Purpose: The aim of this study is to analyze longitudinal trends of adult emergency department (ED) CT utilization in one large tertiary hospital.
Materials and methods: This study retrospectively analyzed data from one adult ED (age>18 years) of a large tertiary hospital. Numbers of ED visits and CT examinations over five years (2012 – 2016) were retrospectively retrieved from the hospital’s computerized records. Annual CT utilization rate in the ED (annual number of patients that performed CT/annual number of ED visits) was calculated for each year. Linear trend between calendar years and CT utilization rate was evaluated (Spearman’s rank order correlation). CT examinations were grouped according to nine body regions: head, abdomen (including non contrast renal colic protocol), chest (including CT pulmonary angiography protocol), chest-abdomen, spine (cervical, thoracic and lumbar), extremities (upper and lower), pelvis, CT angiography (cervical, extremities, aorta) and miscellaneous (other CT examinations not included in previous groups). The percentages of each group from the total of CT examinations were calculated. One way ANOVA with Tukey post hoc testing evaluated differences in CT utilization between the groups.
Results: Overall, there were 467,109 ED visits of which 73,113 patients underwent CT examinations during the study period. A statistically significant strong linear (r=0.9, p=0.037) increase of 13.2% of CT utilization rate was observed during the study period (2012 – 2016), with an average annual increase of 3.3%. The percentages of each of the nine CT groups were: 65.9%, 10.2%, 2.4%, 2.6%, 8.2%, 2.6%, 1.3%, 5.2% and 1.6% from the total number of performed CT examinations, thus making head CT the largest group with 65.9% (p<0.001).
Conclusion: ED CT utilization rate showed an average annual increase of 3.3% over the last five years. Head CT constitutes by far the largest group of performed CT examinations. Clinical decision protocols aimed at reducing ED CT utilization rate may a Pareto have the highest yield when targeting head CT.
