183. Impact of Nosocomial Infection on Readmission: Analysis of Electronically Captured Data
Session: Poster Abstract Session: Antibiotic Stewardship
Friday, October 21, 2011
Room: Poster Hall B1

Patients with hospital-onset infections may be readmitted shortly after index discharge. Traditional manual infection surveillance tends to focus on the impact of infections  during the index hospitalization among critical care patients. We sought to examine the association of nosocomial infections and readmissions using electronically captured data for all hospitalized patients.


We analyzed electronic clinical and administrative data between 10/1/2008 to 8/30/2009 from  14 teaching and 6 non-teaching hospitals. We identified hospital-onset infections using previously validated Nosocomial Infection Marker™ (NIM). A NIM is defined as a positive microbiologic specimen with a non-duplicate hospital isolate, where the specimen is collected from a single source. This algorithm-based system accounts for timing of specimen collection in relation to patient admission and location.  It excludes common contaminations. For readmission analysis we excluded from the index population discharges in which the patient expired. We estimated the impact of NIM on readmission within 7, 14, and 30 days using multivariable regression, controlling for age and principal diagnosis based clinical conditions. 


Among 277,582 index discharges (220,048 unique patients) during the study period, 11,861 NIM cases were identified (43 NIM cases per 1,000 discharges).  The overall unadjusted readmission rates within 7, 14, and 30 days for NIM vs. non-NIM patients were 23.7% vs. 4.8%;  32.0% vs 7.4%; and 42.4% vs. 11.5% (all P<0.0001).  The corresponding  adjusted odds ratios and (95% CI) were: 4.65 (4.44, 4.88), 4.47 (4.28, 4.67), and 4.37 (4.20, 4.55), respectively (all P<0.0001). Types of  NIMs associated with the highest 30-day readmission rates were: C. difficile (50.5%),  wound (48.0%), and  blood (45.4%) infections.  The most frequent principal diagnoses for readmissions included sepsis, complications, C. difficile, or other infections.


Patients with NIM were more than 4 times likely to be readmitted shortly after discharge from an index hospitalization, adjusting for age and clinical conditions. These findings may have clinical management and health care policy implications.

Subject Category: N. Hospital-acquired and surgical infections, infection control, and health outcomes including general public health and health services research

Phillip Francis, MD, MS1, Ying P. Tabak, PhD2, Karen G. Derby, BA2, Chad Glover, MBA3, Linda Hyde, BS, RHIA2, Xiaowu Sun, PhD2 and RS Johannes, MD, MS4, (1)CareFusion, MedMined Services, Birmingham, AL, (2)MedMined Services, Clinical Research, CareFusion, Marlborough, MA, (3)CareFusion/MedMined Services, Birmingham, AL, (4)MedMined Services, Clinical Research, CareFusion and Harvard Medical School, Marlborough, MA


P. Francis, CareFusion: Employee, Salary

Y. P. Tabak, CareFusion: Employee, Salary

K. G. Derby, CareFusion: Employee, Salary

C. Glover, CareFusion: Employee, Salary

L. Hyde, CareFusion: Employee, Salary

X. Sun, CareFusion: Employee, Salary

R. Johannes, CareFusion: Employee, Salary

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.