mortality has steadily declined in korea since the mid-1950s ( 1 ) . despite the favorable trend in the overall mortality , however , understanding cause - specific death rates and their temporal trends would shed some light on the areas for improvement in developing health care and disease prevention programs . the 10 leading causes of death in korea accounted for 70.5% of total deaths in 2012 and were malignant neoplasms , heart diseases , cerebrovascular diseases , intentional self - harm , diabetes mellitus , pneumonia , chronic lower respiratory diseases , diseases of the liver , transport accidents , and hypertensive diseases ( 2 ) . the purpose of this study is to analyze trends in the 10 leading causes of death in korea from 1983 to 2012 using a joinpoint regression analysis ( 3 , 4 , 5 ) . death rates in korea from 1983 to 2012 were derived from the korean statistics information service ( kosis ) database ( 6 ) . the causes of death in kosis data were classified according to the international classification of diseases , tenth revision , clinical modification ( icd-10-cm ) codes . the icd-10 codes used for the 10 leading causes of death based on 2012 mortality were c00-c97 for malignant neoplasms , e10-e14 for diabetes mellitus , i00-i13 for hypertensive diseases , i20-i51 for heart diseases , i60-i69 for cerebrovascular diseases , j12-j18 for pneumonia , j40-j47 for chronic lower respiratory diseases , k70-k76 for diseases of the liver , v01-v99 for transport accidents , and x60-x84 for intentional self - harm . the age - standardized death rates ( asr ) for all causes and the 10 leading causes of death were calculated to account for the aging of the population using the 2010 korean standard population ( 7 ) . to pursue the objective of this study , we adopted joinpoint regression analysis . the joinpoint regression model was developed to identify the occurrence of changes in trends in distinct periods of time rather than a single summary statistic for the whole interval . joinpoint regression analysis detects when a significant change in trend occurs and thus provides a much clear picture of what is happening during a given period ( 8) . therefore , we used joinpoint regression analysis to estimate the number of the " joinpoints " where mortality trend changes its slope statistically significantly and to identify the years when the significant changes occurred . joinpoint regression selects the optimal model using three different methods : the sequence of permutation tests , bayesian information criterion ( bic ) , and modified bic which was proposed to improve the performance of the traditional bic method . as a result , the finally selected model is the most parsimonious model that best fits data ( 8) . the number of joinpoints started from 0 and was increased to test if the addition of joinpoints improved the fitness of model significantly . the best - fitting model was estimated separately for men and women . the annual percent rate change ( apc ) was calculated for each segment of the best - fitting model using generalized linear models that assumed the poisson distribution . the apc was tested to determine whether it was significantly different from the null hypothesis of no change ( 0% ) . the statistical power to determine if an apc is different from 0 is a function of the length of the interval , potentially rendering a short segment rising at a steep rate statistically insignificant . significance tests were performed using a monte carlo permutation technique ( two - sided p<0.05 ) . the joinpoint regression program version 4.1.4 ( us national cancer institute , bethesda , md , usa ) was used for the statistical analysis . approval from the institutional review board was not required for this study as it analyzed the anonymised data made publicly available . death rates in korea from 1983 to 2012 were derived from the korean statistics information service ( kosis ) database ( 6 ) . the causes of death in kosis data were classified according to the international classification of diseases , tenth revision , clinical modification ( icd-10-cm ) codes . the icd-10 codes used for the 10 leading causes of death based on 2012 mortality were c00-c97 for malignant neoplasms , e10-e14 for diabetes mellitus , i00-i13 for hypertensive diseases , i20-i51 for heart diseases , i60-i69 for cerebrovascular diseases , j12-j18 for pneumonia , j40-j47 for chronic lower respiratory diseases , k70-k76 for diseases of the liver , v01-v99 for transport accidents , and x60-x84 for intentional self - harm . the age - standardized death rates ( asr ) for all causes and the 10 leading causes of death were calculated to account for the aging of the population using the 2010 korean standard population ( 7 ) . the joinpoint regression model was developed to identify the occurrence of changes in trends in distinct periods of time rather than a single summary statistic for the whole interval . joinpoint regression analysis detects when a significant change in trend occurs and thus provides a much clear picture of what is happening during a given period ( 8) . therefore , we used joinpoint regression analysis to estimate the number of the " joinpoints " where mortality trend changes its slope statistically significantly and to identify the years when the significant changes occurred . joinpoint regression selects the optimal model using three different methods : the sequence of permutation tests , bayesian information criterion ( bic ) , and modified bic which was proposed to improve the performance of the traditional bic method . as a result , the finally selected model is the most parsimonious model that best fits data ( 8) . the number of joinpoints started from 0 and was increased to test if the addition of joinpoints improved the fitness of model significantly . the best - fitting model was estimated separately for men and women . the annual percent rate change ( apc ) was calculated for each segment of the best - fitting model using generalized linear models that assumed the poisson distribution . the apc was tested to determine whether it was significantly different from the null hypothesis of no change ( 0% ) . the statistical power to determine if an apc is different from 0 is a function of the length of the interval , potentially rendering a short segment rising at a steep rate statistically insignificant . significance tests were performed using a monte carlo permutation technique ( two - sided p<0.05 ) . the joinpoint regression program version 4.1.4 ( us national cancer institute , bethesda , md , usa ) was used for the statistical analysis . approval from the institutional review board was not required for this study as it analyzed the anonymised data made publicly available . table 1 summarizes the trends in overall and cause - specific death rates for the 10 leading causes of death of korean men and women from 1983 to 2012 . asr from all causes combined was 638.8 deaths per 100,000 men and 587.5 per 100,000 women in 2012 , representing decreases of 61.6% and 51.2% , respectively , over the 30-yr study period . asr from all causes combined has steadily and significantly declined in both genders except for the period of 1998 - 2001 . temporal trends in asr for the 10 leading causes of death varied by cause of death and by gender ( tables 2 , 3 , and fig . 1 ) . asrs from malignant neoplasms in both genders increased until 1994 and thereafter declined except for the period of 1998 - 2002 . asrs from diabetes mellitus increased up to 2003 and 2002 for men and women , respectively , but thereafter declined at a significant rate until they leveled off in 2009 . overall , asrs from diabetes mellitus increased by 91.8% for men and 176.0% for women over the entire study period . asrs from hypertensive diseases , heart diseases , and cerebrovascular diseases decreased by 94.4% , 53.8% and 76.0% for men and by 77.1% , 36.5% , and 67.8% for women , respectively . asrs from cerebrovascular diseases declined from 1983 to 1990 and after an increase from 1991 to 1994 , continued to decrease . cerebrovascular diseases , which were the first leading cause of death for women and the second one for men in 1983 , ranked as the third leading cause of death in both genders in 2012 following malignant neoplasms and heart diseases . asrs from diseases of the liver declined significantly and consistently except for the early 1990s , leading to an overall 78.9% and 79.9% decrease in men and women , respectively . asrs from pneumonia declined until 1995 for men and 1993 for women only to increase again , leading to overall increases of 16.9% and 44.2% for men and women , respectively . apart from diabetes mellitus , chronic lower respiratory diseases had the greatest number of joinpoints identified for both men and women ( n=5 ) . asrs from transport accidents increased significantly at an apc of 15.0% for men and 16.6% for women between 1983 and 1990 , but they started to decline significantly in the mid-1990s . the apc in asrs from intentional self - harm was 12.1% for men in the period of 1991 - 1998 and 7.7% for women in the period of 1989 - 2009 , contributing to a 122.2% and 217.4% increase , respectively , over the entire study period . over the last three decades , crude death rates from all causes in korea declined . the favorable trends in mortality from all causes became more pronounced when asrs were examined and were shown to be consistent as evidenced by the number of joinpoints identified ( n=2 ) . the consistently favorable trends in the overall death rate may be attributable to a number of factors including advances in diagnostic and medical technologies , improved access to care due to expansion of health insurance coverage , and the rapidly progressed economy that the country witnessed during the study period . by contrast , the increasing , albeit insignificant , trend in the overall death rate in 1998 - 2001 may have been caused by the 1997 asian financial crisis that hit korea hard . the generally consistent , favorable trends observed in the overall death rate were not replicated in some cause - specific death rates . malignant neoplasms were the first leading cause by a narrow margin ( 1% ) for men and the second leading cause of death for women in 1983 . asrs from malignant neoplasms increased to a peak in 1994 and thereafter declined except for a brief ascent from 1998 to 2002 . together , asrs from malignant neoplasms declined by 9.1% for men whereas it remained virtually unchanged for women since 1983 . despite the significantly downward trend since 2002 , however , malignant neoplasms was the first leading cause of death by a wide margin in 2012 , due in large part to the remarkable progresses made for other major causes of death such as cerebrovascular diseases . nevertheless , the downward trend in death rates from malignant neoplasms in the last decade is encouraging , given the significant increase in malignant neoplasms incidence in korea for the corresponding period ( 9 ) . decrease of cancer mortality along with increase of cancer incidence in japan ( 3 ) and italy ( 8) in the 1990s was mostly attributed to a number of factors including early detection and treatment , and various public health strategies . the recent decline in cancer mortality in korea may be explained by decreases in stomach , liver and uterine cancer mortality , due at least in part to the nationwide cancer screening program introduced in 1999 and subsequently expanded ( 10 ) . asrs from diabetes mellitus increased since the mid-1980s up to the early 2000s , showing a similar pattern to mortality in the united states ( 5 , 11 ) . despite the brief decline in 2002 - 2003 , asrs from diabetes mellitus more than doubled between 1983 and 2012 . consequently , diabetes mellitus was the second highest increasing cause of death among all causes of death examined in this study , surpassed only by intentional self - harm . the steep rise in diabetes mortality may be due to the reported six- to seven- fold increase in the prevalence of diabetes in korea over the last four decades ( 12 ) . asrs from hypertensive diseases , heart diseases and cerebrovascular diseases decreased significantly during the study period . especially , asrs from heart diseases in korea had been steadily decreasing until recently , except for a spike in women in the mid-1990s . similarly , a steady and marked decline in death rates from heart diseases was also observed in the united states since 1970 ( 5 , 13 ) , in tandem with continuously improved control of hypertension , a major risk factor for cardiovascular disease ( 14 ) , and due in part to the use of effective medical and surgical treatments ( 13 ) . markedly declining death rates from coronary heart diseases since the 1970s were also observed in latin america and europe ( 14 , 15 , 16 ) . death rates from cerebrovascular diseases have also decreased consistently and markedly in many countries around the world since the 1960s ( 14 , 16 , 17 ) , which was attributed to a decrease in the intake of dietary salt and saturated fat ( 17 ) . the most consistently downward trend of death rate was observed in diseases of the liver , resulting in the greatest reduction in mortality among the leading causes of death examined . the favorable trend in mortality from liver diseases in korea may be ascribed to the declining prevalence of hepatitis b surface antigen ( hbsag ) from the 1980s due in no small part to increased hepatitis b vaccination rates ( 18 ) . mortality from cirrhosis has shown favorable trends around the world since 1980 , due in part to reductions in alcohol consumption and hepatitis b and c virus infections ( 19 , 20 ) . in the united states , however , the favorable trends in death rates from hepatitis b and c virus infections did not continue in the 1990s , although death rates from alcohol - related chronic liver disease declined ( 21 , 22 , 23 ) . a follow - up analysis of closely investigating the trends in mortality from diseases of the liver by specific cause is needed . while infectious disease mortality , especially for pneumonia and influenza , was known to fluctuate from year to year , pneumonia remained among the leading causes of illness and death even in the industrialized countries ( 24 , 25 ) . in our analysis , death rates from pneumonia decreased until the mid-1990s and thereafter increased , resulting in overall increases of 16.9% and 44.2% for men and women , respectively . older people have higher risk of death from infectious diseases including pneumonia than younger people do ( 25 ) . the resurgence of pneumonia in korea appears to be attributable to the fact that korea has the rapidest aging population in the world ( 27 ) , which distinguishes the country from other countries where asrs of pneumonia declined in recent decades ( 28 ) . the finding warrants reinforcement of pneumonia surveillance and control programs in korea , which could include increasing pneumococcal and influenza vaccination rates as well as a more judicious use of antibiotics ( 28 ) . asrs from chronic lower respiratory diseases declined by around 50% from 1983 to 2012 despite the periodic fluctuations . in the united states , mortality from the diseases has decreased over the last decade although they remained the third leading cause of death in 2010 ( 29 ) . moreover , the worldwide death rates from chronic respiratory diseases were projected to decline up to 2020 ( 30 ) . chronic lower respiratory diseases are a set of various diseases affecting the lower respiratory tract including asthma , chronic bronchitis , and chronic obstructive pulmonary disease ( copd ) , suggesting that further research is needed to illuminate the trend . for example , the increasing death rates from copd in the earlier decades appeared to have stabilized in the 2000s in the united states ( 5 ) . death rates from copd also tended to decline around the world but not in korea ( 31 , 32 ) . asrs from transport accidents in korea grew at an accelerated pace until the late 1980s and continued to grow , albeit at a slower rate , in the mid-1990s when the rates started to decline . the relationship between economy and transport mortality was reported to be non - linear such that economic development initially would contribute to an increasing number of motor vehicles resulting in more traffic accidents , but further investment in transport infrastructure would decrease deaths from transport accidents ( 33 ) . perhaps , the most alarming mortality trend was observed for intentional self - harm . in fact , the overall percentage increase in the death rates from intentional self - harm for 30 yr was the highest among all the leading causes of death examined . consequently , suicide mortality now surpasses the death rates from diabetes , pneumonia and liver disease , highlighting urgency with which increasing suicide mortality should be addressed . suicide rates were reported to increase in times of economic crisis in respective countries ( 26 , 34 ) . the impact of changes in economy , employment and other socioeconomic factors on suicide rates may have been greater among men in recent decades ( 35 ) . the 2008 global economic crisis increased suicide rates disproportionately more among men in many countries ( 36 ) . in the present study , however , from the asr % change for intentional self - harm over 30 yr was shown to be higher for women while their asrs stayed consistently lower throughout the period , compared with men . the finding might be a sign that women who had the comparatively low suicide mortality three decades earlier were catching up with men . similarly , there were substantial differences between genders in death rates from malignant neoplasms , diseases of the liver , and transport accidents , but the disparities tended to narrow in recent years . in other countries , diverging temporal trends between genders were reported for stroke and copd mortality ( 37 , 38 ) . to our knowledge , this study is the first to statistically test the long - term trends in the leading causes of death in korea . nonetheless , the findings of this study should be interpreted with caution in light of the following limitations . first , the data source used in this study may be subject to potential misclassification of causes of death in official death certificates . a previous study noted that the registered causes of death in korea may be inaccurate : agreement rates between death certificates and medical charts were 80.4% in malignant neoplasms and 76.6% in circulatory diseases in a regional district in 1998 ( 39 ) . second , the accuracy of causes of death on death certificates may have evolved over time due to advances in diagnostic techniques , potentially rendering some mortality data incomparable between different time periods . third , the icd-9 coding scheme in kosis data was replaced with the icd-10 in 1995 , which may have influenced the trends . previously , it was suggested that changes in temporal pattern of mortality might reflect changes in documentation and diagnostic coding rather than real improvement in survival ( 40 ) . in conclusion , death rates from all causes in korea decreased significantly in both genders in the last three decades except for a period following the economic crisis in the late 1990s . despite the great strides made in the overall mortality , temporal trends in cause - specific mortality varied widely by cause . whereas hypertensive diseases , heart diseases , cerebrovascular diseases and diseases of the liver showed favorable trends , malignant neoplasms , diabetes mellitus , pneumonia and intentional self - harm showed unfavorable trends . the persistently high and increasing causes of death should be addressed with the highest priority , and disease surveillance and control systems targeting the diseases should be implemented .
this study aimed to analyze trends in the 10 leading causes of death in korea from 1983 to 2012 . 
 death rates were derived from the korean statistics information service database and age - adjusted to the 2010 population . 
 joinpoint regression analysis was used to identify the points when statistically significant changes occurred in the trends . between 1983 and 2012 , the age - standardized death rate ( asr ) from all causes decreased by 61.6% for men and 51.2% for women . 
 asrs from malignant neoplasms , diabetes mellitus , and transport accidents increased initially before decreasing . 
 asrs from hypertensive diseases , heart diseases , cerebrovascular diseases and diseases of the liver showed favorable trends ( asr % change : -94.4% , -53.8% , -76.0% , and -78.9% for men , and -77.1% , -36.5% , -67.8% , and -79.9% for women , respectively ) . 
 asrs from pneumonia decreased until the mid-1990s and thereafter increased . 
 asrs from intentional self - harm increased persistently since around 1990 ( asr % change : 122.0% for men and 217.4% for women ) . in conclusion , 
 death rates from all causes in korea decreased significantly in the last three decades except in the late 1990s . despite the great strides made in the overall mortality , temporal trends varied widely by cause . 
 mortality trends for malignant neoplasms , diabetes mellitus , pneumonia and intentional self - harm were unfavorable.graphical abstract