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CASES OF NOTE

Effect of Troponin I Point-of-Care Testing on Emergency Department Throughput Measures and Staff Satisfaction

Koehler, Jeanniline BS; Flarity, Kathleen PhD; Hertner, George MD; Aker, Judy BSN; Stout, John Patrick MD; Gifford, Marilyn MD; Campbell, Bruce MD

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Advanced Emergency Nursing Journal: July/September 2013 - Volume 35 - Issue 3 - p 270-277
doi: 10.1097/TME.0b013e31829d2048
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Abstract

OVERCROWDING DUE to increasing patient volume along with hospital bed and staffing shortages is a major challenge for many emergency departments (EDs; Bradley, 2005; Derlet, 2002). The 2009 National Hospital Ambulatory Medical Care Survey indicates that chest pain is the third most common reason for ED visits. Patients with chest pain require rapid triage and evaluation so that an accurate diagnosis can be made and optimal patient disposition and treatment can be implemented (Pitts, Niska, Xu, & Burt, 2008). Troponin is the preferred cardiac biomarker for the evaluation of patients with chest pain presenting to the ED according to American Heart Association/American College of Cardiology and National Academy of Clinical Biochemistry Laboratory Medicine Practice Guidelines for the management of patients with non-ST-elevation myocardial infarction (MI; Anderson et al., 2007; Morrow et al., 2007). The recommended turnaround time (TAT) for troponin testing is within 30–60 min of ED arrival (Anderson et al., 2007; Christenson & Azzazy, 2009; Gibler et al., 2005). Timely availability of the troponin test facilitates medical decision making in the treatment of time-sensitive conditions such as acute chest pain and acute MI. The Centers for Medicare & Medicaid Services (CMS, 2010) notes that timeliness of access to troponin test results is a marker of quality because it results in more timely treatment decisions and treatment delivery, which, in turn, should result in improved patient outcomes. In addition, the evaluation of time-to-troponin test results is a proposed addition to Cycle 4 Society of Cardiovascular Patient Care Accreditation (Society of Cardiovascular Patient Care, 2013).

This challenge to triage and treat more patients in a shorter period of time to meet quality measures can lead to increased pressure on ED staff. Implementation of point-of-care (POC) testing is one solution that may streamline staff workflow and shorten troponin TATs if acceptable results cannot be achieved with conventional laboratory testing (Christenson & Azzazy, 2009). The primary objective of this open-label before-and-after study was to determine the impact of cardiac troponin testing with a POC testing system on TATs, door-to-result times, and ED length of stay (LOS) in a high-volume ED.

Although the use of POC cardiac testing is becoming more common in EDs, few studies have evaluated the impact of POC testing on workflow, delivery of care, staff satisfaction, and communication among health care team members. In one study evaluating the impact of POC troponin testing in a university-based ED, physicians and nurses expressed satisfaction with POC testing, noting that it enhanced their degree of involvement in patient care and reduced length of care for patients with chest pain (Singer, Ardise, Gulla, & Cangro, 2005). In another study, physicians and nurses reported greater satisfaction with POC testing facilitated via a satellite laboratory (urinalysis, pregnancy testing, glucose, cardiac markers) than testing conducted in the central laboratory (Singer et al., 2005). A secondary objective of the current study, and one that differentiates it from previous evaluations of POC testing, was to determine how ED nurses and physicians perceive POC testing with respect to patient throughput, productivity, and ease of use.

MATERIALS AND METHODS

Study Setting, Population, and Design

This study was conducted at Memorial Hospital Central, a part of Memorial Health System in Colorado Springs, CO. Memorial Hospital Central has approximately 590 beds, and the 68-bed ED has an annual census of 105,000 visits. Data were collected from all patients with chest, abdominal, or shoulder pain presenting consecutively to the ED and for whom a cardiac troponin test was ordered as part of their clinical workup. When a chest pain protocol was initiated by a nurse, a troponin test was also automatically ordered. This was an open-label, before-and-after study that evaluated the impact of troponin POC testing in the ED. The pre-POC testing period evaluated was from March 15, 2010, to March 19, 2010. The post-POC testing period evaluated was from April 25, 2010, to May 30, 2010, July 2010, and September 2010. Twenty-four patient medical records were evaluated in the pre-POC testing phase, and 177 patient medical records were evaluated in the post-POC testing phase. Before POC testing, laboratory testing for patients with chest pain consisted of a cardiac marker panel (troponin I, creatine kinase-MB [CK-MB], and myoglobin), a basic metabolic panel, and a complete blood count. At the time POC testing was implemented, the ED physicians and cardiologists at Memorial Hospital Central replaced the cardiac marker panel with troponin testing only for patients with chest pain, as recommended in the 2007 patient management guidelines from the American Heart Association and American College of Cardiology (Anderson et al., 2007). In the pre-POC testing period, samples requiring troponin testing were sent to the central laboratory and analyzed using the ADVIA Centaur XP Immunoassay System, TnI-Ultra assay (Siemens, Deerfield, IL). Troponin values more than 0.78 mcg/L were considered positive and values less than 0.04 mcg/L were considered negative. Values that fell in between the two were considered indeterminate and required further review by the provider.

In the post-POC testing period, samples requiring troponin testing were analyzed in the ED using a POC testing system (the i-STAT cTnI assay; Abbott Point of Care, Princeton, NJ). Troponin values more than 0.61 mcg/L were considered positive and values less than 0.08 mcg/L were considered negative (values that fell in between the two were considered indeterminate and required further review by the provider). During both phases of the study, a second troponin test was performed at 2 hr on the basis of “clinical judgment by the provider.” In the post-POC testing period, providers were able to order CK-MB and myoglobin tests as needed, but they were no longer part of the standard order for patients with chest pain.

Data Collection and Analysis

The following outcome measures were evaluated for the population of patients with chest, abdominal, or shoulder pain presenting to the ED and for whom a cardiac troponin test was ordered:

  • Troponin TAT, defined as time from receipt of specimen to completion of testing.
  • Door-to-troponin result, defined as time from ED arrival to completion of troponin testing.
  • ED LOS, defined as time from ED arrival to discharge from ED.
  • TAT for nontroponin tests analyzed in the central laboratory, defined as time from receipt of sample by laboratory to completion of test.

In the pre-POC testing phase, data were collected retrospectively by conducting patient medical record reviews and evaluating hospital laboratory data. In the post-POC testing phase, data were retrospectively abstracted from the electronic medical record system. Outliers, for example, patients remaining in the ED for more than 12 hr (n = 5), were removed from the analysis. The data presented represent the mean values and were analyzed using Microsoft Excel. In the case of door-to-troponin results, the percentage of the samples that fell within the 60-min timeframe was calculated.

Staff Satisfaction Survey

An Internet-based survey was conducted to evaluate the staff satisfaction of i-STAT System users (nurses, technicians, and physicians) who were either responsible for collecting blood and running tests on the i-STAT System, communicating results to physicians, or utilizing the results in making patient treatment decisions. The survey was designed to measure the perceived impact of POC testing on care delivery and workflow; it was conducted by a third-party research company. The survey was programmed for online data collection, and a link was distributed to all ED physicians, nurses, and ED technicians via an e-mail. The survey period was from July 29, 2011, to August 20, 2011. Likert scales are an industry standard in measuring satisfaction; a 1 to 10-point scale is commonly used as a means to measure overall satisfaction providing greater discrimination in responses. The 10-point scale was used for the overall satisfaction measure, and a 5-point fully anchored scale was used for detailed attribute questions. Top-three scores (8–10) for the 10-point scale and top-two scores (4–5) for the 5-point scale were considered the top scores. Regarding the reliability of the instrument, assuming a universe of 200 possible users, we are 95% confident the results are within ±4.3%.

RESULTS

All conclusions are based on a statistical significance level of 0.05. Univariate statistics were used, and data were examined for normalcy of distribution.

Patient Flow Evaluation

Prior to study implementation, Memorial Health System convened a Strategic Capacity Management team with the goal of transforming the patient experience and patient flow. The group mapped the patient flow pathway in the ED and identified a delay in the provision of test results, particularly for patients with chest pain presenting to the ED. A recommendation was made to implement POC troponin testing in the ED. A multidisciplinary team, with representation from the laboratory (POC manager, administrative director, and medical director), the ED (medical directors, operations manager and director, ED nurses, and clinicians) as well as finance, information support, the process improvement team, and the catheterization laboratory, was formed to oversee the implementation of this process change. Emergency department technicians and nurses were trained by the POC manager to perform POC testing. Competency was assessed periodically as required.

Patient Flow Metrics

The average number of ED visits per day for patients with chest pain was 48–50 for both testing periods (pre- and post-POC). During the 5-day pre-POC testing time period, a total of 344 patients with chest pain presented to the ED. A power analysis was performed to calculate minimum pretest sample size required (p = 0.03). In the 65-day post-POC testing time period, a total of 4,907 patients with chest pain presented to the ED. Of the 344 patients presenting to the ED in the pre-POC arm, 24 patient medical records were selected for analysis; of the 4907 patients presenting to the ED in the post-POC arm, 177 were selected for analysis.

The average door-to-result time, defined as the time from ED arrival to receipt of troponin test results, was 51 min in the post-POC testing period compared with 105 min in the pre-POC testing period (see Table 1). This change was determined to be significantly different (p < 0.000; 95% confidence interval [CI], difference in medians [32.07, 82.93]). A random sample of the patient records was reviewed to determine how many samples had a door-to-troponin result time of less than 1 hr; the proportion of tests in the pre-POC period with a door-to-troponin result time of less than 1 hr was 0% (0/24) compared with 74% of tests (130/175) with a door-to-troponin result time of less than 1 hr in the post-POC period.

Table 1
Table 1:
Comparison of TATs, door-to-result times, and ED LOS before and after the implementation of POC testing

As a result of moving troponin testing to the bedside and eliminating standard CK-MB and myoglobin testing from the standard order set for patients with chest pain, the average TAT for nontroponin tests (basic metabolic panel and complete blood cell count) for patients with chest pain decreased from 50 min in the pre-POC testing period to 25 min in the post-POC testing period, a 50% reduction (see Table 1). The decrease in TAT for nontroponin tests was statistically significant (p < 0.000; 95% CI, difference in medians [17.58, 30.42]).

Average ED LOS was also reduced in the post-POC testing period. Prior to the implementation of troponin testing at the point of care, the average LOS for patients with chest pain in the ED was 290 min compared with 255 min in the post-POC testing time period. Both cohorts passed tests for normalcy. A two-sample t test concluded that there was no difference in the means for the pre- and post-POC testing cohorts (p = 0.082; 95% CI [−4.8, 75.4]), indicating that—although the mean LOS was shorter after POC testing—this change was not significant.

Although physicians could still order CK-MB and myoglobin as needed, the volume of CK-MB orders decreased 98% after adopting a single-marker approach (data not shown).

Staff Satisfaction Survey

Whenever change is implemented in an ED, staff satisfaction and identified value added can contribute to the success of the change. The ED staff members involved in POC troponin training were surveyed regarding their satisfaction with the process. A total of 93 staff members (75%) responded to the satisfaction survey (46 nurses, 24 physicians, and 23 ED technicians). Using a 1- to 10-point Likert scale, the participants rated their perception and satisfaction with the process. The majority (88%) felt that POC testing encourages communication among patient care team members. Overall, satisfaction was high; 82% of respondents rated their satisfaction as excellent. Staff perceptions of the impact of POC testing were determined by their response to set questions (e.g., “Indicate your level of agreement with the statement below. Of respondents with experience using POC testing with the i-STAT System, 86% of physicians, 81% of nurses, and 74% of ED technicians reported being satisfied (see Figure 1). More than 90% of physicians agreed that POC testing improves workflow processes, facilitates clinical decision making, improves laboratory result TATs, and shortens patient LOS (see Figure 2). In addition, physicians also reported that bedside POC testing encourages communication among team members (73%), encourages team alignment (77%), and positively impacts physician productivity (86%). The most often reported reasons for dissatisfaction were downloading issues and issues with connectivity.

Figure 1
Figure 1:
Overall satisfaction by physicians, nurses, and ED technicians who have used the i-STAT System or have used the results generated by the i-STAT System. Respondents rated overall satisfaction on a 10-point scale: 1 = “not satisfied” and 10 = “very satisfied.” Respondents giving one of the top-three scores (8, 9, or 10) were considered “satisfied”. Respondents giving scores of 4–7 were considered “neutral,” and respondents giving scores of 1–3 were considered “not satisfied.” ED = emergency department.
Figure 2
Figure 2:
Perceived impact of POC testing as reported by physicians. Scores represent the percentage of physician respondents who agreed with each statement (a rating of 4 or 5 on a 5-point scale in which 1 means “disagree completely” and 5 means “agree completely”). POC = point of care.

Point-of-care testing performed at the patient bedside is increasingly performed by nursing personnel and could be viewed as an additional burden to an already-heavy workload. All nurses surveyed (100%) agreed that bedside POC testing improves departmental workflow (see Figure 3). Almost two thirds of nurses (62%) reported that POC testing did not take away time from their other functions, and 84% of nurses in our survey reported that POC testing positively impacted nurse productivity. Furthermore, 81% of nurses reported that POC testing encouraged communication among patient care team members. Finally, more than three quarters of nurses (78%) agreed that the i-STAT System was easy to use. The most commonly cited reason for dissatisfaction with the i-STAT System was difficult or redundant charting. Overall, these results indicate that the ED staff at Memorial Hospital Central is very satisfied with bedside POC testing, finding that it is easy to use and provides important benefits to patient care.

Figure 3
Figure 3:
Perceived impact of POC testing as reported by nurses. Scores represent the percentage of nurses who agreed with each statement (a rating of 4 or 5 on a 5-point scale in which 1 means “disagree completely” and 5 means “agree completely”). POC = point of care.

DISCUSSION

In this study, the evaluation of the delays in patient flow and the resulting process improvement initiative to implement POC troponin testing in patients with chest pain presenting to the ED had a positive impact on several ED metrics. The average troponin TAT was 11 min with POC testing, and an increase from 0% to 74% in the percentage of samples with a door-to-troponin time of less than 1 hr was also observed. Furthermore, by moving troponin testing to the point of care and eliminating CK-MB and myoglobin from the standard order set for patients with chest pain, the hospital was able to improve the efficiency of the central laboratory. The overall TAT for nontroponin testing (basic metabolic panel and complete blood cell count) for patients with chest pain in the central laboratory was reduced by 25 min.

A notable time-saving of 35 min in patient throughput for patients with chest pain in the ED was observed with POC testing in this study. These improvements are in line with future CMS outpatient ED performance measures that will be evaluated for payment determination in CY2013: Median Time From ED Arrival to ED Departure for Discharged ED Patients [OP-18].

During both study periods (before and after the availability of a POC troponin test), serial troponin testing was performed in a subset of patients with chest pain at 0 and 2 hr, at the discretion of the treating physician. Although the study protocol was not limited to those patients requiring serial troponin testing, one could speculate that the effect of a rapid troponin test on patient throughput would be even greater in those patients requiring multiple troponin tests.

Staff satisfaction is very important as improvements in the process of patient care are implemented. This study is unique in that a detailed staff satisfaction survey was conducted to evaluate the impact of the POC testing program on processes, staff workflow, and patient care. The survey of ED personnel revealed a high degree of satisfaction with POC testing and agreement that faster laboratory testing at the patient bedside facilitates clinical decision making and shortens patient LOS, as well as encourages communication and alignment among team members. At Memorial Health System, POC testing is performed by nursing staff and ED technicians at the patient bedside. Approximately a third of nursing and ED technician respondents indicated that POC testing takes time away from their other functions, and 84% of nurses indicated that it positively impacts nursing productivity. These positive staff satisfaction results are an important indicator of the benefits of POC testing, particularly in the current health care environment where they are often faced with the challenge of “doing more with less.”

LIMITATIONS

One of the limitations of the study and an external threat to validity was that it was a retrospective, unblinded convenience sample from the same institution; the findings may not be reflective of all EDs. In addition, the participants were able to self-select to participate in the staff satisfaction survey and there is a potential inaccuracy of self-reported data. Changes were made to the protocol at the same time this study was conducted (CK-MB and myoglobin were eliminated) and could have impacted study findings. Finally, the LOS for patients with no chest pain was not evaluated or compared during this study.

CONCLUSIONS

Introduction of POC troponin testing in the ED can help institutions reduce door-to-troponin result times and ED LOS, a measure that will be important for CMS payment determination in CY2013. Establishing a multidisciplinary team that included leaders and clinicians from the central laboratory, catheterization laboratory, and the ED was key to the successful implementation of POC testing at Memorial Hospital Central. Because of the success of POC troponin testing at our institution, all troponin testing in the ED is now done at the POC; central laboratory troponin testing is ordered only if a patient is admitted.

In addition, ED staff satisfaction with POC testing at Memorial Hospital Central was high, supporting the benefits of POC testing on improved patient flow, quality of care, and employee productivity. Future research should continue to evaluate staff satisfaction regarding POC testing.

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    Keywords:

    door-to-troponin result time; emergency department (ED); length of stay (LOS); point-of-care (POC) testing; troponin (cTnI); turnaround time (TAT); staff satisfaction

    © 2013 by Lippincott Williams & Wilkins.