Health inequality across prefectures in Japan
Authors: Churnrurtai Kanchanachitra, Viroj Tangcharoensathien
Journal: The Lancet (2017)

Japan has exemplary records in human development as measured by a human development index of 0·903 in 2016 (ranked 17th in the world).1United Nations Development ProgrammeHuman Development Report 2016: Human Development for Everyone.http://hdr.undp.org/sites/default/files/2016_human_development_report.pdfDate: 2016Google Scholar Universal access to health services with no financial barrier for every citizen in Japan launched in 1961 and has contributed to nearly equitable access and relatively small gaps in health status across regions and socioeconomic groups in the country.2Ikeda N Saito E Kondo N et al.What has made the population of Japan healthy?.Lancet. 2011; 378: 1094-1105Summary Full Text Full Text PDF PubMed Scopus (294) Google Scholar Ageing is homogeneously distributed across all communities,3Japan Statistics BureauMinistry of Internal Affairs and CommunicationsJapan statistical year book 2017. Population and Households.http://www.stat.go.jp/english/data/nenkan/66nenkan/1431-02.htmGoogle Scholar which has led to high demand for health care in all prefectures (provinces). Despite these achievements in the past, health inequity is increasing and has become a challenge for Japan. In The Lancet, Shuhei Nomura and colleagues4Nomura S Sakomoto H Glenn S et al.Population health and regional variations of disease burden in Japan, 1990–2015: a systematic subnational analysis for the Global Burden of Disease Study 2015.Lancet. 2017; (published online July 19.)http://dx.doi.org/10.1016/S0140-6736(17)31544-1Summary Full Text Full Text PDF PubMed Scopus (112) Google Scholar use trend data for burden of disease between 1990 and 2015 to document comprehensive health measures on mortality, morbidity, and injuries and variations across prefectures in Japan. Between 1990 and 2015, average life expectancy has increased by 4·2 years. Although similar rises have occurred between men and women, the gap between the lowest and highest prefectures widened from 2·5 years in 1990 to 3·1 years in 2015. The average health-adjusted life expectancy (HALE) overall increased by 3·5 years over this period, but the disparity between HALEs in the highest and lowest performing prefectures has slightly widened across the period, from 2·3 years in 1990 to 2·7 years in 2015. In Nomura and colleagues' study,4Nomura S Sakomoto H Glenn S et al.Population health and regional variations of disease burden in Japan, 1990–2015: a systematic subnational analysis for the Global Burden of Disease Study 2015.Lancet. 2017; (published online July 19.)http://dx.doi.org/10.1016/S0140-6736(17)31544-1Summary Full Text Full Text PDF PubMed Scopus (112) Google Scholar Japan performs well in reducing years of life lost (YLL) over time, probably driven by the reduction in mortality from cardiovascular diseases and neoplasms rather than by reducing the numbers of years living with disability (YLD) between 1990 and 2015. Age-standardised disability-adjusted life years (DALYs) were reduced by 19·8%: age-standardised YLDs contributed a 3·5% reduction and YLLs contributed a 33·4% reduction. Although mortality from other diseases is declining, both the numbers of deaths and age-standardised mortality from Alzheimer's disease and other dementias have increased; possibly leading to a slow down of progress in population health since 2005. There has also been a slow pace of reduction in age-standardised mortality rates from cardiovascular diseases since 2005 in Japan. Clearly health status progress overall has been hampered by a leveling off of mortalities from cardiovascular diseases, Alzheimer's disease, and other dementias after 2005. Primary prevention of Alzheimer's disease and dementias is therefore a major policy priority taken by the prefecture governments. Notably, Alzheimer's disease, breast cancer, and other neoplasms are the only three diseases that have little variation across prefectures.4Nomura S Sakomoto H Glenn S et al.Population health and regional variations of disease burden in Japan, 1990–2015: a systematic subnational analysis for the Global Burden of Disease Study 2015.Lancet. 2017; (published online July 19.)http://dx.doi.org/10.1016/S0140-6736(17)31544-1Summary Full Text Full Text PDF PubMed Scopus (112) Google Scholar This study also shows prefecture variations in burden of diseases; for example, Shiga prefecture located in the western region of Honshu island has the highest number of diseases with mortality rates that are significantly lower than the national mean, hence Shiga has the highest life expectancy at birth in 2015. By contrast, Aomori prefecture in the most northern part of Honshu island has the highest number of diseases with mortality rates that are significantly higher than the national mean. For example, in Shiga the age-standardised mortality rate in 2015 for ischaemic heart disease was 39·8 deaths per 100 000 individuals, whereas in Aomori the mortality rate was 50·1 deaths per 100 000 individuals; the national average was 44·7 deaths per 100 000 individuals. Such large variations in age-standardised mortality rates across prefectures should prompt further investigation of the causes and policy interventions to minimise the prefecture gaps. Although this study offers a comprehensive assessment of the health status trends and prefecture variations of mortality and DALYs in Japan, it provides little by way of what explains these variations. Exposure to risks, variations in lifestyle, and other socioeconomic and poverty trends and profiles in each prefecture are not fully analysed. That said, the study shows no significant correlation between age-standardised mortality rates or DALYs and health system indicators (health expenditure per capita in 2015 and health workforce density in 2014). But the 1-year cross-sectional health system factors might not be long enough to determine health status variations. Historical trends between 1990 and 2015 might offer some clues. Disparities in socioeconomic status, material and social deprivations, poverty, and other lifestyle factors also contribute to health status variations, as well as a decade of economic recession in Japan.5Sugisawa H Harada K Sugihara Y et al.Socioeconomic status and self-rated health of Japanese people, based on age, cohort, and period.Popul Health Metr. 2016; 14: 27Crossref PubMed Scopus (16) Google Scholar, 6Kondo N Subramanian SV Kawachi I Takeda Y Yamagata Z Economic recession and health inequalities in Japan: analysis with a national sample, 1986–2001.J Epidemiol Community Health. 2008; 62: 869-875Crossref PubMed Scopus (120) Google Scholar A 2014 study,7Hiyoshi A Fukuda Y Shipley M Brunner E Health inequalities in Japan: The role of material, psychosocial, social relational and behavioral factors.Soc Sci Med. 2014; 104: 201-209Crossref PubMed Scopus (25) Google Scholar showed that material factors (such as home ownership and living density); behavioural factors (such as sleep insufficiency, unbalanced diet, irregular meals, physical inactivity, excessive alcohol, and smoking); psychosocial factors, in particular perceived stress, and social relational factors (married or living alone) contribute to variations in difference in self-rated health status. These contributing factors, which may contribute to prefecture health disparities, were not fully assessed by Nomura and colleagues.4Nomura S Sakomoto H Glenn S et al.Population health and regional variations of disease burden in Japan, 1990–2015: a systematic subnational analysis for the Global Burden of Disease Study 2015.Lancet. 2017; (published online July 19.)http://dx.doi.org/10.1016/S0140-6736(17)31544-1Summary Full Text Full Text PDF PubMed Scopus (112) Google Scholar The findings from Nomura and colleagues4Nomura S Sakomoto H Glenn S et al.Population health and regional variations of disease burden in Japan, 1990–2015: a systematic subnational analysis for the Global Burden of Disease Study 2015.Lancet. 2017; (published online July 19.)http://dx.doi.org/10.1016/S0140-6736(17)31544-1Summary Full Text Full Text PDF PubMed Scopus (112) Google Scholar are similar to those of Fukuda and colleagues8Fukuda Y Nakao H Yahata Y Imai H Are health inequalities increasing in Japan? The trends of 1955 to 2000.Biosci Trends. 2007; 1: 38-42PubMed Google Scholar of decreased geographical health inequalities before 1995 and increased inequalities thereafter—confirming the rising health inequality in Japan that needs to be investigated for contributing factors. In addition to health determinants, political, socioeconomic, and environmental factors significantly contribute to health disparities;9Crombie I Irvine L Elliott L Wallace H Closing the health inequalities gap: an international perspective. WHO Regional Office for Europe, Copenhagen2005Google Scholar and are often more considerable than health factors.10Marmot M Allen J Social determinants of health equity.Am J Public Health. 2014; 104: S517-S519Crossref PubMed Scopus (293) Google Scholar The lower socioeconomic classes have higher exposures to occupational hazards and injuries,11Williams DR Mohammed SA Leavell J Collins C Race, socioeconomic status and health: complexities, ongoing challenges and research opportunities.Ann N Y Acad Sci. 2010; 1186: 69-101Crossref PubMed Scopus (829) Google Scholar and risk-related lifestyle behaviours such as alcohol consumption, in particular binge drinking,12Fone DL Farewell DM White J et al.Socioeconomic patterning of excess alcohol consumption and binge drinking: a cross-sectional study of multilevel associations with neighbourhood deprivation.BMJ Open. 2013; 3: e002337Crossref Scopus (87) Google Scholar domestic violence and drug abuse,13Nagassar RP Rawlins JM Sampson NR et al.The prevalence of domestic violence within different socio-economic classes in Central Trinidad.West Indian Med J. 2010; 59: 20-25PubMed Google Scholar and higher smoking prevalence.14Hiscock R Bauld L Amos A Fidler JA Munafò M Socioeconomic status and smoking: a review.Ann N Y Acad Sci. 2012; 1248: 107-123Crossref PubMed Scopus (918) Google Scholar Poverty and material deprivation can also result in less than needed access to health services. Now is an opportune time to identify prefecture-specific social determinants of health inequity that will support the sustainable development goals, leaving no one behind and where all prefectures have equitable health status. We declare no competing interests. Population health and regional variations of disease burden in Japan, 1990–2015: a systematic subnational analysis for the Global Burden of Disease Study 2015Japan 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. Full-Text PDF Open Access