Validation of the surveillance and reporting of central line-associated bloodstream infection data to a state health department

Background: The primary goal of health care-associated infection reporting is to identify and measure progress towards achieving the irreducible minimum number of infections. Assessing the accuracy of reporting data using independent validation is critical to this goal. In January 2008, all 30 acute care hospitals in Connecticut began mandatory reporting of central line-associated bloodstream infections (CLABSI) to the National Healthcare Safety Network (NHSN) system. Methods: A state nurse epidemiologist performed a blinded retrospective chart review for NHSN-reported CLABSI based on positive blood cultures from October to December 2008. Results: Of 476 septic events, 48 met the NHSN CLABSI definition, of which 23 (48%) had been reported to NHSN. Concordance of non-CLABSI events was 99% sensitive. Components of the case definition that were a source of misinterpretation included the following: NHSN surveillance definition of primary and secondary bacteremia (45%), CLABSI rules (19%), CLABSI terms (10%), and differentiation between laboratory-confirmed bloodstream criterion 1 (recognized pathogen) and criterion 2 (skin contaminant) (13%). Conclusion: The validation study identified >50% underreporting of CLABSI, most related to misinterpretation of components of the NHSN definition. Continued validation and training will be needed in Connecticut to improve completeness of reported health care-associated infection data and to assure that publicly reported data are valid.