Higher hospital costs and lengths of stay associated with quinolone-resistant Salmonella enterica infections in Hong Kong

Objectives: The study sought to determine the differences in lengths of stay and medical costs between patients admitted to hospital with non-typhoidal salmonellosis that were either quinolone resistant (QR) or quinolone susceptible (QS). Design: We examined medical records of all patients 1 year of age or older admitted to a Hong Kong hospital between 2003 and 2008 with confirmed salmonellosis diagnosis. Data were collected on length of stay, age, sex, comorbidities, antibiotics and other medication use, diagnostic tests completed, serotype and susceptibility characteristics of isolated and the circumstances of discharge from hospital. We used Cox proportional regression to determine the differences in lengths of stay and quantile regression for differences in hospital costs. Results: Median duration of hospitalization among QR salmonellosis patients was 1 day (33; 95 CI: 13-47) longer than those with QS salmonellosis, adjusting for confounders. Adjusted median costs were US $399 (35) and 75th percentile costs were US $760 (43) higher in the QR group than those in the QS group, indicating a greater difference among sicker patients. Conclusion: The finding of substantially longer stays and higher costs associated with QR indicates that interventions that decrease QR prevalence will lead to significant savings for the health system in the management of hospitalized salmonellosis cases.