Long-Term Effect of Income Level on Mortality after Stroke: A Nationwide Cohort Study in South Korea

Seungmin Jeong,So Yeon Kong,Sung-Il Cho

doi:10.3390/ijerph17228348

Abstract

We investigated whether income level has long-term effects on mortality rate in stroke patients and whether this varies with time after the first stroke event, using the National Health Insurance Service National Sample Cohort data from 2002 to 2015 in South Korea. The study population was new-onset stroke patients ≥18 years of age. Patients were categorized into Category (1) insured employees and Category (2) insured self-employed/Medical Aid beneficiaries. Each category was divided into three and four income level groups, retrospectively. The study population comprised of 11,668 patients. Among the Category 1 patients (n = 7720), the low-income group’s post-stroke mortality was 1.15-fold higher than the high-income group. Among the Category 2 patients (n = 3948), the lower income groups had higher post-stroke mortality than the high-income group (middle-income, aOR (adjusted odds ratio) 1.29; low-income, aOR 1.70; Medical Aid beneficiaries, aOR 2.19). In this category, the lower income groups’ post-stroke mortality risks compared to the high-income group were highest at 13–36 months after the first stroke event(middle-income, aOR 1.52; low-income, aOR 2.31; Medical Aid beneficiaries, aOR 2.53). Medical Aid beneficiaries had a significantly higher post-stroke mortality risk than the high-income group at all time points.

Highlights

Stroke is the second leading cause of death and a major cause of disability worldwide, which is the third-largest factor influencing disability-adjusted life years (DALYs) [1]
In the insured employee category, the proportion of male patients increased from high-income (50.0%) to low-income group (56.0%), while the proportion of male patients decreased from high-income (54.9%)
In the insured self-employed/Medical Aid beneficiary category, while a lower income was linked to a higher risk of mortality, this association was varied with both income level and time since the first stroke event

Summary

Introduction

Stroke is the second leading cause of death and a major cause of disability worldwide, which is the third-largest factor influencing disability-adjusted life years (DALYs) [1]. Despite significant advances in the treatment and prevention of stroke, there still remain striking disparities. It has long been recognized that significant socioeconomic disparities exist in stroke risk [2,3,4,5]. Many stroke patients suffer from reoccurrence, sequelae, and complications after the stroke [6,7]. Patients with a chronic condition like stroke often require long-term treatment and management for optimal outcomes and recovery, which may be prolonged with financial consequences.

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Results

Discussion

Conclusion