Citation

Khang YH, Yang S, Cho HJ, Jung-Choi K, Yun SC. Int. J. Epidemiol. 2010; 39(6): 1656-1666.

Affiliation

Department of Preventive Medicine, University of Ulsan College of Medicine, Seoul, Korea, Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, Quebec, Canada, Department of Family Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea, Department of Preventive Medicine, Ewha Womans University School of Medicine, Seoul, Korea and Department of Clinical Epidemiology and Biostatistics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Copyright

(Copyright © 2010, International Epidemiological Association, Publisher Oxford University Press)

DOI

10.1093/ije/dyq117

PMID

20647268

Abstract

BACKGROUND: Differences in life expectancy at birth across social classes can be more easily interpreted as a measure of absolute inequalities in survival. This study quantified age- and cause-specific contributions to life expectancy differences by income among 4 million public servants and their dependents in South Korea (9.1% of the total Korean population). METHODS: Using 9-year mortality follow-up data (208 612 deaths) on 4 055 150 men and women aged 0-94 years, with national health insurance premiums imposed proportionally based on monthly salary as a measure of income, differences in life expectancy at birth by income were estimated by age- and cause-specific mortality differences using Arriaga's decomposition method. RESULTS: Life expectancy at birth gradually increased with income. Differences in life expectancy at birth between the highest and the lowest income quartile were 6.22 years in men and 1.74 years in women. Mortality differentials by income among those aged >/=50 years contributed most substantially (80.4% in men and 85.6% in women) to the socio-economic differences in life expectancy at birth. In men, cancers (stomach, liver and lung), cardiovascular diseases (stroke), digestive diseases (liver cirrhosis) and external causes (transport accidents and suicide) were important contributors to the life expectancy differences. In women, the contribution of ill-defined causes was most important. Cardiovascular diseases (stroke and hypertensive disease) and external causes (transport accidents and suicide) also contributed to the life expectancy differences in women while the contributions of cancers and digestive diseases were minimal. CONCLUSIONS: Reductions in socio-economic differentials in mortality from stroke and external causes (transport accidents and suicide) among middle-aged and older men and women would significantly contribute to equalizing life expectancy among income groups. Policy efforts to reduce mortality differentials in major cancers (stomach, liver and lung) and liver cirrhosis are also important for eliminating Korean men's socio-economic inequalities in life expectancy.

Language: en