Excess suicides in Japan: A three-year post-pandemic assessment of gender and age disparities.

This study offers an in-depth analysis of Japan's suicide trends three years after the COVID-19 outbreak. Using data from the National Police Agency (January 2010-May 2023), we examined suicide rates across genders and age groups. Employing the quasi-Poisson regression, we predicted monthly death counts. Findings indicate a steady rise in female suicides from April 2020 to January 2023. Notably, male cohorts aged 50-59 and over 80 in 2022 displayed heightened death rates. While these trends may reflect the impacts of the pandemic, it is essential to consider other factors, including socio-economic changes, to fully understand the context of Japan's suicide patterns.

The impact of alternate HPV vaccination and cervical screening strategies in Japan: a cost-effectiveness analysis.

Background: The Japanese 2020 cervical screening guidelines recommend conventional cervical cytology screening every 2-years for women aged 20-69 years. The nonavalent human papillomavirus (HPV) vaccine has also recently been approved in Japan. We therefore evaluated the cost-effectiveness of cervical cancer screening strategies alongside universal nonavalent HPV vaccination of girls (12-16 years). Methods: A cost-effectiveness analysis was performed using an age-specific Markov microsimulation model for Japan to evaluate total costs, quality adjusted life-years (QALYs) gained, incremental cost-effectiveness ratios (ICER), colposcopies, biopsies, precancer and cervical cancer treatments for 29 combined vaccination and screening strategies (conventional cytology, liquid-based cytology (LBC), HPV testing, and HPV self-collection). A cohort of 100,000 girls (12-16 years old) over a lifetime offered the nonavalent HPV vaccine was used (current vaccination coverage = 0.08%, current screening coverage = 43.7%). A discount rate of 3% was applied to costs and QALYs. Univariate and probabilistic sensitivity analysis was performed to assess robustness of the findings. Costs were reported in US dollars (2023). Findings: Compared with conventional cytology, evaluated strategies would incur an additional cost of US$839,280-738,182,669 and gain 62,755-247,347 quality-adjusted-life-years. HPV testing distinguishing HPV16/18 with reflex LBC (3-yearly) would be most cost-effective (ICER = US$7511 per QALY gained). At a willingness-to-pay (WTP) of 1-times gross domestic product (GDP) per capita, the probability of it being cost-effective was 70%. At historically high vaccination coverage (70%) ICERs decreased overall but did not affect the ranking of the most cost-effective strategy. While a 5-yearly interval became more cost-effective than a 3-yearly interval. Including HPV self-collection for under-screened women made all strategies more cost-effective. Interpretation: At current cervical screening participation (43.7%) and low vaccination coverage (<1.0%), HPV testing distinguishing HPV16/18 with reflex LBC (3-yearly) would be the most cost-effective screening strategy compared to conventional cytology (2-yearly). Funding: Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (17H03589) and Grants of the National Cancer Center Japan (Gan Kenkyu Kaihatsuhi 31-A-20 and 2023-A-23).

Economic effects of healthy ageing: functional limitation, forgone wages, and medical and long-term care costs.

This study aims to estimate the potential economic benefits of healthy ageing by obtaining estimates of the economic losses generated by functional limitations among middle-aged and older people. Utilising two data sources retrieved from nationally representative samples of the Japanese people, we analysed the association between functional limitation and economic indicators, including labour market outcomes, savings, investment, consumption, and unpaid activities among individuals aged ≥ 60. Using the estimated parameters from our micro-econometric analyses and the official statistics by the Japanese government and a previous study, we calculated the financial costs that can be averted if healthy ageing is achieved as foregone wages and formal medical/long-term care costs incurred by functional limitations. Our micro-econometric analyses found that functional limitation was associated with a 3% point increase in retirement probability, with a stronger association among those aged 60-69. Moreover, functional limitation was linked with higher total health spending and less active involvement in domestic work. Foregone wages generated by functional limitation were estimated to be approximately USD 266.4 million, driven mainly by individuals in their 60s. Long-term care costs, rather than medical care costs, for older people aged ≥ 85 accounted for most of the additional costs, indicating that the estimated medical and long-term costs generated by functional limitations were approximately USD 72.7 billion. Health interventions can yield economic benefits by preventing exits from the labour market due to health issues and reducing medical and long-term care costs.

Assessment of Traffic Accidents in Japan during the COVID-19 Pandemic vs. Previous Years: A Preliminary Report.

Beginning in April 2020, social distancing measures were implemented to mitigate the COVID-19 pandemic in Japan. We assessed whether traffic accident rates had decreased from April 2020 to December 2021 as compared with previous years. The analysis included 2,934,477 traffic accidents, and the trend of decreasing rates of traffic accidents in recent years and seasonal fluctuations in traffic accidents were considered. The yearly change in the traffic accident rate between 2015 and 2019 was estimated, and the traffic accident rate in 2020 and 2021 was predicted. This was followed by the comparison of observed vs. predicted traffic accident rate. In 2020, the observed vs. expected rates of traffic accidents were lower in April to December 2020, and the rate of traffic accidents in Japan was 30-40% lower in April-May 2020 than would be expected based on trends from previous years. In 2021, rates of traffic accidents remained lower than expected between January and November, but the magnitude of decrease was not as pronounced. These findings could be explained by social distancing policies, including the declaration of the state of emergency, and the relaxation of public health and social measures over time.

Salaries, degrees, and babies: Trends in fertility by income and education among Japanese men and women born 1943-1975-Analysis of national surveys.

BACKGROUND: While fertility rates have decreased during the second half of the 20th century in Japan, little is known regarding trends in the number of children that men and women have across birth cohorts and whether these differ by education and income. METHODS: We used data from four rounds of the National Fertility Survey (1992, 2005, 2010 and 2015) and included men and women aged 40-49 years (16728 men and 17628 women). By 5-year birth cohorts, we assessed the distribution of number of children (0, 1, 2 and 3 or more) and total fertility (the mean number of children) at completed fertility (age 45-49 or 40-44 years depending on birth cohort). We assessed trends in these fertility outcomes in men and women separately, and by education (no university education; university education) for men and women and by reported annual income (0 to <3 000 000 JPY; 3 000 000 to <6 000 000 JPY; ≥6 000 000 JPY) for men. RESULTS: When comparing those born in 1943-1948 with those born in 1971-1975, the proportion with no children had increased from 14.3 to 39.9% for men and from 11.6 to 27.6% for women. This increase coincided with a decrease in the proportions of individuals with 2 or more children. Total fertility had decreased from 1.92 to 1.17 among men and from 1.96 to 1.42 among women. For men, those with a university degree were more likely to have children than those without a university degree in all birth cohorts except 1943-1947. Men with higher income were more likely to have children across birth cohorts. While the proportion who had children had decreased in all income groups, the decrease was steeper among those in the lowest income group. Among women born 1956-1970, those with a university degree were less likely to have children than those without a university degree; this difference was no longer seen among those born 1971-1975. For both men and women, trends in having children and total fertility across birth cohorts did not differ by educational status. CONCLUSIONS: The decline in the total fertility rate in Japan can be attributed to both an increasing proportion of the population who have no children and a lower number of children among those who have children. Men with lower education and income were less likely to have children and the disparity in the number of children that men have by income had increased in more recent birth cohorts. Among women, higher education was associated with lower fertility, although this pattern was no longer observed among those born in 1971-1975.

Fish in the sea: Number, characteristics, and partner preferences of unmarried Japanese adults - analysis of a national survey.

BACKGROUND: A large proportion of adults in Japan remain unmarried even though they intend to marry during their lifetime. To provide data for policy makers and those searching for partners in the Japanese marriage market, we estimated the number and characteristics of unmarried women and men with marriage intention and assessed their partner preferences. Based on the findings, we hypothesized regarding potential mismatches between the individuals available in the marriage market and the type of partners they are looking for. METHODS: We used data from the National Fertility Survey (2015), a nationally representative survey in Japan, and included 20,344 participants aged 18-49 years, of which 6,568 were unmarried with marriage intention. We estimated the total number of unmarried women and men who intend to marry, extrapolated their characteristics to the Japanese population, and assessed their partner preferences, as well as their ideal age of marriage and the ideal age of their partner. RESULTS: In 2015, there were 8.48 million unmarried women and 9.83 million unmarried men aged 18-49 years with marriage intention in Japan. Surpluses of around 600,000 men were observed in non-densely inhabited areas (men-to-women ratio: 1.31) and in the Kanto region (1.23). Most of the women and men in the marriage market had annual incomes lower than 3,000,000 JPY (28,000 USD) and only 263,000 women (3%) and 883,000 men (9%) had an income of 5,000,000 JPY (47,000 USD) or more; 167,000 men (2%) had an income of 7,000,000 JPY (66,000 USD) or more, with roughly three-quarters of them having a university degree. When asked about eight items that one may consider in a potential partner, the proportion of women listing an item as "important" tended to be larger than those of men across all items (education, occupation, finances, personality, mutual hobbies, cooperation/understanding regarding one's work, and attitude towards/skills in housework and childrearing) except appearance. The largest differences were observed for finances (proportion of women vs. men listing the item as "important" or "would consider:" 94.0% vs. 40.5%, p<0.001), occupation (84.9% vs. 43.9%, p<0.001), and education (53.9% vs. 28.7%, p<0.001). While women, on average, preferred men who were around 1-3 years older than themselves, men preferred women around their own age until the age of 26 years, at which point men preferred women who were younger than themselves, with the preferred age difference increasing substantially with age. As such, the number of men preferring a younger partner was larger than the number of women who preferred an older partner. CONCLUSIONS: By providing data on the number, characteristics and partner preferences of individuals in the marriage market, our study could inform decisions for those searching for marriage partners in Japan. Moreover, we hypothesize that mismatches in geographical location, the supply-demand disparity for partners with higher income, and age preferences could partly explain the large number of Japanese women and men who remain unmarried despite intending to get married. Further studies are needed to assess if, and to what extent, the identified mismatches may affect marriage rates.

Tracking sectoral allocation of official development assistance: a comparative study of the 29 Development Assistance Committee countries, 2011-2018.

Background: Official development assistance (ODA) is one of the most important means for donor countries to foster diplomatic relations with low- and middle-income countries and contribute to the welfare of the international community.Objective: This study estimated the sectoral allocation of gross disbursements of ODA of the 29 Development Assistance Committee (DAC) member countries of the Organisation for Economic Co-operation and Development (OECD) for the duration of 2011 to 2018, by aid type (bilateral, multilateral, and both aids).Methods: Data from the OECD iLibrary were used. The sector definition was based on the OECD sector classification. For core funding to multilateral agencies that do not specialize in each aid sector, we estimated ODA and its flows based on the OECD methodology for calculating imputed multilateral ODA.Results: For all 29 countries, during the period of 2014-2018 where data were available for all the countries, the sector with the highest average annual ODA contribution was health at 20.34 billion USD (13.21%), followed by humanitarian aid at 18.04 billion (11.72%). Humanitarian aid has increased in the sectoral share rankings in both bilateral and multilateral aid, and the sectoral share for refugees in donor countries has increased in bilateral aid. While the 29 countries show relatively similar trends for sectoral shares, some countries and sectors display unique trends. For instance, infrastructure and energy sectors in bilateral aid of Japan are particularly high accounts for 48.48% of the total bilateral ODA of the country in 2018.Conclusions: This paper evaluated ODA trends by major donors of DAC countries in the pre-COVID-19 pandemic periods. We hope that our estimates will contribute to the review of the strategic decision-making and the effective implementation of future ODA policy discussions in the DAC countries while ensuring transparency.

Assessment of Suicide in Japan During the COVID-19 Pandemic vs Previous Years.

Importance: There are concerns that suicide rates may have increased during the coronavirus disease 2019 (COVID-19) pandemic. Objective: To assess whether suicide rates in Japan increased in April through November 2020 compared with previous years. Design, Setting, and Participants: This cross-sectional study used national data obtained from the Ministry of Health, Labor and Welfare from 2016 to 2020 on the monthly number of individuals who died of suicide in Japan from January to November of 2016 to 2020. Exposure: 2020 vs previous years. Main Outcomes and Measures: The main outcome was monthly suicide rates, calculated as the number of individuals who died of suicide divided by the total population. A difference-in-difference regression model was used to estimate the change in monthly suicide rates in April to November 2020 vs these months in 2016 to 2019. Results: Analyses included 90 048 individuals (61 366 [68.1%] men) who died of suicide from 2016 to 2020. The difference-in-difference analysis of men showed that there was no increase in suicide rates from April through September 2020 compared with these months in 2016 to 2019, but that suicide rates were increased in October (difference-in-difference, 0.40 [95% CI, 0.14 to 0.67] suicide deaths per 100 000 population) and November (difference-in-difference, 0.34 [95% CI, 0.07 to 0.60] suicide deaths per 100 000 population). Among women, suicide rates in 2020 compared with 2016 to 2019 increased in July (difference-in-difference, 0.24 [95% CI, 0.09 to 0.38] suicide deaths per 100 000 population), August (difference-in-difference, 0.30 [95% CI, 0.16 to 0.45] suicide deaths per 100 000 population), September (difference-in-difference, 0.29 [95% CI, 0.15 to 0.44] suicide deaths per 100 000 population), October (difference-in-difference, 0.62 [95% CI, 0.48 to 0.77] suicide deaths per 100 000 population), and November (difference-in-difference, 0.29 [95% CI, 0.15 to 0.44] suicide deaths per 100 000 population). In secondary analyses in which the suicide rates of 2020 were compared with the expected rates based on trends from 2011 to 2019, the increases in suicide rates were most pronounced among men aged younger than 30 years (eg, November: observed vs expected rate ratio [RR], 1.48 [95% CI, 1.26-1.71]) and women aged younger than 30 years (eg, October: observed vs expected RR, 2.14 [95% CI, 1.76 to 2.52]) and 30 to 49 years (eg, October: observed vs expected RR, 2.30 [95% CI, 2.01 to 2.58]). Conclusions and Relevance: These findings suggest that compared with previous years, suicide rates in Japan in 2020 increased in October and November for men and in July through November for women.

Ongoing debate on data governance principles for achieving Universal Health Coverage: a proposal to post-G20 Osaka Summit meetings.

The Group of 20 Summit (G20) in Osaka, which Japan chaired for the first time in June 2019 has created a tailwind for achieving universal health coverage (UHC) globally. In response to the rapid digitalization, the G20 leaders commenced negotiations for the Osaka Track framework to formulate international rules on data flow across borders and systematize the concept of 'Data Free Flow with Trust (DFFT).' The strategic harnessing of the power of data to strengthen the healthcare system can allow for rapid and affordable progress toward achieving UHC. However, world leaders have yet to discuss what data governance approaches the Osaka Track will follow, or even on what values it will seek to create and maximize. In this paper, we propose a people-centered, trust-oriented approach as the key principle of data governance toward achieving UHC, using Japan's experience as an example. We believe that this approach is compatible with other prevailing approaches (e.g. the General Data Protection Regulation (GDPR) in the European Union), and can serve as a bridge to their conceptual differences. We hope that our proposed principles will be fully discussed in post-G20 Osaka Summit meetings.

Tracking Japan's development assistance for health, 2012-2016.

BACKGROUND: Development assistance for health (DAH) is one of the most important means for Japan to promote diplomacy with developing countries and contribute to the international community. This study, for the first time, estimated the gross disbursement of Japan's DAH from 2012 to 2016 and clarified its flows, including source, aid type, channel, target region, and target health focus area. METHODS: Data on Japan Tracker, the first data platform of Japan's DAH, were used. The DAH definition was based on the Organisation for Economic Co-operation and Development's (OECD) sector classification. Regarding core funding to non-health-specific multilateral agencies, we estimated DAH and its flows based on the OECD methodology for calculating imputed multilateral official development assistance (ODA). RESULTS: Japan's DAH was estimated at 1472.94 (2012), 823.15 (2013), 832.06 (2014), 701.98 (2015), and 894.57 million USD (2016) in constant prices of 2016. Multilateral agencies received the largest DAH share of 44.96-57.01% in these periods, followed by bilateral grants (34.59-53.08%) and bilateral loans (1.96-15.04%). Ministry of Foreign Affairs (MOFA) was the largest contributors to the DAH (76.26-82.68%), followed by Ministry of Finance (MOF) (10.86-16.25%). Japan's DAH was most heavily distributed in the African region with 41.64-53.48% share. The channel through which the most DAH went was Global Fund to Fight AIDS, Tuberculosis, and Malaria (20.04-34.89%). Between 2012 and 2016, approximately 70% was allocated to primary health care and the rest to health system strengthening. CONCLUSIONS: With many major high-level health related meetings ahead, coming years will play a powerful opportunity to reevaluate DAH and shape the future of DAH for Japan. We hope that the results of this study will enhance the social debate for and contribute to the implementation of Japan's DAH with a more efficient and effective strategy.

Limited alignment of publicly competitive disease funding with disease burden in Japan.

OBJECTIVE: The need to align investments in health research and development (R&D) with public health needs is one of the most important public health challenges in Japan. We examined the alignment of disease-specific publicly competitive R&D funding to the disease burden in the country. METHODS: We analyzed publicly available data on competitive public funding for health in 2015 and 2016 and compared it to disability-adjusted life year (DALYs) in 2016, which were obtained from the Global Burden of Disease (GBD) 2017 study. Their alignment was assessed as a percentage distribution among 22 GBD disease groups. Funding was allocated to the 22 disease groups based on natural language processing, using textual information such as project title and abstract for each research project, while considering for the frequency of information. RESULTS: Total publicly competitive funding in health R&D in 2015 and 2016 reached 344.1 billion JPY (about 3.0 billion USD) for 32,204 awarded projects. About 49.5% of the funding was classifiable for disease-specific projects. Five GDB disease groups were significantly and relatively well-funded compared to their contributions to Japan's DALY, including neglected tropical diseases and malaria (funding vs DALY = 1.7% vs 0.0%, p<0.01) and neoplasms (28.5% vs 19.2%, p<0.001). In contrast, four GDB disease groups were significantly under-funded, including cardiovascular diseases (8.0% vs 14.8%, p<0.001) and musculoskeletal disorders (1.0% vs 11.9%, p<0.001). These percentages do not include unclassifiable funding. CONCLUSIONS: While caution is necessary as this study was not able to consider public in-house funding and the methodological uncertainties could not be ruled out, the analysis may provide a snapshot of the limited alignment between publicly competitive disease-specific funding and the disease burden in the country. The results call for greater management over the allocation of scarce resources on health R&D. DALYs will serve as a crucial, but not the only, consideration in aligning Japan's research priorities with the public health needs. In addition, the algorithms for natural language processing used in this study require continued efforts to improve accuracy.

An assessment of self-reported COVID-19 related symptoms of 227,898 users of a social networking service in Japan: Has the regional risk changed after the declaration of the state of emergency?

BACKGROUND: In the absence of widespread testing, symptomatic monitoring efforts may allow for understanding the epidemiological situation of the spread of coronavirus disease 2019 (COVID-19) in Japan. We obtained data from a social networking service (SNS) messaging application that monitors self-reported COVID-19 related symptoms in real time in Fukuoka Prefecture, Japan. We aimed at not only understanding the epidemiological situation of COVID-19 in the prefecture, but also highlighting the usefulness of symptomatic monitoring approaches that rely on self-reporting using SNS during a pandemic, and informing the assessment of Japan's emergency declaration over COVID-19. METHODS: We analysed symptoms data (fever over 37.5° and a strong feeling of weariness or shortness of breath), reported voluntarily via SNS chatbot by 227,898 residents of Fukuoka Prefecture during March 27 to May 3, 2020, including April 7, when a state of emergency was declared. We estimated the spatial correlation coefficient between the number of the self-reported cases of COVID-19 related symptoms and the number of PCR confirmed COVID-19 cases in the period (obtained from the prefecture website); and estimated the empirical Bayes age- and sex-standardised incidence ratio (EBSIR) of the symptoms in the period, compared before and after the declaration. The number of symptom cases was weighted by age and sex to reflect the regional population distribution according to the 2015 national census. FINDINGS: Of the participants, 3.47% reported symptoms. There was a strong spatial correlation of 0.847 (p < 0.001) at municipality level between the weighted number of self-reported symptoms and the number of COVID-19 cases for both symptoms. The EBSIR at post-code level was not likely to change remarkably before and after the declaration of the emergency, but the gap in EBSIR between high-risk and low-risk areas appeared to have increased after the declaration. INTERPRETATION: While caution is necessary as the data was limited to SNS users, the self-reported COVID-19 related symptoms considered in the study had high epidemiological evaluation ability. In addition, though based on visual assessment, after the declaration of the emergency, regional containment of the infection risk might have strengthened to some extent. SNS, which can provide a high level of real-time, voluntary symptom data collection, can be used to assess the epidemiology of a pandemic, as well as to assist in policy assessments such as emergency declarations. FUNDING: The present work was supported in part by a grant from the Ministry of Health, Labour and Welfare of Japan (H29-Gantaisaku-ippan-009).

Progress towards universal health coverage in Myanmar: a national and subnational assessment.

BACKGROUND: Attainment of universal health coverage is a global health priority. The Myanmar Government has committed to attainment of universal health coverage by 2030, but progress so far has not been assessed. We aimed to estimate national and subnational health service coverage and financial risk protection. METHODS: We used nationally representative data from the Myanmar Demographic and Health Survey (2016) and the Integrated Household Living Condition Assessment (2010) to examine 26 health service indicators and explored the incidence of catastrophic health payment and impoverishment caused by out-of-pocket payments. We used logistic regression models of inequalities in, and risk factors for, indicators of universal health coverage. FINDINGS: Nationally, the coverage of health service indicators ranged from 18·4% (95% CI 14·9-21·9) to 96·2% (95·9-96·5). Coverage of most health services indicators was below the universal health coverage target of 80%. 14·6% (95% CI 13·9-15·3) of households that used health services faced catastrophic health-care payments. 2·0% (95% CI 1·7-2·3) of non-poor households became poor because of out-of-pocket payments for health. Health service coverage and financial risk protection varied substantially by region. Although the richest quintiles had better access to health services than the poorest quintiles, they also had a higher incidence of financial catastrophe as a result of payments for health care. Of the indicators included in the study, coverage of adequate sanitation, no indoor use of solid fuels, at least four antenatal care visits, postnatal care for mothers, skilled birth attendance, and institutional delivery were the most inequitable by wealth quintile. INTERPRETATION: Attainment of universal health coverage in Myanmar in the immediate future will be very challenging as a result of the low health service coverage, high financial risk, and inequalities in access to care. Health service coverage and financial risk protection for vulnerable, disadvantaged populations should be prioritised. FUNDING: Japanese Ministry of Health, Labour and Welfare, Ministry of Education, Culture, Sports, Science and Technology of Japan.

The G7 presidency and universal health coverage, Japan's contribution.

PROBLEM: If universal health coverage (UHC) is to be achieved globally, it needs sustained promotion and political awareness and support. APPROACH: During its presidency of the Group of Seven (G7) industrialized nations in 2016, Japan aimed to raise the issue of UHC to the top of the global health agenda. LOCAL SETTING: Japan has promoted a health agenda at all of the G7 summits since 2000 that it has hosted. Human security has been the core foundation of Japan's foreign diplomacy for several decades and, consequently, there was no apparent opposition within Japan to the inclusion of UHC on the agenda of the summit in 2016. Other G7 governments appeared keen to promote such coverage. RELEVANT CHANGES: Since the 2016 summit, UHC has remained a central agenda item for the United Nations and World Health Organization, even though the leaders of both these global organizations have changed. In 2017, Japan hosted the UHC Forum in Tokyo. The participants, who were the heads of United Nations agencies, politicians and other decision-makers from all over the world, showed their continued commitment towards UHC. LESSONS LEARNT: In the raising of awareness of an item on the global health agenda, high-level champions are critical. Although they may be very diverse, all relevant stakeholders need to be connected and allowed to discuss policies with each other. Having too many allies can, however, lead to policy fragmentation, especially when there is commitment from the highest echelons within each country.

Population health and regional variations of disease burden in Japan, 1990-2015: a systematic subnational analysis for the Global Burden of Disease Study 2015.

BACKGROUND: Japan has entered the era of super-ageing and advanced health transition, which is increasingly putting pressure on the sustainability of its health system. The level and pace of this health transition might vary across regions within Japan and concern is growing about increasing regional variations in disease burden. The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 (GBD 2015) provides a comprehensive, comparable framework. We used data from GBD 2015 with the aim to quantify the burden of disease and injuries, and to attribute risk factors in Japan at a subnational, prefecture-level. METHODS: We used data from GBD 2015 for 315 causes and 79 risk factors of death, disease, and injury incidence and prevalence to measure the burden of diseases and injuries in Japan and in the 47 Japanese prefectures from 1990 to 2015. We extracted data from GBD 2015 to assess mortality, causes of death, years of life lost (YLLs), years lived with disability (YLDs), disability-adjusted life-years (DALYs), life expectancy, and healthy life expectancy (HALE) in Japan and its 47 prefectures. We split extracted data by prefecture and applied GBD methods to generate estimates of burden, and attributable burden due to known risk factors. We examined the prefecture-level relationships of common health system inputs (eg, health expenditure and workforces) to the GBD outputs in 2015 to address underlying determinants of regional health variations. FINDINGS: Life expectancy at birth in Japan increased by 4·2 years from 79·0 years (95% uncertainty interval [UI] 79·0 to 79·0) to 83·2 years (83·1 to 83·2) between 1990 and 2015. However, the gaps between prefectures with the lowest and highest life expectancies and HALE have widened, from 2·5 to 3·1 years and from 2·3 to 2·7 years, respectively, from 1990 to 2015. Although overall age-standardised death rates decreased by 29·0% (28·7 to 29·3) from 1990 to 2015, the rates of mortality decline in this period substantially varied across the prefectures, ranging from -32·4% (-34·8 to -30·0) to -22·0% (-20·4 to -20·1). During the same time period, the rate of age-standardised DALYs was reduced overall by 19·8% (17·9 to 22·0). The reduction in rates of age-standardised YLDs was very small by 3·5% (2·6 to 4·3). The pace of reduction in mortality and DALYs in many leading causes has largely levelled off since 2005. Known risk factors accounted for 34·5% (32·4 to 36·9) of DALYs; the two leading behavioural risk factors were unhealthy diets and tobacco smoking in 2015. The common health system inputs were not associated with age-standardised death and DALY rates in 2015. INTERPRETATION: Japan has been successful overall in reducing mortality and disability from most major diseases. However, progress has slowed down and health variations between prefectures is growing. In view of the limited association between the prefecture-level health system inputs and health outcomes, the potential sources of regional variations, including subnational health system performance, urgently need assessment. FUNDING: Bill & Melinda Gates Foundation, Japan Ministry of Education, Science, Sports and Culture, Japan Ministry of Health, Labour and Welfare, AXA CR Fixed Income Fund and AXA Research Fund.