Cost Analysis of Individualized Parenteral Nutrition Bags in a Saudi Tertiary-Care Hospital: A Retrospective Cohort Study and Implications for Cost-Effective Clinical Practice

<b>Background:</b> Parenteral nutrition (PN) is a life-sustaining therapy essential for patients who are unable to meet their nutritional needs enterally. However, individualized PN formulations impose substantial economic burdens on healthcare systems. This study aims to quantify the cost of individualized PN bags across different patient populations and identify key cost drivers to inform cost-effective clinical practice and policy development. <b>Methods:</b> A retrospective cohort study was conducted at King Fahad Medical City, Riyadh, Saudi Arabia, analyzing 900 unique patient-specific PN orders between February 2023 and August 2023. Patients were stratified into three groups: adults (≥18 years), pediatrics (1 month to 17 years), and neonates (<1 month), with 300 unique patients per group. The cost assessment included macronutrients, micronutrients, consumables, equipment, and personnel time, all measured using a standardized work sampling methodology. Descriptive statistics characterized demographic and clinical profiles. One-way ANOVA was used to compare costs across groups, and multivariate linear regression identified significant cost predictors, with log-transformation applied to address the skewness in the cost data. <b>Results:</b> Mean cost per PN bag varied significantly among patient groups (ANOVA, <i>p</i> < 0.001): adults 517.1 ± 274 SAR, pediatrics 383.2 ± 86.75 SAR, and neonates 243.14 ± 98 SAR. We found that PN volume, lipid dose, and the number of additives were the primary modifiable drivers of PN cost. Multivariate regression analysis identified PN volume (β = 0.182, <i>p</i> < 0.001), lipid dose (β = 0.145, <i>p</i> = 0.002), and number of additives (β = 0.098, <i>p</i> = 0.028) as significant predictors of cost, explaining 91.2% of the cost variance (R² = 0.912). Consumables contributed 18-22% of total costs across groups. Pediatric patients demonstrated markedly longer therapy duration (median 98 days, IQR 65-142) compared to adults (median 18 days, IQR 8-35) and neonates (median 24 days, IQR 12-42). <b>Conclusions:</b> This study provides the first stratified, real-world cost benchmarks for individualized PN in a Saudi tertiary-care setting and quantifies actionable cost drivers. Actionable implications include standardizing stable-patient procedures, implementing pharmacist-led appropriateness screening, and earlier transition to enteral nutrition to reduce costs while maintaining quality of care. Future research should evaluate the cost-effectiveness of standardized versus individualized formulations and investigate the relationship between cost variations and clinical outcomes.