Socioeconomic status and the use of computed tomography in the emergency department

Introduction — Low socioeconomic status (SES) is associated with adverse health outcomes, potentially due to worse health status, differential access to healthcare, and differences in care provided by clinicians. The objective of this study is to determine whether SES is associated with computed tomography (CT) utilization in the emergency department (ED).

Methods — The researchers conducted a retrospective cohort study of patients presenting to EDs using administrative databases in Ontario. SES quintile was assigned based on median neighbourhood income. CT utilization was compared by SES quintile overall and in chief complaint subgroups (headache, abdominal pain, complex abdominal pain [age >= 65, CTAS 1-3, and admitted]) using multivariate logistical regression.

Results — In adjusted analyses, higher SES patients were more likely to undergo CT imaging overall and in all clinical subgroups, with the exception of complex abdominal pain. Compared to the lowest SES quintile, the odds (aOR) of undergoing a CT scan in the highest SES quintile were 1.08 (95% CI 1.07-1.09), 1.28 (95% CI 1.22-1.34), and 1.24 (95% CI 1.21-1.27) for all patients, headache, and abdominal pain patients, respectively. For patients presenting with complex abdominal pain, no difference in CT utilization was observed between the highest and lowest SES quintiles (aOR 1.09, 95% CI 0.97-1.20).

Conclusions — Lower SES is associated with lower utilization of CT scans in the ED overall and in patients with headache and abdominal pain. No difference was seen among complex abdominal pain patients, suggesting that as clinical indications for CT become more clear-cut, utilization across SES quintiles differs less. These results may indicate that some of the differential access to diagnostic testing among low SES patients reflects physician decision making.