Reducing intravenous contrast utilization for CT: A health-system wide intervention with sustained impact.

Abstract

To determine the volume of intravenous iodinated contrast media utilized for CT before, during, and after the global iohexol shortage over a total of 17 months at a multisite health system. This retrospective study included all patients who underwent CT at a large health system with 12 sites. Standardized contrast doses for 13 CT examinations were implemented 5/23/22. Mean contrast utilization per CT encounter was compared between 3 periods (pre-intervention 1/1/22-5/22/22; intervention 5/23/22-9/11/22; post-intervention 9/12/23-6/30/23). Contrast doses and CT encounter data were extracted from the enterprise data warehouse. Categorical variables were compared with a chi-squared test and continuous variables were compared with a two-tailed t-test. Multivariable linear regression assessed significance, with coefficients noted to determine magnitude and direction of effect. Pre-intervention, there were 152,009 examinations (87,722 with contrast, 57.7%), during the intervention 120,031 examinations (63,217 with contrast, 52.7%), and post-intervention 341,862 examinations (194,231 with contrast, 56.8%). Pre-intervention, mean contrast dose was 89.3 mL per exam, which decreased to 78.0 mL following standardization (Δ of -12.7%) (p<0.001). This decrease continued throughout the intervention and persisted in the post-intervention period (80.4 mL; Δ -10.0%, p<0.001). On multivariable analysis, patient weight, sex, and performing site were all associated with variations in contrast dose. Most but not all sites (9/12) sustained the decreased contrast media dose in the post-intervention period. Implementing standardized contrast media dosing for commonly performed CT examinations led to a rapid decrease in contrast media utilization which persisted over 1 year.