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Allergy to Holter

Mark V. Williams, MD | July 1, 2004
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The Case

A 52-year-old man was admitted for palpitations and chest pain. As part of the evaluation, on hospital day 4 the patient was sent to the cardiac clinic to start a continuous recording of his electrocardiogram via Holter monitor.

Since the patient was ambulatory and had gone for other tests on his own, he was told to go to the cardiology clinic for a check-up of his heart rhythm. He was handed a "Request for Consultation" form, on which there was only one word: "Holter." The form did not state the patient's name or the department.

The patient had been told the clinic was on the fifth floor of the ambulatory building, so he took the elevator to that floor. He presented himself to the reception desk of the first clinic he saw—the allergy clinic (which is on the same floor as the cardiology clinic)—where the nurse took his consultation form, and told him, "Mr. Holter, you are in the right place." She then proceeded to conduct a complete pin-prick skin sensitivity test on his back, which showed no evidence of allergies. Armed with a form that showed his "Holter" test was negative, the patient walked back to his ward.

Upon his return, the patient told his ward nurse, "I've just finished the Holter test." —"And where is the Holter device?" asked the nurse. —"It is on my back and does not hurt at all!"

The nurse looked at the patient's back and realized that he had had an allergy test. She then escorted him to the cardiac clinic to have an actual Holter monitor placed. There was no harm (fortunately) to the patient, other than an unnecessary test and a brief delay in the ECG recording.

Additional investigation revealed that the patient was able to read and there was no language barrier. The workload for the allergy clinic nurse was light. She had merely glanced at, but did not read, the consultation form. Since it was not the first time a patient had received an unnecessary allergy test, the hospital published the event in their incident report newsletter and changed the signs to clinics on that floor. The nurse retired from practice (as previously scheduled) the following month.

The Commentary

Do your patients understand you? This patient obviously did not understand what Holter monitoring entailed when his physician told him to go get a "check-up of his heart rhythm." While we should not completely eschew use of medical terminology, as patients find it validating (1), we should also not allow our use of medical terms to obfuscate our intentions. Unfortunately, physicians' facile use of medical terminology and dependence on it often leads to confusion.(2) Physicians often bombard patients with a litany of medical terminology, resulting in misunderstood diagnostic and treatment plans. In this journal, Schillinger (3) described the impact of patients' health literacy—a patient's ability to read, comprehend, and act on medical instructions (4)—on their ability to understand medical information. Though patients' health literacy strongly correlates with their reading ability, the "Mr. Holter" case demonstrates how literate patients can have inadequate health literacy. An astute friend who learned to read as an adult gave me this insight—"Remember, what's clear to you is clear to you!"

While this patient's misadventure may seem humorous at first glance, it resulted in a delay in care and might have been associated with significant morbidity or even mortality if an anaphylactic reaction had occurred during the allergy testing. The initial case in the Quality Grand Rounds series published in Annals of Internal Medicine was the first report in the medical literature of a patient undergoing an invasive procedure intended for another.(5) Incident reporting data suggest that many such major misidentifications occur every year.(5) In fact, AHRQ WebM&M cases have included identification mix-ups involving patients (6,7), surgical sites (8), patient charts (9), and laboratory specimens.(10)

Why did "Mr. Holter" undergo the wrong test? While some may be inclined to impugn the nurse nearing retirement for the episode, latent conditions—"system faults that can be remedied and act within individual hospitals to increase the probability that individuals will make errors, that errors will do harm, or both" (5) —appear to favor a recurrence. Adequate communication, identity verification, and teamwork seem lacking. The physicians clearly did not adequately communicate with the patient and confirm his understanding. It is not clear who instructed the patient to go to the cardiology clinic (physician or nurse), nor who incompletely documented the consultation form. Moreover, a standardized protocol to verify patient identity was lacking. Such verification is being mandated by the Joint Commission on Accreditation of Healthcare Organizations (JCAHO). JCAHO's National Patient Safety Goals (11) include a goal to eliminate wrong site surgery, which is also applicable to wrong patient procedures. The "Universal Protocol for Preventing Wrong Site, Wrong Procedure, Wrong Person Surgery" (12) recommends a "time out" immediately before starting a procedure to "conduct a final verification of the correct patient, procedure, site..." Following such a protocol probably would have prevented this error, and patients can often help in their own identification.

Although patients can help reduce major patient identification mix-ups, they may also contribute to these and other medical errors through the complexity and seriousness of their condition, language and communication barriers, psychological factors (eg, excessive anxiety), or personality features, such as minimization of complaints or frank personality disorders.(13) This, of course, raises an important question: to what extent should patients be involved in facilitating their own care in the hospital? The airline industry does not ask passengers to help fly airplanes, but there is an expectation that they will assist with deplaning in cases of emergency (eg, opening exit doors), and certainly they are expected to identify themselves (multiple times these days) before being allowed on board. Historically, patients have played passive roles in their own health care, especially when hospitalized. However, the movement toward "patient-centered care" (14) suggests that patients play a more active role in their care, including engagement in medical decision making.(15) In addition to its ethical basis, expanded patient involvement in care yields improved health outcomes.(16)

Can patients play a role in preventing errors in the hospital? The recent medical literature has seen a sharp increase in articles on patient safety and medical error, but few have focused on the role of the patient. Articles mentioning the role of the patient in reducing errors have tended to be opinion pieces. One notable exception comes from the infection control literature. When patients were empowered to "protect themselves" by asking their health care workers to wash their hands, there was a marked increase in soap usage associated with overall positive response from health care workers.(17) To succeed in actively engaging patients in their own care and error prevention mandates adequate communication and education (ie, informed consent), followed by assessment of the patient's comprehension.(18) "Asking that patients recall and restate what they have been told" is one of AHRQ's recommended 11 top patient safety practices based on strength of scientific evidence.(19)

So, how might recurrences of this wrong procedure misadventure be prevented? Though admirable disclosure of the error to staff occurred (publication of the event in the hospital's newsletter), I doubt that this intervention would preclude recurrence. Standardized procedure request forms that require patient identification and travel with the patient from their hospital room to a testing area would be easily implemented and would facilitate communication and prevent misidentification. Ideally, requests for a medical procedure should be made with computerized physician order entry, coupled with a bar-coding system. The testing site could scan the patient's bar-coded identification bracelet to confirm the right patient is undergoing the right procedure. Finally, the patient should be properly informed about the procedure beforehand and then, as importantly, asked to confirm ("teach back") what procedure they are to undergo. Simple steps (Table) should greatly enhance patient understanding and compliance. Combining technological advances, heedful interrelating and teamwork, involvement of the patient in their care when possible, and use of the "teach-back" method to confirm patient understanding would all together markedly reduce medical errors and enhance care.

Mark V. Williams, MD Associate Professor of Medicine Director, Hospital Medicine Unit Emory University School of Medicine


1. Ogden J, Branson R, Bryett A, et al. What's in a name? An experimental study of patients' views of the impact and function of a diagnosis. Fam Pract. 2003;20:248-53.[ go to PubMed ]

2. Williams MV, Davis T, Parker RM, Weiss BD. The role of health literacy in patient-physician communication. Fam Med. 2002;34:383-9.[ go to PubMed ]

3. Schillinger D. Fatal aspiration of a syringe cap. AHRQ Web M&M [serial online]. March 2004. Available at: [ go to commentary ]. Accessed June 29, 2004.

4. Health literacy: report of the Council on Scientific Affairs. Ad Hoc Committee on Health Literacy for the Council on Scientific Affairs, American Medical Association. JAMA. 1999;281:552-7.[ go to PubMed ]

5. Chassin MR, Becher EC. The wrong patient. Ann Intern Med. 2002;136:826-33.[ go to PubMed ]

6. Shojania KG. Patient mix-up. AHRQ WebM&M [serial online]. February 2003. Available at: [ go to commentary ]. Accessed June 29, 2004.

7. Kaplan H. Transfusion "slip". AHRQ WebM&M [serial online]. February 2003. Available at: [ go to commentary ]. Accessed June 29, 2004.

8. Vincent C. The other side [Spotlight]. AHRQ WebM&M [serial online]. October 2003. Available at: [ go to commentary ]. Accessed June 29, 2004.

9. Rosenthal MM. Check the wristband. AHRQ WebM&M [serial online]. July 2003. Available at: [ go to commentary ]. Accessed June 29, 2004.

10. Gandhi T. Urine a tough position. AHRQ WebM&M [serial online]. October 2003. Available at: [ go to commentary ]. Accessed June 29, 2004.

11. Joint Commission on Accreditation of Healthcare Organizations. 2004 national patient safety goals. Available at: [ go to related site ] Accessed June 29, 2004.

12. Joint Commission on Accreditation of Healthcare Organizations. Universal protocol for preventing wrong site, wrong procedure, wrong person surgery. Available at: [ go to related site ] Accessed June 29, 2004.

13. Vincent C. Understanding and responding to adverse events. N Engl J Med. 2003;348:1051-6.[ go to PubMed ]

14. Stewart M. Towards a global definition of patient centred care. BMJ. 2001;322:444-5.[ go to PubMed ]

15. Kravitz RL, Melnikow J. Engaging patients in medical decision making. BMJ. 2001;323:584-5.[ go to PubMed ]

16. Greenfield S, Kaplan S, Ware JE Jr. Expanding patient involvement in care: effects on patient outcomes. Ann Intern Med. 1985; 102:520-8.[ go to PubMed ]

17. McGuckin M, Waterman R, Porten L, et al. Patient education model for increasing handwashing compliance. Am J Infect Control. 1999;27:309-14.[ go to PubMed ]

18. Bridson J, Hammond C, Leach A, Chester MR. Making consent patient centred. BMJ. 2003; 327:1159-61.[ go to PubMed ]

19. Shojania KG, Duncan BW, McDonald KM, Wachter RM, eds. Making health care safer: a critical analysis of patient safety practices. Rockville, MD: Agency for Healthcare Research and Quality; 2001: 1-8. AHRQ publication 01-E058. Evidence report/technology assessment. no. 43. [ go to related site ] Accessed June 29, 2004.


Table. Steps to Enhance Patients' Understanding and Compliance.

Use "living room language"

Show or draw pictures

Limit information; repeat instructions

Use a "teach back" or "show me" approach to confirm understanding

Be respectful, caring, and sensitive

This project was funded under contract number 75Q80119C00004 from the Agency for Healthcare Research and Quality (AHRQ), U.S. Department of Health and Human Services. The authors are solely responsible for this report’s contents, findings, and conclusions, which do not necessarily represent the views of AHRQ. Readers should not interpret any statement in this report as an official position of AHRQ or of the U.S. Department of Health and Human Services. None of the authors has any affiliation or financial involvement that conflicts with the material presented in this report. View AHRQ Disclaimers
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