Abstract
Background
Health insurance plays a critical role in healthcare accessibility and outcomes, particularly for patients with end-stage kidney disease (ESKD). This retrospective observational study evaluated the relationships between health insurance status and rates of hospitalization and in-hospital mortality among patients with ESKD visiting the emergency department (ED).
Methods
We retrospectively analyzed data from the National Emergency Department Information System in South Korea from January 2018 to December 2021. Patients were identified on the basis of their ICD-10 codes (N18.5) and categorized by health insurance type (Medical Aid [MA] recipients vs. National Health Insurance [NHI] beneficiaries). The primary outcomes were rates of hospitalization and in-hospital mortality from ED admission. Multivariate logistic regression models were used to assess the associations between insurance type and outcomes.
Results
Among the 157,794 ED visits, 23.5% were by MA recipients and 76.5% by NHI beneficiaries. The participants in the MA group were younger than those in the NHI group, and the proportions of females and those with severe disease were lower in the MA group. After adjusting for age, sex, and the Korean Triage and Acuity Scale score, the MA group had a lower hospitalization risk but a risk of death similar to that of the NHI group. Patients <60 years of age had a lower hospitalization rate but a higher in-hospital mortality.
Conclusion
Young, economically active MA patients were less likely to be admitted but had poor clinical outcomes after admission, suggesting their reluctance toward hospitalization for economic reasons.
Keywords: Emergency room visits, Health insurance, Hospitalization, Hospital mortality, Renal insufficiency
Graphical abstract
Figure 4. Subgroup analysis for the risk factors for hospitalization (A) and in-hospital mortality (B) according to health insurance status.
(A) Medical Aid (MA) recipients aged 30–60 years demonstrated significantly lower hospitalization rates than did National Health Insurance (NHI) beneficiaries. The lower admission rates were not affected by sex. (B) Overall, in-hospital mortality rates were not different between MA recipients and NHI beneficiaries. However, MA recipients aged younger than 60 years presented significantly higher in-hospital mortality rates than did NHI beneficiaries.
CI, confidence interval; KTAS, Korean Triage and Acuity Scale; OR, odds ratio.
Introduction
The incidence of end-stage kidney disease (ESKD) has been increasing worldwide. Although the incidence of newly registered ESKD slightly decreased after the coronavirus disease outbreak, it is still one of the greatest socioeconomic burdens, causing excessive healthcare costs [1]. The incidence and prevalence of ESKD in Korea are high. This increasing incidence of ESKD is partly due to an aging society and an increase in morbidities such as diabetes and hypertension [2,3].
Patients with ESKD are likely to visit the emergency department (ED) more frequently and have poorer clinical outcomes after visiting the ED than those without chronic kidney disease (CKD) because of ESKD-related complications and underlying comorbidities [4]. Infection, electrolyte imbalance, and cardiovascular events are common causes of ED visits for patients with ESKD [5]. In a recent paper, we demonstrated that patients with ESKD have significantly higher rates of hospitalization and in-hospital mortality than do those without CKD [6].
Moreover, hemodialysis patients with low socioeconomic status have even poorer clinical outcomes. Our previous study using the Korean hemodialysis quality assessment database revealed that patients receiving Medical Aid (MA) have significantly greater risks of hospitalization and mortality than those receiving National Health Insurance (NHI) [7]. However, few studies have directly investigated the influence of health insurance status on acute healthcare outcomes in ESKD patients, and the existing evidence has been inconclusive [8,9]. Therefore, we compared the rates of hospitalization and in-hospital mortality after ED admission between MA recipients and NHI beneficiaries among patients with ESKD.
Methods
Study design
This retrospective observational study was conducted using ED visit data from regional and local emergency medical centers between January 1, 2018 and December 31, 2021. Data were obtained from the National Emergency Department Information System (NEDIS), which is operated by the National Emergency Medical Center in Korea. The NEDIS is a comprehensive database that captures nearly all ED visits across South Korea (covering >95% of emergency centers and hundreds of hospitals), recording detailed information on patient demographics, diagnoses, treatments, and outcomes for each visit [10].
This study was performed in accordance with the Declaration of Helsinki after approval by the Institutional Review Board of Ulsan University Hospital, and the requirement for informed consent was waived (No. UUH2024-01-017, UUH2023-10-034).
Study population
We included all adult patients aged 20 years or older who were diagnosed with ESKD and visited the ED during the study period. Patients with ESKD were identified via the International Classification of Diseases, 10th Revision (ICD-10) code N18.5 as either the primary or secondary diagnosis. ESKD was defined as CKD stage 5, regardless of whether the patient was undergoing hemodialysis or peritoneal dialysis. Additional exclusion criteria included missing values for key variables such as the Korean Triage and Acuity Scale (KTAS), ED outcomes (discharge, admission, or death), and ED length of stay. The patients were categorized according to their insurance type as either MA recipients or NHI beneficiaries before analysis.
Study variables and study outcome
The collected variables included age, sex, level of emergency medical center, insurance type, route of ED arrival, KTAS classification, length of ED stay, ED outcome, and cause of the ED visit. Ages were grouped into 10-year intervals. The levels of emergency medical institutions, as designated by the Ministry of Health and Welfare, were categorized into regional emergency medical centers, community emergency medical centers, and community emergency medical institutes. The routes of ED arrival included direct visits, transfer from another hospital, transfer from an outpatient clinic, and others. The KTAS classification, which is based on patient severity, is divided into five levels: resuscitation, emergent, urgent, less urgent, and nonurgent. The causes of ED visits were categorized into cardiovascular disease, cerebrovascular disease, infection, vascular access issues, electrolyte imbalance, and others. The primary study outcomes were the hospitalization rate and in-hospital mortality following ED visits according to health insurance type. Hospitalization following the ED visit was defined as admission to the general ward or intensive care unit. In-hospital mortality was defined as death occurring during hospitalization following the ED visit.
Statistical analysis
Categorical variables were compared via the chi-square test, whereas continuous variables were analyzed via t tests or analysis of variance. The results are presented as frequencies (percentages) for categorical variables and as the means with standard deviations for continuous variables.
To evaluate the impact of insurance type on hospitalization and in-hospital mortality among patients with ESKD, logistic regression analyses were conducted with adjustments for age, sex, and KTAS classification. All the statistical tests were two-sided, and a p-value <0.05 was considered significant. Analyses were performed via R software version 4.0.5 (R Foundation for Statistical Computing).
Results
Baseline characteristics of patients with end-stage kidney disease visiting the emergency department
A total of 26,930,142 emergency visits were recorded between January 2018 and December 2021 in the NEDIS database (Fig. 1). After excluding those with CKD stages 1 through 4 and those without data on the KTAS score, disposition, and length of stay, 21,706,470 ED visits were noted. Among them, 159,456 visits were ESKD-related. After excluding 1,662 ED visits without health insurance information, 157,794 ESKD-related ED visits were included in the analysis. Among them, 37,133 visits (23.5%) were from MA recipients, and 120,661 visits (76.5%) were from NHI beneficiaries.
Figure 1. Study population.
Among the 26,930,142 emergency visits between January 2018 and December 2021, 157,794 end-stage kidney disease (ESKD)-related emergency department (ED) visits with health insurance status information were included in the analysis. Among them, 37,133 visits were from Medical Aid (MA) recipients, and 120,661 visits were from National Health Insurance (NHI) beneficiaries.
CKD, chronic kidney disease; KTAS, Korean Triage and Acuity Scale; NEDIS, National Emergency Department Information System.
The baseline characteristics of the patients according to health insurance status are presented in Table 1. MA recipients were mostly distributed in the 30- to 60-year-old age groups, whereas NHI beneficiaries were mostly older patients. Most patients visited the ED by direct visits (66.2%), while 25.3% were transferred from other hospitals. Compared with MA recipients, NHI beneficiaries had higher rates of KTAS classification, including resuscitation (3.8% vs. 3.3%), emergent (14.9% vs. 14.7%), and urgent (56.2% vs. 55.3%) (p < 0.001). The most common primary diagnoses for ED visits were infection (11.5%), vascular access problems (6.8%), and heart problems (6.4%).
Table 1.
Baseline characteristics of the ESKD ED visits according to health insurance status
| Characteristic | Total | MA | NHI | p-value | SMD |
|---|---|---|---|---|---|
| No. of ED visits | 157,794 (100) | 37,133 (23.5) | 120,661 (76.5) | ||
| Age (yr) | <0.001 | 0.593 | |||
| 20–29 | 1,797 (1.1) | 25 (1.1) | 1,372 (1.1) | ||
| 30–39 | 5,283 (3.3) | 1,821 (4.9) | 3,462 (2.9) | ||
| 40–49 | 12,889 (8.2) | 4,875 (13.1) | 8,014 (6.6) | ||
| 50–59 | 28,710 (18.2) | 10,726 (28.9) | 17,984 (14.9) | ||
| 60–69 | 40,597 (25.7) | 10,377 (27.9) | 30,220 (25.0) | ||
| 70–79 | 41,790 (26.5) | 5,721 (15.4) | 35,989 (29.8) | ||
| ≥80 | 26,808 (17.0) | 3,188 (8.6) | 23,620 (19.6) | ||
| Sex | <0.001 | 0.06 | |||
| Male | 90,425 (57.3) | 22,120 (59.6) | 68,305 (56.6) | ||
| Female | 67,369 (42.7) | 15,013 (40.4) | 52,356 (43.4) | ||
| Hospital service level | <0.001 | 0.084 | |||
| I (REMC) | 62,209 (39.4) | 14,563 (39.2) | 47,646 (39.5) | ||
| II (CEMC) | 83,442 (52.9) | 19,063 (51.3) | 64,379 (53.4) | ||
| III (CEMI) | 12,143 (7.7) | 3,507 (9.4) | 8,636 (7.2) | ||
| Route of arrival | <0.001 | 0.087 | |||
| Direct visit | 104,498 (66.2) | 25,671 (69.1) | 78,827 (65.3) | ||
| Transferred from other hospitals | 39,875 (25.3) | 8,784 (23.7) | 31,091 (25.8) | ||
| Transferred from outpatient clinic | 13,298 (8.4) | 2,648 (7.1) | 10,650 (8.8) | ||
| Others | 121 (0.1) | 30 (0.1) | 91 (0.1) | ||
| Unknown | 2 (0.0) | 0 (0) | 2 (0.0) | ||
| KTAS classification | <0.001 | 0.044 | |||
| Resuscitation | 5,844 (3.7) | 1,237 (3.3) | 4,607 (3.8) | ||
| Emergent | 23,485 (14.9) | 5,466 (14.7) | 18,019 (14.9) | ||
| Urgent | 88,380 (56.0) | 20,534 (55.3) | 67,846 (56.2) | ||
| Less urgent | 28,377 (18.0) | 6,973 (18.8) | 21,404 (17.7) | ||
| Non urgent | 11,708 (7.4) | 2,923 (7.9) | 8,785 (7.3) | ||
| Length of stay (hr) | 8.12 ± 10.19 | 7.69 ± 10.37 | 8.26 ± 10.12 | <0.001 | 0.055 |
| Primary diagnosisa | <0.001 | 0.048 | |||
| Infection | 10,711 (11.5) | 2,276 (10.38) | 8,435 (11.85) | ||
| Vascular access | 6,327 (6.8) | 1,543 (7.04) | 4,784 (6.72) | ||
| Heart disease | 5,945 (6.4) | 1,422 (6.48) | 4,523 (6.35) | ||
| Cerebrovascular disease | 3,252 (3.5) | 750 (3.42) | 2,502 (3.51) | ||
| Electrolyte | 3,416 (3.7) | 821 (3.74) | 2,595 (3.64) | ||
| Others | 63,485 (68.2) | 15,121 (68.94) | 48,364 (67.92) |
Data are expressed as number (%) or mean ± standard deviation.
CEMC, community emergency medical center; CEMI, community emergency medical institute; ED, emergency department; ESKD, end-stage kidney disease; KTAS, Korean Triage and Acuity Scale; MA, Medical Aid; NHI, National Health Insurance; REMC, regional emergency medical center; SMD, standardized mean difference.
The cases with unknown primary diagnosis were excluded from the total counts.
Outcomes following emergency department visits according to health insurance status
Overall, 659 patients (0.4%) died in the ED, while 105,174 (66.7%) were hospitalized. MA recipients were more likely to be discharged (n = 12,931, 34.8%) compared to NHI beneficiaries (n = 36,097, 29.9%; p < 0.001) (Fig. 2). In contrast, NHI beneficiaries were more likely to be hospitalized (n = 81,773, 67.8%) than MA recipients were (n = 23,401, 63.0%; p < 0.001) (Fig. 3). Infection was the most common cause of hospitalization in MA recipients and NHI beneficiaries (Supplementary Table 1, available online).
Figure 2. Outcomes following ED visits according to health insurance status.
Medical Aid (MA) recipients were more likely to be discharged after the ED visit, whereas National Health Insurance (NHI) beneficiaries were more likely to be admitted to the general ward (GW) or intensive care unit (ICU) from the ED.
ED, emergency department.
Figure 3. Hospitalization and in-hospital mortality rates according to health insurance status.
Compared with National Health Insurance (NHI) beneficiaries, Medical Aid (MA) recipients had lower hospitalization rates (63.0% vs. 67.8%, p < 0.001). Compared with NHI beneficiaries, MA recipients also had lower in-hospital mortality rates (4.8% vs. 6.6%, p = 0.002).
Overall, 9,704 patients (9.2%) died during hospitalization. The proportion of in-hospital mortality was greater for NHI beneficiaries (7,926/120,661, 6.6%) than for MA recipients (1,778/37,133, 4.8%; p < 0.001) (Fig. 3). The most common cause of in-hospital death was infection (15.0%) (Supplementary Table 1, available online).
The risk of hospitalization and in-hospital mortality was lower for MA recipients before adjustment (Model 1 in Table 2) than for NHI beneficiaries. Even after adjusting for confounders (age and sex in Model 2, age, sex, and KTAS score, hospital service level, route of arrival, length of stay in Model 3), MA recipients demonstrated a lower risk of hospitalization (odds ratio [OR], 0.90 [95% CI, 0.88–0.92] in Model 2; OR, 0.89 [95% CI, 0.87–0.92] in Model 3) (p < 0.001) than did NHI beneficiaries. However, the risk of in-hospital mortality was not different between MA recipients and NHI beneficiaries after adjusting for confounders (OR, 0.97 [95% CI, 0.92–1.03] in Model 2; OR, 0.97 [95% CI, 0.92–1.03] in Model 3).
Table 2.
Risk of hospitalization and in-hospital mortality according to health insurance status
| Model | Hospitalization | Mortality | ||
|---|---|---|---|---|
| OR (95% CI) | p-value | OR (95% CI) | p-value | |
| Model 1a | ||||
| MA | 0.811 (0.792–0.831) | <0.001 | 0.766 (0.726–0.808) | <0.001 |
| NHI | Reference | Reference | ||
| Model 2b | ||||
| MA | 0.899 (0.877–0.922) | <0.001 | 0.972 (0.919–1.027) | 0.31 |
| NHI | Reference | Reference | ||
| Model 3c | ||||
| MA | 0.891 (0.868–0.916) | <0.001 | 0.969 (0.916–1.026) | 0.28 |
| NHI | Reference | Reference | ||
CI, confidence interval; MA, medical aid; NHI, National Health Insurance; OR, odds ratio.
Unadjusted.
Adjusted by age and sex.
Adjusted by age, sex, and Korean Triage and Acuity Scale score, hospital service level, route of arrival, and length of stay.
Factors associated with the risk of hospitalization via the emergency department according to health insurance status
The risk of hospitalization was 11% lower for MA recipients than for NHI beneficiaries after adjusting for age, sex, and KTAS score, hospital service level, route of arrival, and length of stay (Table 2). When we performed subgroup analysis according to age group, the risk of hospitalization was lower in MA recipients between 30 and 60 years of age (Fig. 4A). The risk of hospitalization did not differ between males and females and did not differ according to the KTAS score.
Factors associated with the risk of in-hospital mortality via the emergency department according to health insurance status
The risk of in-hospital mortality was not different between MA recipients and NHI beneficiaries after adjusting for age, sex, and KTAS score, hospital service level, route of arrival, and length of stay (Table 2). However, when we performed subgroup analysis according to age group, the risk of in-hospital mortality was greater for patients younger than 60 years. The risk of in-hospital mortality was 2.8 times higher in MA recipients than in NHI beneficiaries in their 30s and approximately 1.3 times higher than that of patients in their 40s and 50s (Fig. 4B).
Discussion
We compared the rates of hospitalization and in-hospital mortality after ED admission between MA recipients and NHI beneficiaries among patients with ESKD. Compared with NHI beneficiaries, MA recipients had a lower overall risk of hospitalization in the ED. Specifically, MA recipients between their 30s and 60s had significantly lower rates of hospitalization in the ED than did NHI beneficiaries. In contrast, the overall risk of in-hospital mortality did not differ according to health insurance status. However, MA recipients aged 60 years or younger demonstrated a greater risk of in-hospital mortality than did NHI beneficiaries.
In Korea, every citizen is enrolled in the NHI system if certain conditions are met. Therefore, approximately 97% of the citizens are NHI beneficiaries. Moreover, approximately 3% of the citizens are classified as MA recipients due to their low income. However, the proportion of MA recipients among patients with ESKD is greater (23.3%) than that among the overall patient population [7]. Although the government pays the medical expenses of MA recipients, their accessibility to hospitals is still low. There are several reasons for this. First, most MA recipients lose their jobs or change their jobs to part-time to earn income after they are diagnosed with serious illnesses such as ESKD. Therefore, the hospital utilization rate may decrease. In addition, MA patients may have limitations in terms of active laboratory testing or treatment due to items not covered by medical insurance. A previous study demonstrated that NHI beneficiaries with ESKD had greater out-of-pocket expenditures for admission and the outpatient department than MA recipients with ESKD did [11]. Compared with MA recipients, NHI beneficiaries are more likely to receive better medical care.
Although there has been an effort to improve overall care for MA recipients among patients with ESKD, MA recipients are still at risk of acute complications. Indeed, previous studies have demonstrated that patients with low socioeconomic status are likely to visit the ED more frequently than those with high socioeconomic status. One large-scale population-level study demonstrated that patients reporting low income, lack of community, low educational level, or social isolation have significantly greater risks of ED visits [12]. Another study using the National Center for Health Statistics database demonstrated that socioeconomic status and health insurance coverage are significant determinants of healthcare access [13]. A study with older patients with comorbidities also revealed that socioeconomic status is an independent risk factor for high ED visits after adjusting for confounders [14].
Our study is the first Korean study to classify the clinical outcomes of patients with ESKD visiting the ED according to health insurance status. Our previous study demonstrated that MA recipients have higher rates of hospitalization and patient mortality than do NHI beneficiaries after adjustment for confounders [7]. However, the hospitalization rate was lower for MA recipients after the ED visit than for NHI beneficiaries in the present study. A possible explanation could be that MA recipients who are economically disadvantaged often visit the ED but receive treatment as a temporary measure and then are discharged instead of being hospitalized. Since hospitalization makes it difficult for them to engage in economic activities, they try to receive treatment in the ED and are discharged. In a study conducted in the United States, hemodialysis patients who did not have health insurance were younger and had a lower rate of hospitalization [15]. In support of this information, our subgroup analysis revealed that patients in the most economically active young age group of 30–60 years had a lower rate of hospitalization (Fig. 4A). It is also possible that the patients who declined to be hospitalized from the ED room may have poorer clinical outcomes. In Fig. 2, MA recipients were more likely to be discharged after ED visit while NHI beneficiaries were more likely to be admitted to the hospital. MA recipients may be discharged because they received proper care from the ED room, but on the other hand, MA recipients may be discharged against medical advice due to their financial and personal problems. In contrast, there was no difference in in-hospital mortality between MA recipients and NHI beneficiaries. These results are in line with those of previous studies. One study demonstrated that, compared with patients with high socioeconomic status, older patients with low socioeconomic status have higher hospitalization rates but similar in-hospital mortality rates [16]. Another study also revealed that adult patients visiting the ED with sepsis do not have different in-hospital mortality rates according to health insurance status after propensity score matching [17]. Overall, there was no difference in mortality rates during hospitalization according to health insurance status in our study. However, attention should be given to the in-hospital mortality rates according to age groups. In our study, MA recipients aged 60 years or younger had a higher mortality rate than did NHI beneficiaries. Patients under age 60 years are usually economically active suggesting that they may be reluctant to visit the ED until they become seriously ill. Previous article by Meacock et al. [18] also suggested that higher in-hospital mortality among ED visitors during weekends may reflect a lower probability of admission during weekends. The reduced utilization of primary care and admission rate from ED among young MA recipients may result in serious illness and higher in-hospital mortality. Therefore, in cases where patients with ESKD with low socioeconomic status visiting the ED are hospitalized, the hospitalization rate may be low among younger patients, but the severity and short-term mortality can be greater than those in NHI beneficiaries.
This study has several limitations. First, a large amount of data may be missing because of the retrospective nature of this study. This study was performed via the NEDIS database, which relies on administrative data; therefore, important clinical data, including laboratory data, comorbidities, and duration of ESKD diagnosis, are missing. After adjusting for comorbidity risk, the health insurance status itself may not be an independent risk factor for hospitalization or in-hospital mortality. In addition, we could not classify the patients into those on hemodialysis, peritoneal dialysis, kidney transplant recipients, or predialysis populations since we only classified patients with ESKD using the ICD-10 code (N18.5). Therefore, the clinical outcomes of patients with ESKD include predialysis CKD stage 5, dialysis, and transplant recipients. We only examined in-hospital mortality among patients visiting the ED; therefore, we were unable to assess long-term patient mortality according to health insurance status.
In conclusion, this study highlights the different clinical outcomes following ED visits among patients with ESKD with different health insurance statuses. Compared with NHI beneficiaries, MA recipients were less likely to be hospitalized after an ED visit but had similar in-hospital mortality rates. However, MA recipients aged under 60 years showed higher in-hospital mortality, suggesting delayed care or more severe illness at presentation. These findings highlight the need to improve access and early intervention for socioeconomically disadvantaged ESKD patients.
Footnotes
Conflicts of interest
All authors have no conflicts of interest to declare.
Funding
This research was supported by Hallym University Research Fund 2024 (HURF-2024-60) and a cooperative research fund from the Korean Society of Nephrology (2023).
Acknowledgments
This work is a result of the 2022 memorandum of understanding between the National Emergency Medical Center and the Korean Society of Nephrology Disaster Preparedness and Response Committee. The preliminary results were presented at the 2024 Asia Pacific Congress of Nephrology & Korean Society of Nephrology collaborative research session. The author expresses gratitude to the members of the Korean Society of Nephrology Disaster Preparedness and Response Committee.
Data sharing statement
The data presented in this study are available from the corresponding author upon reasonable request.
Authors’ contributions
Conceptualization: AJC, KDY, YKL
Data curation, Methodology: AJC, KDY, HEY, YKL
Formal analysis: SAJ
Funding acquisition: KDY
Investigation: AJC, KDY, HEY, WC, DHC, JK, HCP, YKL
Visualization: AJC, KDY, HCP, YKL
Writing–original draft: AJC, KDY, HCP, YKL
Writing–review & editing: HCP, YKL
All authors read and approved the final manuscript.
Supplementary Materials
Supplementary data are available at Kidney Research and Clinical Practice online (https://doi.org/10.23876/j.krcp.25.184).
References
- 1.Carriazo S, Aparicio-Madre MI, Tornero-Molina F, et al. Impact of different COVID-19 waves on kidney replacement therapy epidemiology and mortality: REMER 2020. Nephrol Dial Transplant. 2022;37:2253–2263. doi: 10.1093/ndt/gfac234. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Jin DC, Yun SR, Lee SW, Han SW, Kim W, Park J. Current characteristics of dialysis therapy in Korea: 2015 registry data focusing on elderly patients. Kidney Res Clin Pract. 2016;35:204–211. doi: 10.1016/j.krcp.2016.09.006. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Jin DC, Yun SR, Lee SW, et al. Current characteristics of dialysis therapy in Korea: 2016 registry data focusing on diabetic patients. Kidney Res Clin Pract. 2018;37:20–29. doi: 10.23876/j.krcp.2018.37.1.20. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Lovasik BP, Zhang R, Hockenberry JM, et al. Emergency department use and hospital admissions among patients with end-stage renal disease in the United States. JAMA Intern Med. 2016;176:1563–1565. doi: 10.1001/jamainternmed.2016.4975. [DOI] [PubMed] [Google Scholar]
- 5.Mujtaba F, Ahmad A, Dhrolia M, Qureshi R, Nasir K. Causes of emergency department visits among end-stage kidney disease patients on maintenance hemodialysis in Pakistan: a single-center study. Cureus. 2022;14:e33004. doi: 10.7759/cureus.33004. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Cho A, Jeong SA, Park HC, et al. Emergency department visits for patients with end-stage kidney disease in Korea: registry data from the National Emergency Department Information System 2019-2021. Kidney Res Clin Pract. 2025 Jan 17; doi: 10.23876/j.krcp.24.170. [Epub]. DOI: 10.23876/j.krcp.24.170. [DOI] [PubMed] [Google Scholar]
- 7.Park HC, Kwon YE, Choi HY, et al. Health insurance status is related to risk of mortality and hospitalization in Korean maintenance hemodialysis patients: a longitudinal cohort study. Am J Nephrol. 2020;51:975–981. doi: 10.1159/000512855. [DOI] [PubMed] [Google Scholar]
- 8.Lee S, Kim H, Shin S, Cho W, Kang HY. Impacts of implementing case payment system to medical aid hemodialysis patients on dialysis frequencies and expenditure. J Prev Med Public Health. 2004;37:260–266. [PubMed] [Google Scholar]
- 9.Jung JH, Kwon SM, Kim KH, Lee SK, Kim DS. Impact of health insurance type on the quality of hemodialysis services: a multilevel analysis. J Prev Med Public Health. 2010;43:245–256. doi: 10.3961/jpmph.2010.43.3.245. [DOI] [PubMed] [Google Scholar]
- 10.Yoo HH, Ro YS, Ko E, et al. Epidemiologic trends of patients who visited nationwide emergency departments: a report from the National Emergency Department Information System (NEDIS) of Korea, 2018-2022. Clin Exp Emerg Med. 2023;10(S):S1–S12. doi: 10.15441/ceem.23.151. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Shin SM, Lee HW. Comparison of out-of-pocket expenditure and catastrophic health expenditure for severe disease by the health security system: based on end-stage renal disease in South Korea. Int J Equity Health. 2021;20:6. doi: 10.1186/s12939-020-01311-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Guleria I, Campbell JA, Thorgerson A, Bhandari S, Egede LE. Relationship between social risk factors and emergency department use: national health interview survey 2016-2018. West J Emerg Med. 2025;26:307–314. doi: 10.5811/westjem.18616. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Ohaiba MM, Anamazobi EG, Okobi OE, Aguda K, Chukwu VU. Trends and patterns in emergency department visits: a comprehensive analysis of adult data from the National Center for Health Statistics (NCHS) database. Cureus. 2024;16:e66059. doi: 10.7759/cureus.66059. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Lim A, Benjasirisan C, Liu X, et al. Social determinants of health and emergency department visits among older adults with multimorbidity: insight from 2010 to 2018 National Health Interview Survey. BMC Public Health. 2024;24:1153. doi: 10.1186/s12889-024-18613-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.West J, Chan HK, Wang H, et al. Emergency department visits for hemodialysis by insurance status in the United States. J Am Coll Emerg Physicians Open. 2022;3:e12698. doi: 10.1002/emp2.12698. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Wachelder JJ, van Drunen I, Stassen PM, et al. Association of socioeconomic status with outcomes in older adult community-dwelling patients after visiting the emergency department: a retrospective cohort study. BMJ Open. 2017;7:e019318. doi: 10.1136/bmjopen-2017-019318. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Wang GS, You KM, Jo YH, et al. Association of health insurance status with outcomes of sepsis in adult patients: a retrospective cohort study. Int J Environ Res Public Health. 2021;18:5777. doi: 10.3390/ijerph18115777. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Meacock R, Anselmi L, Kristensen SR, Doran T, Sutton M. Higher mortality rates amongst emergency patients admitted to hospital at weekends reflect a lower probability of admission. J Health Serv Res Policy. 2017;22:12–19. doi: 10.1177/1355819616649630. [DOI] [PMC free article] [PubMed] [Google Scholar]
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