An Empirical Assessment of Boarding and ... - Wiley Online Library

ORIGINAL RESEARCH CONTRIBUTION

An Empirical Assessment of Boarding and Quality of Care: Delays in Care Among Chest Pain, Pneumonia, and Cellulitis Patients Shan W. Liu, MD, SD, Yuchiao Chang, PhD, Joel S. Weissman, PhD, Richard T. Griffey, MD, MPH, James Thomas, MD, Suvd Nergui, MD, MPH, Azita G. Hamedani, MD, MPH, Carlos A. Camargo, Jr., MD, DrPH, and Sara Singer, PhD, MBA

Abstract Background: As hospital crowding has increased, more patients have ended up boarding in the emergency department (ED) awaiting their inpatient beds. To the best of our knowledge, no study has compared the quality of care of boarded and nonboarded patients. Objectives: This study sought to examine whether being a boarded patient and boarding longer were associated with more delays, medication errors, and adverse events among ED patients admitted with chest pain, pneumonia, or cellulitis. Methods: This study was a retrospective cohort design in which data collection was accomplished via medical record review from two urban teaching hospitals. Patients admitted with chest pain, pneumonia, or cellulitis between August 2004 and January 2005 were eligible for inclusion. Our outcomes measures were: 1) delays in administration of home medications, cardiac enzyme tests, partial thromboplastin time (PTT), and antibiotics; 2) medication errors; and 3) adverse events or near misses. Primary independent variables were boarded status, boarding time, and boarded time interval. Multiple logistic regression models controlling for patient, ED, and hospital characteristics were used. Results: A total of 1,431 patient charts were included: 811 with chest pain, 387 with pneumonia, and 233 with cellulitis. Boarding time was associated with an increased odds of home medication delays (adjusted odds ratio [AOR] = 1.07, 95% confidence interval [CI] = 1.05 to 1.10), as were boarded time intervals of 12, 18, and 24 hours. Boarding time also was associated with lower odds of having a late cardiac enzyme test (AOR = 0.93, 95% CI = 0.88 to 0.97). Conclusions: Boarding was associated with home medication delays, but fewer cardiac enzyme test delays. Boarding was not associated with delayed PTT checks, antibiotic administration, medication errors, or adverse events ⁄ near misses. These findings likely reflect the inherent resources of the ED and the inpatient units. ACADEMIC EMERGENCY MEDICINE 2011; 18:1339–1348 ª 2011 by the Society for Academic Emergency Medicine

T

he Institute of Medicine (IOM) report ‘‘To Err Is Human’’ brought public attention to the frequency of adverse events in medicine in

the United States.1 Emergency departments (EDs) are an important locus for medical errors,2 due in part to conditions including multiple concurrent tasks,

From the Department of Emergency Medicine (SWL, CAC) and the Department Medicine (YC, JSW, SS), Massachusetts General Hospital, Harvard Medical School, Boston, MA; the Department of Epidemiology (CAC) and Health Policy and Management (SWL, SS), Harvard School of Public Health, Boston, MA; the Division of Emergency Medicine, Washington University School of Medicine (RTG), St. Louis, MO; the Department of Emergency Medicine, Good Samaritan Medical Center (JT), Brockton, MA; the Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine (SN), Sendai, Miyagi, Japan; and the Division of Emergency Medicine, University of Wisconsin School of Medicine & Public Health (AGH), Madison, WI. Received November 10, 2010; revision received January 4, 2011; accepted January 6, 2011. Presented at the American College of Emergency Physicians Scientific Assembly, Boston, MA, October 2009. Funded by the Eleanor and Miles Shore Fellowship and the Risk Management Foundation. The authors have no potential conflicts of interest to disclose. Supervising Editor: Lowell W. Gerson, PhD. Address for correspondence: Shan W. Liu, MD, SD; e-mail: [email protected]. Reprints will not be available.

ª 2011 by the Society for Academic Emergency Medicine doi: 10.1111/j.1553-2712.2011.01082.x

ISSN 1069-6563 PII ISSN 1069-6563583

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AN EMPIRICAL ASSESSMENT OF BOARDING AND QUALITY OF CARE

unpredictable patient presentation, and high workload.3,4 Hospital crowding has emerged as an important factor related to medical error5 and has led to more ‘‘boarded’’ patients (i.e., patients who are admitted but wait in the ED while their inpatient beds become available).6,7 ED care focuses on stabilization and initial diagnosis rather than inpatient management. Because boarded patients receive treatment in areas not designed to function as inpatient units, their care may be suboptimal compared to inpatient levels. Nevertheless, the Joint Commission has mandated that hospitals provide appropriate and adequate care to patients held in temporary bed locations such as the ED.8 The IOM concluded that boarding not only compromises the patient’s experience, but adds to an already stressful environment for ED workers, increasing the potential for errors, treatment delays, and diminished quality of care, and called for the elimination of boarding.9 Important conclusions and policy recommendations regarding boarding have been made with limited supporting data. Studies have shown that longer ED length of stay (LOS) and boarding times are associated with longer hospital LOS, higher rates of recurrent myocardial infarction, increased rates of patients leaving the ED without being seen, diversion, and increased mortality.1,10–18 To the best of our knowledge, no study has compared the quality of care provided to boarded and nonboarded patients. We compared care provided to boarded patients with that given to nonboarded patients. We hypothesized that being a boarded patient and boarding longer increases delays in laboratory checks, administration of antibiotics and home medications, medication errors, and adverse events. METHODS Study Design This was a retrospective cohort study in which data collection was accomplished via medical record review from two urban teaching hospitals. We reviewed records of patients admitted from the ED between August 1, 2004, and January 31, 2005, with chest pain, pneumonia, or cellulitis. Based on pilot work,19 the current study included two sites and an expanded sample size, compared care provided to boarded patients with inpatient unit care, and adapted an instrument from the National Emergency Department Safety Study (NEDSS, a large multicenter study on adverse events20). Our study was approved by the relevant institutional review boards prior to commencement of the study. We received funding from the Eleanor and Miles Shore Grant and the Risk Management Foundation. Study Setting and Population Data came from chart review and administrative databases from two Boston nonprofit, academic, urban teaching hospitals. The hospitals average 54,000 and 80,000 annual ED visits. At one hospital, the emergency physicians (EPs) and ED nurses manage boarded patients; at the other hospital, the inpatient physicians and either ED or inpatient ‘‘float’’ nurses take responsi-

bility for boarded patients. We used a review methodology employed in similar quality-of-care studies:5,20 trained research assistants (RAs) abstracted explicit information from the entire ED chart and first 26 hours of admission. RAs flagged charts containing potential adverse events and copied the entire admission for implicit review (see Data Supplement S1 for the original instrument, available as supporting information in the online version of this paper). We included patients admitted to the hospital from the ED for more than 26 hours with an admission diagnosis of chest pain, pneumonia, or cellulitis. We selected these conditions as they are common reasons for admission, guidelines exist for their care, and they require follow-up laboratory tests and ⁄ or medications that may be delayed for boarded patients.21–26 We used International Classification of Disease, 9th Revision (ICD-9), codes assigned for hospital admission diagnosis to identify patients. We chose a 26-hour window to avoid patients admitted to an observation unit, since only one hospital had an observation unit at the time of the study. At the other hospital, low-risk chest pain patients were often ruled out in the ED and were discharged home. We excluded patients admitted directly to the catheterization suite, transferred from other hospitals, who were less than 18 years of age, needing precaution rooms, and not admitted to standard medicine inpatient units (i.e., operating room, nonmedical teams, or intensive care unit) to minimize extremes of boarding time and maximize patient comparability. Study Protocol We adapted our instrument based on our pilot study,6 the Harvard Emergency Department Quality study,7 standard guidelines for the three conditions,21–26 and the NEDSS project (e.g., by adding questions on time of home medication administration, cardiac enzyme checks, partial thromboplastin time [PTT] checks, and heparin administration).20,27 We refined our instrument (e.g., adding unstable vital signs to the adverse event screen) based on consultation with five board-certified EPs and two doctoral-level health services researchers. Prior to data collection, we piloted chart abstraction forms on 15 pseudo-randomly selected sample charts. The study’s principal investigator (PI, SWL) supervised the administration of chart abstraction and review. RAs (seven medical students, one auxiliary health care student, and one registered nurse) received uniform training that included reviewing sample charts to assure reliability of abstraction using an adapted version of the NEDSS manual.20 RAs used an adapted NEDSS code book that defined important variables. To monitor abstractor performance, there were periodic meetings and evaluations to clarify coding. The PI resolved any data conflicts. Physician reviewers had similar, although less intensive, training. We developed a uniform abstraction form using Microsoft Access, 2003 (Microsoft Inc., Redmond, WA). To establish reliability, the PI reabstracted a randomly selected 4% of charts. Kappa values were 0.84, 0.76, and 0.51 for the presence of a home medication (hydrochlorothiazide), a medication error, and flagging charts as having possible adverse events, indicating

ACADEMIC EMERGENCY MEDICINE • December 2011, Vol. 18, No. 12

moderate to good agreement based on a commonly used classification system.28 Measures Independent Variables. Because no one has determined a specific cutoff point at which quality of care may become compromised for boarding patients, we created three primary independent variables to examine boarding: 1) a dichotomous variable, ‘‘boarded’’ status, indicating whether decision to admit–to–ED departure time was greater than 2 hours using bed request time as a proxy for decision to admit; 2) a continuous variable, ‘‘boarding time,’’ representing the time starting from decision to admit and ending when the patient departed the ED; and 3) a variation on the first and second variables, ‘‘boarded time interval,’’ defined as the time patients spent in the ED starting 2 hours after decision to admit and ending after a 6-, 12-, 18-, or 24hour interval of analysis (see Figure 1). We chose 2 hours after bed request to demarcate boarded patients to be consistent with the ED Benchmarking Summit (the findings of a consensus group created to address standardization of ED performance measures) definition and to create a comparable group of nonboarded patients.29 We defined continuous boarding time according to the ED Benchmarking Summit29 and the Government Accountability Office.3 All nonboarded patients would have been excluded had the start point for the boarding time variable been 2 hours after decision to admit; hence, boarding time had a different start point than the other two variables. We felt that inclusion of all patients better assessed whether boarding time as a continuous variable was related to outcomes. We examined 6-hour intervals given that laboratory tests and medications often have at least 6-hour intervals between tests or administration. ‘‘Nonboarded time’’ represented the time nonboarded patients spent on the inpatient unit starting 2 hours after decision to admit until either 24 hours later or the end of a defined interval of analysis (Figure 1).

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We controlled for certain patient, ED, and hospital characteristics that were potential confounders. At the patient level, we controlled for age, sex, self-reported race ⁄ ethnicity, Emergency Severity Index (ESI), means of ED arrival (e.g., ambulance), and comorbidities, using a Romano-Adjusted Charlson Comorbidity Score (a single variable that aggregates relevant comorbidities modified for use with ICD-9 codes).30–34 We also adjusted for the following ED and hospital characteristics: level of ED crowding at time of bed request, shift when patient arrived at the ED, admission day hospital occupancy, and hospital site.5,10,35 We selected the commonly used Emergency Department Work Index (EDWIN), which includes number of ED patients, admitted patients, ED attending physicians present, treatment bays, and patient triage category, to measure ED crowding. Crowding was divided into three categories based on EDWIN score: 1) active but manageable (2).36,37 Because other studies have examined how crowding affects outcomes, we chose to examine whether boarding, independent of crowding, relates to delays. Hospital occupancy was measured in terms of midnight occupancy. We considered using number of ED patients present to measure crowding, but found that the correlation was less between boarding time and EDWIN. Outcome Measures. Our outcome variables were delays, errors, and adverse events. We examined delays in administration of home medications of all patients, repeat cardiac enzyme checks, PTT tests among chest pain patients, and administration of subsequent antibiotic doses among pneumonia and cellulitis patients. We examined all patients’ usual home medication regimens listed in the admission note and the times first prescribed and administered for the following four medication categories: diabetes, cardiovascular, pulmonary, and gastrointestinal. These medication categories were thought most likely to have clinical relevance if

First 26 hours after admission

“Early Admission Period”

“Boarded time interval” ED work-up period “Boarding time”

B: Decision-toadmit and bed requested

C:

In ED 2 hours after bed request. Becomes “boarded” patient

A: Patients

D:Departure to E:24 hours after Inpatient unit

becoming boarded or nonboarded (26 hours after bed request)

Time

arrive to ED -2h

0h

6h

12h

18h

24h

F:

On inpatient unit within 2 hr of bed request. Becomes “nonboarded” patient

“Nonboarded Nonboarded time” time

Figure 1. Example of flow of boarded and nonboarded patients through the ED. A patient arrives to the ED (Point A). The decision is made to admit the patient and a bed request is made (Point B). After two hours, the patient has either been admitted and is on the floor and is defined as a ‘‘nonboarded’’ patient (Point F), or has not, in which case the patient is still in the ED and is defined as a ‘‘boarded’’ patient (Point C). In this example, the boarded patient stays until the end of the 18 hour ‘‘boarded time interval,’’ which represents 20 hours of ‘‘boarding time’’ (Point D). The ‘‘early admission period’’ represents the 24 hours after the two hour boarded vs. nonboarded demarcation.

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missed. Any medication or its equivalent not administered during a ‘‘reasonable time frame’’ was considered a delayed home medication, unless a reason was specified by the inpatient team. We defined a patient as having delayed home medications if at least 50% of their home medications were delayed. For chest pain patients, we examined delays in obtaining repeat cardiac enzymes as well as PTT tests for patients who received heparin. For cellulitis and pneumonia patients, we examined delays in administration of repeat doses of antibiotics. To calculate laboratory testing intervals, at least two laboratory tests were required for analysis eligibility. Similarly, as antibiotics have different dosing schedules, we calculated intervals only for subsequent doses of the same antibiotic. To define delays and ‘‘reasonable time frame,’’ a panel of three board-certified EPs with administrative and research interests and expertise in quality of care convened prior to data analysis (SWL, RTG, AGH). For laboratory exams, they defined ‘‘delayed’’ as being greater than 2 hours after the standard expected interval between laboratory tests. Eight hours was the standard interval between cardiac tests on the inpatient units at both institutions; therefore, we defined a ‘‘delayed cardiac enzyme’’ as greater than 10 hours after the previous test. Similarly, both institutions used a 6-hour test as the standard after initial heparin administration. Therefore, a ‘‘delayed PTT’’ was 8 hours after starting heparin. We defined ‘‘delayed administration of antibiotics’’ as 30 minutes after the standard dosing interval following Shah and colleagues.38 For home medications, the panel agreed that a ‘‘reasonable time frame’’ was 1.5 times the standard interval for administering the medication. Following the IOM report4 and the NEDSS project,5 we defined an ‘‘error’’ as the failure to complete a planned action or the use of a wrong plan to achieve an aim. ‘‘Medication errors’’ included wrong patient, wrong drug, drug–drug interaction, dose error, route error, frequency error, and incorrect strength. Originally, the NEDSS instrument was used to define medication errors, but we found physician order entry (POE) to affect NEDDS medication events such as lack of date or time. Since one site lacked ED POE, our final definition of medication error only included events unaffected by POE.39 A ‘‘near miss’’ was defined an error that could cause injury, but did not do so because of chance or specific circumstances or because it was intercepted before the injury occurred. An ‘‘adverse event’’ was an injury (a pathologic alteration in condition) that resulted from medical intervention and not from natural progression of the underlying condition; a ‘‘preventable adverse event’’ was an adverse event associated with an error.1,20 Research assistants identified charts with potential adverse events or near misses based on an adapted NEDSS screening instrument.20 Two board-certified EPs then independently verified the presence and preventability of such events (reviewers included SWL, RTG, JT, and AGH). The physicians were required to agree that an event was an adverse event or a near miss and whether they were preventable or intercepted.

Any initial disagreement was resolved through discussion. Data Analysis Differences in characteristics of boarded and nonboarded patients were initially tested with the use of Wilcoxon and chi-square tests. We then calculated differences in frequencies of events. To examine our three independent variables, we had to define an ‘‘exposure period’’ or time frame over which we measured outcomes for each variable. For the dichotomous variable boarded status, the exposure period was the ‘‘early admission period,’’ which represented the first 24 hours after admission starting 2 hours after bed request. To coincide with the start time of the continuous variable boarding time, the exposure period was the first 26 hours after decision to admit. For the boarded time interval variable, our exposure period was the same as the independent variable, which started 2 hours after decision to admit and ended after a 6, 12, 18, or 24-hour interval. Delays or adverse events with a target time within the defined exposure period were eligible for the applicable analysis. We assumed that medication errors occurred during the applicable exposure periods. Because time of medication error was not noted in our instrument, we could not determine exactly when medication errors occurred, only that they occurred sometime during the patient’s ED stay and ⁄ or the first 26 hours after admission. To determine whether boarding was associated with our outcome measures, we used our three definitions of boarding. First, we compared boarded and nonboarded patients in frequency of delays, errors, and adverse events during the early admission period regardless of whether the events occurred in the ED or on the inpatient unit. Second, we examined whether boarding time was associated with outcomes over the first 26 hours of admission. Third, we compared delays and adverse events in patients with boarded time intervals of 6, 12, 18, and 24 hours to nonboarded patients over the same lengths of time. Because boarded patients were censored from analysis if they left the ED before the end of the interval, this analysis localized their outcomes to the ED during that interval. It also allowed for the possibility that events followed a nonlinear pattern. We ran separate logistic regression models for boarded status, boarding time, and boarded time interval for each outcome measure, adjusting for individual, ED, and hospital characteristics previously described. In addition to perceived clinical relevance, variables included in the models were also chosen to control for any imbalance between boarders and nonboarders. All variables in the models were prespecified without employing any of the variable selection techniques. In models with few outcomes, we used a subset of available covariates, retaining those we believed were most related to the dependent variable, to avoid overfitting.40 Model assumptions were checked and model assessment was performed by calculating goodness-of-fit statistics. No adjustment was made for the inflation of type I errors resulting from multiple comparisons.


Sensitivity Analyses We conducted sensitivity analyses by varying the definitions of our outcomes. In addition to our main specifications, we ran multivariable models with patients having delayed home medications if any, 25%, and 75% of their home medications were delayed. For cardiac enzymes, we defined delays as 8 and 9 hours after last check. For PTT, we defined delays to be 6 and 7 hours after heparin was initiated. For antibiotics, we defined delays as 1 and 2 hours after standard dosing interval. We also conducted a within-site analysis. Our pilot study found that 28% of ED patients had an undesirable event while boarding.19 With 1,431 charts, our study had greater than 80% power to detect a 27% difference in undesirable events between boarded and nonboarded patients at the 0.05 level. Originally we powered our study to detect a difference in this composite undesirable event score. However, because patients had variable exposures (e.g., chest pain patients who received heparin had more opportunities for delays than chest pain patients who did not receive heparin) we decided to divide outcomes into separate categories. As a result, we were likely underpowered for certain outcomes such as medication errors and adverse events. Statistical analysis was performed using SAS (Version 9.2, SAS Institute, Cary, NC). RESULTS A total of 1,467 ED patients were eligible for inclusion during the study period. Eleven patients were excluded because they were misclassified (e.g., admission diagnosis stated pneumonia, but patient admitted for abdominal pain). Multiple attempts failed to locate 25 charts. Our final analysis was based on 1,431 charts (811 chest pain, 387 pneumonia, and 233 cellulitis). Characteristics of Study Subjects Our study included 371 nonboarded patients and 1,060 boarded patients. Boarded and nonboarded patients were similar in terms of age, sex, race ⁄ ethnicity, ESI, and adjusted Charlson score (Table 1). Boarded patients arrived more often by ambulance and during the day shift and experienced more ED crowding at the time of bed request. Median time spent in the ED after bed request was 5.2 hours for boarded patients (interquartile range [IQR] = 3.1 to 9.8) and 1.3 hours for nonboarded patients (IQR = 1.0 to 1.7). Main Results Boarded status and boarded time intervals were associated with increases in home medication delays but decreases in some laboratory related delays. Boarded patients had a somewhat higher frequency of missed home medications than nonboarded patients (44%, 95% confidence interval [CI] = 40% to 48% vs. 34%, 95% CI = 28% to 41%) but fewer delayed cardiac enzyme tests (20%, 95% CI = 16% to 23% vs. 34%, 95% CI = 27% to 41%) over the early admission period. There was little difference between boarded and nonboarded patients in terms of antibiotic and PTT test delays (Table 2). Differences in frequency of home medication and cardiac enzyme delays were also observed

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Table 1 Characteristics of Nonboarded Versus Boarded Patients*

Variable

All Patients (n = 1431)

Age, yr, 65 (± 17) mean (± SD) Male (%) 790 (55) Race ⁄ ethnicity, n (%) White 1,047 (73) African American 177 (12) Hispanic 131 (9.2) Asian 25 (1.7) Other 24 (1.7) Not documented 27 (1.9) ESI, mean (± SD) 2.3 ± 0.7 Arrived by 706 (49) ambulance, n (%) Adjusted Charlson 1.0 comorbidity, (0.0–2.0) median (IQR) EDWIN crowding index, n (%) 0 < 1.5 1,050 (73) 1.5–2.0 240 (17) >2.0 141 (9.9) Shift of ED arrival, n (%) 679 (47) Day 7AM–3PM Evening 3PM–11PM 580 (41) 172 (12) Night 11PM–7AM Hospital 89 (± 8) capacity (%), mean (± SD) ED LOS (hours), 9.5 mean (± SD) (± 6.4) Boarding 3.6 time (hours), (2.0–7.6) median (IQR)

Nonboarded Patients (n = 371) 65 (± 16)

Boarded Patients (n = 1,060) 65 (± 17)

197 (53)

593 (56)

257 (69) 62 (17) 34 (9.2) 5 (1.3) 7 (1.9) 6 (1.6) 2.3 ± 0.6 164 (44)

790 (75) 115 (11) 97 (9.2) 20 (1.9) 17 (1.6) 21 (2.0) 2.3 ± 0.7 542 (51)

1.0 (0.0–2.0)

1.0 (0.0–2.0)

300 (81) 52 (14) 19 (5.1)

750 (71) 188 (18) 122 (12)

126 (34) 200 (54) 45 (12) 90 (± 8)

553 (52) 380 (36) 127 (12) 88 (± 8)

5.2 (± 2.4) 1.3 (1.0–1.7)

11.0 (± 6.7) 5.2 (3.1–9.8)

EDWIN = Emergency Department Work Index; ESI = Emergency Severity Index; LOS = length of stay. *Boarded patients are those who stayed in the ED >2 hours after time of bed request.

when we compared nonboarded and boarded time intervals (Table 3). At each 12-, 18-, and 24-hour interval, boarded patients missed home medications more frequently than nonboarded patients. Boarded patients at 6, 12, and 18 hours had significantly fewer delayed cardiac enzymes tests than nonboarded patients (Table 3). After adjusting for covariates, each hour of continuous boarding time increased the odds of delayed home medications by 7% (adjusted odds ratio [AOR] 1.07, 95% CI = 1.05 to 1.10), and 12-, 18-, and 24-hour boarded time intervals were also associated with home medication delays (Table 4). Conversely, boarding time decreased the odds of having a delayed cardiac enzyme check (AOR = 0.93, 95% CI = 0.88 to 0.97), which was also observed at the 12- and 18-hour boarded time intervals. Boarding was not associated with delayed PTT checks or antibiotic administration. We found no differences between boarded and nonboarded patients in terms of medication errors and adverse events. We report these findings in Data Supplement S2 (available

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Table 2 Differences in Delays Between Nonboarded Versus Boarded Patients Over the Early Admission Period

Variable

All Patients

Patients with eligible home meds Delayed home medications, n (%) Chest pain patients Delayed cardiac enzyme check, n (%) Chest pain patients on heparin Delayed prothrombin time, n (%) Pneumonia ⁄ cellulitis patients Delayed antibiotics, n (%)

n= 323 n= 180 n= 102 n= 186

781 (41) 769 (23) 238 (43) 425 (44)

Nonboarded Patients n = 214 73 (34) n = 208 70 (34) n = 77 36 (47) n = 123 50 (41)

95% CI 28 to 41 27 to 41 35 to 59 32 to 50

Boarded Patients n = 567 250 (44) n = 561 110 (20) n = 161 66 (41) n = 302 136 (45)

95% CI 40 to 48

Difference % (95% CI) 10 (2.4 to 18)

16 to 23

)14 ()21 to )6.8)

33 to 49

)5.8 ()19 to 7.7)

39 to 51

4.4 ()6.0 to 15)

Unless otherwise specified, n = patients at risk for outcome.

Table 3 Frequency of Delays During Six-hour Nonboarded and Boarded Time Intervals

Hours Delay

Delay: All Patients at Risk (%)

Home medications 6 50 ⁄ 67 (75) 12 85 ⁄ 150 (57) 18 101 ⁄ 250 (40) 24 79 ⁄ 225 (35) Cardiac enzymes 6 38 ⁄ 120 (32) 12 77 ⁄ 277 (28) 18 72 ⁄ 242 (30) 24 70 ⁄ 211 (33) Prothrombin time 6 23 ⁄ 56 (41) 12 35 ⁄ 82 (43) 18 35 ⁄ 80 (44) 24 36 ⁄ 78 (46) Antibiotics 6 24 ⁄ 41 (59) 12 43 ⁄ 95 (45) 18 48 ⁄ 104 (46) 24 51 ⁄ 127 (40)

Nonboarded Patients Present

Delay: Nonboarded Patients (%)*

95% CI

Boarded Patients Present

214 214 214 214

31 ⁄ 42 (74) 52 ⁄ 104 (50) 71 ⁄ 206 (35) 71 ⁄ 214 (33)

58–86 40–60 28–41 27–40

171 100 44 11

19 ⁄ 25 (76) 33 ⁄ 46 (71) 30 ⁄ 44 (68) 8 ⁄ 11 (73)

55–91 57–84 52–81 39–94

208 208 208 208

38 ⁄ 93 (41) 70 ⁄ 205 (34) 70 ⁄ 208 (34) 70 ⁄ 208 (34)

31–52 28–41 27–41 27–41

162 78 34 3

0 ⁄ 27 (0) 7 ⁄ 72 (9.7) 2 ⁄ 34 (5.9) 0 ⁄ 3 (0)

0–13 4.0–19 0.7–20 0–71

)41 )2 )28 )34

()61 ()37 ()45 ()91

to to to to

)20) )11) )9.8) 32)

20 ⁄ 43 31 ⁄ 66 33 ⁄ 71 36 ⁄ 77

31–62 35–60 35–59 35–59

36 18 9 1

3 ⁄ 13 (23) 4 ⁄ 16 (25) 2 ⁄ 9 (22.2) 0 ⁄ 1 (0)

5.0–54 7.3–52 2.8–60 0–98

)23 )22 )24 )47

()54 ()48 ()60 ()98

to to to to

7.9) 5.4) 11) 49)

39–80 32–56 35–57 32–50

99 57 25 4

10 ⁄ 18 (56) 13 ⁄ 26 (50) 8 ⁄ 17 (47) 1 ⁄ 4 (25)

31–79 30–70 23–72 0.6–81

)5.3 ()36 to 25) 6.5 ()16 to 29) 1.1 ()25 to 27) )16 ()67 to 39)

77 77 77 77 123 123 123 123

(47) (47) (47) (47)

14 ⁄ 23 (61) 30 ⁄ 69 (44) 40 ⁄ 87 (46) 50 ⁄ 123 (41)

Delay: Boarded Patients (%)*

95% CI

Difference % (95%CI) 2.2 ()19 to 24) 22 (5.6 to 38) 34 (19 to 49) 40 (13 to 67)

*For each specific six-hour interval, the denominator represents the number of patients with medications or laboratory tests that would be due before the end of that time interval. The denominator may differ from the number of patients present because no outcome was due before the end of that time interval. The numerator represents the number of outcomes. Outcomes listed for boarding patients differ from Table 2 because patients were censored if they were not in the ED at the end of the interval.

as supporting information in the online version of this paper). Sensitivity Analysis Our findings that boarding time was associated with higher frequency of home medications delays remained robust when the dependent variables were defined as missing any, 25%, or 75% of home medications (AOR = 1.07, 95% CI = 1.04 to 1.10; AOR = 1.07, 95% CI = 1.04 to 1.10; and AOR = 1.09, 95% CI = 1.06 to 1.12, respectively) and even when we conducted a within-site analysis (50% delayed home medications AOR = 1.08, 95% CI = 1.04 to 1.11, for Site 1; and AOR = 1.07, 95% CI = 1.00 to 1.14, for Site 2). Similarly, when we defined cardiac enzymes test delays to be 8 or 9 hours after a previous laboratory draw, boarding time was associated with fewer delays

(AOR = 0.96, 95% CI = 0.94 to 0.99; and AOR = 0.97, 95% CI = 0.94 to 0.99, respectively). Furthermore, analyses of cardiac enzyme delays at 10 hours for Site 1 and Site 2 were both similar (AOR = 0.92, 95% CI = 0.87 to 0.98; and AOR = 0.91, 95% CI = 0.83 to 0.99, respectively). Our heparin, antibiotic, and medication errors sensitivity analyses also supported the original findings. DISCUSSION Despite policy recommendations from several agencies, the issue of boarding in the ED remains widespread. In this study, boarded patients arrived more often during the daytime shift (hospital discharges may have occurred more often in the evening, leading to shorter boarding times for those patients who arrived during


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Table 4 Multivariable Logistic Regression of Boarded Status, Boarding Time, and Boarded Time Intervals on Delays for the Entire Early Admission Period, First Twenty-six Hours of Admission, and Six-hour Intervals Exposure period and independent variables:

Outcomes: Delayed 50% home medications Delayed cardiac enzymes Delayed prothrombin time Delayed antibiotics

Early Admission Period

First 26 hours of Admission

Boarded vs. Nonboarded Patients

Boarding Time (Hours), Adjusted

n = 781 1.23 (0.85–1.78) n = 769 0.70 (0.46–1.05) n = 238 0.91 (0.47–1.78) n = 425 1.08 (0.67–1.73)

n = 781 1.07 (1.05–1.10) n = 769 0.93 (0.88–0.97) n = 238 0.97 (0.92–1.04) n = 425 1.01 (0.97–1.04)

6 Hours*

12 Hours

18 Hours

24 Hours

Boarded Time Interval vs. Nonboarded Time Interval

Boarded Time Interval vs. Nonboarded Time Intervalà

Boarded Time Interval vs. Nonboarded Time Intervalà

Boarded Time Interval vs. Nonboarded Time Interval

n = 67 1.19 (0.37–3.83) NA

n = 150 2.47 (1.16–5.24) n = 277 0.21 (0.09–0.48) n = 82 0.38 (0.11–1.29) n = 95 1.34 (0.54–3.35)

n = 250 4.10 (2.04–8.24) n = 242 0.12 (0.03–0.53) n = 80 0.33 (0.06–1.69) n = 104 1.04 (0.35–3.05)

n = 225 5.21 (1.34–20.27) NA

n = 56 0.35 (0.08–1.43) n = 41 0.81 (0.23–2.85)

NA n = 127 0.51 (0.05–5.04)

Values are presented as n = number of patients at risk for outcome and AOR (95% CI). The models control for age, sex, race ⁄ ethnicity, ESI, means of arrival, Charlson comorbidity, shift of arrival, EDWIN score, hospital capacity, and site, unless otherwise noted. AOR = adjusted odds ratio; EDWIN = Emergency Department Work Index; ESI = Emergency Severity Index; NA = the numerators presented in Table 3: odds ratios are not available when there were no events; PTT = partial thromboplastin time. *Limited to the follow-up time in the specified boarded time interval. Boarded patients were censored from analysis if they left before the end of the interval. Due to limited sample size, these analyses only controlled for age. PTT had no adjustment due to rarity of outcomes. Table 2 lists number of outcomes for boarded versus nonboarded status variable and Table 3 for boarded and nonboarded time interval analysis. The number of outcomes for the boarding time variable was the same as for the boarded status variable. àAdjusted odds ratios, but adjusted for age only outcome due to the limited sample size. The only exception is the row labeled as ‘‘Delayed prothrombin time’’—no adjustment was done for this due to rarity of outcomes.

the evening shift) and had more home medication delays but fewer delayed cardiac enzyme tests than nonboarded patients during the early admission period. There were no differences in PTT tests, antibiotic delays, medication errors, or adverse events. Interval and multivariable regression analysis yielded similar results. Little empirical evidence exists comparing quality of care between ED-boarded patients and nonboarded patients. Although studies suggest that boarding patients have lower satisfaction scores than nonboarding patients, there remains a dearth of information about the effect of boarding.41,42 Viccellio et al.43 found mortality rates to be higher for patients who were admitted to standard inpatients beds than for patients who boarded on inpatient unit hallways, although this may have been due to patient complexity and acuity rather than a hallway benefit. Otherwise, the closest comparable studies examined the transition between ED and inpatient units or ED LOS. Shah et al.38 found that 38% (212 ⁄ 551) of patients who had their first dose of antibiotics in the ED had at least a 30-minute delay in antibiotic administration on the floor. Our study found a similar rate of delay (44% of all patients). Diercks et al.12 found that patients with ED LOS greater than 8 hours had decreased adherence to American Heart Association guidelines for myocardial infarctions

and increased rates of myocardial reinfarction compared to patients with ED LOS of 4 to 8 hours (AOR = 1.23, 95% CI = 1.01 to 1.48). Chalfin et al.14 found that hospital survival was significantly lower in patients transferred to the intensive care unit with ED LOS of greater than 6 hours, compared with less than 6 hours (17.4% vs. 12.9%). However, these latter two studies were based on voluntary, observational data. Richardson11 found that patients with ED LOS of greater than 8 hours had mean hospital LOS of 4.9 days versus 4.1 days for patients with ED LOS of less than 8 hours. While these studies indicate that long ED LOS may be undesirable, none compared care while boarding in the ED with care on inpatient units. From a systems perspective, multiple reasons may account for home medication delays while boarding. First, the inability to transfer patients to inpatient units has been cited as the main contribution to ED crowding.6 As ED crowding increases, EPs turn their attention to new patients before attending to those already evaluated, e.g., boarded patients.44 However, our models controlled for crowding, suggesting that while boarded patients are a component of ED crowding, boarding may be an independent factor. Our results were no different when we removed crowding from our models. Inherent systems issues may impede EDs from providing home medications in as timely a

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manner as provided by inpatient units. This may be secondary to the difference between the ED and inpatient unit environments, such as availability of chronic home medications or nursing perceived scope of practice. Furthermore, longer boarding times mean that many patients remain beyond the shift of the original caregiving team. The more handoffs patients undergo between teams, the greater the likelihood of communication failure and medical errors.45 Conversely, in the case of cardiac enzyme checks, boarding was associated with fewer delays. This suggests that some care provided to boarding patients is better than that found on inpatient units. Multiple reasons may influence why patients have delayed cardiac enzyme tests while on the inpatient units. Inpatient teams are expected to perform more comprehensive histories and physical exams before writing laboratory orders. Also, inpatient laboratory tests depend on phlebotomists’ schedule, while ED samples are drawn by the ED nurses or aides, likely decreasing delays. Furthermore, cardiac enzyme tests sent from the ED may be processed through use of point-of-care testing and may have a quicker turnaround time than those processed at the central laboratory. Finally, ED personnel may be more attuned to cardiac care and therefore be more vigilant about checking cardiac tests than ordering home medications. LIMITATIONS First, as mentioned previously, we powered our study based on a calculation of a composite score from our pilot study. Because we divided outcomes into separate categories, our null findings for PTT, antibiotics, errors, and adverse events may be due to sample size (type II error). We did not adjust for multiple comparisons. Because our home medication and cardiac enzyme outcomes were similar in different analyses, our results are not likely due to chance. Second, chart abstraction methods have inherent limitations in terms of accurately measuring quality of care.46 Valid reasons not documented may account for patients not receiving certain home medications or antibiotics, potentially overstating the frequency of delays. However, this potential bias would likely be distributed similarly across all patients and would unlikely affect our findings. Third, while substantial reliability existed for home medication and medication errors, only moderate agreement appeared for adverse events. This may reflect rarity of adverse events28 and could have led to fewer charts being flagged. Fourth, chart abstractors and physician reviewers were not blinded to our hypothesis, which may affect internal validity. Fifth, we adjusted for several potential confounders; however, residual confounding likely remains. Certain system differences such as presence of POE and point-of-care testing in one hospital and not the other may have biased results. Also, some models lacked full sets of covariates due to scarcity of outcomes. Finally, our instrument has not been validated other than through this study. We adapted our instrument largely from a large national study on ED errors (NEDSS), but no criterion standard for measuring quality of care exists for boarded patients.20

CONCLUSIONS Our study indicates that the quality of care for patients boarding in the ED and patients on inpatient units differs. Care for boarded patients worsens in areas for which the ED is not designed (e.g., delivery of routine home medications). This finding may extend to other routine, nonacute functions of inpatient care. By contrast, ED care is better in areas that are more consistent with typical ED practice, such as cardiac enzyme checks. This study suggests that the quality of care depends on the systems of care and resources available at that location. While the elimination of ED boarding altogether would obviate these issues, such a solution is not imminent. Meanwhile, systems that aim to improve ED care for boarding patients should focus on decreasing those aspects of care that fall outside the routine systems of ED care, such as provision of home medications. This may include creating computer-based flags requiring admission orders or transferring responsibility of boarded patients to inpatient teams. Future studies should examine the generalizability of our findings to other EDs and whether such policies can improve the quality of care provided to boarded patients. We acknowledge Dr. Peter Sprivulis and Dr. Robin Weinick who were instrumental in the formation of this project. We thank physician reviewers Drs. Stephen Thomas and Keith Marill for their labor and time, as well as research assistants, Drs. John Burger, Suvd Nergui, Roberta Capp, Quetzalsol Lopez, Razi Rashid, Jeanie Yoon, Maria Nemethy, Erica Chiu, and Melanie Mathews and Chinna Udoji, for their hard work. We appreciate Dr. Sydney Cash, Donald Halstead, and Alice Storey for their editing assistance.

References 1. Kohn LT, Corrigan J, Donaldson MS. To Err Is Human: Building a Safer Health System. Washington, DC: National Academies Press, 2000. 2. Handler JA, Gillam M, Sanders AB, Klasco R. Defining, identifying, and measuring error in emergency medicine. Acad Emerg Med. 2000; 7:1183–8. 3. Thomas EJ, Studdert DM, Burstin HR, et al. Incidence and types of adverse events and negligent care in Utah and Colorado. Med Care. 2000; 38:261– 71. 4. Studdert DM, Thomas EJ, Burstin HR, Zbar BI, Orav EJ, Brennan TA. Negligent care and malpractice claiming behavior in Utah and Colorado. Med Care. 2000; 38:250–60. 5. Weissman JS, Rothschild JM, Bendavid E, et al. Hospital workload and adverse events. Med Care. 2007; 45:448–55. 6. United States. General Accounting Office. United States Congress, Senate. Committee on Finance. Hospital Emergency Departments Crowded Conditions Vary Among Hospitals and Communities. Available at: http://purl.access.gpo.gov/GPO/LPS 32265. Accessed Jan 22, 2011. 7. Derlet RW, Richards JR. Overcrowding in the nation’s emergency departments: complex causes and disturbing effects. Ann Emerg Med. 2000; 35:63–8.


8. The Joint Commission. New Leadership Standard on Managing Patient Flow for Hospitals. Available at: http://www.ed-qual.com/emergency_medicine_ news/JCAHO_Patient_Flow_Standard.htm. Accessed Jan 22, 2011. 9. Institute of Medicine. Hospital-based Emergency Care at the Breaking Point. Washington, DC: National Academies Press, 2006. 10. Richardson DB. Increase in patient mortality at 10 days associated with emergency department overcrowding. Med J Aust. 2006; 184:213–6. 11. Richardson DB. The access-block effect: relationship between delay to reaching an inpatient bed and inpatient length of stay. Med J Aust. 2002; 177:492–5. 12. Diercks DB, Roe MT, Chen AY, et al. Prolonged emergency department stays of non-ST-segmentelevation myocardial infarction patients are associated with worse adherence to the American College of Cardiology ⁄ American Heart Association guidelines for management and increased adverse events. Ann Emerg Med. 2007; 50:489–96. 13. Pines JM, Hollander JE, Localio AR, Metlay JP. The association between emergency department crowding and hospital performance on antibiotic timing for pneumonia and percutaneous intervention for myocardial infarction. Acad Emerg Med. 2006; 13:873–8. 14. Chalfin DB, Trzeciak S, Likourezos A, Baumann BM, Dellinger RP. Impact of delayed transfer of critically ill patients from the emergency department to the intensive care unit. Crit Care Med. 2007; 35:1477–83. 15. Falvo T, Grove L, Stachura R, et al. The opportunity loss of boarding admitted patients in the emergency department. Acad Emerg Med. 2007; 14:332–7. 16. Hoot NR, Aronsky D. Systematic review of emergency department crowding: causes, effects, and solutions. Ann Emerg Med. 2008; 52:126–36. 17. Fatovich DM, Nagree Y, Sprivulis P. Access block causes emergency department overcrowding and ambulance diversion in Perth, Western Australia. Emerg Med J. 2005; 22:351–4. 18. Schull MJ, Lazier K, Vermeulen M, Mawhinney S, Morrison LJ. Emergency department contributors to ambulance diversion: a quantitative analysis. Ann Emerg Med. 2003; 41:467–76. 19. Liu SW Gordon JA, Hamedani AG, Thomas SH, Weissman J. A pilot study examining undesirable events among emergency department-boarded patients awaiting inpatient beds. Ann Emerg Med. 2009; 53:381–5. 20. Sullivan AF, Camargo CA Jr, Cleary PD, et al. The National Emergency Department Safety Study: study rationale and design. Acad Emerg Med. 2007; 14:1182–9. 21. American College of Emergency Physicians. Clinical policy for the management and risk stratification of community-acquired pneumonia in adults in the emergency department. Ann Emerg Med. 2001; 38:107–113. 22. Smith EE III, Braen GR, Cantrill SV, et al. Clinical policy for the initial approach to adults presenting

•

www.aemj.org

23.

24.

25.

26.

27.

28.

29.

30.

31.

32.

33.

34.

35.

36.

37.

1347

with a chief complaint of chest pain, with no history of trauma. Ann Emerg Med. 1995; 25:274–99. Mandell LA, Wunderink RG, Anzueto A, et al. Infectious Diseases Society of America ⁄ American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in edults. Clin Infect Dis. 2007; 44(Suppl 2):S27–72. Stevens DL, Bisno AL, Chambers HF, et al. Practice guidelines for the diagnosis and management of skin and soft-tissue infections. Clin Infect Dis. 2005; 41:1373–406. Marras TK, Chan CK. Use of guidelines in treating community-acquired pneumonia. Chest. 1998; 113: 1689–94. Campbell SG, Ackroyd-Stolarz S, Pierce S, Burton-Macleod R, Gerami D. An emergency department protocol for the management of cellulitis: a CQI pilot project. Israeli J Emerg Med. 2005; 5:43–54. Burstin HR, Conn A, Setnik G, et al. Benchmarking and quality improvement: the Harvard Emergency Department Quality Study. Am J Med. 1999; 107: 437–49. Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics. 1977; 33:159–74. Welch SJ. The emergency department performance measures and benchmarking summit. EM News. 2006; 28:24–5. Tanabe P, Gimbel R, Yarnold PR, Kyriacou DN, Adams JG. Reliability and validity of scores on The Emergency Severity Index version 3. Acad Emerg Med. 2004; 11:59–65. Romano PS, Roost LL, Jollis JG. Presentation adapting a clinical comorbidity index for use with ICD9-CM administrative data: differing perspectives. J Clin Epidemiol. 1993; 46:1075–9. Romano PS, Roost LL, Jollis JG. Further evidence concerning the use of a clinical comorbidity index with ICD-9-CM administrative data. J Clin Epidemiol. 1993; 46:1085–90. Schneeweiss S, Seeger JD, Maclure M, Wang PS, Avorn J, Glynn RJ. Performance of comorbidity scores to control for confounding in epidemiologic studies using claims data. Am J Epidemiol. 2001; 154:854–64. Eitel DR, Travers DA, Rosenau AM, Gilboy N, Wuerz RC. The emergency severity index triage algorithm version 2 is reliable and valid. Acad Emerg Med. 2003; 10:1070–80. Sprivulis PC, Da Silva JA, Jacobs IG, Frazer AR, Jelinek GA. The association between hospital overcrowding and mortality among patients admitted via Western Australian emergency departments. Med J Aust. 2006; 184:208–12. Bernstein SL, Verghese V, Leung W, Lunney AT, Perez I. Development and validation of a new index to measure emergency department crowding. Acad Emerg Med. 2003; 10:938–42. Jones SS, Allen TL, Flottemesch TJ, Welch SJ. An independent evaluation of four quantitative emergency department crowding scales. Acad Emerg Med. 2006; 13:1204–11.

1348

Liu et al.

•


38. Shah MN, Schmit J, Croley WC, Meltzer D. Continuity of antibiotic therapy in patients admitted from the emergency department. Ann Emerg Med. 2003; 42:117–23. 39. Bates DW, Leape LL, Cullen DJ, et al. Effect of computerized physician order entry and a team intervention on prevention of serious medication errors. JAMA. 1998; 280:1311–6. 40. Ahrens W, Pigeot I (eds). Handbook of Epidemiology. Berlin: Springer, 2005. 41. Pines JM, Iyer S, Disbot M, Hollander JE, Shofer FS, Datner EM. The effect of emergency department crowding on patient satisfaction for admitted patients. Acad Emerg Med. 2008; 15:825–31. 42. Garson C, Hollander JE, Rhodes KV, Shofer FS, Baxt WG, Pines JM. Emergency department patient preferences for boarding locations when hospitals are at full capacity. Ann Emerg Med. 2008; 51:9–12. 43. Viccellio A, Santora C, Singer AJ, Thode HC Jr, Henry MC. The association between transfer of emergency department boarders to inpatient hallways and mortality: a 4-year experience. Ann Emerg Med. 2009; 54:487–91. 44. Hollander JE, Pines JM. The emergency department crowding paradox: the longer you stay, the less care you get. Ann Emerg Med. 2007; 50:497–9.

45. Horwitz LI, Krumholz HM, Green ML, Huot SJ. Transfers of patient care between house staff on internal medicine wards: a national survey. Arch Intern Med. 2006; 166:1173–7. 46. Luck J, Peabody JW, Dresselhaus TR, Lee M, Glassman P. How well does chart abstraction measure quality? A prospective comparison of standardized patients with the medical record. Am J Med. 2000; 108:642–9. Supporting Information The following supporting information is available in the online version of this paper: Data Supplement S1. Chart review instruments. Data Supplement S2. Differences in medication errors and adverse events between nonboarded versus and boarded patients over the early admission period. The documents are in PDF format. Please note: Wiley Periodicals Inc. is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing material) should be directed to the corresponding author for the article.