Benefits of Pharmacist Intervention in the Critical Care Geriatric Patients with Infectious Diseases: A Propensity Score Matching Retrospective Cohort Study

Abstract Background The variabilities of the pharmacotherapeutics’ efficacy and safety in the ICU geriatric patients further highlighted the importance of optimization of antimicrobial therapy. The aim of our study was to assess the impacts of clinical pharmacist intervention on antibiotic use, cost outcomes, and clinical benefits of the geriatric patients with infectious diseases in the critical care unit (ICU). Methods A propensity score matching (PSM) retrospective cohort study was undertaken in ICU patients with infectious diseases from 2017 to 2019. Baseline demographic, pharmacists’ activities and clinical outcomes including the patients’ mortality, antibiotic utilization, length of ICU stay (LOS), and costs of the drugs were compared between these two groups. Univariate analysis and bivariate logistic regression were adopted to illustrate the influencing factors on the mortality outcome. Results Of 1523 patients evaluated during the observed period, a total of 102 geriatric ICU patients with infectious diseases were enrolled in each group after PSM matching. Top 5 recommendations occurred by the pharmacist were medication regimen adjustments by diseases on progression, medication regimen adjustments by microbial results, drug withdrawal by full treatment courses, suggestions for TDM and medication regimen adjustments by de-escalation. The antibiotic use density (AUD) of all antibiotics consumed decreased significantly (p=0.018) from 241.91 DDD/100 bed days in the control group to 176.64 DDD/100 bed days in the pharmacist exposed group. AUD proportion was dropped in carbapenems from 23.07% to 14.43% and tetracyclines from 11.56% to 6.26% after pharmacist interventions. Although the mortality or LOS had no statistical difference between these two groups, the total cost of antibiotics was reduced significantly from $836.3 (IQR 426.88, 1682.09) in the control group to $362.15 (IQR 148.23, 1034.4) (p＜0.001) in the pharmacist intervention group, and cost for all the medications were reduced from $2868.18 ($1268.44, $5059.00) to $1941.5 ($1092.89, $3538.97) (p=0.016). Univariate analyses showed that there was no statistically difference in pharmacist intervention between the groups of survival and death (p=0.288) Conclusions The services provided by the critical care pharmacist could promote the rational use of drugs, which benefit both ICU geriatric patient and hospital care.