Tuberculosis and Diabetes Care Remain Fragmented in the World’s Highest-Burden Countries

Tuberculosis has never been a disease that exists in isolation, and nowhere is that clearer than in the world’s three highest-burden countries. China, India, and Indonesia together carry a staggering share of global tuberculosis cases, and all three are simultaneously witnessing a relentless rise in type 2 diabetes. The collision of these two epidemics is not a hypothetical concern: diabetes roughly triples a person’s risk of developing active tuberculosis, weakens the immune response to infection, and undermines the effectiveness of tuberculosis treatment. Yet a new systematic review published in BMC Health Services Research reveals that, despite more than fifteen years of warnings from the World Health Organization, health systems in these three nations have largely failed to weave their tuberculosis and diabetes services into anything resembling a coordinated whole.

The review, led by Lintang Dian Saraswati of Queensland University of Technology in Australia and Diponegoro University in Indonesia, together with colleagues Jerico Franciscus Pardosi, Bagoes Widjanarko, and Michelle Louise Gatton, set out to answer a deceptively simple question: how integrated are tuberculosis and diabetes services in the countries where both diseases rage hardest? To do this, the team followed the PRISMA reporting guideline and registered their protocol in PROSPERO under registration number CRD42022337104, a step that guards against selective reporting and post hoc changes of plan. Between March and August 2022, they searched seven major databases, including Embase, PubMed, Medline via EBSCO, CINAHL via EBSCO, the Cochrane Library, Web of Science, and Scopus, capturing studies published between 2007 and 2022 that described tuberculosis-diabetes co-management in China, India, or Indonesia.

The search yielded 51 publications, which together described 55 distinct tuberculosis-diabetes service implementations. The researchers then applied a structured analytical lens: the WHO Collaborative Framework for the care and control of tuberculosis and diabetes, which defines a graded hierarchy of service integration. At the lowest rung, Level 1, the two disease programs operate essentially in parallel, with only minimal or informal linkages between them. Level 2 introduces basic coordination, such as cross-referral between tuberculosis clinics and diabetes services. Level 3 represents substantial integration, where screening for one condition is routinely embedded in the management of the other and joint protocols govern care. Level 4, the highest level, describes fully integrated service delivery in which tuberculosis and diabetes are managed as a unified package within the same clinical encounter, with shared staff, records, and governance.

What the classification revealed was sobering. Of the 55 service implementations described, 53 could be assigned a level under the WHO framework; the remaining two lacked sufficient information for classification. Almost half of the classifiable services, 24 out of 53, sat at Level 1, meaning that tuberculosis and diabetes care ran along largely separate tracks. Ten implementations reached Level 2, and seventeen achieved Level 3. Not a single study in the entire body of literature documented a service that had attained Level 4 integration. In other words, across fifteen years of published experience in three of the world’s most populous nations, no program described in the literature had achieved the kind of seamless, fully unified tuberculosis-diabetes care that global guidelines envision as the ideal.

The geographic distribution of the evidence was also telling. Most of the included studies originated from India, which has both the world’s largest tuberculosis burden and one of its largest diabetes populations, a combination that has made it a natural laboratory for pilot programs linking the two diseases. China and Indonesia contributed fewer studies, and the review found no clear temporal trend toward higher integration levels over time. That absence of progress is perhaps the most striking finding of all. One might expect that as the scientific case for bidirectional screening accumulated, and as the WHO issued its Collaborative Framework in 2016, services would gradually climb the integration ladder. The data suggest otherwise: integration has remained stubbornly shallow regardless of the year in which services were implemented.

The reasons for this stagnation are systemic rather than scientific. The authors point to persistent challenges that recur across the three countries: inadequate infrastructure, limited professional knowledge among frontline health workers, poor coordination between tuberculosis and diabetes programs, and constrained budgets. These are not trivial obstacles. Tuberculosis services in high-burden countries are typically organized as vertical programs, historically designed for infectious disease control, with dedicated staff, reporting lines, and funding streams. Diabetes care, by contrast, sits within the growing domain of non-communicable disease management, usually delivered through general outpatient services and increasingly through private providers. Merging these two bureaucratic worlds requires shared training, unified patient records, negotiated financing, and clinical protocols that neither program currently owns. Where any of those ingredients is missing, integration stalls at the level of occasional referrals or one-off screening campaigns.

The methodological rigor of the review lends weight to its conclusions. The team assessed the methodological quality of each included study using the Joanna Briggs Institute appraisal tools, which provide design-specific checklists for everything from randomized controlled trials to prevalence studies, and they synthesized the findings using the Synthesis Without Meta-analysis guideline, a structured approach for combining heterogeneous studies that cannot be pooled statistically. The breadth of study designs captured, spanning analytical studies, case-control and cohort designs, mixed methods, prevalence surveys, and randomized trials, reflects the diversity of program models that have been attempted, from diabetes screening among tuberculosis patients to tuberculosis screening among people with diabetes attending endocrinology clinics.

Why does this matter so much clinically? The bidirectional relationship between the two diseases creates a window of opportunity that fragmented services squander. A person with poorly controlled diabetes who attends a diabetes clinic is an ideal candidate for tuberculosis screening, because their elevated risk means that early detection could prevent disease progression and onward transmission. Conversely, every tuberculosis patient should arguably be assessed for diabetes, because undiagnosed hyperglycemia impairs immune function, delays sputum conversion, and increases the risk of death during tuberculosis treatment. When services operate at Level 1, these screening opportunities are missed by default. Patients must navigate separate facilities, separate appointment systems, and separate medical records, and the burden of coordination falls on the very people least equipped to bear it.

The review’s findings arrive at a moment when global health strategy is increasingly emphasizing the integration of infectious disease and non-communicable disease services, particularly in low- and middle-income settings where primary healthcare systems are being reimagined as platforms for universal health coverage. The WHO Collaborative Framework was designed precisely to guide this transition, offering countries a menu of interventions at different integration levels so that programs can start small and deepen over time. The evidence from China, India, and Indonesia suggests that this progression is not happening organically. Without deliberate policy pushes, dedicated financing, workforce training, and health information systems that can track patients across both conditions, services remain trapped at the lowest rungs of the integration ladder.

The authors’ conclusion is measured but pointed: significant gaps remain in achieving optimal tuberculosis-diabetes service integration in all three countries. For policymakers, the message is that pilot projects and scattered screening initiatives, however well intentioned, have not translated into system-level change. The 51 studies reviewed here represent a decade and a half of experimentation, and their collective verdict is that the deepest level of integration remains entirely uncharted territory in the published literature. As diabetes prevalence continues to climb across Asia and tuberculosis stubbornly persists, the cost of fragmentation will only grow. Closing the gap between the two epidemics, the review makes clear, will require moving beyond parallel programs toward genuinely unified care, a transformation that no country in the highest-burden group has yet achieved.

Subject of Research: Integration of tuberculosis and diabetes mellitus health services in China, India, and Indonesia

Article Title: Level of integration of tuberculosis-diabetes mellitus services in China, India and Indonesia: a systematic review

Article References: Saraswati, L. D., Pardosi, J. F., Widjanarko, B., & Gatton, M. L. (2026). Level of integration of tuberculosis-diabetes mellitus services in China, India and Indonesia: a systematic review. BMC Health Services Research. https://doi.org/10.1186/s12913-026-15727-0

Image Credits: AI Generated

DOI: 10.1186/s12913-026-15727-0

Keywords: tuberculosis, diabetes mellitus, service integration, systematic review, WHO Collaborative Framework, China, India, Indonesia, health systems, screening, non-communicable diseases, public health