Diagnostics
The San Francisco Syncope Rule vs physician judgment and decision making

Presented at the 2003 Annual Meeting of the Society for Academic Emergency Medicine, Boston, Mass.
https://doi.org/10.1016/j.ajem.2004.11.009Get rights and content

Abstract

Objective

To compare a clinical decision rule (San Francisco Syncope Rule [SFSR]) and physician decision making when predicting serious outcomes in patients with syncope.

Methods

In a prospective cohort study, physicians evaluated patients presenting with syncope and predicted the chance (0%-100%) of the patient developing a predefined serious outcome. They were then observed to determine their decision to admit the patient. All patients were followed up to determine whether they had a serious outcome within 7 days of their emergency department visit. Analyses included sensitivity and specificity to predict serious outcomes for low-risk patients and comparison of areas under the receiver operating characteristic curve for the decision rule, physician judgment, and admission decisions.

Results

During the study period, there were 684 visits for syncope with 79 visits resulting in serious outcomes. The area under the receiver operating characteristic curve was 0.92 (95% confidence interval [CI], 0.88-0.95) for the SFSR compared with physician judgment 0.89 (95% CI, 0.85-0.93) and physician decision making 0.83 (95% CI, 0.81-0.87). Physicians admitted 28% of patients in a low-risk group, with a median length of stay of 1 day (interquartile range, 1-2.5 days). The SFSR had the potential to absolutely decrease admissions by 10% in this low-risk group and still predict all serious outcomes.

Conclusions

Physician judgment is good when predicting which patients with syncope will develop serious outcomes, but contrary to their judgment, physicians still admit a large number of low-risk patients. The SFSR performs better than current physician performance and has great potential to aid physician decision making.

Introduction

Syncope is a transient loss of consciousness with a return to preexisting neurologic function. A common problem, 1 of 4 people will faint during their lifetime, and 1% to 2% of all emergency department (ED) visits and hospital admissions are related to a transient loss of consciousness [1], [2], [3], [4].

Patients with syncope create a difficult dilemma for physicians. Most causes are benign, but occasionally, it is a symptom associated with significant morbidity and mortality. Some patients will require emergent hospitalization for workup and treatment of life-threatening or potentially life-threatening causes, others should get outpatient evaluation, whereas some patients need no further evaluation.

It has been suggested that the use of hospitalization for patients with syncope is inefficient and highly variable [5], [6], [7], [8], [9], [10]. Many things can cause syncope and the potential diseases that cause it span multiple specialties, making it difficult to develop an optimal disposition for these patients. Accordingly, a survey of physicians revealed that the disposition of patients with syncope was the second most common decision problem for North American physicians [11]. A highly sensitive and specific decision rule that would aid and improve physician decision making could have the potential to significantly reduce health care costs and improve efficiency and patient care.

The San Francisco Syncope Study is a prospective multiphase study. Phase 1 involved derivation of a decision rule using 684 patients to help predict patients at risk for acute outcomes. Variables were assessed for their interobserver agreement and univariate association with acute outcomes. The final San Francisco Syncope Rule (SFSR), derived from recursive partitioning of the most important variables, was found to be highly sensitive and specific (Fig. 1) [12]. To justify the time and effort involved in validating and disseminating a decision rule, it is important to know if the rule can improve upon the diagnostic accuracy and reliability of unstructured physician judgment and eventual decision making. We sought to determine whether the SFSR would have performed better than physician decision making during phase 1 of the study.

Section snippets

Methods

The multiphase San Francisco Syncope Study was undertaken with reference to previously described guidelines for developing clinical decision rules [13], [14]. In particular, outcomes were clearly defined and predictor variables were carefully chosen before the study began. A significant number of patients independently assessed by 2 physicians to measure agreement for subjective variables and appropriate multivariate methods were used to derive the rule [11].

This prospective cohort study was

Results

This phase of the San Francisco Syncope Study took place from June 30, 2000, to February 28, 2002. There were 684 visits analyzed and their characteristics are summarized in Table 1. Fifty-five percent of all patients were admitted, 59% were female and the average age was 62 years. All patients had some form of follow-up. Ninety-six percent of patients had direct confirmation of their outcome with less than 4% requiring indirect follow-up through checks to local hospital and the death registry.

Discussion

Overall physician judgment is good for discriminating those patients with syncope at risk for serious outcomes. However, unstructured physician judgment is problematic. It still misclassifies a small number of important outcomes, and more importantly, because it is unstructured and variable among physicians, physicians do not trust their judgment and thus decide to admit many low-risk patients. This study has shown that the SFSR performs better than overall physician decision making and there

Conclusions

The limitations of physician judgment have resulted in the variable and inefficient use of admissions for patients presenting with syncope. In the first phase of this study, we have developed a highly sensitive and specific rule and demonstrated its value compared with physician judgment alone for identifying patients at acute risk for serious outcomes and guiding admission decisions. The SFSR is currently under prospective validation. We believe that a reliable decision rule will guide and

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Dr Quinn is supported by the NIH on a career development award K23 AR002137-05.

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