical topics such as “hemodialysis” and “chronic kidney disease” dominated. This shows that early research was rooted in the evaluation of health insurance systems in developed countries [15]

The focus of research then shifted towards macro policy and reform implementation. Keywords in the green cluster (around 2020) such as “economics”, “health care policy”, “health reform”, and “reimbursement” appear in green. This marks a period in which many countries began to undergo a massive transition in their health financing systems [8]. This cluster highlights government policies that use prospective payment systems as the primary instrument for shifting financial risk from payers to service providers in order to promote efficiency [2], [29]. Findings during this period also drew particular attention to the challenges of managing the high costs of chronic diseases, such as kidney failure, which require a more stable public insurance model to ensure long-term services for the community [30].

The most recent topics that are currently trending are closely related to hospital operational efficiency and the impact of the global health crisis. Based on the yellow cluster (after 2022), topics such as hospitalization, cost control, hospital patients, hospital costs, and pharmacoeconomics appear to dominate the yellow area. This indicates that recent research delves deeper into how hospitals practically manage service costs and the shift in research focus from macro policies to the use of DRGs for service quality monitoring, reducing the length of stay, and controlling service costs (quality control and cost control) [4], [28].

a. Shifting Paradigms in DRG Research: An Overlay Visualization

Figure 10. Co-Occurrence Network Map Based on Diagnosis Related Groups Keywords by Year (Overlay Visualization)

The temporal evolution of research themes, as depicted in the Figure 10 overlay visualization, places special emphasis on the Diagnosis-Related Groups cluster. This cluster appears in bright yellow, indicating that the topic has become a primary focus of recent research. Within this contemporary landscape, the DRG system is closely associated with strategic variables such as cost control, clinical patient management, and operational efficiency at the service unit level [4].

The emergence of supporting topics such as “pharmacoeconomics” and “surgery” indicates that DRG implementation is now being analyzed down to the level of medical service units and the use of medicines to minimize waste of resources [4], [28]. The findings of the keywords “cost control”, “drug cost”, and “hospital cost” linked to the DRG cluster confirm that current research trends have shifted towards Value-Based Healthcare [31], [32]. Cost control through DRG is now linked to quality monitoring to ensure that efficiency does not lead to a decline in medical service standards [4], [21], [32], [33].

5. Practical Implications

The use of bibliometric data helps hospital administrators understand cost control patterns that have been successfully implemented in other countries. Healthcare facility administrators can use research findings on cost control and hospital operational efficiency as a basis for strategic policy-making. Prospective payment systems will result in more predictable, transparent, and accountable financing. Hospital management needs to align the performance of medical units and finance departments to improve claim accuracy. Leaders must facilitate coordination between units to minimize the risk of financial losses due to administrative errors. Hospital directors need to integrate quality indicators into sustainable cost efficiency policies.

Management can apply the Value-Based Healthcare model to maintain patient safety amid intense cost control pressures. This approach supports health facilities in improving their competitiveness by providing excellent services to patients through quality control and cost control strategies, thereby ensuring public satisfaction. Doctors, clinicians, and healthcare workers who serve patients are expected to understand the importance of clinical efficiency in accordance with standards, providing quality services, managing patient care duration, and ensuring complete medical record documentation. This will ensure that the coding and billing process runs smoothly in the DRG system.

The findings of this study provide strategic insights for policymakers to adopt the successful strategies of countries that have reformed their health financing frameworks through diagnosis-related groups (DRGs). The government can review health financing regulations based on the provision of standardized, high-quality, efficient, and cost-conscious services to ensure the long-term financial sustainability of national health insurance.

The practical benefit for academic researchers is that they obtain a clear roadmap of topics that are still rarely researched in the field of health financing. This research can serve as a basic reference for future research. Researchers can identify potential collaboration partners from global institutions that have a major influence on DRG research. For the general public, the results of this study can increase insight into how hospitals manage treatment costs in the era of health reform. The public can understand the shift in the service system towards a model that is more transparent and oriented towards quality and patient safety. This knowledge increases readers' awareness of the dynamics of health policy changes that impact access to public services.

6. Limitations of the Study

This study only draws from a single database, Scopus. The use of a single source means that relevant studies may not be represented in other databases such as Web of Science, Dimensions, Google Scholar, or other databases. This research report limits the types of documents to journal articles only, which causes limitations in perspective regarding the topic of health financing reform in the DRG system found in books, proceedings, and government policy reports. The analysis is limited to English-language journal articles, which has the potential to cause language bias that could overlook the dynamics of financing reform at the local level published in national languages other than English. The use of keywords such as “diagnosis related groups” or “payment reform” creates potential bias in the search process. The inability to search using other keywords/terms that have the same meaning as diagnosis related groups and payment reform may affect the completeness of the data analyzed.

Conclusion

This bibliometric study successfully mapped the global landscape of research on Diagnosis-Related Groups (DRG) and health financing reform during the period 2016–2025. Based on an analysis of 143 documents, a significant growth trend in literature was observed, reaching its peak in 2025. The United States and China dominated the research, with Duke University as the most productive institution. Network analysis showed that global research attention has shifted from simply controlling costs to integrating service quality and value-based clinical outcomes.

Using keyword mapping, this study identified four main clusters, namely hospital operational efficiency with an emphasis on cost control; macro policies through reform of the financing system using prospective methods; organizational management with the adaptation of health workers to health financing patterns; and the quality and resilience of health services as assessed by the services received by patients and the financial stability of hospitals that remained strong after the Covid-19 pandemic.

This study is limited to data from the Scopus database, focusing on English-language journal articles. For the advancement of science, future researchers can involve various multilingual databases to provide broader literature coverage and enrich the analysis of global trends. Given the limited scientific publications on the DRG system in Indonesia, future research is recommended to conduct in-depth comparative studies between DRG models in Asian countries (such as China or Thailand) and local implementations in Indonesia.