Potential for Risk Adjustment for Central Line-Associated Bloodstream Infections Using Comorbidity Measures Derived from Medical Records from a Tertiary Care Hospital
Background: Current risk adjustment for central line-associated bloodstream infections (CLABSI) follows National Healthcare Safety Network (NHSN) Centers for Disease Control and Prevention (CDC) guidelines, which only adjust for ICU type. With increasing public reporting policies at the state and national level, improved risk adjustment methods are needed. Our aim was to investigate whether comorbid conditions from ICD9 components of the Charlson Comorbidity Index (CCI) and the medication-components of the Chronic Disease Score (CDS) provide information useful for further adjustment.
Methods: We studied a University of Maryland Medical Center cohort of adult ICU patients admitted from July 2010 to December 2012. Data, including comorbid conditions, were from electronic medical records. CLABSIs were defined by infection preventionists. Eligible patients had a central line for at least 48 hours and no prior CLABSI during the study period. Two separate logistic regression models were constructed, one using CDS and the other using CCI components. Both models also included the number of line days.
Results: 4011 subjects with 4950 central lines were included, with a total of 32577 line days at risk and 76 CLABSIs (CLABSI rate: 2.33 per 1000 line day). The mean ICU length of stay for those with a CLABSI was 30.1 days and 14.7 days for those without a CLABSI (p<0.0001). The mean days with a central line for those with a CLABSI was 10 days and 5.8 days for those without a CLABSI (p<0.01); line days was predictive of CLABSI in both models. In the CDS model, medication use associated with hypercholesterolemia and hypertenstion (calcium channel blockers) was protective, while hypertension (beta blockers) and kidney disease were associated with CLABSI (Fig 1). In the CCI model, myocardial infarction and kidney disease were associated with CLABSI (Fig 2).
Conclusion: We demonstrate several risk factors for the development of CLABSI, including duration of central line and several components of the CDS and CCI such the use of lipid-lowering agents. These factors are commonly measured and often available in electronic medical records. Further study is warranted to determine if these and other risk factors will improve risk adjustment methods used by the NHSN/CDC.
C. S. Pepin,
M. Masnick, None
M. A. Preas, None
L. Pineles, None
A. D. Harris, None