Collect that Stool! The Impact of Delay in Specimen Collection to NHSN Lab ID C. difficile Events

Abstract

BACKGROUND Despite multiple rapid laboratory tests available for Clostridium difficile infection (CDI), delays in specimen collection may contribute to delays in diagnosis and treatment. Additionally, specimen collection delays may contribute to falsely increased National Health and Safety Network (NHSN) laboratory-identified (Lab ID) hospital onset (HO) CDI rates. Time from order to specimen collection and the impact of collection delays on HO CDI rates is unknown. METHODS Two community hospitals (450 and 472 licensed beds) conducted a retrospective review of electronic data from March-October 2018, including date of order for C. difficile toxin assay and date of specimen collection. Time to collection was compared for hospital of admission, level of care (intensive care unit [ICU] versus other) and shift of order (day versus night) using Mann-Whitney U (SPSS) and Chi-square analysis (Epi Info). The impact of delay on HO CDI cases was assessed. RESULTS 1516 stool specimens were collected. On average, there were 7.7?hours between order and collection (maximum delay = 7.9 days). Hospital A, ICU level of care, and night shift were correlated with significantly shorter time to specimen collection (p = 0.01, 0.02. 0.02, respectively). 330 specimens (22%) were collected on a subsequent calendar day, although this was only significantly impacted by level of care (p = 0.04). Of the 31 cases determined to be HO-CDI per NHSN Lab ID definition, 4 (13%) would have been CO had they been collected on the day ordered. Conclusions In this sample, delay in specimen collection for C. difficile testing was common, with many tests delayed to the next day. This may have a considerable impact on HO CDI rates, impacting reimbursement and hospital reputation. Future research is needed to remedy these delays. Until that time, use of order date and time should be considered for inclusion into NHSN Lab ID event definitions.