key: cord-0039082-g47mwwnq
authors: Chen, Shey-Ying; Su, Chan-Ping; Chiang, Wen-Chu; Lai, Ting-I; Chen, Wen-Jone
title: In reply:
date: 2004-09-21
journal: Ann Emerg Med
DOI: 10.1016/j.annemergmed.2004.02.048
sha: e6cc2c03cdf6725d293ccb16f3b0c32d4c1e7b5b
doc_id: 39082
cord_uid: g47mwwnq

nan

are indeed very useful first steps in developing diagnostic strategies for this new infectious disease. Nonetheless, I would like to discuss some areas of concern in interpreting and applying the results.

First, it should be noted that in all of these studies, patients were only included if they had documented fever (body temperature >38°C [>100.4°F]). Although Chen et al 1 and Su et al 4 suggested that their scoring systems could be used in settings where mass screening for SARS is required, application will actually be limited to febrile patients with temperatures greater than 38°C (>100.4°F).

In mass screening, if patients with low-grade fever (37.5°C to 38°C [99.5°F to 100.4°F]) are not included, a substantial number of patients in the early stages of the disease will likely be missed. In a study from our ED-based SARS screening clinic during the outbreak in Hong Kong (which included afebrile patients), it was shown that 19% of SARS patients initially presented without fever, and that radiographic evidence of pneumonia often preceded fever. 5 Therefore, a more useful tool for mass screening would have included fever or body temperature as a variable, thus allowing the evaluation of afebrile cases. 2 Furthermore, the study of Wang et al 3 actually enrolled only those cases that met the World Health Organization (WHO) criteria for suspected SARS. Although their scoring system was shown to have a sensitivity of 100%, this perfect figure will apply only specifically to those patients already screened as positive by the WHO criteria or case definition. Unfortunately, the WHO criteria for suspected SARS have been shown to have a sensitivity of only 26%. 5 In practice, therefore, if 100 SARS patients presented to the ED for screening, only 26 would be correctly triaged to undergo the scoring system evaluation. Thus, relying on this strategy, despite the implementation of a near-perfect decision rule, will still result in an unacceptable number of missed cases.

Finally, the performance of chest radiography was not adequately examined in these studies. We believe that chest radiography will likely be the single most important screen for SARS in the ED setting. It has been shown to be the strongest predictor available in the ED, with an odds ratio of 17.4. 6 During the outbreak, we performed screening chest radiography on virtually every patient with fever greater than 38°C (>100.4°F), regardless of symptomatology. It remains to be proven whether the scoring systems in these studies, given the limitations addressed by the authors, can significantly outperform chest radiography.

In addition to the multilobar infiltrates evaluated by Wang et al, 3 it will be important also to analyze the predictive values for lobar, segmental, or even patchy infiltrative changes. A detailed time sequence of radiographic pro-gression, in relationship to the progression of symptoms, may prove to be useful, as well. In reply:

We thank Dr. Chan for his interest in our articles. His comments provide an opportunity for further discussion about triaging potential severe acute respiratory syndrome (SARS) patients.

In regard to his first comment, some patients actually contract SARS-coronavirus and develop clinical symptoms and chest radiographic infiltrates without fever (defined as body temperature >38°C [>100.4°F]). However, such atypical presentations of SARS have mostly been reported in patients with congestive heart failure, compromised immunity, and the elderly. 1,2 From April 3 to May 12, 2003, there were 2,765 patients (including 602 patients with exposure risk) who presented to our emergency department (ED) for SARS screening without documented fever. Even without fever, they were admitted as long as there were infiltrates on chest radiography. Only 3 of them were finally confirmed to have SARS. All 3 patients were elderly with comorbidities such as heart failure or compromised immunity.

To the contrary, in patients with normal immunity, fever was near universally presented. [2] [3] [4] It has been proposed that SARS-coronavirus pneumonia is largely an immunologically mediated process. 3, 5 Patients with normal immunity, in our experience, may have pulmonary infiltrates preceding respiratory symptoms, but rarely before signs of systemic inflammation. 5 However, there are 2 caveats that should be addressed. First, 40.5% (32/79) of SARS patients documented fever at home but not on arrival to the ED, as

a result of the intermittent fever curve induced by SARS infection. Second, fever may be the only initial presentation of SARS. Of our SARS patients, 13.9% (11/79) reported fever as the only symptom in the ED, yet 9 of them had radiographic infiltrates. Were it not for the practice of regularly checking body temperature, they might be regarded as cases ''with radiographic evidence of pneumonia preceding the fever.'' Thus, from our experience, we believe that routinely measuring body temperature provides an important step in the early detection and screening of potential SARS infection.

Finally, although a detailed time sequence of radiographic progression might be theoretically useful in the diagnosis of SARS, this information was nearly unavailable in the ED. More importantly, our purpose of proposing this model was to provide an aide to shape triage decisions in case of mass casualty management, rather than to make definite diagnosis in the ED. 

To the Editor:

In the February 2004 issue of Annals, Gresenz and Studdert 1 provide interesting insight into the health plan denial and appeal process; however, it should be noted that this study was conducted under the premise that California has a prudent layperson standard for insurance coverage of emergency department (ED) visits. Actually, California has a more generous standard for ED access than the conventional prudent layperson standard, wherein the law states that a health plan (excepting Kaiser) must pay for emergency care unless ''the patient should have known that they did not have an emergency.'' 2 This language is uniquely subjective in that it refers to the patient's frame of mind rather than to ''the opinion of a prudent layperson.'' Because it would be very difficult to prove a negative on the basis of what the patient should have known, the frequency of denials should have been much lower if these plans were obeying the law.

In addition, a statement in the accompanying editorial by Stapczynski 3 deserves clarification. He compares postvisit review to efforts to reduce ED visits by requiring preauthorization, noting a similar lack of utility. The inference is that the practice of pre-authorization for ED visits was abandoned because it wasn't useful, or perhaps that it was unsafe or inaccurate per the references cited. On the contrary, managed care gatekeeping was primarily abandoned not because it lacked utility for health plans, but because of complaints and regulatory activity instigated by providers and consumers. For example, prior authorization in the ED was prohibited after emergency physicians in California convinced the Office of Inspector General that it was a violation of the Emergency Medical Treatment and Active Labor Act. 4 These comments illustrate the importance of placing socioeconomic data in the appropriate historical and legal context. 

Atypical presentations of SARS

The severe acute respiratory syndrome

Clinical progression and viral load in a community outbreak of coronavirus-associated SARS pneumonia: a prospective study

Sequential symptomatic analysis in probable severe acute respiratory syndrome cases

Lung pathology of fatal severe acute respiratory syndrome

Disputes over coverage of emergency department services: a study of two health maintenance organizations

California Health and Safety Code

Is the prudent layperson standard really a ''standard

Office of Inspector General/Health Care Financing Administration Special Advisory Bulletin on the Patient Anti-dumping Statute Related to Managed Care Plans, 64 Federal Register

The defining feature of a prudent layperson standard is its reference to ex ante expectations of patients, as opposed to professional judgment, as the basis for determining the appropriateness of emergency department (ED) use. A prudent layperson standard operates in California. Dr. Johnson suggests that the statutory formulation of the prudent layperson standard in California implies a more generous standard for access to ED services than other states, one that is ''uniquely subjective.''