Assessment of rabies immune globulin dose rounding at a university health system.

Purpose: Describe a dose rounding strategy for rabies immune globulin (RIG) administration.

Methods: Multicenter, retrospective, observational review of patients that received RIG following an exposure from an animal with potential to transmit rabies infection in one health-system from March 2011 through December 2021. The primary outcome was to describe the RIG dose rounding strategy and population of patients that received RIG rounded to the nearest vial size compared to those that did not. Secondary outcomes evaluated additional costs and RIG international units (IU) wasted that could have occurred (rounded group) or did occur (not rounded group), re-presentation to the ED or primary care provider (PCP) within 7 days due to RIG related complaint, and occurrence of rabies infection. Data collection included patient demographics, exposure information, and RIG dose administered. Descriptive data and univariate analyses are reported. Cost and RIG IU wasted were calculated for the dosing strategies.

Results: 426 patients were included; 373 (88%) had RIG rounded to the nearest vial size and 53 (12%) did not (mean age 36.1 years ±20.5, 51.6% male, most common exposures were bats [50%], type was bite [58%], and category III exposures [92%]). Those that had RIG rounded were younger and had lower total RIG doses, but similar IU/kg doses to those not rounded. A cost savings of $144,815 and prevention of 40,572 RIG IU wasted was calculated from those patients that had RIG rounded. There was no difference in the rate of re-presentation within 7 days and no cases of human rabies infection in the region during the study period.

Conclusions: RIG dose rounding to the nearest vial size is associated with cost savings and prevention of wasting RIG IU. There was no association with re-presentation to the ED or PCP with RIG related issues within 7 days from administration.