Trends in pesticide suicide in South Korea, 1983–2014

AIMS: Self-poisoning using pesticides is among the major methods of suicide worldwide, and accounts for one-fifth of suicides in 2006-2010 in South Korea. We investigated long-term trends in pesticide suicide rates in South Korea and factors related to these trends. METHODS: We calculated age-standardised rates of pesticide suicide in South Korea (1983-2014) using registered death data. We used graphical approach and joinpoint regression analysis to examine secular trends in pesticide suicide by sex, age and area, and a time-series analysis to investigate association of pesticide suicide rate with socioeconomic and agriculture-related factors. Age, period and cohort effects were examined using the intrinsic estimator method. RESULTS: Age-standardised rate of pesticide suicide fluctuated between 1983 and 2000 before it markedly increased in 2000-2003 (annual percent change 29.7%), followed by a gradual fall (annual percent change -6.3%) in 2003-2011. Following the paraquat ban (2011-2012), there was a marked reduction (annual percent change -28.2%) in 2011-2014. Trend in pesticide suicide was associated with divorce rate but not with other factors studied. Declines in pesticide suicide in 2003-2011 were most noticeable in younger groups and metropolises; by contrast, elderly adults aged 70+ living in rural areas showed an upward trend until after the 2011-2012 paraquat ban, when it turned downward. In the age-period-cohort modelling, having been born between 1938 and 1947 was associated with higher pesticide suicide rates. CONCLUSIONS: Pesticide suicide trend changed substantially in South Korea over the last three decades. Effective prevention should include close monitoring of trends and strong regulations of toxic pesticides.