Projecting prevalence of frailty and dementia and the economic cost of care in Japan from 2016 to 2043: a microsimulation modelling study.

BACKGROUND: Dementia and frailty often accompany one another in older age, requiring complex care and resources. Available projections provide little information on their joint impact on future health-care need from different segments of society and the associated costs. Using a newly developed microsimulation model, we forecast this situation in Japan as its population ages and decreases in size. METHODS: In this microsimulation modelling study, we built a model that simulates an individual's status transition across 11 chronic diseases (including diabetes, coronary heart disease, and stroke) as well as depression, functional status, and self-reported health, by age, sex, and educational strata (less than high school, high school, and college and higher), on the basis of nationally representative health surveys and existing cohort studies. Using the simulation results, we projected the prevalence of dementia and frailty, life expectancy with these conditions, and the economic cost for formal and informal care over the period 2016-43 in the population of Japan aged 60 years and older. FINDINGS: Between 2016 and 2043, life expectancy at age 65 years will increase from 23·7 years to 24·9 years in women and from 18·7 years to 19·9 years in men. Years spent with dementia will decrease from 4·7 to 3·9 years in women and 2·2 to 1·4 years in men. By contrast, years spent with frailty will increase from 3·7 to 4·0 years for women and 1·9 to 2·1 for men, and across all educational groups. By 2043, approximately 29% of women aged 75 years and older with a less than high school education are estimated to have both dementia and frailty, and so will require complex care. The expected need for health care and formal long-term care is anticipated to reach costs of US$125 billion for dementia and $97 billion for frailty per annum in 2043 for the country. INTERPRETATION: Japan's Government and policy makers should consider the potential social challenges in caring for a sizable population of older people with frailty and dementia, and a widening disparity in the burden of those conditions by sex and by educational status. The future burden of dementia and frailty should be countered not only by curative and preventive technology innovation, but also by social policies to mitigate the health gap. FUNDING: Japan Society for the Promotion of Science, Hitachi - the University of Tokyo Laboratory for a sustainable society, and the National Institute of Ageing.

Future projection of the health and functional status of older people in Japan: A multistate transition microsimulation model with repeated cross-sectional data.

Accurate future projections of population health are imperative to plan for the future healthcare needs of a rapidly aging population. Multistate-transition microsimulation models, such as the U.S. Future Elderly Model, address this need but require high-quality panel data for calibration. We develop an alternative method that relaxes this data requirement, using repeated cross-sectional representative surveys to estimate multistate-transition contingency tables applied to Japan's population. We calculate the birth cohort sex-specific prevalence of comorbidities using five waves of the governmental health surveys. Combining estimated comorbidity prevalence with death record information, we determine the transition probabilities of health statuses. We then construct a virtual Japanese population aged 60 and older as of 2013 and perform a microsimulation to project disease distributions to 2046. Our estimates replicate governmental projections of population pyramids and match the actual prevalence trends of comorbidities and the disease incidence rates reported in epidemiological studies in the past decade. Our future projections of cardiovascular diseases indicate lower prevalence than expected from static models, reflecting recent declining trends in disease incidence and fatality.

Social policies and change in education-related disparities in mortality in Japan, 2000-2010.

Persistent socioeconomic disparity in mortality is a widely observed phenomenon despite improvements in the economic standard of living and the prevailing universal healthcare coverage policy. In this study, we selected Japan as a case in which public universal coverage has maintained horizontal equity in healthcare access while demographic and economic challenges have affected the life chances of vulnerable subpopulations over the past decade. We assessed the changing trends in the education-related disparity in mortality over a decade across demographic subpopulations for different causes of death, with the goal of generating social policy lessons to contribute to closing the mortality gap. Using a deterministic data merge between nationwide census and death records, we estimated age- and sex-specific mortality rates for 14 causes and their education-related gradients with absolute and relative indices of inequality in 2000 and 2010 via Poisson regression. Estimation parameters were standardized to the age structure of the sub-population of high school graduates in 2000 as the reference. The results demonstrated that the relative gaps in all-cause mortality persisted despite a decrease in the average mortality rate over the study period. The absolute gaps in mortality increased for preventable causes of death associated with lifestyle behavior choices. The average mortality worsened among socioeconomically vulnerable populations such as youth and women, who were left behind in the existing social/economic policy. External causes of death such as suicide and traffic accidents showed decreasing absolute gaps in a subpopulation targeted by universal social and labor policy measures. These change patterns indicate that, compared with a high-risk approach, a universal policy approach to dealing with societal and fundamental causes of health inequality seems more effective in reducing the education-related mortality gap in both absolute and relative terms.

Influenza vaccine supply and racial/ethnic disparities in vaccination among the elderly.

BACKGROUND: The impact of vaccine shortages on disparities in influenza vaccination is uncertain. PURPOSE: The objective of this research was to examine the association between influenza vaccine supply and racial/ethnic disparities in vaccination rates among elderly Medicare beneficiaries. METHODS: Cross-sectional multivariable logistic regression analyses were performed in 2010 to examine whether racial/ethnic disparities in vaccination rates changed across two consecutive seasons: from (Period 1) 2000-2001 and 2001-2002 seasons through (Period 4) 2003-2004 and 2004-2005 seasons. Self-reported receipt of influenza vaccine across consecutive years was examined among community-dwelling non-Hispanic African-American (AA); non-Hispanic white (W); English-speaking Hispanic (EH); and Spanish-speaking Hispanic (SH) elderly enrolled in the Medicare Current Beneficiary Survey (unweighted n=2306-2504, weighted n=8.23-8.99 million for Periods 1 through 4). RESULTS: During Periods 1 and 2, when vaccine supply increased nationally, adjusted racial/ethnic disparities in the influenza vaccination rate decreased by 1.8%-7.4% (W-AA disparity); 4.5%-6.6% (W-EH disparity); and 6.6%-11% (W-SH disparity) (all p<0.001). During Period 4, when vaccine supply declined, adjusted disparities in vaccination rates increased by 2.3% (W-AA disparity) and 6.1% (W-EH disparity) but decreased by 6.6% (W-SH disparity) probably due to a "floor effect" (constant low rates among SH; all p<0.001). CONCLUSIONS: Improved vaccine supply was generally associated with reduced racial/ethnic disparities in influenza vaccination rates, whereas worse supply was associated with increased disparities. To avoid future widening of racial health disparities, policy options include stabilizing the vaccine supply and preferential delivery of vaccines to safety-net providers serving AA and Hispanic populations during a shortage.

Association between Medicaid reimbursement and child influenza vaccination rates.

OBJECTIVE: We examined associations between influenza vaccination rates and Medicaid reimbursement rates for vaccine administration among poor children who were eligible for Medicaid (<100% of the federal poverty level in all states). METHODS: We analyzed 3 consecutive National Immunization Surveys (NISs) to assess influenza vaccination rates among nationally representative children 6 to 23 months of age during the 2005-2006 (unweighted N = 12 885), 2006-2007 (unweighted N = 9238), and 2007-2008 (unweighted N = 11 785) influenza seasons (weighted N = 3.3-4.0 million per season). We categorized children into 3 income levels (poor, near-poor, or nonpoor). We performed analyses with full influenza vaccination as the dependent variable and state Medicaid reimbursement rates (continuous covariate ranging from $2 to $17.86 per vaccination) and terms with income levels as key covariates. RESULTS: In total, 21.0%, 21.3%, and 28.9% of all US children and 11.7%, 11.6%, and 18.8% of poor children were fully vaccinated in the 2006, 2007, and 2008 NISs, respectively. Multivariate analyses of all 3 seasons found positive significant (all P < .05) associations between state-level Medicaid reimbursement and influenza vaccination rates among poor children. A $10 increase, from $8 per influenza vaccination (the US average) to $18 (the highest state reimbursement), in the Medicaid reimbursement rate was associated with 6.0-, 9.2-, and 6.4-percentage point increases in full vaccination rates among poor children in the 2006, 2007, and 2008 NIS analyses, respectively. CONCLUSION: Medicaid reimbursement rates are strongly associated with influenza vaccination rates.

Effects of an ongoing epidemic on the annual influenza vaccination rate and vaccination timing among the Medicare elderly: 2000-2005.

OBJECTIVES: We assessed short-term responsiveness of influenza vaccine demand to variation in timing and severity of influenza epidemics since 2000. We tested the hypothesis that weekly influenza epidemic activity is associated with annual and daily influenza vaccine receipt. METHODS: We conducted cross-sectional survival analyses from the 2000-2001 to 2004-2005 influenza seasons among community-dwelling elderly using the Medicare Current Beneficiary Survey (unweighted n = 2280-2822 per season; weighted n = 7.7-9.7 million per season). The outcome variable was daily vaccine receipt. Covariates included the biweekly changes of epidemic and vaccine supply at 9 census-region levels. RESULTS: In all 5 seasons, biweekly epidemic change was positively associated with overall annual vaccination (e.g., 2.7% increase in 2003-2004 season) as well as earlier vaccination timing (P < .01). For example, unvaccinated individuals were 5%-29% more likely to receive vaccination after a 100% biweekly epidemic increase. CONCLUSIONS: Accounting for short-term epidemic responsiveness in predicting demand for influenza vaccination may improve vaccine distribution and the annual vaccination rate, and might assist pandemic preparedness planning.