Risk factors associated with Clostridium difficile infection in hospitalized patients with hospital-onset healthcare facility-associated Clostridium difficile infection

Abstract number: O162

Emons M.F., Nathanson B.H., Yu H.T., Haidar T., Alemao E., Gardiner D., Spoeri R.K.

Objective: To assess risk factors associated with Clostridium difficile infection (CDI) in hospitalised patients with hospital-onset healthcare facility-associated (HO-HCFA) CDI.

Methods: This retrospective analysis utilised data from April 1, 2005 to December 31, 2008 within Cerner's Health Facts® database. Qualifying cases were adults with an inpatient encounter with a primary or secondary diagnosis of pseudomembranous colitis (ICD-9-CM code: 008.45) AND a positive C. difficile toxin test AND the first positive C. difficile test (index event) was ordered more than 72 hours after admission. Non-CDI controls were hospitalised for at least 72 hours with no diagnosis of pseudomembranous colitis AND no C. difficile culture or toxin assays during the study period. Stepwise logistic regression with bootstrapping and a Bayesian Information Criterion analysis were used to identify variables with the strongest association with HO-HCFA CDI. Logistic regression was used to quantify the variables' effect on HO-HCFA CDI. The area under the receiver operating characteristic (AUROC) curve and Hosmer-Lemeshow (HL) statistic were used to assess the model's overall fit.

Results: Among 34,261 inpatients, 1,454 met the study definition of HO-HCFA CDI. A final model of 26 variables (AUROC = 0.89, HL statistic = 10.82, P = 0.21) is reported in the table. Factors most associated with increasing the odds of CDI include evidence of impaired immune function (odds ratio [OR] = 4.77; 95% CI, 3.73–6.10), an unknown infection source (OR = 4.35; 95% CI, 2.92–6.46), and being admitted from a skilled nursing facility (OR = 3.47; 95% CI, 2.39–4.92). The antibiotic tigecycline was associated with lower risk of CDI (OR = 0.21; 95% CI: 0.06–0.76).

Conclusions: Impaired immune function, a high comorbidity burden, advanced age, and the presence of other infections were seen as risk factors for HO-HCFA CDI. Antibiotic therapy has been known to play a central role in the pathogenesis of CDI but the observation of tigecycline exposure's protective effect is unexpected. Additional research is needed to better understand the differential risks and benefits of various broad spectrum antibiotics among patients at risk for HO-HCFA CDI.

Table. Significant risk factors associated with Clostridium difficile infection

VariableOdds ratio95% CIP value
Evidence of impaired immune function4.7673.725–6.101<0.001
Admitted from skilled nursing facility (referent = ER admission)3.4702.387–4.922<0.001
Admitted from unknown location (referent = ER admission)2.7991.540–5.0880.001
Gram-positive infection1.8011.531–2.118<0.001
Age (per 10 year increase)1.1511.054–1.2580.002
Charlson Comorbidity Index (per unit)1.1181.086–1.152<0.001
Southern hospital location (referent = Northeast)0.4040.208–0.7830.007
Hospital beds: 300 to 499 (referent = 500 or more beds)0.3570.160–0.7950.012
Unknown race (referent = White)0.1180.032–0.4380.003
Chronic conditions on or 12 months prior to hospital admission   
  Acute renal failure2.6632.246–3.158<0.001
  Cerebrovascular disease other than intracranial/intracerebral hemorrhage2.3911.624–3.519<0.001
  Heart failure1.7461.436–2.123<0.001
  Cardiac dysrhythmias1.6811.421–2.002<0.001
Infection source   
  Other or unknown4.3472.924–6.464<0.001
  Skin infection2.0521.766–2.384<0.001
  Gastrointestinal other than CDI1.6491.346–2.020<0.001
Total number of systemic antibiotic (by drug class) received before index event (referent = 0)   
  geqslant R: gt-or-equal, slanted31.8211.418–2.338<0.001
Use of medications before index event   
  Miscellaneous antibiotics2.5871.992–3.361<0.001
  Third/fourth generation cephalosporins1.6401.449–1.857<0.001
  Proton pump inhibitors1.6081.342–1.927<0.001
ER: emergency room; CDI: Clostridium difficile infection.

Session Details

Date: 10/04/2010
Time: 00:00-00:00
Session name: Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases
Location: Vienna, Austria, 10 - 13 April 2010
Presentation type:
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