Beyond Traditional Inventory Matrices: A Multidimensional Inventory and Safety Model for an Outpatient Pharmacy

Effective outpatient pharmacy inventory management in tertiary care hospitals requires balancing rigorous cost containment with absolute clinical safety over multi-year operational cycles. Traditional ABC (Always, Better, Control) and VED (Vital, Essential, Desirable) matrices focus heavily on financial and basic clinical parameters but often overlook direct patient safety indicators and longitudinal consumption trends.

This study aimed to evaluate outpatient pharmacy inventory patterns across three consecutive fiscal years (FY 2023-24 to FY 2025-26) using ABC and VED analyses, assess longitudinal changes in expenditure and clinical criticality, and integrate High-Alert Medication and Look-Alike, Sound-Alike assessments to identify medication-safety risks and opportunities for inventory optimization.

A retrospective longitudinal inventory analysis spanning three consecutive fiscal years (FY 2023-24, FY 2024-25, and FY 2025-26) was conducted using annual consumption and expenditure data from the outpatient pharmacy at a premier tertiary care teaching hospital in New Delhi. Total unique medication lines analyzed ranged from 6,207 to 6,468 items per year, representing a cumulative multi-billion-rupee expenditure. Each annual dataset was subjected to ABC Pareto analysis and VED classification mapped against the National List of Essential Medicines (NLEM 2022). Algorithmic string matching and established safety guidelines were utilized to isolate high-alert medication (HAM) and look-alike/sound-alike (LASA) vulnerabilities longitudinally.

Total annual pharmacy expenditure grew from ₹3.80 billion in FY 2023-24 to ₹4.57 billion in FY 2024-25, and ₹5.54 billion in FY 2025-26. Across all three years, Class A items demonstrated a stable Pareto expenditure distribution while shrinking in item volume from 276 (4.45%) down to 179 (2.77%). VED analysis revealed an escalating financial concentration in non-essential ambulatory care, with Desirable medications expanding from 3,362 (57.57%) of expenditure in FY 2023-24 to 3,516 (72.58%) by FY 2025-26. Vital life-saving drugs remained consistently under 1.36% by volume (n = 79-88) and under 0.07% by financial value. Safety audits identified between 27 and 32 HAM annually, alongside persistent high-risk LASA pairs (similarity >85%).

Longitudinal analysis demonstrates that relying solely on single-year ABC-VED matrices is insufficient for modern hospital administration. Integrating HAM and LASA metrics across multi-year cycles enables proactive cost-containment in expanding non-essential outpatient categories while upholding rigorous national accreditation standards for medication management and safety.