Healthcare-associated infections in acute ischaemic stroke patients from 36 Japanese hospitals: risk-adjusted economic and clinical outcomes


  • Conflicts of Interest: None declared.

  • Funding: This study was supported in part by a Health Sciences Research Grant from the Ministry of Health, Labour and Welfare of Japan, and a Grant-in-aid for Scientific Research from the Japan Society for the Promotion of Science.

Yuichi Imanaka*, Department of Healthcare Economics and Quality Management, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto, 606-8501 Japan.


Background Healthcare-associated infections are a major cause for worsening in ischaemic stroke patients. In addition to increased morbidity and mortality, healthcare-associated infections also result in a potentially preventable increase in economic costs.

Aims The aim of this study was to identify healthcare-associated infection incidence in ischaemic stroke patients in Japanese hospitals, and to conduct a risk-adjusted analysis of the associated economic and clinical outcomes.

Methods Healthcare-associated infections were identified in 36 Japanese hospitals using an administrative database. Identification was carried out using a combination of International Classification of Diseases-10 codes and antibiotic utilisation patterns that indicated the presence of an infection. Risk-adjusted hospital charges and length of stay were calculated using multiple linear regression analyses correcting for patient and hospital factors. A logistic regression model was used to analyse the association between healthcare-associated infection infection and mortality.

Results There was an overall healthcare-associated infection incidence of 16·4 %, with an interhospital range of 4·7–28·3%. After risk-adjustment, infected cases paid an additional US$3 067 per admission (interhospital range US$434–US$7 151) and were hospitalised for an additional 16·3-days (interhospital range: 5·1–25·1-days) when compared with uninfected patients. Healthcare-associated infections also had a strongly significant association with increased mortality (odds ratio=23·2, 95% confidence intervals: 12·5–43·2).

Conclusions We observed a wide range of healthcare-associated infection incidence between the hospitals. Healthcare-associated infections were found to be significantly associated with increased hospital charges, length of stay, and mortality. Furthermore, the use of risk-adjusted multi-institutional comparisons allowed us to analyse individual performance levels in both infection and cost control.