Saleh Alghamdi
Background: Clinical pharmacists play a crucial role in identifying and resolving drug-related problems (DRPs) in hospitals. However, there is limited empirical evidence concerning their effect on service organizations in smaller regional facilities in Saudi Arabia. Methods: A retrospective serial cross-sectional study was conducted using three years of administrative data (2023-2025) from two public hospitals in the Al-Baha region. A total of 1812 different database records were identified after full-scale data cleaning, validation, and deduplication. The statistical framework included chi-square test of independence, pairwise two-proportions Z-test, three multivariate binary logistic regression models, Cramer's V association analysis, and Ward's hierarchical cluster modeling. Results: Active intervention rates significantly increased from 48.9% in 2023 to 72.4% in 2024 (z = -8.58, p < 0.001), stabilizing at 69.6% throughout 2025 (p < 0.001 versus the 2023 baseline), because 2023 data came from a different source system than 2024 to 2025 data, this pattern is reported descriptively rather as a programmatic integration. The most frequent clinical actions addressed therapy optimization (28.4%), inappropriate dosage regimens (23.6%), and missing drug orders (18.8%). Most entries recorded were for adult intensive care units (ICUs) (74.1%), and most involved patients aged 65 years or older (61.1% of records). ICU setting was independently associated with the intervention being classified as therapy optimization (adjusted odds ratio [aOR] 2.64, p < 0.001), but it was an inverse predictor of dosage-error tracking (OR 0.30, p < 0.001). Conclusions: This is among the first serial cross-sectional studies to build an evidence-based framework describing clinical pharmacy practices in the Al-Baha region, showing pharmacists' roles and prioritizing advanced clinical training programs, reinforcing the need for critical analysis of health cluster policies across peripheral Saudi networks.