Estimating central line–associated bloodstream infection incidence rates by sampling of denominator data: A prospective, multicenter evaluation

Abstract

Background: Large-scale, prospective, evaluation of sampling for central lineeassociated bloodstream infection (CLABSI) denominator data was necessary prior to National Healthcare Safety Network (NHSN) implementation. Methods: In a sample of volunteer hospitals from states in the Emerging Infections Program, prospective collection of CLABSI denominators (patient days, central line days [CLDs]) was performed in eligible locations for 6 and 12 consecutive months using the current NHSN method (daily collection) and also by a second data collector who sampled the denominator data 1 d/wk. The quality of the sampled data was evaluated and used to calculate estimated CLDs and CLABSI rates, which were compared with actual CLDs and CLABSI rates (daily counts). Results: In total, 89 locations in 66 acute care hospitals participated. Sampled data were collected as intended 88% of the time; the quality of the data was comparable with the data collected daily. In locations with higher CLDs per month ( 75), estimated CLDs and CLABSI rates were similar to actual CLDs and CLABSI rates; however, there were significant differences in actual and estimated values among locations with lower (74) CLDs per month.Sampling was successfully implemented, but significant differences in the accuracy of estimated CLDs and CLABSI rates, based on the actual number of CLDs per month, were noted. Conclusion: For locations with a higher number of CLDs per month, sampling 1 d/wk is a valid and accurate alternative to daily collection of CLABSI denominator data.