Contribution of different causes of death to socioeconomic mortality inequality in Korean children aged 1-9: findings from a national mortality follow-up study.

OBJECTIVES: To determine the contribution of different causes of death to absolute socioeconomic inequalities in mortality for the whole population of children of South Korea aged 1-4 years and 5-9 years. METHODS: A cohort study based on the national birth and death registers of Korea was performed for 3,724,347 children born in 1995-2000 and 657,209 children born in 1995 to analyse mortality among children aged 1-4 and 5-9 years old, respectively. Adjusted mortality, risk difference (RD), slope index of inequality (SII), RR and relative index of inequality were calculated. The contributions of different causes of death to absolute mortality inequalities were calculated as percentages based on RD and SII. RESULTS: Injuries other than from transport accidents contributed the most to total SIIs for male deaths at ages 1-4 (30.0% for father's education). The second largest contribution was from transport accident injuries (19.6% for father's education). For male deaths at ages 5-9, transport accident injuries and other injuries also accounted for most of the educational and occupational differentials in absolute mortality (63.5-90.5%). Patterns in cause-specific contribution to total inequalities in mortality among girls were generally similar to those among boys. CONCLUSIONS: The major contributing causes to absolute socioeconomic inequality in all-cause mortality for children aged 1-9 were external. To reduce the absolute magnitude of socioeconomic inequalities in childhood mortality, policy efforts should be directed towards injury prevention and treatment in South Korea.

Socioeconomic differentials in cause-specific mortality among 1.4 million South Korean public servants and their dependents.

BACKGROUND: A growing number of investigations have explored the contribution of cause of death to socioeconomic inequalities in mortality in Europe and North America, but few such studies have been performed on Asian populations. OBJECTIVES: To analyse the socioeconomic inequality of cause-specific death rates from both an absolute and relative perspective, and to evaluate the contribution of cause of death to total mortality inequality in South Korea. METHODS: Data were obtained from public servant health insurance beneficiary records. 1,403,297 subjects aged 35-64 years were followed for 9 years. Health insurance premium levels were used as a socioeconomic position indicator. The outcome variables were all-cause, 11 broad causes and 41 specific causes of death. Mortality differentials were examined using cause-specific age-adjusted mortality, relative indices of inequality, and slope inequality indices. RESULTS: Graded inverse associations between income and mortality were found for most, but not all, specific causes of death. The major contributors to income differentials in total mortality in men were liver disease (15.4%), stroke (12.8%), land transport accidents (10.0%), lung cancer (7.1%) and liver cancer (7.0%). In women, stroke (30.7%), diabetes (9.1%), land transport accidents (6.6%), liver cancer (6.0%) and liver disease (5.1%) were important. Conclusions The contribution of the cause of death to socioeconomic inequality in mortality in South Korea differed from Western countries. To develop a policy to reduce the magnitude of socioeconomic inequality, an understanding of the major causes of death that contribute to mortality inequality is required.

Explaining age-specific inequalities in mortality from all causes, cardiovascular disease and ischaemic heart disease among South Korean male public servants: relative and absolute perspectives.

OBJECTIVE: To examine age-specific patterns in the ability of major cardiovascular risk factors to explain relative and absolute socioeconomic inequalities in mortality from all causes, cardiovascular disease (CVD), and ischaemic heart disease (IHD). DESIGN: Prospective cohort study. SETTING: South Korea. SUBJECTS: 575 377 male public servants aged 30-64 with 16 998 deaths between 1995 and 2003. MAIN OUTCOMES: All-cause, CVD, and IHD mortality. RESULTS: Four cardiovascular risk factors (cigarette smoking, blood pressure, fasting serum glucose, and serum total cholesterol) were significantly associated with mortality risk. Changing relationships in socioeconomic distribution of risk factors with age were observed. The magnitude of reduction in percent change in absolute risk was greater than that in relative risk. While the risk factors explained only 15.2% of excess RR for all-cause mortality in low-income men aged 30-44, the absolute excess risk of all-cause mortality was reduced by 48.3% when the risk factors were removed from the whole population. This pattern was generally true for all causes, CVD, and IHD, and true for all age groups and risk factors examined. Cigarette smoking and hypertension were the leading contributors in explaining relative and absolute inequality in mortality. CONCLUSION: Policy efforts to eliminate major cardiovascular risk factors in the general population may have a significant effect on reducing the absolute burden of socioeconomic inequality in mortality. Policy efforts to attenuate socioeconomic inequality in cardiovascular risk factors need to be directed to younger age groups in South Korea.