Nonconcordance between Clinical and Head CT Findings: The Specter of Overdiagnosis.

Background. It is unclear whether history and physical examination findings can predict abnormalities on head computed tomography (CT) believed to indicate increased risk of lumbar-puncture- (LP-) induced brain herniation. The objectives of this study were to (1) identify head CT findings felt to be associated with increased risk of brain herniation and (2) to assess the ability of history and physical examination to predict those findings. Methods. Using a modified Delphi survey technique, an expert panel defined CT abnormalities felt to predict increased risk of LP-induced brain herniation. Presence of such findings on CT was compared with history and physical examination (H&P) variables in 47 patients. Results. No H&P variable predicted "high-risk" CT; combining H&P variables to improve sensitivity led to extremely low specificity and still failed to identify all patients with high-risk CT. Conclusions. "High-risk" CT is not uncommon in patients with clinical characteristics known to predict an absence of actual risk from LP, and thus it may not be clinically relevant. "Overdiagnosis" will be increasingly problematic as technological advances identify increasingly subtle deviations from "normal."

Derivation of a decision instrument for selective chest radiography in blunt trauma.

BACKGROUND: To derive a decision instrument (DI) that identifies patients who have virtually no risk of significant intrathoracic injury (SITI) visible on chest radiography and, therefore, no need for chest imaging. METHODS: This is a prospective observational study. At three Level 1 trauma centers, physicians caring for blunt trauma patients aged >14 years were asked to record the presence or absence of 12 clinical criteria before viewing chest imaging results. SITI was defined as pneumothorax, hemothorax, aortic/great vessel injury, two or more rib fractures, ruptured diaphragm, sternal fracture, and pulmonary contusion on official radiograph readings. The κ (interrater reliability) and screening performance of individual criteria were determined. By using recursive partitioning, the most highly sensitive combination of criteria for SITI was derived. RESULTS: Of the 2,628 subjects enrolled, 271 (10.3%) were diagnosed with a total of 462 SITIs, with rib fractures (73%), pneumothorax (38%), and pulmonary contusion (29%) as the most common injuries. Chest pain and chest wall tenderness had the highest sensitivity for SITI (65%). The DI of chest pain, distracting injury, chest wall tenderness, intoxication, age >60 years, rapid deceleration, and altered alertness/mental status had the following screening performance: sensitivity 99.3% (95% confidence interval [CI], 97.4-99.8), specificity 14.0% (95% CI, 12.6-15.4), negative predictive value 99.4% (95% CI, 97.8-99.8), and positive predictive value 11.7% (95% CI, 10.5-13.1). All seven criteria in the DI met the predetermined cut off for acceptable κ (range, 0.51-0.81). CONCLUSIONS: We derived a DI consisting of seven clinical criteria that can identify SITI in blunt trauma patients with extremely high sensitivity. If validated, this instrument will allow for safe, selective chest imaging with potential resource savings.

External validation of the San Francisco Syncope Rule.

STUDY OBJECTIVE: We externally validate the ability of the San Francisco Syncope Rule to accurately identify syncope patients who will experience a 7-day serious clinical event. METHODS: Patients who presented to a single academic emergency department (ED) between 8 am and 10 pm with syncope or near-syncope were prospectively enrolled. Treating physicians recorded the presence or absence of all San Francisco Syncope Rule risk factors. Patients were contacted by telephone at 14 days for a structured interview. A 3-physician panel, blinded to the San Francisco Syncope Rule score, reviewed ED medical records, hospital records, and telephone interview forms to identify predefined serious clinical events. The primary outcome was the ability of the San Francisco Syncope Rule to predict any 7-day serious clinical event. A secondary outcome was the ability of the San Francisco Syncope Rule to predict 7-day serious clinical events that were not identified during the initial ED evaluation. RESULTS: Of 592 eligible patients, 477 (81%) provided informed consent. Direct telephone contact or admission/outpatient records were successfully obtained for 463 (97%) patients. There were 56 (12%) patients who had a serious 7-day clinical event, including 16 (3%) who received a diagnosis after the initial ED evaluation. Sensitivity and specificity of the San Francisco Syncope Rule for the primary outcome were 89% (95% confidence interval [CI] 81% to 97%) and 42% (95% CI 37% to 48%), respectively, and 69% (95% CI 46% to 92%) and 42% (95% CI 37% to 48%), respectively, for the secondary outcome. Estimates of sensitivity were minimally affected by missing data and most optimistic assumptions for missing follow-up information. CONCLUSION: In this external validation cohort, the San Francisco Syncope Rule had a lower sensitivity and specificity than in previous reports.

Impact of patient race on receiving head CT during blunt head injury evaluation.

OBJECTIVES: Prior evidence suggests that physicians may alter process of care based on race/ethnicity. The objective of this study was to determine whether race/ethnicity predicts whether a patient receives computed tomography of the head (head CT) during evaluation of blunt head injury. METHODS: This was a nonconcurrent cohort study set in an emergency department of a Level 1 trauma center in a university medical center. Consecutive patients presenting with blunt head injury from January 2000 to December 2000 were enrolled. The main outcome measure was whether or not a patient received head CT during evaluation of blunt head injury. RESULTS: The unadjusted probability of receiving head CT was similar among minority (33.9%; 95% confidence interval [CI] = 30.0% to 38.1%) and non-Hispanic white patients (36.4%; 95% CI = 33.5% to 39.3%). After adjusting for important clinical and socioeconomic predictors, minority patients had a probability of receiving head CT 0.84 times as high as that of non-Hispanic whites, but this result was not statistically significant (95% CI = 0.67 to 1.09). CONCLUSIONS: Minority and non-Hispanic white patients may not have significantly different rates of receiving head CT during evaluation of blunt head injury. A multicenter prospective study is necessary to confirm these preliminary findings.