Background: The increasing antimicrobial resistance poses a challenge to surveillance systems and raises concerns about the impact of multidrug-resistant organisms on patient safety.
Objective: The study aimed to estimate extra hospital stay and economic burden of infections due to alert organisms - mostly multidrug-resistant - in a teaching hospital. Methods: The present retrospective matched cohort study was conducted based on the analysis of hospital admissions at Sant’Andrea Teaching Hospital in Rome from April to December 2015. Extra hospital stay was the difference in the length of stay between each case and control. All the patients developing an infection due to an alert organism were considered cases, all others were eligible as controls. The costs of LOS were evaluated by multiplying the extra stay with the hospital daily cost. Results: Overall, 122 patients developed an infection due to alert organisms and were all matched with controls. The attributable extra stay was of 2,291 days (mean 18.8; median 19.0) with a significantly increased hospitalization in intensive care units (21.2 days), bloodstream infections (52.5 days), and infections due to Gram-negative bacteria (mean 29.2 days; median 32.6 days). Applying the single day hospital cost, the overall additional expenditure was 11,549 euro per patient. The average additional cost of antibiotic drugs for the treatment of infections was about 1,200 euro per patient. Conclusion: The present study presents an accurate mapping of the clinical and economic impact of infections attributable to alert organisms demonstrating that infections due to multidrug-resistant organisms are associated with higher mortality, longer hospital stays, and increased costs. Article Highlights Box: The increasing antimicrobial resistance poses a challenge for surveillance systems and raises concerns about the impact of multidrug-resistant organisms on patient safety. • Healthcare-associated infections (HAIs) have historically been recognized as a significant public health problem requiring close surveillance. • Despite several and reliable findings have been achieved on clinical issues, our knowledge on the economic impact of healthcare-associated infections due to multidrug-resistant organisms needs to be widened. • Estimating the cost of infections due to multidrug-resistant organisms in terms of extra hospital stay and economic burden is complex, and the financial impact varies across different health systems. • Evaluations of social and economic implications of hospital infections play an increasingly important role in the implementation of surveillance systems. • The costs of infection prevention and control programs and dedicated personnel are relatively low and self-sustainable when efficient.