Excess mortality and long-term disability from healthcare-associated staphylococcus aureus infections: a population-based matched cohort study.
BACKGROUND
Staphylococcus aureus is a leading cause of healthcare-associated infections (HAIs), but the impact of S. aureus HAIs on the long-term survival and functional status of hospitalized patients remain unknown. This study aimed to examine whether S. aureus HAIs increase the risks for long-term mortality and disability.


METHODS
We conducted a retrospective population-based matched cohort study of inpatients at 8 medical centers, 43 regional hospitals, and 63 local hospitals which participated in the Taiwan Nosocomial Infection Surveillance (TNIS). We individually matched 3070 patients with S. aureus HAIs to 6140 inpatients without HAIs at a 1∶2 ratio by age, gender, hospital, specialty, underlying diseases, and the length of stay before onset of the S. aureus HAI. Main outcome measures are one-year excess risks for mortality, new-onset chronic ventilator dependence, and new-onset dialysis-dependent end-stage renal disease.


RESULTS
We found that patients with S. aureus HAIs had an excess one-year mortality of 20.2% compared with matched uninfected inpatients (P<0.001). The excess risk for new-onset chronic ventilator dependence and dialysis-dependent end-stage renal disease was 7.3% and 2.6%, respectively (Ps<0.001). S. aureus HAIs were also associated with an excess hospital stay of 12 days and an extra cost of $5978 (Ps<0.001).


CONCLUSIONS
S. aureus HAIs have substantial negative effect on the long-term outcome of hospitalized patients in terms of both mortality and disability, which should be taken into consideration in future cost-effectiveness studies of the control and prevention interventions for S. aureus HAIs.
Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
Chiu-Hsia
CH
Su
Shan-Chwen
SC
Chang
Jer-Jea
JJ
Yan
Shu-Hui
SH
Tseng
Li-Jung
LJ
Chien
Chi-Tai
CT
Fang
D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D003428:Cross Infection / Q000401:mortality*; D006233:Persons with Disabilities / Q000706:statistics & numerical data*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007297:Inpatients / Q000706:statistics & numerical data*; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000401:mortality*; D013211:Staphylococcus aureus / Q000502:physiology; D013624:Taiwan / Q000453:epidemiology