The scale of the challenge is stark when the numbers are laid side by side. Indonesia carries the world’s second-largest tuberculosis epidemic, with approximately one million cases and 130,000 deaths each year, many from diseases with known cures. Stroke and other non-communicable diseases have become the leading causes of death, while maternal mortality remains stubbornly high at around 144 deaths per 100,000 live births nationally. Yet those national averages conceal a geography of inequality that is among the most dramatic in the world. Across Nusa Tenggara, Maluku and Papua, maternal mortality reaches 317 per 100,000 live births, close to three times the 114 recorded across Java and Bali. Infant mortality follows the same gradient: 9 deaths per 1,000 live births in Jakarta compared with 37 per 1,000 in the Papua Pegunungan highlands, meaning infants there are almost four times less likely to survive simply because of where they were born.

The Commission’s authors describe how these disparities pull the system in two directions at once. In Java’s crowded cities, the binding constraint is congestion: long waits, full wards and overstretched staff. In the eastern islands and highlands, the constraint is distance itself. A woman in obstructed labour may face a sea crossing to reach the nearest hospital, and the limiting factors are transport, workforce and unreliable basic infrastructure rather than the availability of clinical protocols. Between these extremes lies a third, quieter failure: patients across the country often lack access to integrated, continuous care that connects primary care, hospital services and post-acute or long-term support into a single pathway. Any system designed for Indonesia must answer for the urban patient in a crowded waiting room and the highland patient cut off by water and terrain simultaneously.

On paper, Indonesia has already built one of the most ambitious instruments for universal coverage anywhere in the world. The Jaminan Kesehatan Nasional, administered by BPJS Kesehatan, is the largest single-payer health insurance scheme in existence, and by 2024 roughly 98 percent of the formal identification-holding population was registered. The Commission is careful, however, to draw a distinction that has become central to global health policy debates: coverage is not access. A card cannot be used where facilities are absent, distant or overwhelmed. Disparities in who is actually reached, and in the quality of care once reached, persist across geographic and socioeconomic gradients. The financial sustainability of JKN also bears directly on the quality and reach of services, making the interplay between the public scheme and private systems a core question for reform rather than a technical afterthought.

The timing of the Commission is dictated by demography. Indonesia faces a double burden of disease in which persistent communicable illness coincides with a rapid rise in non-communicable disease, all against the backdrop of an ageing population and an epidemiological transition that demands a pivot from curative medicine towards preventative and geriatric care. Climate-related disasters and conflict add a compounding layer of risk. Layered over all of this is a narrow demographic window: the period around 2030 to 2035, when the working-age share of the population is projected to peak. This is the limited interval in which demographic structure can still be converted into durable economic and social gains. Reforms that arrive after that window closes will yield less, as the ageing population grows and the dependency ratio shifts. The evidence needed to guide those reforms, the authors argue, must be produced now.

Some of the most revealing findings in the Commission’s framing concern the blind spots of the data systems themselves. When Indonesia first assembled its national suicide data, the true toll proved to be many times what official records had shown, concentrated in provinces and rural communities that the aggregate picture had rendered invisible. This is not an isolated artefact. Routine systems poorly capture the experiences of the poorest, most marginalised and most remote populations, so national averages systematically conceal who is being left behind. Health-system data remain fragmented across institutions and administrative levels, with uneven quality that limits rigorous benchmarking. And, perhaps most fundamentally, there is as yet no agreed, measurable definition of what a health system for a high-income Indonesia should actually deliver.

The Commission’s organising concept is what it calls the Centennial Gap: the distance between the health system as it performs today and the system a prosperous, high-income Indonesia will require by 2045. The gap is to be measured across four dimensions: access and coverage, quality and outcomes, efficiency and financial sustainability, and equity and resilience. Defining that gap rigorously, identifying where it most threatens the national ambition, and charting how it can be closed constitutes the Commission’s core mandate. The work is organised into seven interconnected working groups spanning the entire system, from benchmarking current performance to equity and cultural safety, primary care redesign within a decentralised system, hospitals as hubs within people-centred networks, equitable technology adoption across uneven infrastructure, care that withstands climate disaster and conflict, and sustainable financing through revenue mobilisation and insurance reform together.

Methodologically, the Commission commits to harmonised indicators, a consistent standard of method, and case studies that capture subnational realities, with a national narrative that deliberately disaggregates data to expose the inequalities that aggregate figures hide. It is explicitly Indonesia-led, bringing together researchers, clinicians, policy makers and people with lived experience alongside international collaborators, and it positions itself as a partner to reform rather than a substitute for it. The authors note that the government has already set measurable national targets through its medium-term development plan, RPJMN 2025–2029, pursued through an active health-transformation agenda. What is needed now, they argue, is not another vision but independent, rigorous evidence to judge what is working, identify where course-correction is required, and measure progress against a coherent long-term standard.

Beyond the report itself, the Commission intends to strengthen Indonesia’s research and publication ecosystem through partnerships with universities and research institutes across the archipelago, building capacity in the country’s periphery so that local researchers can articulate the challenges of their own regions. This capacity-building dimension reflects a broader recognition that the evidence gap is not merely technical but structural: the institutions best placed to document the realities of remote eastern provinces have historically had the least access to international publication channels and the funding that flows through them.

The case for acting, the authors conclude, is at once moral and economic. Leaving inequity, fragmented evidence and constrained financing unaddressed perpetuates preventable suffering among those already least served while weakening the foundations of Indonesia’s prosperity, since sustained, broad-based growth is impossible without a healthy, productive population and ill health across the life course erodes the human capital on which the Indonesia Emas 2045 vision rests. The Commission began its launch with a single question that frames everything that follows: how can Indonesia develop a healthcare system that provides quality healthcare for the poorest, most remote and most marginalised people in the country? The answer, delivered as evidence-based, actionable recommendations over the coming years, will carry lessons far beyond the archipelago for every nation pursuing universal coverage across difficult terrain.

Subject of Research: Health system reform and universal health coverage in Indonesia ahead of its 2045 centenary

Article Title: Reimagining healthcare in Indonesia for 2045: a Lancet Regional Health – Western Pacific Commission

Article References: Onie, S., Irmansyah, Agustina, R., Nugraheni, W. P., Idris, H., Padmawati, R. S., Balqis, Fuady, A., Dhamanti, I., Hendrartini, J., Dartanto, T., Maharani, A., Haedar, A., Nurdiati, D. S., Ferdiana, A., Good, B. J., Asnawi, A., & Thabrany, H. (2026). Reimagining healthcare in Indonesia for 2045: a Lancet Regional Health – Western Pacific Commission. The Lancet Regional Health – Western Pacific, Article 101992. https://doi.org/10.1016/j.lanwpc.2026.101992

Image Credits: AI Generated

DOI: 10.1016/j.lanwpc.2026.101992

Keywords: Indonesia, universal health coverage, JKN, health equity, maternal mortality, tuberculosis, non-communicable diseases, demographic dividend, health financing, The Lancet Regional Health Western Pacific, Indonesia Emas 2045, primary care

The modeling effort drew on the National Health and Nutrition Survey (NHNS), an annual cross-sectional household examination survey that has tracked the diet, physical activity, lifestyle, anthropometrics, and laboratory profiles of approximately 8,000 to 11,000 Japanese residents aged one year and older since its restructuring in 2003. The team focused on glycemic data from adults aged 40 and above, defining diabetes as glycated hemoglobin A1c at or above 6.5 percent under the National Glycohemoglobin Standardization Program, or self-reported use of glucose-lowering medication. This definition corresponds to the official NHNS category of ‘strongly suspected diabetes’ rather than strictly diagnosed disease, a choice the authors argue is well suited to capturing the full population-level burden for surveillance and long-term projection. HbA1c values measured under earlier Japanese Diabetes Society guidelines were converted to NGSP equivalents using a standard linear formula, ensuring consistency across the entire 2003 to 2019 observation window.

What sets this study apart from earlier forecasting efforts is its treatment of three distinct temporal dimensions that conventional models typically ignore. Age effects capture how diabetes risk changes across the lifespan as glucose metabolism deteriorates with biological aging. Period effects reflect influences that operate across the entire population at a given calendar moment, such as expanded healthcare access, mass screening programs, and rising consultation rates. Cohort effects, the most subtle of the three, capture how people born in particular eras carry distinct lifetime risks shaped by early-life nutrition, wartime deprivation, and generational lifestyle patterns. Because age, period, and cohort are mathematically linearly dependent, the researchers relied on identifiable non-linear components, or curvatures, and fitted smoothing priors using first- and second-order random walks within a hierarchical Bayesian framework implemented in the R bamp package.

To test whether this added complexity actually buys predictive power, the team pitted the BAPC model against two conventional alternatives: one assuming constant prevalence frozen at 2019 levels, and another assuming monotonic change based on mean percentage shifts observed from 2003 to 2019. Splitting the data into a training period from 2003 to 2014 and a validation window from 2015 to 2019, they measured performance using root mean square error, or RMSE, which quantifies the average annual discrepancy between projected and observed case counts. The BAPC model achieved the lowest error for the total population and for both sexes, and its projections for 2022 through 2024 aligned more closely with the officially reported NHNS prevalence than either conventional model, providing a rare external validation of a long-range health forecast against real-world data.

The headline projections reveal a nation moving in two directions at once. Overall crude prevalence is projected to rise from 12.6 percent in 2020 to 14.0 percent in 2040, with total cases climbing from roughly 9.9 million to 10.4 million. Among men, the burden is heaviest in older age brackets: prevalence among those aged 70 to 74 is projected to reach 26.7 percent by 2040, and among those 75 to 79 it may hit 29.1 percent. Women show the opposite trajectory, with prevalence declining across nearly every age group, dropping most steeply among those aged 55 to 64. Notably, when the researchers age-standardized their estimates using the 2015 Japan Standard Population, the apparent rise in men largely flattened out, indicating that population aging, rather than worsening age-specific risk, is the dominant engine of the male increase.

A formal decomposition analysis confirmed this interpretation, attributing the growing prevalence in men to both rising age-specific prevalence and demographic aging, with the latter contributing more. The age-effect patterns estimated by the model showed an upward curvature in men that intensified until ages 65 to 69 and continued climbing thereafter, consistent with aging-related deterioration in glucose metabolism. The cohort effects told an equally revealing story. In men, prevalence rose gradually across successive generations, with modest upward curvature in older and intermediate birth cohorts. In women, the model detected downward curvature in intermediate and younger cohorts, suggesting that diabetes risk has been falling steeply among women born after the mid-twentieth century, a divergence the authors link partly to sex differences in body mass index trends and lifestyle factors.

The shadow of history looms over these cohort patterns. The intermediate birth cohort in the analysis, spanning those born between roughly 1940 and 1955, came of age amid the social upheaval of World War II and its aftermath, conditions that likely produced poor early-life nutrition. Prior research, including studies of the Dutch famine, has shown that nutritional deficiencies in early life can trigger elevated diabetes incidence decades later in adulthood. The researchers also point to more recent pressures: declining dietary fiber intake, reduced physical activity, and rising body mass index over the last decade, trends that have been notably more pronounced among Japanese men than women. Meanwhile, increasing healthcare access and consultation rates for diabetes may be raising detected and treated case counts, contributing to the estimated period effects even as serum glucose levels in the broader population have reportedly stabilized.

The projections come with important caveats. The 95 percent credible intervals widen dramatically as the forecast horizon extends, reaching as high as 40.8 percent for men by 2040, reflecting the genuine uncertainty inherent in predicting two decades into the future. The NHNS was suspended in 2020 and 2021 due to the COVID-19 pandemic, and the definition based on ‘strongly suspected diabetes’ may underestimate true prevalence by excluding the ‘diabetes cannot be ruled out’ category. The models also could not adjust for socioeconomic factors, lifestyle variables, or body mass index directly, and the 17-year observation window, constrained by the availability of standardized HbA1c data since 2003, is relatively short for long-horizon projection. Sensitivity analyses using stronger smoothing priors and down-sampled data for the expanded 2012 and 2016 survey cycles, however, produced results consistent with the main findings.

For policymakers, the message is unambiguous: Japan’s diabetes burden is set to grow, and it will fall disproportionately on men and the elderly. The authors urge a reform of public health policy encompassing strengthened primary care screening and early detection, targeted attention to the health needs of older adults and men, sustained monitoring of the disease burden, and preventive lifestyle interventions to head off complications. Previous Japanese modeling work has shown that rising diabetes prevalence partly offset reductions in coronary heart disease deaths achieved between 1980 and 2012 through medical advances and favorable risk factor changes, underscoring how easily gains in cardiovascular health can be eroded by a swelling diabetic population. As other nations in the Western Pacific grapple with similar demographic transitions, Japan’s experience, and the Bayesian tools used to forecast it, may offer a preview of the region’s metabolic future.

Subject of Research: Projection of diabetes mellitus prevalence and case numbers in Japan through 2040 using Bayesian age-period-cohort modeling of national survey data

Article Title: Projections of diabetes mellitus in Japan through 2040: a bayesian age-period-cohort analysis of the national health and nutrition survey population

Article References: Mondal, R., Ogata, S., Kiyoshige, E., Nakaoku, Y., Nakatsuka, K., Watanabe, T., Teramoto, K., Kadota, A., Miura, K., Kypridemos, C., Yoshikawa, Y., & Nishimura, K. (2026). Projections of diabetes mellitus in Japan through 2040: a bayesian age-period-cohort analysis of the national health and nutrition survey population. The Lancet Regional Health – Western Pacific, 74, Article 101988. https://doi.org/10.1016/j.lanwpc.2026.101988

Image Credits: AI Generated

DOI: 10.1016/j.lanwpc.2026.101988

Keywords: diabetes mellitus, Japan, Bayesian age-period-cohort model, prevalence projection, National Health and Nutrition Survey, population aging, cohort effects, sex differences, public health policy, HbA1c, epidemiology, The Lancet Regional Health Western Pacific