Direct hospital costs and cost drivers in Greek intensive care units: a micro-costing analysis

Abstract

Introduction: Intensive Care Units (ICUs), though comprising a small proportion of total hospital beds, represent a disproportionately high share of healthcare expenditure. Accurate cost assessment is vital for optimizing resource allocation, particularly in resource-limited settings like Greece.

Aim of the study: To estimate the direct cost of ICU hospitalization in adult patients using a micro-costing approach and to identify clinical and organizational factors driving these costs.

Material and Methods: A prospective surveillance study was conducted over two years in four multidisciplinary adult ICUs in the Attica region. Detailed patient-level data on demographics, clinical status, interventions, and resource use were collected daily. Direct ICU costs, both fixed and variable, were calculated from the hospital perspective using a bottom-up micro-costing approach. Multivariable linear regression was used to identify independent predictors of ICU costs.

Results: The analysis included 500 patients, representing 12,689 patient-days. The total hospitalization cost was 6.33 million euros. The median cost per ICU admission was 7,756.8 euros, with variable costs comprising 72.5% of total expenditures. Antibiotics accounted for nearly 50% of variable costs. Significant independent cost drivers included blood transfusion (additional 2,063 euros), prolonged ICU stay (each day added approximately 264 euros), ventilator-associated events (+2,374 euros), central line-associated bloodstream infections (+1,877 euros), surgical site infections (+6,609 euros), and patient-to-nurse ratios >2 (+5,000 euros).

Conclusions: ICU costs are shaped not only by patient severity and interventions but also by modifiable structural factors such as infection rates and staffing ratios. Investments in infection prevention, evidence-based transfusion practices, and adequate nurse staffing could yield substantial cost savings while improving patient outcomes in Greek ICUs. These insights provide critical, evidence-informed guidance for strengthening critical care in resource-limited settings.