Greater CT use in emergency departments to evaluate common chest symptoms has not improved rate of clinically significant diagnoses, study indicates

Despite dramatically increased usage of computer tomography (CT) in emergency departments (EDs) to evaluate common chest (CC) symptoms, the proportion of related ED visits associated with a clinically significant diagnosis has decreased, study data suggest. The data were obtained from the National Hospital Ambulatory Medical Care Survey. Two three-year periods were evaluated--from 1997 through 1999 and from 2005 through 2007. Federal hospitals were not included in the survey data, and only...

Despite dramatically increased usage of computer tomography (CT) in emergency departments (EDs) to evaluate common chest (CC) symptoms, the proportion of related ED visits associated with a clinically significant diagnosis has decreased, study data suggest.

The data were obtained from the National Hospital Ambulatory Medical Care Survey. Two three-year periods were evaluated--from 1997 through 1999 and from 2005 through 2007. Federal hospitals were not included in the survey data, and only ED-related data for patients aged at least 15 years were analyzed.

The primary outcome of interest was the proportion of CC symptom-related visits associated with a CT order. Visits with symptoms of chest pain, shortness of breath and labored breathing were identified and coded as a CC symptom-related visit.

Secondary outcomes were clinically significant CC diagnoses, including acute myocardial infarction, acute coronary syndrome, pulmonary embolism (PE) and infarction, heart failure, pneumonia, organism unspecified and unspecified pleural effusion. Incidental findings included diagnoses of intrathoracic lymph nodes, a swelling, mass or lump in the chest, abdominal mass and coin lesion lung.

In all, data were available for 136,751 ED visits during the six years analyzed (53,145 for the earlier period and 83,606 for the later period). A CC symptom-related visit was recorded for 17,098 of the visits. Using these data, the researchers estimated that approximately 11 million CC symptom-related ED visits occurred in the United States each year during the study period, representing 13 percent of all ED visits for patients in the age group analyzed.

Both time periods had similar proportions of CC symptom-related ED visits.

The proportion of CC symptom-related visits associated with a CT order was significantly greater in the later period than in the earlier period for all CC symptoms combined (11.5 percent vs. 2.1 percent) and for each individual CC symptom. Further, not only did the rate of CT ordering increase from the first three-year period to the second three-year period, but it also nearly doubled during the later period, increasing from 8.6 percent in the first six months of 2005 to 15.8 percent in the last six months of 2007.

After adjustments were made for demographic variables, the researchers found that the CC symptom-related ED visits made from 1997 through 1999 were more likely to be associated with a clinically significant diagnosis than were the visits made from 2005 through 2007 (23.6 percent vs. 19.1 percent).

The researchers noted that myocardial infarction was the largest contributing diagnosis in the rate discrepancy between the earlier and the later period.

Of all the ED visits associated with CC symptoms in either time period, less than half of 1 percent were associated with a diagnosis of PE, and the proportion of visits that were associated with a PE diagnosis did not change significantly between the two periods. The percentage of CC symptom-related visits that were associated with an incidental diagnosis also did not change significantly from the earlier to the later period. However, the CC symptom-related visits during the 2005-07 period were significantly more likely than were those during the 1997-99 period to be associated with a clinically nonsignificant diagnosis.

"With increases in the number of nonspecific diagnoses and no improvements in clinically significant diagnoses such as PE and pneumonia among patients presenting with CC symptoms, increased utilization seems to provide little to add in the diagnostic work-up and certainly is not altering treatment in the setting of inappropriate ordering," the researchers commented.

"There are also risks associated with repeated intravenous contrast, and an emotional burden can be placed on a patient being informed about a potential diagnosis of cancer," they added, noting that of the 81 patients (out of 459 who underwent cardiac CT) in whom incidental pulmonary nodules were found, none developed lung cancer after two years of follow-up.

"With the radiation risks associated with CT becoming more apparent, utilization of health care resources from an evidential and public health-based approach is warranted," the researchers concluded.

These data were published in the January/February issue of the Journal of the American Board of Family Medicine.