Price for waiting: the adverse outcomes of boarding critically ill elderly medical patients in the emergency department

Abstract

Purpose

Boarding, the period in which a patient spends in the emergency department (ED) before admission, may be hazardous to critically ill patients, particularly the elderly. This study investigated the associations of boarding with hospital course, prognosis, and medical expenditure in older patients.

Methods

From January 2019 to December 2021, the medical records of older patients (age ≥ 65) visiting the ED of a tertiary referral hospital who were admitted to the medical intensive care unit (ICU) were retrospectively reviewed. Eligible patients were categorized into two groups according to boarding time with a cutoff set at 6 h. Primary outcomes were in-hospital mortality, ICU/hospital length of stay, and total/average hospitalization cost. Subgroup analyses considered age and disease type.

Results

Among 1318 ICU admissions from the ED, 36% were subjected to boarding for over 6 h. Prolonged boarding had a longer ICU (8.9 ± 8.8 vs. 11.2 ± 12.2 days, P < .001) and hospital (17.8 ± 20.1 vs. 22.8 ± 23.0 days, P < .001) stay, higher treatment cost (10.4 ± 13.9 vs. 13.2 ± 16.5 thousands of USD, P = .001), and hospital mortality (19% vs. 25% P = .020). Multivariate regression analysis showed a longer ICU stay in patients aged 65–79 (8.3 ± 8.4 vs. 11.8 ± 14.2 days, P < .001) and cardiology patients (6.9 ± 8.4 vs. 8.8 ± 9.7 days, P = .001). Besides, the treatment cost was also higher for both groups (10.4 ± 14.6 vs. 13.7 ± 17.7 thousands of USD, P = .004 and 8.4 ± 14.0 vs. 11.7 ± 16.6 thousands of USD, P < .001, respectively).

Conclusion

Extended ED boarding for critically ill medical patients over 65 years old was associated with negative outcomes, including longer ICU/hospital stays, higher treatment costs, and hospital mortality.

 

What is already known on this topic—Prolonged boarding in the ED may lead to negative outcomes.

What this study adds—We focused on the elderly population to investigate the associations of ED boarding with hospital courses and healthcare expenses. Patients who experienced prolonged boarding before admission to the ICU due to cardiovascular diseases and those between the ages of 65 and 80 tended to have longer hospitalizations, lengthier ICU stays, and higher healthcare costs.

How this study might affect research, practice or policy—As the phenomenon of global aging perpetuates, healthcare providers should implement strategies to reduce boarding times. This study highlights the importance of effectively allocating medical resources to improve healthcare quality and outcomes for this vulnerable population.

Future Research Questions 

• 1) Extending Findings to Non-Critical Older Patients—It remains unclear whether the adverse outcomes resulting from prolonged boarding can be extended to non-critical older patients. This investigation is essential for determining the universality of the impact of prolonged boarding on patients with varying degrees of severity.

• 2) Focus on Specific Diseases—Subsequent research efforts may be warranted to concentrate on specific diseases rather than broad diagnostic categories.

• 3) Enhancing Resource Allocation for Older Critical Patients—It may be necessary to develop new strategies for more effective allocation of healthcare resources to the vulnerable population. Further research is required to identify the specific factors leading to delayed ICU admission.

Bullet Points Outlining the Main Message 

• 1) Prolonged boarding in the ED for critically ill medical patients over 65 years old correlates with negative outcomes, including longer ICU/hospital stays, higher treatment costs, and hospital mortality.

• 2) In the relatively young population (i.e. aged between 65 and 80) and those admitted to the ICU due to cardiovascular diseases, our findings reveal that prolonged boarding is associated with longer hospitalization, extended ICU stays, and higher healthcare costs.

• 3) We may need to effectively allocate intensive care resources for older patients and specific populations.

Introduction

As the global elderly population continues to grow, the healthcare industry faces numerous challenges [1], particularly the shortage of intensive care units (ICUs) for the critically ill [2, 3]. This not only places an additional burden on emergency care personnel who are at the forefront of emergency care, but also poses a serious threat to older patients who are more vulnerable than their younger counterparts because of their accompanying comorbidities [2, 4–6].

Previous studies have shown that patients who have waited for extended periods for a hospital bed in the emergency department (ED) are more likely to experience adverse outcomes, particularly in terms of mortality during hospitalization [7–9]. However, few studies have specifically focused on critically ill elderly patients [8, 10–12]. Moreover, most previous literature on critical care has defined ED boarding as the time eclipses between the patient’s arrival at the ED and ICU admission, including the time spent on examination and treatment [11, 13, 14]. One pitfall of such a definition is that it may not accurately reflect the actual delay in receiving definite intensive care as the time spent on initial diagnostic and therapeutic procedures in the ED, which varies according to complexity of the patient’s condition, are mandatory [13]. Therefore, by defining boarding as the time from ICU booking to ICU admission [15], this study aimed at providing a more accurate insight into the impact of prolonged boarding on the clinical course, prognosis, and medical expenses among older patients with critical medical illness. Besides, we attempted to identify specific populations having an increased risk of adverse outcomes.

Methods

This retrospective cohort study was approved by the institutional review board of Kaohsiung Veterans General Hospital (IRB No. KSVGH23-CT8-15). All data were collected from electronic health record data, with the institutional review board waiving the need for informed consent.

Settings and study design

The current study was conducted at a 1482-bed tertiary medical center with an annual emergency visit volume of ~86 000 [16]. To provide high-quality care for patients in an unstable condition, the ED has an 11-bed designated critical area overseen by an attending and a resident physician with a nurse-to-patient ratio being maintained at ~1:3 to 1:4. Real-time data on blood pressure, respiratory rate, cardiac rhythm, and oxygenation levels of all patients are continuously being monitored to enable prompt intervention. If the patient’s condition remains unstable after completion of diagnostic and treatment procedures in the ED, ICU admission is considered. The procedure of ICU booking starts with a computer registration that clearly indicates the time when the decision is made. When patients cannot be immediately admitted to the ICU due to a bed shortage, they are temporarily boarded in the critical care area of the ED for continuous monitoring. For the current study, boarding time was strictly defined as the time from ICU booking to ICU admission. Eligible patients were divided into two groups based on their boarding time: non-prolonged group with a boarding time of within 6 h and prolonged group with a boarding time of over 6 h. For subgroup analysis, patients were further divided into two age groups: those aged 65 to <80 and those aged 80 or older. We also investigated the impact of the nature of the patients’ diseases (e.g. cardiac, respiratory) on the outcome of prolonged boarding.

Study population

Between January 2019 and December 2021, older patients aged 65 years and above who were admitted to medical ICU from the ED were deemed eligible. During the boarding period, (i) patients who were transferred to other institutes, (ii) those whose condition was downgraded so that intensive care was no longer needed, (iii) those being discharged against medical advice, or (iv) those who expired were excluded.

Data collection

Data on critically ill patients in the ED who were admitted to the ICU were collected retrospectively from an electronic database. The following data were extracted: baseline demographics, namely age, gender, body mass index (BMI), and Do-Not-Resuscitate status (DNR); specific comorbidities, including hemodialysis or peritoneal dialysis, cancer, autoimmune diseases, and organ transplantation; other chronic comorbidities, including coronary artery disease (CAD), hypertension, diabetes mellitus, hyperlipidemia, chronic kidney disease, chronic liver disease; disease severity indices, namely Charlson Comorbidity Index score (CCIS); qSOFA scores, triage results, and APACHE II score; laboratory findings of blood samples, including white blood cell and platelet counts, as well as concentrations of hemoglobin, glucose, creatinine, C-reactive protein, and lactate; and ED visit timing, including shift and weekend.

Outcome measures

The study’s endpoints included in-hospital mortality of any cause, length of stay (LOS) in the ICU/hospital, total cost of hospitalization (measured in thousands of US dollars), and average daily hospitalization cost (measured in US dollars). All outcome measures were assessed at the time of hospital discharge for the significance of difference between the prolonged boarding group and the non-prolonged boarding group. To minimize bias in the results of subgroup analyses, potential confounders including gender, CCIS, Taiwan triage and acuity scale, and qSOFA scores were adjusted in the stepwise logistic regression model.

Statistical analyses

Differences in acquired data between the prolonged and non-prolonged boarding groups were compared using one-way analysis of variance (ANOVA) for continuous variables and χ² test or Fisher’s exact test for categorical variables. Using in-hospital mortality as binary dependent variables, we adopted multivariable logistic regression analysis to examine the effect of prolonged boarding. We also used a multivariable regression model to investigate the effect of prolonged boarding on the LOS and medical costs. The odds ratios and their 95% confidence intervals CIs from logistic regression analyses served as estimates of relative risk. In addition, the effects of age and nature of the patient’s disease on the outcomes of prolonged boarding were addressed with stratification analysis. All statistical analyses were performed using the Statistical Analysis Software (SAS; version 9.4; SAS System for Windows) and the Statistical Package for Social Sciences (statistical software 20, IBM Corp., Armonk, NY). Statistical significance was set at a two-tailed P < .05.

Results

Demographic and baseline characteristics

Over a period of 3 years, a total of 1607 older patients with critical medical conditions were subjected to boarding in the ED for ICU admission. After eliminating those who met the exclusion criteria, a total of 1318 older patients were enrolled in this study (Fig. 1). Of these patients, 841 were admitted to the ICU within 6 h (non-prolonged group), while the remaining 477 were admitted after 6 h (prolonged group). At baseline, those who were in the prolonged group were significantly older (77.6 ± 8.3 years) than those in the non-prolonged group (76.6 ± 8.6 years) (P = .039) without significant differences in gender, BMI, or whether a DNR consent was signed in advance between the two groups. There were no significant differences in the incidence of specific or chronic comorbidities, including hemodialysis or peritoneal dialysis, cancer, autoimmune diseases, organ transplantation, CAD, hypertension, diabetes mellitus, hyperlipidemia, chronic kidney, and liver diseases, except that the prolonged group had a higher CCIS (1.9 ± 2.4 vs. 1.6 ± 2.2, P = .032), qSOFA scores (1.8 ± 0.8 vs. 1.6 ± 0.8, P < .001), and APACHE II score (21.4 ± 10.6 vs. 17.2 ± 9.6, P < .001) than those in the non-prolonged group. Regarding laboratory data, those undergoing boarding over 6 h had a higher white blood cell count (11.8 ± 11.1 vs. 10.4 ± 5.2 per cubic mm, P = .003), creatinine levels (2.4 ± 2.6 vs. 2.0 ± 2.1 mg/dl, P = .008) andC-reactive protein levels (5.9 ± 7.5 vs. 4.8 ± 6.9 mg/dl, P = .008) but lower hemoglobin concentration (11.6 ± 2.7 vs. 12.3 ± 2.4, P < .001) compared to those admitted to the ICU within 6 h, while no significant difference was noted in platelet count as well as concentrations of glucose and lactate. There was no difference in whether they sought medical attention at the ED during the weekend. (Table 1) The main reason for admission was cardiac conditions (54%), followed by respiratory (17%), neurological (10%), infectious (7%), renal (4%), gastrointestinal (3%), rheumatic and immunological (1%) diseases, as well as metabolic (1%), hematological, oncological (1%), and other medical (1%) disorders (Table 2).

Since April 2020, Taiwan has implemented enhanced social distancing measures and stricter border control policies in response to severe acute respiratory syndrome coronavirus 2, known as coronavirus disease 2019 (hereafter COVID-19) pandemic [17]. Paradoxically, our results showed a beneficial impact of the COVID-19 pandemic on the prevalence of prolonged medical ICU boarding with a lower percentage of prolonged boarding (41% before COVID-19 vs. 29% during COVID-19) and a shorter average boarding time (12.0 vs. 10.6 h) during that period (Supplemental Table S1) Additionally, the total number of patients visiting the ED was lower during the pandemic (Supplemental Fig. S1).

Outcomes

The prolonged boarding group had a higher in-hospital mortality rate than that in the non-prolonged group [118 (25%) vs. 162 (19%), P = .020]. Besides, both the duration of ICU stay (11.2 ± 12.2 vs. 8.9 ± 8.8 days, P < .001) and total hospital stay (22.8 ± 23.0 vs. 17.8 ± 20.1 days, P < .001) were higher in the former. On the other hand, despite the significantly higher overall cost of hospitalization of the prolonged boarding group (13.2 ± 16.5 thousands of USD) than that in the non-prolonged group (10.4 ± 13.9 thousands of USD, P < .001), there was no significant difference in the average daily cost between the two groups (Table 3).

Multivariate analysis showed no significant association of prolonged boarding with in-hospital mortality rate and average daily cost of hospitalization in patients aged 65–79 and those ≥80. On the other hand, boarding correlated with a significantly longer ICU [adjusted beta 0.31; 95% CI 0.21–0.42, P < .001] and total hospital [adjusted beta 0.20; 95% CI 0.07–0.32, P = .002] stay, as well as a higher total hospitalization cost [adjusted beta 0.24; 95% CI 0.08–0.40, P = .004] in those aged 65–79, while boarding had no notable impact on these parameters among those aged greater than or equal to 80 (Table 4) .

Subsequent analysis of the correlation between disease entities and the outcomes of prolonged boarding demonstrated a significant link between cardiovascular diseases with a longer ICU [adjusted beta 0.20; 95% CI 0.09–0.32, P = .001] and total hospital [adjusted beta 0.23; 95% CI 0.08–0.37, P = .002] stay, as well as a higher total hospitalization cost [adjusted beta 34.1; 95% CI 34.0–34.1, P < .001]. In contrast, prolonged boarding had no significant effect on the duration of ICU and total hospital stay or total hospitalization cost in those admitted for respiratory diseases or other disorders. Additionally, there was no correlation between the nature of disease and average daily cost of hospitalization or in-hospital mortality rate (Table 5).

Discussion

Although previous studies have suggested a relationship between poor patient outcomes and the LOS in the ED [7, 11, 13, 18], the majority of studies defined boarding time as the period between ED triage and ICU admission [11, 13, 14] that did not account for the time spent on mandatory diagnostic and therapeutic procedures in the ED due to severity of the patient’s disease [13]. Such a definition may overestimate the boarding time for patients in a more critical condition who require a longer period for initial stabilization of vital signs in the ED before the decision of ICU admission. Therefore, we defined “boarding” as the time between ICU booking and actual transfer to the ICU [15] to more accurately reflect the impact of boarding on the patient’s outcomes. Taking into account that patients who are allocated to the critical care area in the ED with comparable disease severity followed the “first-come, first-served” principle of ICU admission, the impact of disease complexity on the duration of boarding is minimal. This criterion was established based on the recommendations of the American Thoracic Society Bioethics Task Force, which explicitly states that in situations where the demand for ICU beds exceeds the available resources, patients should be admitted in order of arrival [19].

The current investigation demonstrated a positive correlation between prolonged boarding and in-hospital mortality in older patients in need of intensive care. Our results further showed that prolonged boarding was associated with longer overall hospitalization and ICU stay as well as a higher total cost compared to those admitted to the ICU within 6 h. Our findings were inconsistent with those of a previous study on adult patients requiring intensive care that demonstrated no impact of a prolonged stay in the ED on in-hospital mortality [8, 12]. The discrepancy in outcome may be attributed to our focus on older patients aged over 65. Furthermore, the APACHE II score, known for its strong discriminant capability in predicting mortality among ICU patients [20], was also higher in the prolonged group.

Despite being equipped with advanced monitoring equipment in the designated ED critical care area, the quality of critical care in the ED is still not comparable to that in the ICU. The focus of emergency care, which primarily focuses on the stabilization of the patient’s condition in a busy environment, may not allow meticulous care equivalent to the ICU standard (e.g. intake/output recording) [18]. Besides, in our hospital, compared with the ED, there is a lower nurse–patient ratio with one nurse attending to every two or three patients in the ICU. In addition, emergency physicians, who were trained for frontline care, may not be able to deliver a level of care comparable to that of a specialist, thereby leading to a delay in definitive treatment [21]. The lack of team care (e.g. respiratory therapist, dietitian), which is an ICU routine, is also unavailable in the ED.

Despite our finding of a negative impact of prolonged boarding on the overall in-hospital mortality in the older population, our subgroup analysis demonstrated no significant impact of prolonged boarding on various adverse outcomes when focusing on those aged greater than or equal to 80. Conversely, those who were relatively young (i.e. aged 65–79 years) were found to be more susceptible to the impact of prolonged boarding as reflected by a lengthened ICU and total hospital stay, as well as higher overall costs. There were several explanations for such apparently paradoxical findings. First, patients aged greater than or equal to 80 may tend to receive conservative treatment instead of costly invasive procedures [21, 22], which may account for the lack of impact of prolonged boarding on medical expenditure. Second, comorbidities that often accompany the elderly population and their generally poor condition may outweigh the benefit of a short boarding time [23], thereby contributing to a nonsignificant effect of a prolonged boarding on overall in-hospital mortality as well as ICU and total hospital stay.

Another interesting finding of our subgroup analysis was the identification of a significant association of prolonged boarding with a longer ICU and total hospital stay as well as higher total hospitalization costs in those being admitted to the ICU due to cardiovascular diseases, but without significant differences in average daily costs and in-hospital mortality rates compared to those afflicted with other disorders. The prolonged total hospital stay may be attributed to the guidelines of routine postcatheterization intensive care adopted by most cardiologists regardless of the duration of postintervention observation in the ED [24] in accordance with the European Society of Cardiology recommendation of observation for at least 24 h after percutaneous coronary intervention (PCI) [25]. Complications that occurred during the ED boarding may also cause an extended ICU as well as total hospital stay [26], which accounted for higher medical expenses compared to those admitted to ICU because of other disease entities. On the other hand, the lack of impact of prolonged boarding on the overall in-hospital mortality in those presenting with cardiovascular diseases may be attributed to timely PCI for patients diagnosed with ST elevation myocardial infarction (STEMI) regardless of the location (e.g. ED vs. ICU) or the crowding condition in the ED to comply with the door-to-balloon time frame as reported in previous studies [24, 27]. The management strategy is in accordance with that proposed by the European Society of Cardiology guidelines that recommend post-PCI observation in any units with continuous monitoring and specialized care, not necessarily restricted to the cardiac ICU [25]. Consistently, the American Heart Association recommends direct admission of low-risk STEMI patients to the step-down unit after successful PCI [28].

During the COVID-19 pandemic, the reduction in ED patient volume may be associated with concerns about viral transmission and the implementation of social restrictions [16, 17]. Simultaneously, these factors may contribute to a decrease in the occurrence of other airborne/droplet-transmitted infectious diseases [16]. This reduction in patient volume has the potential to improve the physician-to-patient ratio, thereby alleviating ED overcrowding [29]. Consequently, this could be a contributing factor to the observed decrease in both the prevalence of prolonged boarding and the average boarding time during the pandemic.

Conclusion

The current study, which focused on older patients in need of intensive care, showed an association of prolonged boarding in the emergency department with a higher in-hospital mortality rate, longer overall hospital and ICU stays, as well as increased total costs than those being admitted to the ICU within 6 h. Our results also demonstrated longer hospitalization, lengthier ICU stays, and higher healthcare costs when subjected to prolonged boarding in the relatively young population (i.e. aged between 65 and 80) and those admitted to the ICU due to cardiovascular diseases. Our findings may highlight the need for effective allocation of intensive care resources for older patients and particular populations.

Strengths and limitations

Although numerous studies have shown the adverse effects of ED boarding, our study is among the few that concentrate on older patients and also incorporate healthcare expenses into the analysis. There were several limitations in our study. First, our single center setting may limit extrapolation of our findings. Moreover, as with all retrospective studies, there may be potential confounding variables that were not accounted for. Finally, our exclusive focus on older patients warrants further investigation to elucidate the impact of boarding on clinical outcomes in other age groups.

Acknowledgements

The authors thank personnel at the Health Examination Center and Department of Medical Education and Research of Kaohsiung Veterans General Hospital for providing information in response to inquiries and assistance in data processing.

Conflict of interest statement

None declared.

Funding

This research was funded by the National Science and Technology Council (NSTC 112-2314-B-075B-020), Kaohsiung Veterans General Hospital (grant KSVGH112-122).

Data availability

The data generated or analyzed during the current study available from the corresponding author on reasonable request.

Institutional review board statement

Approval was obtained from the Institutional Review Board (IRB) of Kaohsiung Veterans General Hospital (IRB No. KSVGH23-CT8-15).

Author contributions

Study conception and design: Kuang-Wen Huang, Renin Chang.

Acquisition of data: Chun-Hao Yin.

Analysis and interpretation of data: Kuang-Wen Huang, Chun-Hao Yin, Renin Chang.

Writing (original draft preparation): Kuang-Wen Huang, Renin Chang.

Writing (review and editing): Kuang-Wen Huang, Renin Chang, Jin-Shuen Chen, Yao-Shen Chen.

References