J Korean Med Sci.  2023 Jan;38(4):e38. 10.3346/jkms.2023.38.e38.

Area-Level Socioeconomic Inequalities in Intracranial Injury-Related Hospitalization in Korea: A Retrospective Analysis of Data From Korea National Hospital Discharge Survey 2008–2015

• Park HA
• Vaca FE
• Jung-Choi K
• Park H
• Park JO

• KMID: 2539193
• DOI: http://doi.org/10.3346/jkms.2023.38.e38

Abstract

Background
Although inequality in traumatic brain injury (TBI) by individual socioeconomic status (SES) exists, interventions to modify individual SES are difficult. However, as interventions for area-based SES can affect the individual SES, monitoring or public health intervention can be planned. We analyzed the effect of area-based SES on hospitalization for TBI and revealed yearly inequality trends to provide a basis for health intervention.
Methods
We included patients who were hospitalized due to intracranial injuries (ICIs) between 2008 and 2015 as a measure of severe TBI with data provided by the Korea National Hospital Discharge Survey. Area-based SES was synthesized using the 2010 census data. We assessed inequalities in ICI-related hospitalization rates using the relative index of inequality and the slope index of inequality for the periods 2008–2009, 2010–2011, 2012–2013, and 2014–2015. We analyzed the trends of these indices for the observation period by age and sex.
Results
The overall relative indices of inequality for each 2-year period were 1.82 (95% confidence interval, 1.5–2.3), 1.97 (1.6–2.5), 2.01 (1.6–2.5), and 2.01 (1.6–2.5), respectively. The overall slope indices of inequality in each period were 38.74 (23.5–54.0), 36.75 (21.7–51.8), 35.65 (20.7–50.6), and 43.11 (27.6–58.6), respectively. The relative indices of inequality showed a linear trend for men (P = 0.006), which was most evident in the ≥ 65-year age group.
Conclusion
Inequality in hospitalization for ICIs by area-based SES tended to increase during the observation period. Practical preventive interventions and input in healthcare resources for populations with low area-based SES are likely needed.

Keyword

Health Inequality; Intracranial Injury; Socioeconomic Status; Area-Level SES; Hospitalization Rate; Traumatic Brain Injury

Figure

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  Fig. 1 Study flow.KNHDS = Korea National Hospital Discharge Survey.

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  Fig. 2 Age-standardized hospitalization rates due to intracranial injury according to area-level deprivation. Rates are shown in sex and study periods.ICI = intracranial injury, Q1 = least deprived group, Q5 = most deprived group.

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  Fig. 3 Time trends in the indices of inequality in intracranial injury-related hospitalization. Estimates are displayed by age group. SII indicates the absolute difference in rate per 100,000 populations. Arrows indicate a significant linear trend.RII = relative index of inequality, SII = slope index of inequality, CI = confidence interval.

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