Cost-effectiveness of screening for carbapenemase-producing Enterobacterales in a university-affiliated tertiary care hospital in Hong Kong: a real-world analysis of data from 2015 to 2024

BACKGROUND: Carbapenemase-producing Enterobacterales (CPE) are a major healthcare-associated threat due to multidrug resistance, gastrointestinal colonization, and hospital transmission. We evaluated the cost-effectiveness of CPE screening using real-world data from 2015 to 2024. METHODS: We conducted a healthcare provider-perspective economic evaluation at Queen Mary Hospital, using electronic health records and hospital data. Screening episodes, clinical outcomes, lengths of stay, and costs (laboratory testing, staffing, personal protective equipment, and disinfection) were analyzed. We calculated the number needed to screen (NNS), incremental cost-effectiveness ratio (ICER) for infection prevention, and cost per quality-adjusted life-year (QALY) gained. RESULTS: Among 375,213 hospitalization episodes in which CPE testing was performed (447,745 tests), 10,046 (2.7%) were positive; 390 (3.9%) were clinical infections and 9,656 (96.1%) colonizations. After patient-level deduplication (149,965 individuals), 3,628 (2.4%) were CPE-positive, with 153 clinical infections. Mean cost per CPE infection was US＄35,290 and per colonization US＄7,721. Annual screening program cost was US＄1,487,969. An estimated 63.6 infections were averted and 47.8 QALYs gained annually (NNS = 590). Compared with no screening, it was cost-saving (annual saving US＄757,604). Sensitivity analyses showed NNS most sensitive to screening effectiveness (-40.9% to +59.2%); screening remained dominant except at lower limit of effectiveness (ICER = US＄1,958; cost/QALY = US＄2,048). Worst-case scenario ICER was US＄31,019 (cost/QALY = US＄29,831). All values were below the World Health Organization cost-effectiveness threshold of US＄54,301 (Hong Kong gross domestic product/capita). CONCLUSION: CPE screening was cost-saving and highly cost-effective, remaining robust across sensitivity analyses. These findings support sustained screening in high-volume tertiary settings.