Retrospective cohort analysis based off the NHAMCS dataset, with all the inherent limitations within.
We have a 330% increase in the use of CT in the Emergency Department – up from 3.2% in 1996 to 13.9% in 2007. This increase is pretty stable across all age groups (including a rate of up to nearly 5% now in patients under 18 years of age). The interesting part of the paper that’s something we didn’t already know, is their data regarding the adjusted rate of hospitalization or transfer after receiving CT. In 1996, 26% of patients receiving a CT were admitted to the hospital, while now only 12% of patients receiving CT are admitted to the hospital.
The problem is, I’ve seen news organizations running with the conclusion: CT rates might be higher, but since the relative risk of hospitalization is lower after a CT, therefore, it must be preventing hospitalizations. But, you can’t draw any such conclusion from the data – particularly considering hospitalizations have climbed over that same period.
We just aren’t seeing any data that links the increase in CT use to improved outcomes. Increased CT usage certainly has its place as the standard of care in many instances, but there’s no silver lining to this 330% increase.
“National Trends in Use of Computer Tomography in the Emergency Department.”
www.ncbi.nlm.nih.gov/pubmed/21115875