Understanding the contribution of suicide to life expectancy in South Korea

Abstract

(ProQuest: ... denotes formulae omitted.)1.IntroductionSuicide - intentional death resulting from a victim's own action - is the product of a complex interplay between individuals and society (Durkheim 1952). Since the mid1990s, South Korea (hereafter Korea) has experienced an unprecedented increase in suicide, and currently has the third highest suicide rate in the world, after Guyana (44.2 per 100,000) and North Korea (38.5 per 100,000) (World Health Organization 2014). In 2010, Korea had both the highest suicide rate and the highest rate of increase in suicide among the Organization for Economic Co-operation and Development (OECD) countries (Figure 1). At 33.5 per 100,000, Korea's suicide rate was nearly 2.5 times higher than the average rate for OECD countries (13.3 per 100,000) (World Health Organization Statistical Information System 2014). For Korea, this rate translates into about 40 suicides every day, or about one suicide every 37 minutes. Indeed, the suicide epidemic has become one of the most important and urgent public health concerns in Korea (Kim and Yoon 2013).The alarming rise in Korea's suicide rate has occurred alongside a rapid increase in life expectancy. In 1960, life expectancy in Korea was only 53.0 years, which was well below the OECD average; by 2012 it had risen to 81.4 years, surpassing the OECD average (World Bank Group 2013; Yang et al. 2010) (see Figure 2). This equates to an increase of nearly 28.4 years over the last five decades, or more than one-half year each year, a remarkable gain. With the rapid rise in the suicide rate that began in the mid-1990s, understanding the contribution of suicide to life expectancy has become more critical because it is important for designing effective public policies to promote better population health.The effect of suicide on life expectancy depends on two factors, the proportion of people who commit suicide (that is, the lifetime risk of dying from suicide), and the average age of suicide victims. Hence the effect of change in suicide on change in life expectancy is a function of change in the proportion of people who commit suicide (the suicide rate) and change in the average age of suicide victims compared to their life expectancy. We subsequently describe a method for estimating the separate contributions of change in the suicide rate (the 'incidence component') from change in the average age of suicide victims (the 'age component'). The important point to note here is that change in the suicide rate is not the entire story. Because suicide victims tend to be disproportionately young or middle-aged, the effect of rising suicide rates on life expectancy can be substantially diminished if the age of the suicide victims also rises. Likewise, the effect of falling suicide rates can be diminished if the age of suicide victims declines.To understand the contributions of suicide to life expectancy in Korea, this study examines how much the rise in suicide rate has reduced life expectancy in Korea and why, using the age-incidence decomposition method to separate the age component from the incidence component (Firebaugh et al. 2014). Specifically, this study addresses the following questions. Has the reduction been a) entirely a function of the change in suicide rate (i.e., no age component), or b) a function of change in suicide rates and an age component? If the reduction has been a function of change in suicide rates and an age component, is the age component positive (indicating that the adverse effect of the rising suicide rate has been attenuated), or negative (indicating that the adverse effect of the rising suicide rate has been amplified)?2.Suicide in the Korean contextGiven the unprecedented increase in suicide rates in Korea in the past two decades, its contribution to total mortality is worthy of study. The importance of considering the role of suicide in life expectancy is apparent: Suicide is the leading cause of death for all individuals in their teens, twenties, and thirties. …