Correlation between case mix index and antibiotic use in hospitals
Open Access
- 27 June 2008
- journal article
- research article
- Published by Oxford University Press (OUP) in Journal of Antimicrobial Chemotherapy
- Vol. 62 (4), 837-842
- https://doi.org/10.1093/jac/dkn275
Abstract
To compare the quantitative antibiotic use between hospitals or hospital units and to explore differences, adjustment for severity of illness of hospitalized patients is essential. The case mix index (CMI) is an economic surrogate marker (i.e. the total cost weights of all inpatients per a defined time period divided by the number of admissions) to describe the average patients’ morbidity of individual hospitals. We aimed to investigate the correlation between CMI and hospital antibiotic use. We used weighted linear regression analysis to evaluate the correlation between in-hospital antibiotic use in 2006 and CMI of 18 departments of the tertiary care University Hospital Zurich and of 10 primary and 2 secondary acute care hospitals in the Canton of Zurich in Switzerland. Antibiotic use varied substantially between different departments of the university hospital [defined daily doses (DDD)/100 bed-days, 68.04; range, 20.97–323.37] and between primary and secondary care hospitals (range of DDD/100 bed-days, 15.45–57.05). Antibiotic use of university hospital departments and the different hospitals, respectively, correlated with CMI when calculated in DDD/100 bed-days [coefficient of determination (R2), 0.57 (P = 0.0002) and 0.46 (P = 0.0065)], as well as when calculated in DDD/100 admissions [R2, 0.48 (P = 0.0008) and 0.85 (P < 0.0001), respectively]. Antibiotic use correlated with CMI across various specialties of a university hospital and across different acute care hospitals. For benchmarking antibiotic use within and across hospitals, adjustment for CMI may be a useful tool in order to take into account the differences in hospital category and patients’ morbidities.This publication has 25 references indexed in Scilit:
- Reply to Dalton et alClinical Infectious Diseases, 2007
- Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America Guidelines for Developing an Institutional Program to Enhance Antimicrobial StewardshipClinical Infectious Diseases, 2007
- Comorbidity risk-adjustment measures were developed and validated for studies of antibiotic-resistant infectionsJournal of Clinical Epidemiology, 2006
- Discrepancies between prescribed daily doses and WHO defined daily doses of antibacterials at a university hospitalBritish Journal of Clinical Pharmacology, 2006
- Hospital usage of antibacterial agents in relation to size and type of hospital and geographical situationPharmacoepidemiology and Drug Safety, 2005
- Use of antibiotics at hospitals in Stockholm: a benchmarking project using internetPharmacoepidemiology and Drug Safety, 2003
- Trends in antimicrobial utilization at a Spanish general hospital during a 5-year periodPharmacoepidemiology and Drug Safety, 2003
- Consumption of Imipenem Correlates with β-Lactam Resistance in Pseudomonas aeruginosaAntimicrobial Agents and Chemotherapy, 2002
- Antiviral Therapies for Herpes Zoster InfectionsPharmacoEconomics, 2000
- Trends in Medical Care CostsMedical Care, 1980