Inpatient radiology utilization: trends over the past decade.

OBJECTIVE The objective of our study was to assess patterns of use of radiology services for inpatients at our institution between 1993 and 2002. MATERIALS AND METHODS We retrospectively reviewed the administrative data about adult inpatients for fiscal years 1993-2002 in a 721-bed tertiary care institution. Examinations were coded according to imaging technique: conventional (plain films and fluoroscopy), sonography, nuclear medicine, CT, or MRI. We assessed workload trends using relative value units (RVUs). Linear regression analysis was used to assess the significance of trends for the number of examinations and RVUs per case-mix-adjusted admission (CMAA). RESULTS There was a significant decrease in the total number of examinations per CMAA (p < 0.001). This was due to significant decreases in the use of conventional studies (p < 0.001) and sonograms (p < 0.001), despite significant increases in the number of nuclear medicine (p = 0.046), CT (p < 0.001), and MRI (p < 0.002) examinations per CMAA. The RVUs per CMAA increased significantly (p < 0.01) during the study period. CONCLUSION Newer imaging technologies (nuclear medicine, CT, and MRI) are replacing older ones in the evaluation of inpatients. Despite the significant decrease in the total number of imaging examinations per CMAA, we observed a significant increase in RVUs per CMAA during the 10-year study period. Understanding the impact of this change in practice on the quality of care would be useful in justifying the increasing use of these new technologies, and decreasing their inappropriate use should be a priority in efforts that focus on controlling imaging expenditures.