Epidemiology of Non-Emergent Cancer-Related Emergency Department Visits in Korea between 2016 and 2020.

INTRODUCTION

Cancer is a major public health problem worldwide. 1 , 2 As cancer screenings and treatment technologies advance, cancer prevalence rises. 2 , 3 Cancer is usually treated in an outpatient and inpatient basis; however people living with cancer sometimes experience uncontrolled cancer-related symptoms and treatment complications. 4 , 5 , 6 As the prevalence of cancer increases, the number of cancer-related emergency department (ED) visits also increases. 7 , 8

ED is a place where many resources are concentrated for the treatment of emergency patients. ED visits are stressful in itself for patients, and overcrowding of ED due to non-essential visits is an important problem of healthcare resource allocation. 9 , 10 , 11 To improve patient comfort and provide timely and appropriate care to emergency patients, much attention is given to reduce non-emergent ED visits. 12 , 13 However, there is no clear definition of what non-emergent visit is. A study from the United States (US) developed an algorithm based on the patient’s diagnosis to classify avoidable ED visit. 14 , 15 Other studies defined avoidable visits based on ED disposition, while assuming that patients who were discharged without hospitalization or discharged without laboratory or radiology tests could be treated on an outpatient care basis. 15 , 16 , 17 There were also attempts to investigate avoidable visits for people living with cancer who frequently visited the ED. 13 , 18 The US study assumed that patients who visited the ED for symptoms that frequently occurred during cancer treatment were avoidable, because if they were prescribed symptomatic medication in advance or visiting outpatient clinic instead of the ED, they could avoid visiting the ED. 13 Other study of people living with gynecologic cancer defined patients who were not hospitalized after ED treatment as potentially avoidable ED visit. 18 Based on these definitions, previous studies reported that half of cancer-related ED visits were deemed avoidable. 13 , 18 However, since these studies were conducted in small areas or with sample data, it is difficult to estimate the magnitude of non-emergent visit relative to the total cancer-related ED visits or to investigate general characteristics of non-emergent visit.

In Korea, the National Health Insurance (NHI) is applied to all citizens; therefore, healthcare accessibility is high, including visits to the ED. 19 As a result, the number of cancer-related ED visits over a period of 5 years, from 2015 to 2019, reached 1.4 million. 7 A single-center study conducted by retrospective medical record review reported that 55% of ED visits of people living with cancer were avoidable in Korea. 16 However, although cancer-related ED visits are increasing, the size or characteristics of non-emergent visits on a national scale are still unknown. 7

This study aimed to estimate the size of non-emergent cancer-related ED visits using the nationwide ED database and to investigate its characteristics. Through this, it is intended to be used as basic data to find ways to improve the quality of care for people living with cancer and find ways to increase supportive care resources besides ED.

MATERIALS AND METHODS

Study design and setting

A cross-sectional study was conducted using a nationwide ED-based database.

Korea has the NHI system, which covers a total population of 50 million people. The government has been operating NHI as a single insurer since 1989. Since NHI covers emergency care, as well as inpatient and outpatient care, and EDs are open to all NHI beneficiaries, accessibility to emergency care in Korea is high. 19 , 20 In addition, insurance benefits are greater for severe diseases, such as cancer; therefore, when patients living with cancer use medical services, including ED, for reasons related to cancer, they pay less out-of-pocket. 21

In Korea, the Ministry of Health and Welfare (MoHW) classifies the ED into three levels according to their resources and capacity. A level 1 ED, designated by the MoHW, has the highest standard of medical personnel, equipment, and facilities, and has the role of final treatment for critically ill patients and response to disaster in the region. A level 2 ED is designated by the local government where the institution is located, and is in charge of treating critically ill patients in the area. A level 3 ED performs both roles of providing urgent care and emergency care in a smaller area. 22 , 23 Although level 1 and 2 EDs have role of treating critically ill patients, there are no restrictions on ED visits according to the ED level and patients can visit any level of ED regardless of acuity. 19

The National Cancer Center has reported an “annual report of cancer incidence, survival and prevalence in Korea” since 2007, based on the Korea Central Cancer Registry (KCCR). 3 This report includes the information regarding morbidity and mortality of each cancer type every year.

Data collection

This study was conducted using the National Emergency Department Information System (NEDIS) database, which was constructed in 2013 by MoHW and operated by the National Emergency Medical Center. In 2019, a total of 402 EDs sent information of patients visiting EDs across the country. All participating EDs automatically transferred patient information, including demographics, vital signs, ED diagnoses and management, and clinical outcomes, to a central server within 14 days of the hospital discharge. The NEDIS database collected all diagnosis entered at the time of discharge from the ED and hospital using an International Classification of Diseases, 10th edition (ICD-10) code (up to 40 codes). Detailed information on the NEDIS database was reported previously. 23 , 24

The NEDIS collects information on patients’ triage levels twice, on initial ED arrival and on secondary ED discharge. A triage tool called Korean Triage and Acuity Scale (KTAS), which was developed based on the Canadian Triage and Acuity Scale, has been applied to all ED patients since 2016. 25 A triage nurse with more than 4 years of ED experience and special education/training evaluates the initial KTAS when the patient arrives at the ED, and an emergency physician or ED nurse evaluates the final KTAS when the patient is discharged from the ED. KTAS is a symptom-oriented triage tool that determines the severity and acuity of an emergency patient and does so on a scale of 1–5 (1: resuscitation, 2: emergency, 3: urgent, 4: less-urgent, 5: non-urgent). 26 A KTAS of 1–3 is classified as an emergency condition and 4–5 as a non-emergency condition. 25

Study population

The study population was cancer-related ED visiting patients of level 1 and 2 EDs from January 2016 to December 2020. Since level 3 ED is an ED for both emergency and non-emergency patients originally, it was not included in this study. Cancer-related ED visits were defined as patients having at least one of the cancer diagnoses C00–C97 (malignant neoplasm) in the NEDIS database as an ED diagnosis. In the NEDIS database, the ED diagnosis information field is entered with the disease that caused the ED visit along with the disease that affected it. In Korea, people living with cancer benefit from insurance when they visit the ED for a cancer-related cause. 21 If it turns out that a cancer diagnosis is entered in a case that is not actually related to cancer, the insurance money is cut. Therefore, the physician who treats the patient in the ED evaluates the association between the ED visit and cancer and enters the cancer diagnosis to the ED diagnosis information field only when the patient visits the ED with cancer-related cause. 7 Therefore, ED visits due to cancer-related symptoms or diseases exacerbated by cancer were included in the study, and visits due to events unrelated to cancer, such as traffic accidents, were not included. Cases with unknown information on triage levels were excluded. Patients who were dead on arrival (DOA) or had cardiac arrest upon arrival to the ED were also excluded.

Outcome measures

The study outcome was non-emergent cancer-related ED visits, defined as patients who triaged into the non-emergency condition (KTAS 4–5) on both initial ED arrival and ED discharge and were discharged after care in the ED. There is no established single definition of preventable/avoidable ED visit. Previous studies used simple criteria, such as ED disposition or diagnosis, to investigate the characteristics of avoidable visit. 13 , 15 , 18 Based on these, we assumed that patients who were determined as non-emergency conditions both at the time of visiting the ED and ED discharge and were discharged without hospitalization would have a potential to be treated at places other than the ED if there are other available resources, such as an outpatient clinic. Such cases were defined as non-emergent visits. 15 , 18

Variables definitions and measurements

The following variables were used from the NEDIS database: 1) demographics (age, sex, and insurance type); 2) route of ED visit (direct, transfer-in, and others) and use of ambulance; 3) ED information [ED visit time and date, location of ED (urban/rural and metropolitan), and level of ED]; 4) ED management [mental status at ED entrance, chief complaint, type of cancer, length of stay, diagnosis (ICD-10 code, multiple) and ED disposition]. Type of cancer was classified based on the ICD-10 code according to the classification of KCCR. 3 Diagnosis was classified as a cancer diagnosis when there was no other diagnoses other than cancer.

Statistical analysis

A descriptive analysis was conducted according to whether or not the ED visits were non-emergent. Categorical variables were presented by counts (%) and compared by chi-square test. Continuous variables with non-parametric distribution were presented as median (interquartile range, IQR) and compared by Kruskal-Wallis test. A descriptive analysis according to KTAS were presented as supplementary table ( Supplementary Table 1 , only online). Temporal trends of non-emergent cancer-related ED visits were evaluated by the Cochran Armitage test for trends and presented as graphs. Top 15 frequent chief complaints and diagnoses of cancer-related ED visits were investigated by non-emergent visits or not. 13 A list of top five common chief complaints is presented for the top five common types of cancers ( Supplementary Table 2 , only online). The proportion of non-emergent ED visits were evaluated by the type of cancer. 3

A multivariable logistic regression analysis was conducted to evaluate the determinants associated with non-emergent cancer-related ED visits. The adjusted odds ratios and 95% confidence intervals for patient demographics and characteristics were calculated.

Ethics statements

This study was approved by the Institutional Review Boards of Seoul National University Hospital (approval No. SNUH-2012-104-1183), and the requirement for informed consent was waived due to the retrospective nature of this study. All methods were performed in accordance with relevant guidelines and regulations.

RESULTS

Patients flow

Among a total of 27573111 ED visits of level 1 and 2 EDs over a 5-year period, 1185871 cancer-related ED visits were included, excluding DOA, cardiac arrest at ED arrival (n=3787), and cases with unknown information on initial triage scale (n=519), or final triage scale (n=2).

Characteristics and annual trends of non-emergent cancer-related ED visits

Among a total of 1185871 cancer-related ED visits, non-emergent cancer-related ED visits were 19.0% (n=225491). Non-emergent visits less used ambulance (8.6% vs. 21.5%, p <0.001) and stayed in the ED for a median (IQR) of 2.9 (1.4–5.0) hours, which was shorter than the median (IQR) of 5.9 (3.4–11.9) hours for emergent visits ( Table 1 ).

During the study period, non-emergent cancer-related ED visits showed a decreasing trend from 18.6% in 2016 to 17.6% in 2020 (p-for-trend, <0.001) ( Supplementary Fig. 1 , only online).

Chief complaint and diagnosis of non-emergent cancer-related ED visits

Of the most common 15 chief complaints, ascites (2.4%), pain in the lower limb (2.0%), difficulty passing urine (1.8%), dressing of skin or wound (1.7%), constipation (1.5%), hematuria (1.5%), paracentesis (1.4%), and painful micturition (1.3%) were reported only in non-emergent visits and not in emergent visits. Melena (1.5%), headache (1.5%), hematemesis (1.4%), epigastric pain (1.3%), hematochezia (1.3%), diarrhea (1.3%), and chest pain (1.3%) were included in emergent visits only and not in non-emergent visits ( Table 2 ). The distribution of chief complaints in the top five cancer types with the most ED visits is also presented ( Supplementary Table 2 , only online).

The top five diagnoses for non-emergent visits were abdominal pain (2.7%), ascites (2.5%), fever (2.2%), gastroenteritis (1.6%), and functional gastrointestinal (GI) disorder (1.5%). The top five diagnoses for emergent visit were pneumonia (4.1%), fever (3.2%), other GI disease (3.1%), ileus (2.6%), and agranulocytosis (2.6%). Non-emergent visits were more likely to have no diagnosis other than cancer in the ED compared to emergent visits (55.8% vs. 27.2%) ( Table 3 ).

Non-emergent cancer-related ED visit by cancer type

Among the top 20 cancer types with the most ED visits, the cancers with the highest proportion of non-emergent visits were thyroid (32.4%), prostate (30.4%), lip, oral cavity and pharynx (26.9%), breast (26.6%), and bladder cancer (26.0%) ( Table 4 ).

Factors associated with non-emergent ED visits among cancer-related ED visits

In the logistic regression analysis, adults (19–64 years old) compared with children [0.64 (0.62–0.66)] and older adults [0.75 (0.75–0.76)], female [1.05 (1.04–1.06)], medical aid insurance [1.30 (1.27–1.32)] compared with NHI, urban/rural ED [1.18 (1.17–1.19)] compared with metropolitan, direct visit compared with transfer-in [0.19 (0.19–0.20)], no ambulance use compared with ambulance use [0.27 (0.27–0.28)], weekend visit [1.19 (1.18–1.20)], and level 2 ED visit [1.42 (1.40–1.43)] showed higher odds ratio of being non-emergent cancer-related ED visits ( Table 5 ). The results of logistic regression for the top five cancer types were also similar ( Supplementary Table 3 , only online).

DISCUSSION

Using a nationwide ED database, this study evaluated the magnitude of non-emergent cancer-related ED visits and demonstrated the characteristics of such visits. When non-emergent ED visits were defined as non-emergency conditions in the initial and final ED triages and discharged without hospitalization, approximately 20% of cancer-related ED visits were evaluated as non-emergent. In addition to the common chief complaints in emergent visits, such as abdominal pain and fever, non-emergent visits had more chief complaints that sometimes required simple procedures, such as abdomen distension/ascites (paracentesis), and difficulty passing urine (catheterization). Also, non-emergent visits were more likely to have no diagnosis other than cancer in the ED compared to emergent visits. A better understanding of the characteristics of non-emergent ED visits can serve as basic data for finding ways to improve the quality of care for people living with cancer and increase supportive care resources other than ED.

People living with cancer suffer inevitably due to the associated symptoms and treatment-related complications. Since an ED visit itself can be a distressing experience for patients, there have been many efforts to investigate and reduce ED visits that can be treated outside of the ED. 12 , 13 , 27 There is no universally accepted definition for preventable/avoidable ED visits. Therefore, it is defined in various ways: 1) non-emergent severity based on the diagnosis, 2) patients discharged without hospitalization after ED treatment, or 3) judgement based on medical record review. 14 , 15 , 16 , 17 , 18 , 28 Various definitions used by previous studies have their own pros and cons. The medical staff evaluation has the advantage of allowing a more detailed assessment of whether the visit could be prevented by taking into account the comorbidities or resources used in the ED. 16 , 17 However, they were generally conducted through medical record review and could be conducted at the one or two hospital. 16 , 17 Definitions using ED disposition or diagnosis have the disadvantage that some cases may be misclassified as it is difficult to know the specific situation of a patient. 13 , 14 , 15 , 28 However, it has the advantage of applying simple pre-defined criteria, allowing studies to investigate the characteristics of population using a database. In Korea, one published study investigated avoidable visits of people living with cancer through medical record review at one hospital. 16 However, no study was conducted to investigate the general characteristics or the size of non-emergent ED visits using large-scale nationwide data. Therefore, to investigate the general characteristics and estimate the size of non-emergent visit, the present study defined non-emergent visits using two simple criteria combined: 1) non-emergent condition at the initial and final ED triages, and 2) discharged without hospitalization (treat-and-release). As a result, in this study, non-emergent visits accounted for 20% of all cancer-related ED visits, which was about half of the 40%–50% reported in previous studies. 13 , 16 , 18 Although this study used a simple definition without medical record review, non-emergent visits were defined as an intersection of non-emergency condition (31.5%) and ED treat-and-release criteria (39.6%). As a result, the proportion might be smaller compared to previous studies. Previous studies used only one of these two criteria. 13 , 16 , 18

Since people living with cancer may experience various discomforts during treatment, previous studies used the following symptom listing tools to evaluate avoidable ED visits of people living with cancer: the Centers for Medicare & Medicaid Services proposed Admissions and Emergency Department Visits for Patients Receiving Outpatient Chemotherapy Measure (CMS metric), and the Symptom Tracking and Reporting Patient-Reported Outcomes (PRO) tool. 13 , 29 , 30 Pain, GI symptoms, and fever, which are important cancer-related symptoms in the CMS metric or PRO tool, were the most common symptoms of emergent and non-emergent cancer-related ED visits. However, in non-emergent visits, there were more symptoms that could be resolved with simple procedures, such as ascites, difficulty passing urine, and dressing, than by emergent visits. Paracentesis, simple dressing, and urinary catheterization can be performed on an outpatient basis if appropriately prepared. These results suggest the possibility that non-emergency visits can be reduced through active symptom control and advance preparation during outpatient clinic or hospitalization.

The strength of this study is that the size of non-emergent ED visits was estimated at the national level using a representative nationwide ED database. Approximately 20% of the cancer-related ED visits were non-emergent, accounting for 230000 patients over 5 years or over 40000 patients per year. Most of the patients presented with cancer-related symptoms and discomfort that require a simple procedure, and were discharged within 3 hours. The non-essential ED visit itself can be a painful experience for patients and caregivers, while the ED overcrowding worsens the care outcomes of other emergent patients. 31 , 32 People living with cancer are at high risk of experiencing various discomfort during the course of treatment. Therefore, it is necessary to increase supportive care resources for people living with cancer, including accessible outpatient clinics for simple procedures and the prescription of sufficient symptom medication in advance at oncology inpatient and outpatient clinics.

This study had several limitations. First, we defined the non-emergent visits using triage and ED disposition results. Since we did not review each patient’s medical record, there is a possibility of misclassification of specific cases. Large databases, such as the NEDIS, have the disadvantage of having little information on individual patients but have the advantage of estimating the size of the study population at the national level and investigating general characteristics from representative data. This study tried to estimate the size of non-emergent cancer-related ED visits, which could not be possible in a single-center study, and to figure out its characteristics. Second, the NEDIS database did not contain information about the time of diagnosis, stage, and treatment of cancer. It is difficult to know the time from cancer diagnosis and ED visit and the association between the cancer stage and non-emergent ED visit. It is also unknown what kind of cancer treatments the patients were receiving at the time of ED visits and whether the ED visits were associated with that treatment, and what procedures were performed related to the cancer complication. Third, since NEDIS is an anonymous ED database, multiple visits are unknown. The characteristics of patients who had multiple non-emergent ED visits or association with higher risk of mortality are unknown. Fourth, the characteristics of non-emergent ED visits were investigated based on the diagnoses and chief complaints recorded in the NEDIS database. Although the NEDIS is a qualified database managed by the government, there may have been omitted diagnoses or symptoms in the database. Also, there can be variations in coding chief complaints. For example, for ascites, various chief complaints can be coded, such as ascites, abdomen distension, and abdomen pain. It is the limitation of a retrospective study. Fifth, since this study was conducted using a large database, the statistical significance can be attributed to the large sample size. The clinical significance should be considered when interpreting the results of this study.

In conclusion, using a national database, we found that about 20% of cancer-related ED visits may be non-emergent. The frequent reasons for non-emergent visits were common cancer-related symptoms requiring simple procedures, such as ascites and difficulty in urination. To improve the quality of care for people living with cancer, active symptom control and appropriate supportive care resources besides ED are needed.

ACKNOWLEDGEMENTS

This study was supported by the National Medical Centre for data use. The NEDIS data were administrated by the National Medical Center, and financial support was provided by the Ministry of Health and Welfare.

Footnotes

The authors have no potential conflicts of interest to disclose.

AUTHOR CONTRIBUTIONS: Conceptualization: Sun Young Lee and Young Sun Ro. Data curation: Sun Young Lee, Young Sun Ro, and Eujene Jung. Formal analysis: Sun Young Lee and Young Sun Ro. Investigation: Sang Do Shin and Seong Jung Kim. Methodology: Sun Young Lee and Young Sun Ro. Project administration: Sang Do Shin and Seong Jung Kim. Resources: Young Sun Ro and Seong Jung Kim. Software: Sun Young Lee and Young Sun Ro. Supervision: Young Sun Ro and Sang Do Shin. Writing—original draft: Sun Young Lee and Young Sun Ro. Writing—review & editing: Sun Young Lee, Young Sun Ro, and Eujene Jung. Approval of final manuscript: all authors.

SUPPLEMENTARY MATERIALS

Supplementary Table 1

Demographics of Cancer-Related ED Visits by Triage Level at Time of Discharge

Supplementary Table 2

Common Presenting Complaints of Cancer-Related ED Visits by Type of Cancer

Supplementary Table 3

Determinants Associated with Non-Emergent Cancer-Related Emergency Department Visits by Type of Cancer

Supplementary Fig. 1

Trends of non-emergent cancer-related emergency department visits.

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Associated Data

Supplementary Materials

Supplementary Table 1

Demographics of Cancer-Related ED Visits by Triage Level at Time of Discharge

Supplementary Table 2

Common Presenting Complaints of Cancer-Related ED Visits by Type of Cancer

Supplementary Table 3

Determinants Associated with Non-Emergent Cancer-Related Emergency Department Visits by Type of Cancer

Supplementary Fig. 1

Trends of non-emergent cancer-related emergency department visits.