Article, Emergency Medicine

Emergency department visits: we are not prepared

Unlabelled imageAmerican Journal of Emergency Medicine (2012) 30, 1364-1370

Original Contribution

Emergency department visits: we are not prepared?,??

Charles P. Davis MD, PhD

Department of Emergency Medicine, Methodist Texsan Heart Hospital, San Antonio, TX 78229, USA

Received 16 August 2011; revised 21 September 2011; accepted 23 September 2011

Abstract Emergency department (ED) staff comments frequently about how patients are poorly prepared to answer important medical questions. To determine if the impression that patients were or were not prepared, a total of 309 patients were all asked a series of important medical questions and were graded as positive (or prepared) if they answered the question completely or negative (unprepared) if they partially answered, did not answer, or changed their answer during the ED stay. The patient population was older (mean age, 60 years) and was seen at 1 specialty hospital. Results indicated that many people were not prepared with information about their allergies, medications, medical and surgical histories, and some, even their physician’s names. Patients were least prepared to know about an advance directive (79%) or to know their complete medical history (70%). Results indicated that most patients (99%) were not prepared to answer at least 1 or more important medical questions. The discussion considers why patients and others are not prepared for an ED visit and provides examples of ways to help people better prepare for such a visit.

(C) 2012

Introduction

Most people do not want to make a visit to an emergency department (ED) usually because it costs them time, money, and sometimes, discomfort plus admission to a hospital. However, statistics indicate that approximately 117 million times per year in the United States, people will visit an ED as a patient. This number indicates that for every 100 people in the United States, there will be approximately 40 ED visits per year. When repeat patient visits per year are factored into these numbers of yearly visits, the data still indicate that approximately 1 person in every 4 (approximately 25% of the US population) visits an ED once per year [1]. Consequently, ED visits are common in the United States, and that for everyone in the United States, there is approximately a 1 in 4 chance that they will, during any given year, visit an ED as a patient [1].

? Support source: None.

?? Previous presentation of article: None.

E-mail address: [email protected].

Although many people understand that they or a close relative or friend will likely need to be seen in an ED, physicians, nurses, technical aids, and registration clerks complain about the “lack of information” they experience daily from people that become patients in an ED. This lack of information covers many common topics that ED staff needs to know about to give appropriate care to the patients [2,3]. This perceived problem seems to be encountered daily in almost every ED (and frequently in physician’s offices) in the United States. Common points of information include answers to questions about the various topics listed below:

    • Name, age, birth date, home address, home telephone or cellphone number
    • Allergies
    • Medications
    • Medical history
    • Surgical history
    • Name of patient’s physician(s)
    • Person(s) to contact in case of an “emergency”

0735-6757/$ – see front matter (C) 2012 doi:10.1016/j.ajem.2011.09.026

    • Prior ED visits
    • Advance directive(s)
    • Insurance information

Although there can be many more items added to the above topic list, questions about the topics listed are basically asked to almost every ED patient seen in the United States and, except for prior ED visits, also asked of almost every patient who visits a physician’s office. Consequently, this information should be available to many patients who visit an ED because it is likely that they have had to provide it at some point previously to a physician’s office or another ED.

Why are ED staffs so concerned about these topics? Each topic provides important information to the staff that can affect the patient in many ways. For example, allergies can indicate what drugs may be harmful to the patient, medications may show the physician what is already in the patient’s system, medical and surgical history helps rule in or exclude some diagnoses, the physicians’ name can provide a potential additional source for information and treatment, emergency contacts provide additional people that may provide help (emotional, physical), prior ED visits may give insight into a recurrent problem and provide otherwise missing information about the patient, Advance directives can provide the staff with treatment options desired by the patient or guardian, while insurance information can provide ED staff with information about the group(s) of consulting physicians that are designated (approved) to care for the patient (at less or no cost to the insured patient). These examples are not all inclusive, but they begin to illustrate the potential importance of arriving with such information points when patients go to an ED for care.

The purpose of this study is to determine if there is validity in the claims by ED staff that many patients arrive in the ED without answers or information on topics that often bear directly on their diagnosis, treatment, continuing care, and disposition in the ED. The patient population was limited to those who arrived at a single hospital that has been a specialty heart hospital for approximately 7 years and had a high percentage of insured, older patients with ongoing private medical caregivers. Because of their often chronic problems, many of these patients have had Previous ED visits to this and other EDs. The assumption was that the data garnered would represent a best-case example for compli- ance data for patients making visits to the ED because they likely had prior experience with questions from ED staff members and education about what information they should bring if they need an ED visit.

Materials and methods

All patient data were garnered by a single physician over 6 months. Patients were assigned a number, interviewed,

diagnosed, treated, and given a disposition by this same physician during their ED stay; the only patients excluded were those that began, finished their workup, or were given a disposition by another physician before this physician began or ended his ED shift. All other patients were seen from their initial workup to disposition by this physician and were included in this study. All patients were seen during day shifts (7 AM-7 PM) at 1 small (5 bed) hospital ED, Texsan Heart Hospital, in San Antonio, TX. This hospital is a specialty hospital that has mainly cardiac patients as inpatients. It recently (2011) changed its name to Methodist Texsan Hospital.

Data were collected by the verbal response of the patient to questions asked by the physician, nursing staff, and registration clerk and documented for each patient at the time of patient disposition. In addition, after the patient interview, family members, friends, home health care givers, and the patient’s physician(s) were also interviewed to help confirm or correct the data collected by the patient’s verbal response. Occasionally, the patient produced written documentation as an answer to questions. For the written documentation to be considered a patient response, the patient had to have the document on his or her person while undergoing an interview, not a document provided at a later time by someone else.

The data then were recorded as either yes (+) or no (-) for some questions or complete (+) or incomplete (-). A

few questions garnered responses that lead to follow-up questions. These follow-up questions allowed additional information to be gained but were only asked when a specific question was answered as “no” or “…ask–” or “… check with–” (see questions below). When the patient produced written documentation to answer a question, this written documentation was then determined to be complete or incomplete by checking with family members, friends, home health care givers, patient records (charts), and the patient’s physician(s) to the best of our ED staff’s ability, depending on the availability of access to these sources. The questions that were asked and evaluated or followed- up with additional questions are as follows:

    • Allergies–Do you have any allergies to medicine, foods, or other things? Answer + if list is complete (verbal or written); answer – if patient does not remember allergies or has to refer the staff to another person or their previous medical record. If the allergy list is later revised or is found to be incomplete, this fact was noted.
    • Medications–Do you have a list of your medica- tions, including strength and time(s) of day taken? Answer is + if patient produces an up-to-date list of medications, including strength and time(s) of day taken, either written or verbal format; answer is – or incomplete if the verbal or written list is not current or is revised during the ED stay. A – response to the medication question generated a secondary question:

where or who can we contact to get this medical information? Patient responses to this question were documented. For example, if the patient said to ask his wife or to check his medical records or call his doctor, the first “contact or source for information” suggested by the patient was documented.

    • Medical history–Could you describe your current and past medical history. A + response was a verbal or written medical history that was complete. A – or incomplete history occurred when the patient said they do not remember, check my medical records, revised their history during the ED stay or if other sources (for example, relatives, old charts or the patient’s doctor) are consulted to complete the medical history.
    • Surgical history–Could you describe any surgical procedures done at anytime during your life? A + response was a verbal or written medical history that was complete. A – or incomplete history occurred when the patient said they do not remember, check my medical records, revised their history during the ED stay, or if other sources (for example, relatives, old charts or the patient’s doctor) are consulted to complete the medical history.
    • Name of patient’s doctor(s)–Who is your primary care doctor and who are any other doctors who treat you? A + answer is the name(s) of at least 1 doctor who potentially can be contacted by the ED staff; A – answer was the equivalent of “I do not have a doctor” or provide a doctor’s name but no way for the ED staff to contact the doctor (for example, Dr Jones at an out-of-state hospital whose hospital’s name the patient cannot recall).
    • Person(s) to contact in case of an “emergency”–Who can we contact in case of an emergency? A + response is a person’s name and their telephone number; a – response is no named person or a named person with an incorrect or no telephone number, unless that person accompanied the patient to the ED and provided the information to the ED staff. Unfortunately, verification of the contact person’s information was not routinely recorded.
    • Prior ED visits–Have you ever been a patient in this ED? A + response is a yes answer and is confirmed by checking the ED records; a – response is either a no answer or a yes that is not confirmed by the hospital ED records
    • Advance directive(s)–A + response is a yes answer to any type of written directive; a – answer was a no answer to the first question. If the patient’s answer was that they had a directive, a follow-up question was asked: do you have a copy of the directive with you? The answer to the follow- up question (yes or no) was recorded.
    • Insurance information–Do you have health insurance? A + response is yes and was verified by the ED staff clerk; a – response is either a yes or no answer, but if the patient said yes they had insurance but the clerk could not verify the insurance, the response was documented

as a no answer. This insurance question was asked sometime after initial ED triage of the patient was completed; the examining doctor had no insurance information before seeing the study patients.

Patients comprised a convenience sample; all patients (or their guardians) were interviewed, treated, and either released, admitted, transferred to another hospital, or decided to leave against medical advice. None died during the ED shifts when the examining ED physician was on duty. All patients who arrived at the ED were seen regardless of their complaint or condition. For a statistical power of 0.95 with a margin of error at 5% and the response distribution minimized at 50%, the calculated recommended sample size equaled 212 (actual sample size was 309).

Results

Over a 6-month period, a total of 309 patients were seen from arrival to disposition in the hospital ED by a single physician who recorded patient responses to questions. Two patients left against medical advice, and 3 were transferred to other hospitals and were included in this study population. Table 1 shows the demographics in percentages of the sex and race of the 309 patients included in the study. Most of the patients were Anglo and Hispanic Males and females (total, 93%). When compared with the population of people in San Antonio, Texas, our patient population was considerably older with a median age of 60 years, 28 years older than the mean age (32 years) of the city’s population (Table 2) [4]. In addition, the hospital had a disproportionate share (48%) of Anglo vs Hispanic patients (45%) as compared with the city’s population (Table 2), but both Anglo and Hispanic patients had the same percentage of insured and Uninsured patients who arrived at the hospital (93% insured vs 7% uninsured). When all patients’ insurance statistics were calculated and compared with the national average of insured patients seen in EDs across the United States, the hospital

Table 1 Percentage of patients, sex, and race a

Sex

Male

% 53

Female

47

Race

%

Anglo male

26

Hispanic male

24

Anglo female

22

Hispanic female

21

Black male

4

Black female

2

Asian male

0

Asian female 1

a Percentage derived from a total of 309 patients.

Table 2 Hospital (ED) and city population statistics

ED

Patients

Median age (y) Race

Hispanic Anglo Black Asian Other

60 b

City a

32

45 b

48

6

1

0

61.2

28.9

6.6

2

1.3

a Represents city (San Antonio, TX).

b Represents percentage of people.

clearly showed a higher percentage of insured patients who visited its ED (91.5% insured vs 83.7% nationally in the United States) [5]. Every patient had a contact person listed (100%), but the accuracy of this contact person information was not confirmed in this study. The few repeat visits during the 6-month period were counted as individual visits.

Fig. 1 indicates that initial patient responses to allergy questions were good, with only 4% of patients initially responding they did not know, could not remember, or could not respond to the question. However, this Percentage changed during the ED stay; the second bar shows the percentage of patients whose allergy response required a documented change in the ED medical record because of additional information later provided in the ED by others such as family members, physician ‘s office records, a previous

100

4

17

96

83

90

80

70

% of responses

60

50

40

30

20

10

0

Fig. 1 Responses to allergy questions. First column: responses to “Are you allergic to any medications”; gray bar indicates percentage that “know” their allergies, white column represents those patients who do not know their allergies; second column: gray bar, percentage of patients who had no change from first response; white bar, percentage of patients who modified their original response to the allergy question in the ED. Numbers in columns represent percentage of patients with response.

medical chart, or eventually “remembered or omitted” by the patient. This changing situation to an important question about allergies occurred in 17% of patients seen (Fig. 1).

Fig. 2 indicates the overall percentages of patients who arrived with a list of medications, their strengths, and daily frequency of dose; the ED staff accepted both written and verbal generated lists and still found that 38% of all patients admit that they did not have a complete list of medications. This figure became higher; the revision of these Medication lists during the ED stay occurred in almost half of all patients seen (46%; Fig. 2). In addition to documenting the revision, the source(s) for the revision in medications were also documented by the ED staff. Although occasionally more than 1 source was listed per patient, Fig. 3 shows the 10 listed sources patients used or requested in the ED to correct or complete their medication documents. The sources are listed in order beginning with the source that was the primary one for individual patients. “Check my chart for my medications” is the paraphrased answer of 23.5% of patients, whereas 19.1% corrected, completed, or updated their own list while being evaluated in the ED. Most of the other sources were closely related relatives and were female (51.3% total), mainly a daughter (22.6%) or wife (21.7%). The few other sources were documented as parents, husband, or son (5.2%).

Patents, in general, showed a poor ability (77%) to give

a complete medical history (Fig. 4). Their ability to give a complete surgical history was over twice as good (68% vs 33%) as their medical history (Fig. 4). Even with marked

100

38

46

62

54

90

80

70

60

% of responses

50

40

30

20

10

0

Fig. 2 Patient responses to medication list questions. First column is the percentage saying that they have a medication list (gray bar); percentage saying that they have no complete list (white bar). Second column: percentage having complete list (gray bar) and percentage revising the list (white bar); numbers represent patient responses.

25 100%

23.5

22.6

21.7

19.1

3.5

2.6 2.6

1.7

0.9 0.9

90%

20 80%

% of people

% of patients

70%

15 60%

50%

10 40%

30%

5 20%

10%

0 0%

20

43

56.3

79

99

80

57

44.3

21

1

1 2 3 4 5 6 7 8 9 10

Fig. 3 Percentage of people (115 persons) who modified their original medication list and who or what the patient said supposedly had a correct list of their medications. Categories of who or what had to correct the original list of their medications: 1, medical chart; 2, daughter; 3, wife; 4, patient who just remembered changes; 5,

mother; 6, sister; 7, parents; 8, husband; 9, niece; and 10, son; total percentage less than 100% because of rounding.

improvement over medical histories, approximately one third (32%) of patients’ surgical histories were still incomplete (Fig. 4).

Fig. 5 shows that 44.3% of patients in this study were admitted to the hospital from the ED (column 1). Admission rates were substantially higher than the national ED average (44.3% vs national average of approximately 13%). However, the yearly ED admission rate for all patients for this hospital has ranged from 40.1% to 44.2% since 2008, so this rate is not unusual for this study population. Only 21% of all patients (Fig. 5, column 2) said that they had any type of advance directive (such as a do not resuscitate, power of attorney, legal guardianship). Column 3 shows that 57% of all patients seen in this hospital ED during this study had been seen previously by this hospital’s ED staff and had been discharged or admitted to the hospital. Column 4 shows that 80% of all study patients seen could identify at least 1 physician whom the ED staff could contact who had treated the patient previously (Fig. 5).

The patients who were admitted to the hospital (125/309 in this study) had most of primary complaints (86%) that fit into 5 major categories: chest pain, dyspnea, arrhythmias,

1 2 3 4 5

Fig. 5 Percentage of patients admitted to the hospital, percentage of patients saying they have directives, percentage of patients with no active directive, percentage of patients with prior ER visit, and percentage of patients with identified physicians. Column 1, gray bar, percentage of patients admitted; white bar, percentage of patients discharged. Column 2, gray bar, percentage of patients saying they have a directive; white bar, percentage of patients without directive. Column 3, gray bar, percentage of patients with an active directive in the ED; white bar, percentage of those without directive in ER. Column 4, gray bar, percentage of patients with prior visit to study ER; white bar, percentage of those with no prior visit to study ED. Column 5, gray bar, percentage of patients who could identify a treating physician; white bar, percentage of those with no physician.

stroke/transient ischemic attack, and weakness (Fig. 6, columns 1-5). Many of these complaints could possibly be serious, even those with other complaints (Fig. 6, column 6), and because the patients may warrant admission because of their symptoms, their ability to have documentation to determine their care wishes was examined. The data showed that 99% of all patients admitted to this hospital did not have an advance directive that was brought to the ED with them (Fig. 6, column 7). Not all patients, however, with potentially serious complaints were admitted. When all of the patients who were seen in the ED with a chief complaint of chest pain were compared by numbers of admitted vs numbers not admitted, 52% were admitted and 48% were sent home from the ED.

99

100

77

32

68

33

90

80

70

% of patients

60

50

40

30

20

10

100

90

46

21

14

9

6

4

80

% of patients admitted

70

60

50

40

30

20

10

0

1 2 3 4 5 6 7

0

Fig. 4 Percentage of patients with complete or incomplete medical and surgical history. Column 1, medical history; column 2, surgical history; gray bars represent percentage of patients with complete histories, white bar represents percentage of patients with incomplete histories.

Fig. 6 Percentage of patients admitted with potentially serious complaints and no current advance directive. Columns 1 to 6 represent chief complaints of admitted patients: 1, chest pain; 2, dyspnea; 3, arrhythmias; 4, stroke/transient ischemic attack; 5, weakness; 6, all other complaints (pneumonia, gastrointestinal pain, leg/groin pain, etc). Column 7: percentage of patients admitted without current copy of directive.

Discussion

The data in Tables 1 and 2 clearly show that the patient population in this study was composed of similar numbers of males and females that represented an older population (median age, 60 years). The population had about the same number of Anglo and Hispanic patients who comprised the most of the patients. Although the city of San Antonio has a predominant Hispanic population (61.2%), the number of uninsured Hispanic people is high (approximately 24%- 30%) [1,3]. The patient population studied at this hospital had almost exactly the same number of insured Hispanic and Anglo populations. One reason for this may be that the hospital was well known to be a private hospital that was mainly designed as a specialty and referral hospital to care for patients with a cardiac history or complaint; another reason may be that the high median age of the patients (60 years), so that a high percentage of patients could be eligible for Medicare insurance coverage.

The patient response to commonly asked questions was surprising in several ways. First was the revisionism exhibited by a large number of patients and their caregivers about allergies (17%) and medications (46%) along with the lack of completeness of surgical (32%) and especially medical histories (77%) found while they were being examined, treated, or admitted (Figs. 1-4). Second was the number of patients and caregivers that either modified or expected sources other than themselves to provide essential information about medications to the ED staff and the additional finding that female relatives (51.3%) were considered to be one of the main repositories of such information (Fig. 3). The third surprise was the high number of patients (71%) that had no written directives (Fig. 5), and fourth was the high number of patients with physicians (80%) and those with previous ED visits to the study- centered hospital (57%) who arrived without a directive (99%). These patients should have already encountered the questions asked in this study and been given instructions about what they needed to bring with them to an ED visit. Finally, of the patients admitted to the hospital with serious complaints, the enormous percentage (99%) of patients who, on admission, had no updated or current directive available to the ED or hospital staff (Fig. 6) was disturbing because these patients had problems serious enough to cause hospital admission but almost none had a directive that could help the ED personnel carry out the desires of the patient.

The specialty hospital ED staff was especially concerned because at least 57% of patients had at least 1 prior visit to the hospital and most (80%) of the patients had physicians who likely had asked the patients similar questions in an office setting and thus had experienced most or all of the questions asked in this study before the recorded ED visit in this study. Consequently, it is likely that patients had been given advice about what to bring with them if a future ED or physician’s office visit happened. Part of the discharge information given to admitted or discharged patients in our

hospital ED addresses the need for the patient to prepare for future visits. This study suggests that either a large number of patients cannot or will not take the advice to prepare for a future ED visit or perhaps the ED staff is failing to get their message to prepare for future visits across to patients and caregivers. The poor preparation could also be caused by a combination of all 3 situations. However, part of reason for this lack of preparation may be specific situations para- phrased below; ED personnel heard these responses repeatedly, and such responses helped produced some of the data (Figs. 1-6):

    • Denial–“Emergencies don’t happen to me–I know all the answers to all of my medical questions–I have an advanced directive…somewhere.”
    • Lack of preparation or forethought–“I will get that information together soon–the information is at home, I think–I don’t need an advanced directive yet–We have not discussed an advanced directive even though we should.”
    • Dependence–“All that stuff is in my chart–My wife has all of that information; ask her–Call my doctor’s office for that information.”
    • Detachment or lack of focus–“I don’t know or cannot remember–I don’t know, my wife made me come here– Why are you asking me that.”

We had thought that the data would represent a best-case example for compliance data for patients making visits to the ED because the patient population likely had prior experience with questions from ED staff members and education about what information they should bring if they need another ED visit. Our data showed that 57% of the patients seen had a prior visit to the study hospital’s ED and 80% had a physician they could name, which suggests prior experience with common health-related questions. Although the data provided us with disturbing compliance data for an older patient population (median age, 60 years), we cannot conclude that the data represent a best-case example for all people because we did not compare this specialty hospital population to nonspecialty hospital populations that repre- sent the San Antonio population.

Although our ED staff has had extensive experience with such hospitals, we do not have comparison data, and although our experiences suggest that compliance may be similar or even worse than what we currently report for this older patient population, there is no comparison study available. However, such a study, using the same methods used in this study, could compare and contrast findings in multiple EDs with different predominant age groups and that have more variability in the emergent health problems. Several studies do suggest that our findings may represent a broader base of patients. In a study of 104 patients, Cohen and Java [6] suggested that accuracy of recall about patient medical history was only 53%. In an ED study of 114 patients, Neugut and Neugut determined that 38% of their

patients gave incorrect reasons why they had a previous visit to the same ED [7]. In a large recent study by Mai et al [8], after interviewing 1019 patients enrolled in a breast cancer clinic, only 40% to 60% of the patients correctly identified other family members with breast cancer, depending on the cancer type. Although these findings do not directly suggest that many ED patients will have many parts of their medical information missing, it does suggest that other patient populations may not have complete medical information to give to their ED and other physicians.

Health care personnel, when discharging or admitting patients, may mention the need for preparation for future ED visits but may fail to give patients the support and perhaps the example that the patients need to accomplish the task. The evidence for the first part of this conclusion is based on the data that although 57% of the patients seen in this study had a previous visit to this ED, these same patients still had very poor responses to questions about important information such as their medical history and the advance directive. Although the question of “example” is not addressed directly with data in this research, the results have made us, as ED personnel, examine our own preparation for an ED visit. An anecdotal query of our own hospital physicians and ED support staff (approxi- mately 25 professionals) was done; preliminary results showed that we were about as poorly prepared as our patients. If health care personnel need better preparation from our patients, perhaps we as health care professionals should begin by showing good example by doing what we advise others to do. We speculate that our situation is not unique.

Although the results of this study showed that older people (median age, 60 years) are not well prepared with important information that should be available to ED personnel, it did not offer ways to improve this situation. However, the results did encourage us to attempt to find ways that are available to people to help them to better prepare for an ED or physician’s office visit, partially because we wanted to find easy ways to help ourselves prepare. A recent Internet article contained a summary of various methods established by a number of companies that would assist patients by establishing an electronic medical record or wireless access to patient-derived medical information [2]. These sources of patient information are

password protected and provide a way to simply follow a preset format to fill in medically related information that may be quickly accessed by ED personnel. Some are free (WebMD), some charge a fee (Health Minder Software), and yes, there is an “app” for that information storage for cellphones termed My Medical. However, these templates are only as accurate as the person (or patient) providing the data, and although most do not have all of the various information categories available, we urge patients and their caregivers to consider using a template system to make their next ED visit faster, easier, and safer. This study has encouraged our ED staff to improve templates: in the future, we hope to provide a method for ourselves and ED patients to attain a complete medical information system that is secure, complete, portable, durable, and immediately available for updates, even while the patient is in an ED, physician’s office, or almost anywhere.

Acknowledgments

The author would like to thank all of the nurses, technical persons, and clerks at Methodist Texsan Hospital for their assistance in gathering the data for this study.

References

  1. Niska R, Bhuiya F, Xu J. National Hospital Ambulatory Medical Care Survey: 2007 Emergency Department Summary. Nat Health Stat Reports 2007;26:1-32.
  2. Nabili ST. Family medical records; 2011. http://www.emedicinehealth. com/family_medical_records/page10_em.htm.
  3. Kellermann AL, Martinez R. The ER, 50 years on. N Eng J Med 2011;364:2278-9.
  4. Texas Medical Association. The uninsured in Texas; 2009. http://www. texmed.org/template.aspx?id=5517.
  5. U. S. Census Bureau, Health Insurance; 2010. http://www.census.gov/ hhes/www/hlthins/data/incpovhlth/2009/tables.html.
  6. Cohen G, Java R. Memory for medical history: accuracy of recall. Appl

Cogn Psychol 1995;9:273-88.

  1. Neugut A, Neugut R. How accurate are patient histories? J Community Health 1984;9(4):294-301.
  2. Mai P, Garceau A, Goraubord B, et al. Confirmation of family cancer history reported in a population-based survey. J Natl Cancer Inst 2011;103(10):788-97.

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