Multicenter validation of a novel medication-regimen complexity scoring tool.

Background: The MRC-ICU, a novel regimen complexity scoring tool, provides an objective measure of medication regimen complexity in critically ill patients. The MRC-ICU may have the ability to evaluate the impact of critical care pharmacists on patient outcomes but requires further validation. The objective of this study was to confirm the external validity of the MRC-ICU scoring tool at multiple institutions and intensive care unit (ICU) settings.

Methods: This was a multicenter, prospective, observational study. The electronic medical record was reviewed to collect patient demographics and patient outcomes, and the medication administration record was reviewed to collect MRC-ICU scores at 24 hours, 48 hours, and ICU discharge. Validation was performed by assessing convergent and divergent validity of the score. Spearman rank-order correlation was used to determine correlation.

Results: A total of 230 patients were evaluated across both centers in both medical ICUs and surgical ICUs. Differences between the original center and the new site included that total number of orders (29 vs 126; P < 0.001) and total number of medication orders (17 vs 36; P < 0.001) were higher at the new site, whereas the original site had higher overall MRC-ICU scores (14 vs 11; P = 0.004). The MRC-ICU showed appropriate convergent validity with number of orders and medication orders (all P < 0.001) and appropriate divergent validity with no significant correlation found between age, weight, or gender (all P > 0.05).

Conclusions: External validity of the MRC-ICU has been confirmed through evaluation at an external site and in the surgical ICU population. The MRC-ICU scoring tool requires prospective evaluation to provide objective data regarding optimal pharmacist use.