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Which Comorbid Conditions Should We Be Analyzing as Risk Factors for Healthcare-Associated Infections?

  • Anthony D. Harris (a1), Lisa Pineles (a1), Deverick Anderson (a2) (a3), Keith F. Woeltje (a4) (a5), William E. Trick (a6) (a7), Keith S. Kaye (a8), Deborah S. Yokoe (a9), Ann-Christine Nyquist (a10), David P. Calfee (a11) and Surbhi Leekha (a1)...



To determine which comorbid conditions are considered causally related to central-line associated bloodstream infection (CLABSI) and surgical-site infection (SSI) based on expert consensus.


Using the Delphi method, we administered an iterative, 2-round survey to 9 infectious disease and infection control experts from the United States.


Based on our selection of components from the Charlson and Elixhauser comorbidity indices, 35 different comorbid conditions were rated from 1 (not at all related) to 5 (strongly related) by each expert separately for CLABSI and SSI, based on perceived relatedness to the outcome. To assign expert consensus on causal relatedness for each comorbid condition, all 3 of the following criteria had to be met at the end of the second round: (1) a majority (>50%) of experts rating the condition at 3 (somewhat related) or higher, (2) interquartile range (IQR)≤1, and (3) standard deviation (SD)≤1.


From round 1 to round 2, the IQR and SD, respectively, decreased for ratings of 21 of 35 (60%) and 33 of 35 (94%) comorbid conditions for CLABSI, and for 17 of 35 (49%) and 32 of 35 (91%) comorbid conditions for SSI, suggesting improvement in consensus among this group of experts. At the end of round 2, 13 of 35 (37%) and 17 of 35 (49%) comorbid conditions were perceived as causally related to CLABSI and SSI, respectively.


Our results have produced a list of comorbid conditions that should be analyzed as risk factors for and further explored for risk adjustment of CLABSI and SSI.

Infect Control Hosp Epidemiol 2017;38:449–454


Corresponding author

Address correspondence to Anthony D. Harris, MD MPH, 10 S. Pine St, MSTF 330, Baltimore, MD 21201 (


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Which Comorbid Conditions Should We Be Analyzing as Risk Factors for Healthcare-Associated Infections?

  • Anthony D. Harris (a1), Lisa Pineles (a1), Deverick Anderson (a2) (a3), Keith F. Woeltje (a4) (a5), William E. Trick (a6) (a7), Keith S. Kaye (a8), Deborah S. Yokoe (a9), Ann-Christine Nyquist (a10), David P. Calfee (a11) and Surbhi Leekha (a1)...


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