Medication regimen complexity is associated with pharmacist interventions and drug‐drug interactions: A use of the novel MRC‐ICU scoring tool

Abstract Background Clinical pharmacists are established members of the interprofessional patient care team, but limited guidance for the optimal utilization of pharmacy resources is available. Objective measurement of medication regimen complexity offers a novel process for evaluating pharmacist activity. The purpose of this study was to evaluate the relationship between medication regimen complexity, as measured by a novel medication regimen complexity scoring tool (MRC‐ICU), and both pharmacist interventions and drug‐drug interactions (DDIs). Methods This was a multi‐center, prospective, observational study. The electronic medical record was reviewed to collect patient demographics, patient outcomes, and MRC‐ICU and modified MRC‐ICU (mMRC‐ICU) score at 24, 48 hours, and at discharge. Pharmacist interventions were recorded during the patients' intensive care unit (ICU) stay. DDIs were also evaluated at 24, 48 hours, and at discharge. Spearman's rank‐order correlation was used to determine any correlation between the MRC‐ICU score at each time point and the number of pharmacist interventions and DDIs. Results A total of 153 patients were evaluated from both centers. The median MRC‐ICU at 24 hours was 11 (interquartile range IQR 7‐15). MRC‐ICU at 24 hours was correlated with interventions at 24 hours ( r s .439, P <.001). Furthermore, MRC‐ICU was correlated with total DDIs ( r s .4, P < .001). A modified version of the MRC‐ICU was also correlated with number of pharmacist interventions ( P < .001) and DDIs ( P < .001). Conclusions Medication regimen complexity showed a relationship with number of pharmacist interventions and number of DDIs.