Use of advanced radiology during visits to US emergency departments for injury-related conditions, 1998-2007.

CONTEXT

Excessive use of medical imaging increases health care costs and exposure to ionizing radiation (a potential carcinogen) without yielding significant benefits to all patients.

OBJECTIVE

To determine whether there has been a change in the prevalence of emergency department visits for injury-related conditions for which computed tomography (CT) or magnetic resonance imaging (MRI) was obtained and whether there has been a change in the diagnosis of life-threatening conditions and patient disposition.

DESIGN, SETTING, AND PARTICIPANTS: Retrospective cross-sectional analysis of emergency department visits using data from the National Hospital Ambulatory Medical Care Survey (1998-2007). Sampled visits were weighted to produce estimates for the United States.

MAIN OUTCOMES MEASURES

Proportion of visits for injury-related conditions during which a CT or MRI was obtained, a life-threatening condition was diagnosed (eg, cervical spine fracture, skull fracture, intracranial bleeding, liver and spleen laceration), and which resulted in hospital and intensive care unit admission.

RESULTS

The prevalence of CT or MRI use during emergency department visits for injury-related conditions increased from 6% (95% confidence interval [CI], 5%-7%) (257 of 5237 visits) in 1998 to 15% (95% CI, 14%-17%) (981 of 6567 visits) in 2007 (P < .001 for trend). There was a small increase in the prevalence of life-threatening conditions (1.7% [95% CI, 1.2%-2.2%; 89 of 5237 visits] in 1998 and 2.0% [95% CI, 1.6%-2.5%; 142 of 6567 visits] in 2007; P=.04 for trend) [corrected].There was no change in prevalence of visits during which patients were either admitted to the hospital (5.9% [95% CI, 4.9%-6.9%] in 1998 and 5.5% [95% CI, 4.7%-6.5%] in 2007; P = .50 for trend) or to an intensive care unit (0.62% [95% CI, 0.40%-1.00%] in 1998 and 0.80% [95% CI, 0.53%-1.21%] in 2007; P = .14 for trend). Visits during which CT or MRI was obtained lasted 126 minutes (95% CI, 123-131 minutes) longer than those for which CT or MRI was not obtained.

CONCLUSION

From 1998 to 2007, the prevalence of CT or MRI use during emergency department visits for injury-related conditions increased significantly, without an equal increase in the prevalence of life-threatening conditions.