Background: Due to staffing constraints, several hospitals have defined targeting strategies for pharmacist-led medication order review, leaving non-targeted patients exposed to potential harmful drug-related problems (DRPs). Using targeting criteria to stratify medication order review level (level 1 (L1): orders, basic patient characteristics; level 2 (L2) or comprehensive medication order review: orders, patient characteristics, medical records, laboratory results) could make it possible to save time and increase the overall number of medication order reviews. This study aims to define targeting criteria to stratify medication order review level and estimate the time saved for the performance of additional medication order reviews. Method: This retrospective single-centre study included all medication order reviews performed in 2020; DRPs were collected to assess the medication order review level required to detect them. Logistic regressions were performed to define patient characteristics associated with L2. These targeting criteria were applied to the cohort to estimate the time saved and the number of additional medication order reviews which could have been performed using this approach. Results: 2478 DRPs were reported; 54.2% (1343/2748) could have been detected using an L1 medication order review (representing 48.2% of the patients (829/1721)). L2 medication order reviews were significantly associated with age ≥65 years, male, and renal clearance <60 mL/min (OR≥75yo=1.79; OR65-74yo=1.74; ORfemale=0.74; OR30-59mL/min=1.67; OR<30mL/min=2.62; p<0.05). Sex being a confounding factor, only age and renal clearance were used as targeting criteria. The time saved was estimated at 274 hours per year, leading to an additional 1720 medication order reviews (54 hospital beds). Conclusion: The proposed approach would maintain a satisfying level of safety and quality for patients, by performing an L2 medication order review for targeted patients based on age and renal clearance, while improving medication order review coverage with an L1 medication order review for non-targeted patients, using the available workforce.