Correspondence
Clinical Problem-Solving: If at First You Don't Succeed
N Engl J Med 1996; 334:918-920April 4, 1996
- Article
To the Editor:
In the case of the 22-year-old Laotian immigrant described in the Clinical Problem-Solving article entitled “If at First You Don't Succeed” (Dec. 7 issue),1 does the one-year interval between the first medical consultation and the complete relief of symptoms by curative antituberculosis chemotherapy indicate that she received high-quality health care? The record says that her physical examination was “normal.” Can one assume that signs of thyrotoxicosis were sought in the eyes and not found? That post-tussive rales were absent? That a goiter was absent? What has happened to the practice of comprehensive history taking and physical examination? Is thoroughness no longer considered the foundation of high-quality medical care? Physicians have been told that chest x-ray films should not be taken routinely because they are not “cost effective.” Have physicians come to accept cost effectiveness as the preeminent justification for a medical procedure?
Before practice guidelines and issues of cost effectiveness came to dominate medical care, a symptom-driven initial presentation of a patient to a physician would mandate a prompt follow-up appointment for a comprehensive examination, which would include the recording of both positive and pertinent negative points of the history and physical examination, complete blood count, erythrocyte sedimentation rate, urinalysis, chest x-ray films, and skin testing with intermediate-strength purified-protein-derivative tuberculin.
In this case, the actual diagnosis of pulmonary tuberculosis could and should have been made within the first week of presentation. This would have reflected medical care of high quality and true cost effectiveness. As it was presented, the record indicates ineffective care of unacceptable quality.
1 ReferencesAlan F. Carpenter, M.D.
1890 Granger Ave., Los Altos, CA 940241
Ross JM ,Sox HC . If at first you don't succeed. N Engl J Med 1995;333:1557-1560
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To the Editor:
In view of the fact that the patient in the Clinical Problem-Solving case was a Laotian immigrant, a chest film should have been obtained during the initial diagnostic workup in the clinic. The prevalence of tuberculosis in the immigrant population was cogently described by McKenna and colleagues.1 Also, the workup assessing the eosinophilia should have included duodenal aspiration for strongyloides larvae or a Beale string test.
1 ReferencesRobert B. Price, M.D.
720 Camp Branch Rd., Waynesville, NC 287861
McKenna MT ,McCray E ,Onorato I . The epidemiology of tuberculosis among foreign-born persons in the United States, 1986 to 1993. N Engl J Med 1995;332:1071-1076
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To the Editor:
In their Clinical Problem-Solving article, Drs. Ross and Sox failed to discuss the misdiagnosis of iron deficiency and the danger of prescribing iron in the absence of objective laboratory evidence of iron deficiency. The patient was treated with iron because of a mild microcytic anemia without any tests of iron metabolism ever being performed. Moreover, the expert physician considered several possible reasons for the failure of iron therapy but never once suggested that tests for iron status — transferrin saturation and measurement of transferrin and ferritin — are indicated before anyone is given iron. The laboratory is more sensitive and specific than the clinician in making a diagnosis of iron deficiency or iron overload. Iron therapy can injure patients with thalassemia, who may already be overloaded with iron.
The authors also state that the alpha-thalassemia trait was diagnosed by hemoglobin electrophoresis. Such a diagnosis is not usually possible except among newborns in whom Bart's hemoglobin can be demonstrated. A defect in alpha-chain production has an equal effect on the synthesis of hemoglobin A and A2 and fetal hemoglobin. Therefore, the alpha-thalassemia trait is not associated with electrophoretic abnormalities. Theoretically, you might predict the presence of a faint hemoglobin H band in persons with the alpha-thalassemia trait, but this is not encountered in actuality. Therefore, the questions to be answered are how the alpha-thalassemia trait was diagnosed in this patient, and whether the diagnosis was correct.
Raymond Gambino, M.D.
Corning Clinical Laboratories, Teterboro, NJ 07680Henry Soloway, M.D.
Associated Pathologists Laboratories, Las Vegas, NV 89119To the Editor:
The Clinical Problem-Solving article “If at First You Don't Succeed” raised a number of important issues. We would like to comment on one: the need for adequate interpretation. In the case described, a non–English-speaking Laotian woman underwent an extensive workup for a series of elusive symptoms. From the outset, because they did not share a common language, both the patient and the doctor were at a great disadvantage. The patient could not directly express her worries or describe her symptoms, and the doctor could not exploit the opportunities afforded by an examination of the patient's history to generate prior probabilities.
Interpreters bridge language barriers. Since finding a trained interpreter may be difficult, patients and providers often rely on strangers with unknown language skills or on family members, including minor children, to interpret. The use of such interpreters raises serious practical, ethical, and even legal questions.1 In the case presented, the patient's husband served as interpreter. The use of untrained interpreters, particularly family members, raises two important questions. First, was his English good enough to provide accurate translation, particularly with regard to medical terminology? Perhaps ineffective communication was the real reason for her noncompliance with H2-blocker therapy. Second, would the patient be willing to share all pertinent information with her husband? It is possible that the patient might not discuss issues such as physical or emotional abuse or an extramarital relationship (e.g., in the context of assessment of risk for the human immunodeficiency virus) in his presence. (Perhaps, more important, she may have been unable to give informed consent for iodine-131 treatment.)
Where could the clinician have found a trained interpreter? Possibilities include local language banks (sometimes hospital- or university-based) and community organizations. Although it can be awkward to use, the AT&T language line may be a useful option for uncommonly spoken languages or during off hours when interpreters may not be available. Many clinicians lack experience in working with an interpreter. Fortunately, both written and videotaped instructions are available to help clinicians work effectively with interpreters.2,3
Effective communication is important to every aspect of care, and it is fundamental to achieving the kind of long-term doctor–patient relationship that is rightly lauded at the conclusion of the case. Trained interpreters make such communication possible between people who speak different languages. As the number of persons with limited proficiency in English grows in the United States, improving access to qualified interpreters will become increasingly important to the practice of good medicine.
3 ReferencesSteven Woloshin, M.D.
Lisa M. Schwartz, M.D.
Veterans Affairs Medical Center, White River Junction, VT 050091
Woloshin S ,Bickell NA ,Schwartz LM ,Gany F ,Welch HG . Language barriers in medicine in the United States. JAMA 1995;273:724-728
CrossRef | Web of Science | Medline2
Putsch RW III . Cross-cultural communication: the special case of interpreters in health care. JAMA 1985;254:3344-3348
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Boston Area Center for Health Education. Bilingual medical interview. Boston: Department of Health and Hospitals, 1987.
To the Editor:
Ross and Sox state that “the sum of all diagnostic probabilities must be one” and that “all but the most accurate tests are most useful when the prior probability is between 30 and 70 percent.” In the case presented, at least two of the three main diagnoses (infection with Opisthorchis sinensis, Graves' disease, and pulmonary tuberculosis) were present simultaneously. This is an example that argues strongly against the truth of the first axiom. A change in the probability of one disease should not necessarily cause a reciprocal change in the probability of other diagnoses. (Does the fact that the battery of your car proves to be dead diminish the probability that you have also run out of gas?) Too often this axiom, which is a didactic simplification for students who are working on an exercise on one given disease, is misleading for clinicians (not for the discussant, who did not take it into account).
A test is useful when it brings probability up or down toward the test threshold or the test-treatment threshold.1 Tests applied on the basis of a prior probability between 30 and 70 percent will in fact have a high numerical yield. Clinicians often order powerful tests in order to increase the probability of disease from 99 percent to 99.99 percent (biopsy) or to lower it from 0.1 percent to 0.001 percent (test for the human immunodeficiency virus) while ruling in or out life-threatening diseases. Is the usefulness of the tests in these cases less than when the probability is increased from 50 percent to 90 percent? Was the yield of the finding of acid-fast bacilli in the case under discussion not as important as the result of skin testing with purified protein derivative? Its absolute yield was certainly much less, since the prior probability of tuberculosis was already high, given the chronic cough, the weight loss, the fatigue, the infiltrate on the chest radiogram, and the positive skin test itself. For life-threatening diseases and for toxic or hazardous treatments, the last steps in the evolution toward certainty are considered by clinicians to be as important as the steps in the middle of the probability range.
We are convinced that the use of a linear scale to represent the probability of a disease is not appropriate for clinicians; rather, clinicians think in terms of a logarithmic scale, on which small numerical differences close to 0 percent and 100 percent can be as important as large numerical differences in the medium range of probability.2
2 ReferencesJef Van den Ende, M.D.
Alfons Van Gompel, M.D.
Institute of Tropical Medicine, B-2000 Antwerp, Belgium1
Pauker SG ,Kassirer JP . The threshold approach to clinical decision making. N Engl J Med 1980;302:1109-1117
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van den Ende J ,van Gompel A ,van den Enden E ,van Damme W ,Janssen P . Bridging the gap between clinicians and clinical epidemiologists: Bayes theorem on an ordinal scale. Theor Surg 1994;9:195-195 abstract.
To the Editor:
I am the public health nurse coordinator who monitored the patient in the Clinical Problem-Solving article during her treatment for tuberculosis. The organism isolated from the patient was not resistant to any antituberculosis medication. Initially, a telephone report from the laboratory indicated resistance to isoniazid and ethambutol. At that time, these medications were dropped from the four-drug regimen and streptomycin and ciprofloxacin were added. When the final printed report came from the laboratory, it indicated sensitivity of the organism to all medications. When the laboratory was asked to clarify these results, it noted that the initial telephone report incorrectly indicated resistance but that the finding was believed to be a result of antibiotic degradation. All subsequent testing indicated 100 percent sensitivity to antibiotics. Rather than changing the drug regimen again, we continued to treat the patient with rifampin, pyrazinamide, streptomycin, and ciprofloxacin.
Valerie F. Benoit, R.N., M.A
Public Health District Office, Claremont, NH 03743-2280Author/Editor Response
The authors reply:
To the Editor: Drs. Van den Ende and Van Gompel are correct in chiding us for failing to say that the probabilities of mutually exclusive events must total one. However, our case does not illustrate their point. To understand our argument, one must first know the definition of probability: a person's estimate of the likelihood of an event. In retrospect our patient had several diseases at once, but since the discussant did not know this until the end of the case, the discussant's probabilities should sum to one. Perhaps, as Drs. Van den Ende and Van Gompel claim, physicians do think in terms of a logarithmic scale of uncertainty. In the absence of any proof of this statement, we stand by our claim that testing will have the largest effect on uncertainty when the pretest probability is intermediate.
The comments of the other letter writers relate to the details of clinical care. Drs. Woloshin and Schwartz eloquently underscore the obligation of physicians caring for those who speak a different language to obtain a qualified interpreter. Dr. Price correctly raises the point that the possibility of infection with strongyloides should have been aggressively pursued, since the sensitivity of a single or even multiple stool specimens is not high. Concentration of the stool increases the yield significantly, and negative serologic results make infection unlikely. Duodenal aspiration in pursuit of this diagnosis is not commonly performed at our institution but is an effective tool in the right clinical setting.
Dr. Carpenter hypothesizes that a comprehensive initial examination would have uncovered clues leading to an earlier diagnosis and implies that the physicians involved in the patient's care might have been distracted by guidelines or cost considerations. A careful review of the patient's record does not support the first contention — the chart documents the performance of careful comprehensive examinations on more than one occasion. Few physicians believe that determination of the erythrocyte sedimentation rate or chest radiography would have been appropriate at the patient's first visit. The larger concern, that physicians might become less careful given the pressures of cost containment and managed-care incentives, is certainly appropriate, although not germane in our largely fee-for-service setting. A chest x-ray film and tuberculin skin test should have been done far earlier in the patient's clinical course.
We agree with Drs. Gambino and Soloway that the laboratory diagnosis of iron deficiency would have greatly assisted the clinicians caring for the patient. They further question whether hemoglobin electrophoresis could have diagnosed both the hemoglobin E and alpha-thalassemia traits. In this case, electrophoretic quantification of hemoglobin E revealed a value of 27 percent, which is lower than is usually seen with the hemoglobin E trait and more suggestive of a mixed hemoglobinopathy with alpha-thalassemia trait.1 Finally, Ms. Benoit has reported that the patient's strain of Mycobacterium tuberculosis was not drug-resistant. This information was known to her medical team but absent from the records we reviewed.
1 ReferencesJonathan M. Ross, M.D.
Harold C. Sox, M.D.
Dartmouth–Hitchcock Medical Center, Lebanon, NH 037561
Tuchinda S ,Rucknagel DL ,Minnich V ,Boonyaprakob U ,Balankura K ,Suratee V . The coexistence of the genes for hemoglobin E and α thalassemia in Thais, with resultant suppression of hemoglobin E synthesis. Am J Hum Genet 1964;16:311-335
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