In addition to unhealthy behaviors, such as smoking, poor diet, or lack of exercise, recent evidence suggests that socioeconomic status is a key underlying factor that influences health. Various studies consistently found that low socioeconomic status is associated with ill health [1
]. Socioeconomic status assessed by income, education, or occupation is associated with various health problems, such as depression [1
], hypertension, and functional status [3
]. Mortality rates are also higher among individuals of low socioeconomic status [4
]. To tackle such health disparities across different socioeconomic strata, the World Health Organization (WHO) recently published a report entitled “Closing the gap in a generation: health equity through action on the social determinants of health, Final Report of the Commission on Social Determinants of Health” [5
]. The report clearly states that such inequalities in health arise out of the environment in which we live; grow up, work, and age. In addition, countries at all levels of income, health and illness follow a social gradient: the lower the socioeconomic position, the worse the health of the population is.
Although socioeconomic status is clearly associated to morbidity and mortality, structural links for such associations are less comprehensible. One such link might be knowledge. For example, education provides knowledge and life skills necessary to gain access to information and resources that promote health. This is partly explained by the fact that unhealthy lifestyles are more prevalent among people of low socioeconomic status [6
]. Education also provides more opportunities for higher income that may provide better living conditions, such as nutrition, housing, and schooling. Employment status is another important factor in determining health. Unemployed individuals have worse health than their employed counterparts. Less educated people are more likely to be unemployed. Higher socioeconomic status brings us necessary resources to cope with ill health [4
]. Although the association between income and health is stronger in lower income brackets, such associations are observed among richer populations as well. This is supported by a comparative study of 11 European nations which observed health disparity across socioeconomic status groups even in relatively egalitarian societies, such as Sweden or Norway [8
]. Furthermore, redistributive policies play an important role in reducing health disparity. A study by Navarro et al.
analyzed data over a 50-year period in OECD nations and found that redistributive policies have a salutary effect on infant mortality or life expectancy at birth [9
In addition to income, education, and occupation, access to health care is a vital determinant of health regardless of the nation’s income level [5
]. Yet, the access to care problem has not been fully examined in richer nations. Among studies conducted in such nations, Shi and Stevens affirmed that lower socioeconomic status individuals have poorer access to health care by using the national representative sample in the US [10
]. Access to care generally encompasses two dimensions. One is physical access, such as the distance to health care facilities or transportation. Another is financial access, such as cost of care or medication. Various studies demonstrated that when co-insurance increased, those with lower income tended to stop going to doctors. Reimbursement under co-insurance system is based on percent basis. This is different from a co-payment, which is a fixed cash amount paid to the beneficiary per procedure or per day in the hospital [11
]. Although such systems may offer financial protection, how such a system is framed may influence population health. A study in Japan demonstrated that when co-insurance increased from 20% to 30%, a significant decrease in physician visits was observed among diabetic patients with no complications [12
]. A comparative study on three European nations (i.e.
, France, Germany, and Spain) detailed that an increase in patient cost sharing reduced the frequency of physician visits, especially among people in lower social classes [13
]. Similar results are reported in other nations, such as South Korea or Taiwan [14
]. These studies also underscored that while increases in patient cost sharing reduced visits to physicians, hospital admissions increased especially among lower income people, suggesting that an increase in out of pocket expenditures might have a negative effect on health through lost opportunities for timely care.
Brief description of Japanese National Health Insurance System
Japan has maintained a nationwide social health insurance system built on the German social health insurance model for more than 30 years. This system covers almost the entire population and is financed by premiums paid by insured persons, employers, and government compensation. The relatively low-cost, universal health insurance system is recognized as a major achievement. Japanese citizens receive services from any physician or hospital, with no difference in cost, and physicians are, in principle, free to treat or prescribe as they see fit. Under this system Japan’s low infant mortality rate and high life expectancy at birth are among the best in the world [16
]. However, pressures are mounting for health care reform to restrain future medical costs in the face of an increasing aging population. In Japan, the National Health Insurance System reimburses on a percentage basis, and the patient pays co-insurance. As the system currently pays 70% of the medical charges, patients (except for children and the elderly) pay the remaining 30%.
Recently, however, there is an issue which requires attention. As of April, 2008, a new health insurance system was launched for the elderly 75 years and older. With the establishment of this system, the government intended to separate the elderly who need more medical attention and use a higher portion of health care resources compared to younger generations. The government intends to restrain an increase in medical costs among the elderly. This system might pose barriers to necessary care, especially among low income individuals.
In this paper, we discuss the associations between socioeconomic status and access to care by investigating possible barriers to health care, examining the scope of health disparities across different socioeconomic groups, and exploring factors which contribute to their associations among the elderly in Japan.