Brief Report

Etiology of uncompleted exercise Stress testing after ED chest pain evaluation

Brittany A. Zwischenberger ^a,?, Billy J. Moore PhD ^b, Samuel D. Luber MD, MPH ^c, Florence J. Dallo PhD, MPH ^d

^aThe University of Texas Southwestern Medical School, Dallas, TX 75390, USA

^bCenter for Knowledge Translation & Clinical Innovation, Parkland Health and & Hospital System, Dallas, TX 75235, USA

^cDepartment of Surgery, Division of Emergency Medicine, University of Texas Southwestern Medical Center, Dallas,

TX 75390, USA

^dThe University of Texas School of Public Health, Dallas, TX 75390, USA

Received 9 October 2009; accepted 11 January 2010

Abstract

Objective: Emergency department (ED) chest pain protocols often include an exercise stress test (EST) in an outpatient setting to further risk stratify patients initially identified as low risk for acute coronary syndrome. Our goal was to characterize the noncompliant patient population and delineate reasons for uncompleted EST.

Methods: We conducted retrospective chart review of all ED-scheduled ESTs over a 6-month period. Demographic and compliance information was abstracted using standardized instrument, a 1-month consecutive patient subset was identified, and a telephone interview was conducted with noncompliant patients to determine why they did not complete their EST.

Results: From January to July 2007, 57% (378/668) of patients were noncompliant with the ED-scheduled EST. In the subset, 78% (78/100) did not complete the EST: 58 patients never showed for their scheduled EST and 20 patients showed but could not initiate the EST because it was deemed inappropriate by health care workers in the cardiovascular laboratory or they began the test and it was nondiagnostic. Noncompliant patients were more likely to be male, unmarried, African American, and uninsured compared to compliant patients (P b .05). The most commonly stated reasons for noncompliance were miscommunication, financial, or inconvenience of scheduled time. Employed patients were more likely to state financial reasons for noncompliance, whereas unemployed patients were more likely to state personal reasons (P b .05).

Conclusions: Our findings suggest lack of patient comprehension about purpose and logistics of EST completion. Based upon our data, the ED should confirm the appropriateness of the EST for each patient and improve patient communication and EST availability.

(C) 2011

* Corresponding author. Bryan Williams MD Student Center, c/o Suzette Smith, Dallas, TX 75390-9001, USA. Tel.: +1 409 771 6714; fax: +1 214

648 5686.

E-mail address: [email protected] (B.A. Zwischenberger).

0735-6757/$ - see front matter (C) 2011 doi:10.1016/j.ajem.2010.01.001

Introduction

• 1. Background

In 2004, 5.4% of emergency department (ED) visits in the United States were for chest pain [1]. Because only a small fraction actually have an acute coronary syndrome (ACS) as the cause of their chest pain, EDs often follow chest pain algorithms for physicians to establish probability of cardiac ischemia. These algorithms include a combination of history/ physical examination, laboratory studies, and provocative stress testing. Use of provocative testing, including an exercise stress test (EST) or a pharmacologically induced stress test conducted during the ED visit or as an outpatient, is recommended for patients with low risk of clinically significant coronary artery disease and decreases Hospital admission rates [2].

The EST is designed to risk stratify chest pain of Cardiac origin and ultimately identify coronary artery disease [3]. Importantly, ED chest pain algorithms that discharge low- risk patients to an outpatient EST rely heavily on patient compliance to show for the scheduled EST. Previous research has shown that patient compliance is influenced by who schedules the appointment. When ED staff schedule follow-up appointments, patient compliance rates range from 60% to 71% [4,5]. Moreover, when the family physician schedules the EST, patients show 56.1% compliance compared to 72.5%, when the ED staff schedules the appointment [6]. Therefore, many patients referred for EST are lost to follow-up and are at risk of a future ACS event.

In this study, we have 2 aims: (1) characterize the noncompliant ED patient population and (2) determine reasons for noncompliance.

Methods

We conducted a Retrospective electronic chart review of all ED-scheduled ESTs over a 6-month period. In addition, we created a subset of patients that could be contacted for survey via phone. Institutional review board approval was obtained. We conducted this study at an urban tertiary care teaching hospital with a yearly ED census of approximately 87 000 visits in patients aged 18 and older presenting in the ED with chest pain of probable or possible cardiac etiology who subsequently received an outpatient EST appointment. The hospital uses a 5-level triage system for patients presenting to the ED with chest pain. Clear evidence of a ST elevation myocardial infarction is classified as a level 1, and after evaluation and stabilization, the patient is taken to the cardiac catheterization laboratory. Patients with a non-ST elevation myocardial infarction or unstable angina are classified as level 2 and admitted. After History taking and physical examination, patients with chest pain of probable cardiac etiology are designated level 3 and undergo a 9-hour

cardiac marker rule out and evaluation by the cardiology service before admission or discharge with or without outpatient provocative testing. Patients with possible cardiac chest pain (level 4) undergo the same 9-hour biomarker rule out, and if negative, the ED staff schedules an outpatient stress test. Finally, patients with chest pain of noncardiac origin, as determined by history/physical examination, receive a designation of level 5. This algorithm results in an estimated 20% of chest pain patients being discharged with scheduled outpatient EST. If the stress test is positive or abnormal, the patient is referred to cardiology.

Eligible study patients were 18 years or older, designated probable or possible (level 4 and 3, respectively) chest pain of cardiac origin, and had been scheduled for an EST by the ED. We queried the electronic medical records to determine if the patient completed the EST and recorded the outcome. We defined compliance as showing for the EST.

To determine reasons why the EST was not completed, we identified a 1-month consecutive patient subset from the medical records. If the patient was noncompliant, we conducted a phone survey within 1 week of the scheduled EST appointment to determine reasons for noncompliance. We made up to 3 telephone calls, staggered through time of day and day of the week to maximize the likelihood of contacting potential respondents. The subset was created to reduce recall bias during the phone surveys. The key outcome measure was compliance vs noncompliance. If noncompliant, we attempted to determine the reason(s).

We used frequencies and proportions to describe the sample and ?2 tests to compare compliant and non- compliant patients.

Results

Over the 6-month period (from January 1 to July 18, 2007), 3267 patients stated chest pain as their chief complaint, and 668 patients were evaluated as a probable or possible ED chest pain patient and subsequently scheduled for an outpatient EST. Of these, 378 (57%) did not show for their scheduled EST appointment. Compared to compliant patients, noncompliant patients were more likely to be male, not married, African American, and uninsured (P b .05) (Table 1). Noncompliant patients were more likely to have visited the ED 3 or more times in the past year compared to compliant patients (P b .05). In addition, noncompliant patients were more likely to have visited the ED for chest pain 2 or more times in the past 6 months compared to compliant patients (P b .05). There was no significant difference (P N .05) in compliance when comparing the number of days after the ED visit that the staff scheduled the EST (<=7 or N7 days).

From our 6-month cohort, the 1-month subset included 100 patients. Only 22 patients (22%) scheduled for an EST completed the test. Of the 78 patients who did not complete

Reason	Frequency
Communication, did not know EST date	8 (23.5)
Financial	7 (20.6)
Sick	4 (11.8)
Time inconvenient	4 (11.8)
No transportation	3 (8.8)
Admitted before EST date	3 (8.8)
Forgot	2 (5.9)
No longer had chest pain	2 (5.9)
Did not like hospital	1 (2.9)

Table 3 Reasons given by patient for noncompliance: June 19, 2007, to July 18, 2007, n (%), n = 34

the EST, 58 patients never showed and 20 patients were unable to complete the EST. Table 2 illustrates compliant and noncompliant patients did not differ by sociodemo- graphic characteristics. Of the 58 who did not show, we interviewed 34 (Table 3). Others were not surveyed, primarily due to out-of-service telephone numbers.

Table 1 Demographics of patients scheduled for an EST after an ED visit for chest pain: January 1, 2007, to July 18, 2007, n (%), n = 668

Table 2 Demographics of patients scheduled for an EST after an ED visit for chest pain: June 19, 2007, to July 18, 2007, n (%), n = 100

Compliant			Noncompliant	P
Total sample	290	(43.4)	378 (56.6)
Age				NS
22-45	93	(32.1)	122 (32.4)
46-54	96	(33.1)	135 (35.7)
>=55	101	(34.8)	121 (32.1)
Sex				b.05
Female	182	(62.8)	199 (52.7)
Male	108	(37.2)	179 (47.3)
Race/ethnicity				b.05
Black	117	(40.9)	196 (52.4)
White	109	(38.1)	131 (35.0)
Hispanic	44	(15.4)	30 (8.0)
Other	16	(5.6)	17 (4.6)
marital status				b.05
Married	114	(39.9)	102 (27.5)
Not married	172	(60.1)	269 (72.5)
Insurance				b.05
Yes	204	(70.6)	226 (60.0)
No	85	(29.4)	151 (40.1)
NS indicates not significant.

Compliant Noncompliant P
Total sample	42	(42.0)	58	(58.0)
Age					NS
22-45	10	(23.8)	17	(29.3)
46-54	16	(38.1)	18	(31.0)
>=55	16	(38.1)	23	(39.7)
Sex					NS
Female	28	(66.7)	29	(50.0)
Male	14	(33.3)	29	(50.0)
Race/ethnicity					NS
Black	19	(46.3)	27	(47.4)
White	13	(31.7)	16	(28.7)
Hispanic	6	(14.6)	9	(15.8)
Other	3	(7.3)	5	(8.8)
Marital status					NS
Married	15	(36.6)	22	(38.6)
Not married	26	(63.4)	35	(61.4)
Insurance					NS
Yes	29	(69.1)	29	(50.0)
No	13	(31.0)	29	(50.0)

The most common reasons for noncompliance were miscommunication (ie, did not know appointment date, n = 8), financial (n = 7), and scheduled time was inconvenient (n = 4). Patients also provided the following, which we categorized as “personal”: sick (n = 4), no transportation (n = 3), and other (forgot, no longer had chest pain, and did not like hospital, n = 5). Finally, 3 patients were subsequently admitted to the hospital (2 due to recurring chest pain and 1 for an unrelated complaint) during the study period and therefore missed their scheduled outpatient EST. Seven of 8 patients reported they “would have been more likely” to show if the appointment had been offered at the nearby affiliated primary care outpatient clinic rather than the hospital. Those employed were significantly more likely to state financial reasons, and those unemployed were signif- icantly more likely to state personal reasons for not showing

for the EST (Table 4).

Eight (75%) of 12 self-pay patients reported receiving instructions to enroll in the hospital insurance plan before stress testing. Of these 8, 2 (25%) reported they were successful; 3 (37.5%) reported the application process was clear but they were unsuccessful for personal reasons, and 3 reported the process was unclear.

Of 42 patients who showed for the EST, 20 did not complete the test. Six (14.3%) started, but it was non- diagnostic (the patient could not reach the target stress level). Fourteen (33.3%) patients did not start the EST (exercise test was deemed inappropriate). Of these 14 patients, 5 (35.7%) could not walk, 3 (21.4%) had an EST within the past few months, and 3 were hypertensive. Of the 22 patients who completed the test, 9 had normal and 13 had abnormal results. Therefore, 60% of the patients completing the EST had positive results and received a referral to cardiology.

Limitations

Our sample may not be representative of patients at other EDs presenting with a complaint of chest pain. We could only survey patients with working phone numbers, which affects systematic, internal validity. In addition, the surveys could

Total		Time lag		Employment			P
(%)		<=7 d N7 d			Yes No
Personal	38.7	12 (44.4)	0 (0.0)	1 (11.1)		11 (50.0)	b.05
Communication	25.8	7 (25.9)	1 (25.0)	2 (22.2)		6 (27.3)	b.05
Financial	22.6	4 (14.8)	3 (75.0)	5 (55.6)		2 (9.1)	b.05
Time inconvenient	12.9	4 (14.8)	0 (0.0)	1 (11.1)		3 (13.6)	b.05

only be conducted between June and July 2007 due to author availability. We used electronic databases not controlled for quality, and we did not have access to economic databases for confirmatory data. The study was retrospective and not designed to assess outcomes, only compliance.

Table 4 Frequency (n [%]) of reasons given for noncompliance by time lag and Employment status, June 19, 2007, to July 18, 2007, n = 31 ^a

^a “Admitted” patients (n = 3) were not included in this analysis.

Discussion

Our study found that more than 75% of ED-scheduled ESTs were not completed. A previous study conducted at the ED of 10 US hospitals concluded 2.1% of patients with acute myocardial infarction and 2.3% of patients with unstable angina are mistakenly discharged from the ED due to missed diagnosis at the time of presentation [7]. Furthermore, the risk-adjusted ratio of observed to predicted mortality of these patients was 1.7% to 1.9% higher than those initially hospitalized. Clearly, follow-up with patients presenting with symptoms potentially due to ACS and not admitted to the hospital is a valuable step to decrease missed diagnoses. Our findings suggest there is a lack of comprehension about the purpose and logistics of completing the EST. The ED must first confirm the appropriateness of the EST for each patient. Referring patients who cannot complete the EST due to comorbid health conditions or who have recently completed an EST is a poor allocation of resources and delays care. Secondly, ED personnel should confirm the referral date and educate the patient regarding potential Health benefits of completing the EST, as well as communicating payment options. Miscommunication of the appointment date alone prevented a quarter of the interviewed patients from attending their EST appointment. The EST appointment information should be conveyed in both verbal and written form. Hospital personnel should verbally emphasize the importance of receiving the EST to the patient and include a written notice of the appointment date in the discharge packet. Our hospital routinely conducts a telephone reminder 1 to 2 days before an appointment, but the patients surveyed often had not received the call. Clear communication upon ED discharge will deemphasize the need for call reminders. Contracting with patients to formally agree to attend appointments is shown to significantly

increase compliance in settings where noncompliance is a common problem [8].

OutPatient evaluation of low-risk patients with EST is shown to be a safe and cost-effective tool [9]. Increased accessibility, in time and locations offered, may also improve compliance. During the course of the study, the EST was offered Monday to Friday from 7 AM to 10 AM, and patients were scheduled for the “next available” EST. Efforts to increase the hours the test is offered and scheduling the EST appointment at a more convenient time may improve compliance. Tertiary care hospitals should consider offering the EST at satellite Primary care clinics.

Administration of EST during the initial evaluation would preclude a return visit and circumvent compliance issues. The benefit of immediate Exercise stress testing has been achieved by rapid triage of lower risk chest pain patients with nondiagnostic electrocardiograms [10-12]. Moreover, initial use of single-photon emission computed tomography perfusion imaging, possibly supplemented with an EST used to evaluate patients with a negative perfusion imaging, is proposed as a replacement for 12-hour cardiac enzyme markers +- EST [13]. Use of the latter approach is shown to reduce patient’s hospital stay and therefore reduce care cost. Our study also emphasizes the high rate of uncompleted EST even when the patient did show for the appointment (20/ 42 compliant patients). One reason was that patients could not reach their age-predicted heart rate, leading to a designation of “nondiagnostic.” Others have noted this limitation to the EST [14,15]. Diercks et al [16] suggest a scoring system to predict a nondiagnostic EST. The scoring system takes age and comorbidities (ie, diabetes and obesity) into consideration. More targeted ordering of the EST would increase its positive predictive value and decrease a

nondiagnostic result.

Our study stresses the importance of compliance in the design of diagnostic algorithms. The role of the EST, to risk stratify patients initially identified aslowrisk, wasundermined by noncompliance in more than half of the scheduled tests. Although the EST has demonstrated use (N50% were abnormal), noncompliance renders the ED chest pain algo- rithm inadequate in the management of chest pain patients.

Future research on etiologies of uncompleted EST should be conducted as a prospective Multicenter cohort study.

Acknowledgments

This research was a part of the Community Health Fellowship Program supported by a Health Resources and Services Administration grant (no. D56HP05220) to Mark J. DeHaven. We also would like to thank Mark J. Dehaven, PhD, program director, and Nora Gimpel, MD, associate director, for their invaluable input on this project.

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