J Korean Med Sci.  2017 Sep;32(9):1401-1414. 10.3346/jkms.2017.32.9.1401.

Trends of Social Inequalities in the Specific Causes of Infant Mortality in a Nationwide Birth Cohort in Korea, 1995–2009

• Son M
• An SJ
• Kim YJ

• KMID: 2385945
• DOI: http://doi.org/10.3346/jkms.2017.32.9.1401

Abstract

The relationship between social disparity and specific causes of infant mortality has rarely been studied. The present study analyzed infant mortality trends according to the causes of death and the inequalities in specific causes of infant mortality between different parental social classes. We analyzed 8,209,836 births from the Statistics Korea between 1995 and 2009. The trends of disparity for cause-specific infant mortality according to parental education and employment were examined using the Cox proportional hazard model for the birth-year intervals of 1995-1999, 2000-2004, and 2005-2009. Adjusted hazard ratios were calculated after adjusting for infants' gender, parents' age, maternal obstetrical history, gestational age, and birth weight. An increasing trend in social inequalities in all-cause infant mortality according to paternal education was evident. Social inequalities in infant mortality were greater for "Not classified symptoms, signs and findings" (International Classification of Diseases 10th revision [ICD-10]: R00-R99) and "Injury, poisoning and of external causes" (S00-T98), particularly for "Ill-defined and unspecified causes" (R990) and "Sudden infant death syndrome (SIDS)" (R950); and increased overtime for "Not classified symptoms, signs and findings" (R00-R99), "Injury, poisoning and of external causes" (S00-T98) and "Conditions in perinatal period" (P00-P96), particularly for "SIDS" (R950) and "Respiratory distress syndrome of newborns (RDS)" (P220). The specific causes of infant mortality, in particular the "Not classified causes" (R00-R99 coded deaths) should be investigated more thoroughly to reduce inequality in health.

Keyword

Trends of Social Inequalities; Cause-specific Infant Mortality; Maternal Education; Paternal Education; Maternal Employment; Paternal Employment

MeSH Terms

Birth Weight
Cause of Death
Classification
Cohort Studies*
Education
Employment
Gestational Age
Humans
Infant
Infant Death
Infant Mortality*
Infant*
Infant, Newborn
Korea*
Maternal Age
Parents
Parturition*
Poisoning
Proportional Hazards Models
Social Class
Socioeconomic Factors*

Figure

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  Fig. 1 Percentage of cause-specific infant death in the time trend of 1995–1999, 2000–2004, and 2005–2009.

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  Fig. 2 Difference in infant mortality of cause-specific death according to parental education in the time trend of 1995–1999, 2000–2004, and 2005–2009.

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  Fig. 3 Difference in infant mortality of cause-specific death according to parental employment in the time trend of 1995–1999, 2000–2004, and 2005–2009.

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  Fig. 4 Difference in infant mortality of detail cause-specific death according to parental education in the time trend of 1995–1999, 2000–2004, and 2005–2009.

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  Fig. 5 Difference in infant mortality of detail cause-specific death according to parental employment in the time trend of 1995–1999, 2000–2004, and 2005–2009.

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