BackgroundWith an increasingly strained health system budgets, healthcare services need to continually demonstrate evidence of economic benefits. This study sought to evaluate the economic impact of interventions initiated by clinical pharmacists in an adult general tertiary hospital.MethodsA retrospective review of clinical pharmacist interventions was carried out throughout follow-up durations in March 2018, July/August 2018, and January 2019 in Hamad General Hospital (HGH) at Hamad Medical Corporation (HMC) in Qatar. The study included clinical pharmacy interventions data of patients admitted to the internal medicine, critical care, and emergency wards. Included interventions were documented by clinical pharmacists or clinical pharmacy specialists, and approved by physicians. Interventions by non-clinical pharmacists or with missing data were excluded. Adopting the perspective of HMC, we calculated the total economic benefit, which is the sum of the cost savings and the cost avoidance associated with the interventions. Cost savings was defined as the reduced cost of therapy associated with therapy changes minus the cost of intervention and cost avoidance was the cost avoided by eliminating the occurrence of adverse drug events (ADEs). Sensitivity analyses were performed to assess the robustness of results against uncertainties.ResultsA total of 852 interventions, based on 340 patients, were included. The analysis projected an annual total benefit of QAR 2,267,036 (USD 621,106) based on a negative cost-savings of QAR-175,139 (USD-47,983) and a positive cost avoidance of QAR741,898 (USD203,260) over the 3-month follow-up period. The uncertainty analysis demonstrated the robustness of outcomes, including a 100% probability of positive economic benefit.ConclusionsThe clinical pharmacist intervention was associated with an increased cost of resource use, which was overtaken by the cost avoidance generated. The pharmacy intervention, therefore, is an overall economically beneficial practice in HGH, reducing ADEs with considerable consequential positive economic savings.