Target Audience
- Researchers and professionals interested in the development, operation, and use of biobanks and large-scale health data infrastructures.
- Readers who want to understand the characteristics, history, and scientific contributions of major population cohort studies, including UK Biobank and China Kadoorie Biobank.
- Professionals interested in genomics, multi-omics research, international scientific collaboration, health data governance, and the long-term sustainability of research infrastructures.
Executive Summary
- China Kadoorie Biobank (CKB) is one of the world's largest population-based prospective cohort studies, following approximately 513,000 people in China for more than 20 years. Comparable in scale to UK Biobank, it was established to investigate how lifestyle, environmental exposures, and genetic factors influence chronic diseases.
- The concept behind CKB predates UK Biobank. Emerging from epidemiological collaboration between British and Chinese researchers beginning in the 1980s, the project was conceived in the 1990s, secured initial philanthropic funding in 2001, and began large-scale participant recruitment in 2004.
- CKB's scientific value extends far beyond its participant numbers. Its geographic diversity, East Asian genetic characteristics, long-term disease follow-up, linkage to administrative health records, and stored biological samples provide research opportunities that complement UK Biobank.
- CKB has evolved into a platform for population-scale whole-genome sequencing, proteomics, and other molecular research. However, challenges remain, including sustainable funding, changes in participants' lifestyles over time, data quality, and restrictions on international access to genetic data.
- CKB's two-decade history offers important lessons for building and sustaining large-scale health research infrastructures. Long-term investments in data and sample collection can generate scientific value for decades, particularly when supported by continuous follow-up, emerging analytical technologies, and effective data-sharing arrangements.
1. What Is China Kadoorie Biobank?
China Kadoorie Biobank (CKB), known in Chinese as 中国慢性病前瞻性研究, is one of the world's largest population-based prospective cohort studies. It has followed approximately 513,000 people in China for more than 20 years.
Comparable in scale to UK Biobank, CKB aims to investigate the relationships between lifestyle, environmental exposures, genetic factors, and chronic diseases.
However, understanding CKB requires more than simply describing it as a "Chinese version of UK Biobank."
One particularly important characteristic is that the concept behind CKB predates UK Biobank.
The project emerged from epidemiological collaboration between British and Chinese researchers beginning in the 1980s. Its conceptual foundations were developed during the 1990s, and initial funding was secured from a Hong Kong charitable foundation in 2001.
CKB was also designed from the outset as a collaborative project between the United Kingdom and China.
The University of Oxford played a leading role in obtaining initial funding and designing the research methods and information technology systems, while Chinese institutions established the infrastructure required to conduct large-scale population surveys.
Furthermore, participant recruitment was not the endpoint of the project.
Following recruitment between 2004 and 2008, CKB continued to collect information on disease incidence and mortality, conduct repeat surveys, and analyze stored blood samples using genomic and proteomic technologies.
Another distinctive feature is its ability to investigate regional differences within China, including dietary patterns, environmental exposures, disease patterns, and genetic characteristics of East Asian populations.
These characteristics allow CKB to complement studies that have historically focused predominantly on populations of European ancestry.
At the same time, one of CKB's major contemporary challenges concerns international access to research data.
China's regulations governing human genetic resources, restrictions on cross-border data transfers, and the need for sustained funding all influence how effectively CKB's scientific value can be realized internationally.
An especially interesting aspect of its history is that the relationship between CKB and UK Biobank was not simply one in which China adopted an existing British model.
Research methods and information technology systems developed for CKB subsequently influenced the design of UK Biobank.
This relationship is explicitly discussed in a 2025 article published in The BMJ. [1][2]
Key Facts About CKB
| Item | Description |
|---|---|
| Official name | China Kadoorie Biobank (CKB) |
| Chinese name | 中国慢性病前瞻性研究 |
| Study design | Population-based prospective cohort study |
| Number of participants | 512,891 |
| Recruitment period | 2004–2008 |
| Age at recruitment | 30–79 years |
| Study locations | 10 regions in China (5 urban and 5 rural) |
| Follow-up period | Approximately 20 years or longer |
| Major research areas | Chronic diseases, lifestyle, environmental exposures, genetic factors, disease incidence, and mortality |
| Principal institutions | University of Oxford and Chinese research institutions |
| Initial funding organization | Kadoorie Charitable Foundation |
These characteristics are documented in CKB's official materials, information published by Peking University, and related academic publications. [1][3]
2. How Was CKB Conceived and Established?
2.1 The 1980s: Epidemiological Collaboration Between the United Kingdom and China
The origins of CKB can be traced to a period before biobanking became a widely established approach to medical research.
Two central figures were Professor Richard Peto, an epidemiologist at the University of Oxford, and Zhengming Chen (陳錚鳴), a Chinese-born researcher who later became a professor at Oxford.
Professor Peto began visiting China in the early 1980s and worked with Chinese researchers on epidemiological studies of diseases and causes of death.
In 1987, Chen moved to the University of Oxford to study and participated in research including a cohort study involving approximately 10,000 Chinese workers.
The collaboration subsequently expanded to include large-scale clinical trials and studies investigating the causes of death among approximately one million people in China.
These experiences gradually led the researchers toward a broader idea.
Instead of repeatedly conducting separate studies focused on individual diseases, they envisioned a research infrastructure that would collect health information and biological samples from a large general population, follow participants over many years, and support a wide range of future scientific questions.
This was a forward-looking concept at the time.
Whereas conventional epidemiological studies were often organized around specific diseases or hypotheses, CKB was intended to become a long-term research resource that would not be limited to any single disease. [1]
2.2 The 1990s: A Recognized Scientific Need, but Insufficient Funding
Implementing this vision required substantial resources.
The researchers needed funding for surveys involving hundreds of thousands of participants, blood collection and storage facilities, information technology systems, and long-term follow-up infrastructure.
During the 1990s, however, Chen and Peto approached various funding organizations without securing sufficient financial support.
A central obstacle was that conventional research grant systems were not well suited to supporting large, long-term research infrastructures that could not promise specific findings in advance.
At the same time, existing large-scale epidemiological studies were heavily concentrated in populations of European ancestry.
China differed in terms of lifestyle patterns, disease profiles, and genetic backgrounds. Rapid economic development was also changing the country's patterns of disease risk.
A large Chinese cohort therefore had the potential not only to clarify health problems specific to China, but also to test whether medical findings obtained from European populations were applicable to other populations.
This gave the proposed project considerable scientific importance. [1][2]
2.3 2001–2002: A Hong Kong Charitable Foundation Makes the Project Possible
The turning point came in 2001.
Through an introduction by Judith Mackay, a prominent international tobacco-control advocate, Chen and Peto approached the Kadoorie Charitable Foundation in Hong Kong.
The foundation agreed to provide one-time funding to establish the project, on the condition that the study would carry the Kadoorie name.
This is the origin of the name "China Kadoorie Biobank."
On the Chinese side, the project received approval from the Ministry of Health in 2002.
Its original name was the Kadoorie Study of Chronic Disease in China (KSCDC), and it was subsequently renamed China Kadoorie Biobank (CKB).
The establishment process can therefore be summarized chronologically:
- 1990s: Development of the research concept.
- 2001: Initial funding secured.
- 2002: Approval by Chinese health authorities.
- 2004: Beginning of large-scale participant recruitment.
This sequence illustrates how a major research infrastructure emerged from a long period of scientific collaboration, followed by a decisive philanthropic investment. [1][3]
2.4 2004–2008: Large-Scale Recruitment and Infrastructure Development
The early international collaboration involved a relatively clear division of responsibilities.
| Organization or group | Main responsibilities |
|---|---|
| University of Oxford | Initial fundraising, research design, survey procedures, information technology systems, and quality management |
| Chinese research institutions and government organizations | Coordination with study regions, participant recruitment, local staffing, surveys, blood collection, and follow-up infrastructure |
| Joint UK–China research team | Pilot studies, refinement of research methods, scientific strategy, and quality control |
| Kadoorie Charitable Foundation | Initial funding for establishing the project |
According to the University of Oxford, the project developed more than 60 dedicated information technology systems.
Electronic questionnaires incorporated logical consistency checks and error-detection functions, enabling large-scale surveys to be conducted largely without paper-based data collection.
The study regions were selected according to factors including disease patterns, environmental exposures, relatively low population mobility, health insurance coverage, quality of disease registration systems, and local institutional support.
Between June 2004 and August 2008, the project recruited 512,891 participants. [1][3]
3. How CKB Has Evolved Over Time
CKB did not become a completed research project when participant recruitment ended.
Instead, its value as a research infrastructure has continued to grow through long-term follow-up, additional surveys, and advances in analytical technologies.
3.1 The 1980s–1990s: International Collaboration and Concept Development
Epidemiological collaboration between British and Chinese researchers developed over many years.
This collaboration led to the concept of a large prospective cohort that could support research across multiple diseases.
During this period, researchers increasingly recognized the importance of creating a long-lasting research infrastructure rather than conducting only disease-specific investigations.
3.2 2001–2002: Funding and Formal Approval
The Kadoorie Charitable Foundation agreed to provide the initial funding.
In 2002, China's Ministry of Health approved the project, allowing preparations for implementation to proceed.
3.3 2004–2008: Baseline Recruitment
Approximately 513,000 participants were recruited from 10 regions of China.
The project established questionnaires, physical measurement procedures, blood collection systems, and facilities for long-term biological sample storage.
These activities created the foundation of the research infrastructure.
3.4 2008–2014: Strengthening the Follow-Up Infrastructure
The first repeat survey was conducted in 2008, followed by a second repeat survey in 2013–2014.
Each involved approximately 5% of participants.
Linkage with administrative medical records was also expanded, strengthening the ability to follow disease incidence and mortality over time.
3.5 2012–2018: Biological Sample Analysis and Expanded Data Access
Genetic analyses and related research began around 2012.
In 2016, CKB established a data access system for external researchers.
CKB also became recognized as a model for China's national efforts to develop large-scale cohort research infrastructures.
3.6 2020–2023: Repeat Surveys and Advances in Genomic Research
A third repeat survey was conducted in 2020–2021.
In 2023, CKB published genomic findings involving more than 100,000 participants.
It also made PheWeb available, allowing researchers to explore results from genome-wide association studies (GWAS).
3.7 2024–2025: The 20th Anniversary and Expansion Toward Whole-Cohort Analysis
CKB celebrated its 20th anniversary in 2024.
The project made substantial progress toward whole-genome sequencing of the entire cohort.
Research using proteomics and the development of cloud-based analytical environments also advanced.
3.8 As of 2026: An Ongoing International Research Infrastructure
As of 2026, CKB continues its long-term follow-up activities, molecular analysis of stored biological samples, and support for external research.
However, access arrangements differ between non-genetic and genomic data.
The development and deployment of cloud-based research analysis platforms have therefore become important priorities.
This development history is documented in materials from Peking University, CKB's official resources, and the 2025 BMJ article. [2][3][4][5]
4. Distinctive Features of CKB's Research Design
4.1 Studying Regional Differences Within China
CKB is not a nationally representative probability sample drawn randomly from the entire Chinese population.
Instead, it follows residents of 10 regions selected for specific research purposes.
The study design places greater emphasis on comparing regions with substantially different lifestyles, disease risks, and environmental conditions than on estimating a single national average.
Examples of the exposures studied include:
- Dietary patterns
- Smoking
- Alcohol consumption
- Household fuels used for cooking and heating
- Air pollution
- Physical activity
- Socioeconomic circumstances
China has substantial differences in exposure patterns between urban and rural regions, as well as between northern and southern regions.
CKB's geographic design makes it possible to investigate how such differences are associated with disease risks.
This represents one of the study's major scientific strengths. [1][3]
4.2 Connecting Lifestyle Data, Biological Samples, and Disease Outcomes
CKB collected a broad range of information during its baseline surveys.
| Data category | Examples |
|---|---|
| Demographic and socioeconomic information | Age, sex, education, occupation, and marital status |
| Lifestyle | Diet, smoking, alcohol consumption, tea consumption, physical activity, and sleep |
| Environmental exposures | Fuels used for cooking and heating, household air pollution, and regional environmental conditions |
| Physical measurements | Height, weight, blood pressure, lung function, and related measurements |
| Health history | Previous diseases, family history, medications, and female reproductive history |
| Biological samples | Blood-derived DNA and plasma |
| Long-term outcomes | Causes of death, disease incidence, and hospitalization records |
Researchers can link information about participants' initial lifestyles and health measurements with subsequent disease outcomes.
For example, this makes it possible to investigate how frequently stroke occurs among people with particular lifestyle characteristics.
It also allows researchers to examine how genetic factors modify the relationships between lifestyle and disease. [1][3]
4.3 Using Administrative Health Databases for Long-Term Follow-Up
CKB uses participants' personal identification numbers to link research records with administrative systems, including disease registries, mortality registries, and health insurance databases.
The overall process can be described in four stages.
- Baseline data collection (2004–2008): Lifestyle information, physical measurements, and blood samples were collected.
- Linkage with administrative health records: Disease registrations, mortality records, health insurance data, and hospitalization information are used for follow-up.
- Repeat surveys of selected participants: Additional information is obtained on changes in lifestyle, repeat physical measurements, and other biological characteristics.
- Integrated scientific analysis: Long-term disease outcomes are combined with genomic and other omics data to investigate disease risks, prognosis, and genetic factors.
An important advantage is that the project does not need to conduct extensive in-person examinations of all 513,000 participants every year.
By using existing administrative systems, CKB can accumulate information about disease outcomes while controlling the costs associated with long-term follow-up.
However, the scientific value of this approach also depends on the quality of administrative databases and the continued ability to link those data with research records. [2][3]
4.4 Biological Samples Were Stored With Future Technologies in Mind
CKB collected approximately 10 mL of blood from participants and stored plasma and blood components containing DNA for long-term use.
Blood-derived samples have been stored in Beijing and Oxford.
However, the international transfer of samples containing DNA is subject to Chinese regulations, and the project was designed so that DNA-related samples would be managed within China.
The significance of this design is that the samples were not collected solely for analyses available at the time.
They were preserved with the expectation that new analytical technologies would become available in the future.
Indeed, approximately 20 years after recruitment, the analysis of stored samples using large-scale genomic and proteomic technologies has become a major component of CKB's research program. [5]
5. Recent Research Developments and Scientific Achievements
CKB has evolved from a conventional epidemiological cohort into a research platform supporting genetics, molecular biology, and drug discovery.
5.1 Expansion Toward Whole-Genome Sequencing
Progress in genomic research is particularly important for understanding CKB's evolution.
| Period | Development |
|---|---|
| 2012–2013 | Analysis of selected genetic variants in approximately 100,000 participants |
| Subsequently | Genome-wide analysis of approximately 100,000 participants using customized SNP arrays |
| 2021 | Completion of a whole-genome sequencing (WGS) pilot study involving 10,000 participants |
| 2023 | Publication of genomic analyses involving more than 100,000 participants, including newly identified genetic associations with diseases |
| 2024–2025 | Expansion of WGS to approximately 513,000 participants |
| 2025–2026 | Continued development of secure cloud-based environments for analyzing large-scale genomic data and expanding international research access |
According to CKB materials available in January 2025, the target for completing WGS of the entire cohort was the first quarter of 2025.
In August 2025, Singapore's national precision medicine research program, PRECISE, reported that whole-genome sequencing had been completed.
Therefore, although completion of whole-cohort WGS was publicly reported in 2025, this does not necessarily mean that all individual-level WGS data became immediately available to external researchers.
Quality control, analytical infrastructure, and access permissions represent separate stages of development.
A genomic study published in 2023, involving approximately 100,000 participants, also examined the genetic characteristics of CKB participants and regional population genetic structures. [6]
5.2 Expansion of Proteomics Research
Stored blood samples from CKB are also being used in studies that measure proteins and metabolites on a large scale.
A study published in 2025 compared two different proteomic measurement technologies, Olink and SomaScan, using plasma samples from approximately 4,000 individuals.
The principal characteristics were:
- Olink: Measurements related to 2,923 proteins.
- SomaScan: Measurements corresponding to approximately 6,400 proteins.
- Study population: Approximately 3,976 individuals, including cases of ischemic heart disease.
This research provides a basis for understanding differences between measurement technologies and for investigating relationships between molecular biomarkers and diseases.
In September 2025, collaboration between CKB and Metabolon on metabolic research was also announced.
In July 2026, additional protein research relevant to the identification of potential new therapeutic targets for heart disease was reported.
These developments indicate that CKB is moving beyond the identification of epidemiological associations toward investigations of biological disease mechanisms and potential therapeutic targets. [7]
5.3 Representative Scientific Findings
CKB has contributed to a wide range of research areas.
Risk Factors for Different Types of Stroke
China has historically had a higher proportion of hemorrhagic stroke than many Western populations.
CKB has investigated differences in risk factors between ischemic stroke and intracerebral hemorrhage, including detailed classification of stroke subtypes.
Alcohol Consumption and Cardiovascular Disease
Researchers have used genetic variants related to alcohol metabolism that are particularly relevant in East Asian populations.
This approach provided genetic evidence challenging the apparent protective association between moderate alcohol consumption and stroke observed in some conventional observational studies.
Identification of Potential Drug Targets
By combining genomic information, protein measurements, and long-term disease outcomes, CKB researchers are investigating potential therapeutic targets for cardiovascular diseases and other conditions.
The scale of CKB's scientific output has also grown substantially.
According to a 2025 introduction published by PRECISE, more than 600 academic papers had been produced using CKB.
CKB has therefore expanded its contributions from epidemiology into genetics, molecular biology, and drug discovery. [6][7]
6. Comparing China Kadoorie Biobank and UK Biobank
CKB and UK Biobank are both large prospective cohort studies involving approximately half a million participants.
However, they differ in their origins, target populations, operational environments, and data access arrangements.
| Comparison | China Kadoorie Biobank | UK Biobank |
|---|---|---|
| Concept and launch | Conceived in the 1990s; recruitment began in 2004 | Conceived in the early 2000s; recruitment began in 2006 |
| Initial recruitment | 2004–2008 | 2006–2010 |
| Cohort size | Approximately 513,000 | Approximately 503,000 |
| Age at recruitment | 30–79 years | 40–69 years |
| Main population | General population in 10 Chinese regions | General population across multiple regions of the UK |
| Distinctive research strengths | Regional diversity in China, East Asian genetic backgrounds, environmental and lifestyle exposures | Deep phenotyping, imaging research, and broad international research access |
| Long-term follow-up | Linkage with health insurance, disease registries, and mortality records | Linkage with NHS and other health and mortality records |
| Genomic research | Completion of whole-cohort WGS reported in 2025 | WGS data from approximately 500,000 participants available for research |
| Imaging research | Imaging and clinical measurements in selected repeat-survey participants | Whole-body imaging program involving approximately 100,000 participants |
| Data access | Application-based access; individual-level genomic data subject to Chinese regulatory restrictions | International research access framework and Research Analysis Platform |
| Operating model | International collaboration between British and Chinese research institutions | Independent research resource based in the United Kingdom |
The data access arrangements of both projects continue to evolve, and the availability of specific datasets should be verified when planning research. [2][4][6]
6.1 CKB and UK Biobank as Complementary Research Resources
These differences suggest that CKB and UK Biobank should be understood not only as comparable large-scale research projects but also as complementary scientific resources.
For example, researchers can investigate whether genetic associations identified in UK Biobank are also observed in Chinese populations.
Conversely, they can examine whether associations between lifestyle and disease observed in CKB are applicable to British populations.
Comparing populations with different genetic backgrounds may also help distinguish common biological mechanisms of disease from population-specific factors.
Consequently, the value of CKB is not simply that it includes a number of participants comparable to UK Biobank.
The ability to compare populations in China and the United Kingdom is itself an important scientific advantage. [2][6]
7. Current Challenges Facing CKB
CKB faces several important challenges as it continues to develop.
Some have been explicitly identified by the research team in published materials, while others arise from methodological limitations inherent in long-term prospective cohort studies.
It is useful to distinguish these categories.
7.1 Challenge 1: Restrictions on International Access to Genetic Data
One of the most significant challenges for international collaboration is the interaction between China's human genetic resource regulations and global research partnerships.
China introduced regulations governing human genetic resources in July 2019.
These regulations cover the collection and storage of genetic resources, international collaborative research, and certain forms of data use.
CKB has made individual-level non-genetic data available to external researchers, but equivalent international access to genetic data has been more difficult.
An article published in The BMJ in October 2025 explained that, although CKB shares non-genetic data with researchers outside China, including those in the United Kingdom, international access to genetic data has remained limited because of Chinese policy restrictions.
To address this issue, CKB has been developing a cloud-based Research Analysis Platform (RAP).
Rather than transferring sensitive datasets outside China, the system is intended to allow authorized researchers to conduct analyses within a secure computing environment.
However, as of 2026, public descriptions continued to characterize the platform's availability as experimental or phased.
It has therefore not been confirmed that all CKB genomic data are accessible to international researchers under arrangements equivalent to those of UK Biobank. [2][4]
7.2 Challenge 2: Securing Long-Term Research Funding
CKB began with establishment funding from a Hong Kong charitable foundation and subsequently developed a more diversified funding structure.
Major sources of support have included:
- Wellcome in the United Kingdom
- The UK Medical Research Council (MRC)
- The National Natural Science Foundation of China
- China's Ministry of Science and Technology
- Collaborative research involving companies and research institutions
Long-term cohort studies require continued investment in participant follow-up, data management, biological sample preservation, and repeat surveys.
They also require additional funding to apply new technologies such as WGS and proteomics.
CKB's original strategy of storing information and samples for future research has produced significant scientific value approximately 20 years later.
However, realizing that value requires continued financial support.
Changes in regulations and the geopolitical environment surrounding international collaboration can also create restrictions on eligible funding mechanisms and cross-border research financing. [1][2]
7.3 Challenge 3: Baseline Information Becomes Outdated Over Time
Lifestyle and health characteristics measured between 2004 and 2008 do not necessarily reflect participants' circumstances in 2026.
During this period, China has experienced substantial changes in urbanization, dietary patterns, smoking and drinking behaviors, and access to healthcare.
CKB conducted repeat surveys involving approximately 5% of participants in 2008, 2013–2014, and 2020–2021.
However, detailed lifestyle information has not been remeasured at the same frequency for every participant.
This creates several methodological questions:
- How can researchers distinguish baseline exposures from changes in those exposures during follow-up?
- To what extent do measurement errors and long-term lifestyle changes weaken estimated associations between risk factors and diseases?
- How applicable are findings based on living conditions from approximately 20 years ago to today's younger and middle-aged populations?
These issues are not unique weaknesses of CKB.
They are challenges commonly encountered in long-term prospective cohort research. [3]
7.4 Challenge 4: The Cohort Is Not Nationally Representative
CKB selected study regions based on several criteria, including the quality of disease registration, the feasibility of long-term follow-up, and local institutional support.
Consequently, its participants do not constitute a probability sample representing the entire Chinese population.
For research investigating associations between risk factors and disease, the inclusion of regions with different exposures and disease rates is advantageous.
However, disease prevalence or incidence rates observed in CKB cannot automatically be interpreted as national estimates for China.
Estimating the national burden of disease requires additional validation or adjustment using externally representative datasets. [1][3]
7.5 Challenge 5: Medical Data Quality and Standardization Across Regions
Linkage with administrative health data is a major strength of CKB.
However, the existence of medical records does not necessarily guarantee that all information required for scientific research is recorded accurately.
Diagnostic practices, healthcare access, and hospitalization decisions may differ across regions and change over time.
The 2025 BMJ article identified differences in diagnostic quality and standards across cohorts, as well as challenges in harmonizing socioeconomic indicators.
At the same time, CKB has undertaken disease-specific quality improvement activities, including detailed classification and validation of stroke subtypes.
Therefore, it would be misleading to characterize the quality of CKB data uniformly as either high or low.
Data quality needs to be evaluated separately for different diseases and measurements. [2]
7.6 Challenge 6: Limited Biological Samples and Analytical Costs
The quantity of biological material collected from each participant is finite.
If multiple researchers independently request samples for separate projects, stored materials may gradually be consumed, reducing the amount available for future research.
CKB has therefore emphasized the value of large-scale, efficient measurements that can support a broad range of scientific questions rather than using samples exclusively for a small number of individual projects.
By conducting extensive omics measurements and allowing multiple researchers to reuse the resulting data, the project aims to maximize scientific value while preserving scarce biological materials. [5]
7.7 Challenge 7: Regulatory and Geopolitical Friction in International Collaboration
The 2025 BMJ article also discussed broader obstacles to collaboration between Chinese and British researchers.
On the Chinese side, regulations affect the cross-border transfer of genetic resources and research data.
On the Western side, some restrictions have also been introduced concerning collaboration with particular Chinese research institutions.
These measures may create uncertainty about the procedures required for collaboration, as well as additional burdens related to funding, data sharing, and joint analysis.
Because CKB was established through close cooperation between British and Chinese researchers, covering everything from study design to data analysis, its operating model is particularly sensitive to changes in the international research environment. [2]
7.8 Summary of Current Challenges
The main challenges can be summarized as follows.
| Challenge | Current situation | Important future responses |
|---|---|---|
| International genomic data sharing | Significant regulatory restrictions | Secure remote analysis infrastructure |
| Long-term funding | Dependence on multiple funding sources | Diversified funding and collaborative research |
| Changes in lifestyle over time | Repeat surveys cover selected participants | Repeated measurements and statistical adjustments |
| National representativeness | Study regions were intentionally selected | Validation using representative external datasets |
| Standardization of medical records | Differences across regions and diseases | Diagnostic validation and data quality management |
| Preservation of biological samples | Finite quantities of stored material | Large-scale multi-analyte measurements and data reuse |
| International research environment | Regulatory, financial, and institutional uncertainty | Transparent governance and international collaboration arrangements |
Among these issues, data sharing, financing, and the international research environment are primarily operational challenges.
Representativeness and changes in participant characteristics over time are primarily methodological challenges affecting scientific interpretation and analysis.
Distinguishing between these categories is essential when evaluating the long-term future of CKB.
8. Data Sharing and Access for External Researchers
Another important difference between CKB and UK Biobank concerns which datasets external researchers can access and the procedures required to obtain them.
8.1 Current Data Availability
CKB's official website describes the datasets available to external researchers.
| Dataset | Availability described on the official website |
|---|---|
| Baseline questionnaires and physical measurements | Available to external researchers |
| First and second repeat surveys | Available to external researchers |
| Mortality and disease incidence data | Follow-up data through January 1, 2019, available |
| Disease follow-up data from 2019–2024 | Collected and processed within China; scheduled for future release |
| Selected blood biomarkers | Available to external researchers |
| GWAS summary statistics | Available through PheWeb |
| Individual-level genomic and WGS data | Access environment being developed through phased deployment of RAP |
This information reflects the description available on CKB's official Data Overview page at the time of review.
The fact that disease follow-up data from 2019–2024 have not yet been included in external releases does not mean that participant follow-up has stopped. [4]
8.2 Applications and Access Fees
Researchers must submit a research proposal and obtain approval before using CKB data.
According to CKB's publicly available FAQ, researchers based outside mainland China and Hong Kong are charged £2,500 per approved application.
The review of applications and the conclusion of data use agreements also require time.
In addition, access procedures differ between non-genetic and genomic data, with the latter subject to Chinese regulatory requirements. [4][5]
8.3 Official Data Access Resources
Researchers considering the use of CKB data can consult the following official resources:
9. Lessons From CKB's History
When CKB is evaluated as an example of large-scale health data infrastructure development, four lessons stand out.
9.1 Initial Infrastructure Funding and Long-Term Operating Funding Can Be Designed Separately
CKB did not secure all the funding required for its entire lifetime before starting.
Instead, an initial philanthropic investment enabled the research infrastructure to be established.
Subsequent development was supported through combinations of public funding, research grants, and collaborative projects with companies and research institutions.
This demonstrates that initial capital investment and long-term operating costs can be financed through different mechanisms.
However, it does not mean that sustained financial support becomes unnecessary.
Long-term value creation still depends on continued investment in follow-up activities, data management, sample preservation, and new analytical technologies. [1][2]
9.2 Early Decisions About Data and Sample Collection Determine Scientific Value Decades Later
CKB began collecting and preserving blood samples on a large scale at a time when whole-genome sequencing and today's proteomic technologies were not yet widely available.
The project can now apply these newer technologies to samples collected approximately 20 years ago.
This demonstrates the value of designing sample storage and data management systems with future technological advances in mind, rather than limiting their purpose to analyses that are immediately possible.
Such forward-looking decisions have contributed directly to the long-term scientific value of CKB. [5][6]
9.3 The Value of a Research Infrastructure Is Not Determined by Participant Numbers Alone
Recruiting approximately 513,000 participants was an extraordinary achievement.
However, the scientific value of CKB cannot be explained solely by the size of its cohort.
Several additional factors are essential:
- Linkage with administrative health records
- Quality of diagnostic information
- More than 20 years of follow-up
- Availability of stored biological samples
- Inclusion of populations with different geographic and genetic backgrounds
Together, these characteristics enable researchers to study lifestyle, environmental factors, genetic variation, and disease outcomes over long periods and from multiple perspectives.
The lesson is that collecting large numbers of participants is only one part of building a valuable research infrastructure.
Maintaining research-quality data over decades is equally important.
9.4 Possessing Valuable Data Is Different From Making Them Accessible to Researchers Worldwide
CKB has successfully accumulated an exceptionally valuable research resource.
However, international access to individual-level genomic data remains constrained by regulatory requirements.
To increase its value as a global research resource, CKB must combine data quality with effective arrangements for security, legal compliance, and researcher accessibility.
The development of a cloud-based Research Analysis Platform is one response to this challenge. [2][4]
10. Overall Assessment: What CKB's Two-Decade History Tells Us
CKB's development can be understood in four broad phases.
10.1 Concept Development: The 1990s–2002
The project developed the concept of a long-term, disease-spanning research infrastructure and secured philanthropic funding and international research partnerships.
The collaboration between British and Chinese epidemiologists that began in the 1980s provided the scientific foundation.
10.2 Infrastructure Development: 2004–2008
CKB established a large-scale participant recruitment program, survey and sample storage systems, and infrastructure for long-term follow-up through administrative health records.
Beyond recruiting approximately 513,000 participants, the project created a resource of biological samples and research data intended for future scientific use.
10.3 Expansion: 2009–2023
Long-term follow-up, repeat surveys, genomic research, and access for external researchers expanded.
The accumulation of research findings established CKB as one of the world's important epidemiological research resources.
10.4 Advanced Research Infrastructure: 2024–Present
CKB has moved toward whole-cohort WGS, multi-omics analysis, drug discovery research, and secure remote data access.
At the same time, the project continues to face challenges involving international data sharing, regulatory compliance, funding sustainability, and data quality management.
10.5 Looking Ahead: The Future of Large-Scale Health Data Infrastructure
CKB demonstrates how an initial investment in large-scale data and biological sample collection can continue generating scientific value for decades.
Long-term follow-up and advances in analytical technologies have allowed information collected during the original recruitment period to support scientific questions that were not necessarily foreseeable at the time.
The central issue for the future is therefore not simply how much additional data can be collected.
It is also how effectively existing data can be made available for a greater number of high-quality research projects while maintaining legal compliance, ethical standards, and appropriate security protections.
The history of CKB provides valuable lessons both for organizations planning to establish new large-scale health data infrastructures and for those seeking to enhance the value of existing research resources.
References
[1] University of Oxford, “What can half a million Chinese teach us about global health?,” Nuffield Department of Population Health, University of Oxford, 2013.
https://www.ndph.ox.ac.uk/longer-reads/crossing-continents-2013-the-china-kadoorie-biobank
[2] “International collaboration in cohort studies in China: opportunities and challenges,” BMJ, vol. 391, October 23, 2025. DOI: 10.1136/bmj-2024-083354.
https://www.bmj.com/content/391/bmj-2024-083354
[3] Peking University, “中国慢性病前瞻性研究・项目简介” (Introduction to the China Kadoorie Biobank Project), official CKB materials.
https://ckbiobank.pku.edu.cn/xmgk/xmjj.htm
[4] China Kadoorie Biobank, “Data Access” and “Data Overview,” official data access documentation.
https://www.ckbiobank.org/data-access
https://www.ckbiobank.org/data-access/data-overview
[5] China Kadoorie Biobank, “CKB Data Access and Sample Preservation Policy,” official policy documentation.
https://www.ckbiobank.org/data-access/ckb-data-access-and-sample-preservation-policy
[6] “Genotyping and population characteristics of the China Kadoorie Biobank,” Cell Genomics, 2023. DOI: 10.1016/j.xgen.2023.100361.
https://pmc.ncbi.nlm.nih.gov/articles/PMC10435379/
[7] China Kadoorie Biobank, “CKB News,” official news and research updates, 2025–2026.
https://www.ckbiobank.org/news-1
Research reference date: November 4, 2026
Note on the verification status of information:
Research activity as of November 2026 was confirmed through official news announcements. However, definitive and up-to-date information could not be established regarding the final quality-control status of the whole-cohort WGS dataset, the general availability date of the Research Analysis Platform, or the external release date of the latest disease follow-up data.
Accordingly, this article distinguishes between planned activities, reported completion, and actual external data availability.
CKB's access arrangements, dataset availability, and application fees may also change over time. Researchers planning to use the resource should consult the latest official CKB documentation.