Why do Japan and South Korea record very low levels of perceived health despite having very high life expectancies?

Abstract

Japan and Korea follow a unique trend in which, despite reporting two of the highest life expectancies (LEs) among the Organization for Economic Co-operation and Development (OECD) countries, the proportion of people with good self-rated health (SRH) is disproportionately low. We sought to explain this high-LE-low-SRH paradox by examining associations among LE, the prevalence of good SRH, and healthcare utilization. Our hypothesis was that countries with more frequent healthcare use would demonstrate poorer SRH and that SRH would not show a meaningful association with LE among developed countries. This study extracted data from Health at a Glance 2017 by the OECD for 26 countries with valid and comparable information on LE, SRH, and the number of doctor consultations per capita. Correlations among LE, good SRH, and number of doctor consultations per capita were analyzed. The number of annual doctor consultations per capita and the prevalence of good SRH were closely correlated (correlation coefficient=-0.610); excluding outliers produced a higher correlation coefficient (-0.839). Similar patterns were observed when we replaced good SRH with poor SRH. Meanwhile, the correlation coefficient between annual per capita doctor consultations and LE was quite low (-0.216). Although good SRH is closely related to better LE at the individual level, this was not true at the national level. Frequent use of healthcare in Japan and Korea was strongly correlated with poorer SRH, without any meaningful correlation with LE.