Infectious diseases clinical pharmacist-led post-prescription review and therapeutic appropriateness in community-acquired pneumonia: an interrupted time-series study in the United Arab Emirates

Community-acquired pneumonia (CAP) remains a common cause of hospitalization in the United Arab Emirates (UAE). Although well-established international clinical guidelines for CAP are available, antimicrobial prescribing practices continue to vary. This variation may contribute to inappropriate antibiotic use and the growing threat of antimicrobial resistance. Antimicrobial stewardship programs (ASPs) are shown to improve the quality of antimicrobial prescribing and reduce unnecessary antibiotic exposure. A core component of these programs is post-prescription review, which allows for the assessment of antimicrobial therapy based on clinical guidelines and patient’s clinical response. However, evidence evaluating the impact of post-prescription review on the management of CAP in the UAE is limited. This study aimed to assess temporal changes in the appropriateness of antimicrobial therapy following the implementation of a post-prescription review process in adults hospitalized with CAP. This study was conducted using a single-center, quasi-experimental interrupted time series design at a 200-bed tertiary care hospital in Dubai. The study period extended from July 2021 and June 2023. Adult patients aged 18–65 years admitted with CAP were included. Therapeutic appropriateness, assessed across antimicrobial selection, dosing, and duration, was the primary outcome. Length of hospital stay was evaluated as a secondary clinical outcome. Acceptance of clinical pharmacist recommendations during post-prescription review was also analyzed. Post-prescription review was associated with a significant increase in overall therapeutic appropriateness from 24.4% in the pre-intervention phase to 83.3% in the post-intervention phase. Segmented logistic regression demonstrated an immediate step-level increase at the point of intervention (adjusted odds ratio 22.9, 95% CI: 9.8–53.6, p < 0.001), with no significant pre-intervention trend and no significant change in slope post-intervention, indicating a sustained rather than progressive improvement. Acceptance of clinical pharmacist recommendations was high (85.2%). Introduction of post-prescription review was associated with a substantial improvement in therapeutic appropriateness for CAP. This UAE-based study supports strengthening regional antimicrobial stewardship programs through the post-prescription review processes. Larger multicenter trials are warranted. Clinical trial number: not applicable.