Sampling for Collection of Central Line–Day Denominators in Surveillance of Healthcare‐Associated Bloodstream Infections

• Published in: Infection control and hospital epidemiology 2006-04, Vol.27 (4), p.338-342
• Main Authors: Klevens, R. M., Tokars, J. I., Edwards, J., Horan, T.
• Format: Article
• Language: English
• Subjects: Adult; Bacteremia - epidemiology; Bacteremia - etiology; Biological and medical sciences; Blood-Borne Pathogens; Catheterization, Central Venous - adverse effects; Centers for Disease Control and Prevention (U.S.); Child; Cross Infection - blood; Cross Infection - epidemiology; Data sampling; Disease Notification; Error rates; Feasibility Studies; General aspects; Hospital utilization rate; Human infectious diseases. Experimental studies and models; Humans; Infections; Infectious diseases; Intensive care units; Intensive Care Units - standards; Intensive Care Units - statistics & numerical data; Medical sciences; Miscellaneous; Nursing; Original Article; Patient surveillance; Percentiles; Public health. Hygiene; Public health. Hygiene-occupational medicine; Ratios; Sampling errors; Sampling Studies; Seasons; Sensitivity and Specificity; Sentinel Surveillance; Surveillance; Time; United States - epidemiology
• ISSN: 0899-823X; 1559-6834
• DOI: 10.1086/503338

To determine the feasibility of estimating the number of central line-days at a hospital from a sample of months or individual days in a year, for surveillance of healthcare-associated bloodstream infections. We used data reported to the National Nosocomial Infections Surveillance system in the adult and pediatric intensive care unit component for 1995-2003 and data from a sample of hospitals' daily counts of device use for 12 consecutive months. We calculated the percentile error as the central line-associated bloodstream infection percentile based on rates per line-days minus the percentile based on rates per estimated line-days. A total of 247 hospitals were used for sampling whole months and 12 hospitals were used for sampling individual days. For a 1-month sample of central line-days data, the median percentile error was 3.3 (75th percentile, 7.9; 90th percentile, 15.4). The percentile error decreased with an increase in the number of months sampled. For a 3-month sample, the median percentile error was 1.4 (75th percentile, 4.3; 95th percentile, 8.3). Sampling individual days throughout the year yielded lower percentile errors than sampling an equivalent fraction of whole months. With 1 weekday sampled per week, the median percentile error ranged from 0.65 to 1.40, and the 90th percentile ranged from 2.8 to 5.0. Thus, for 90% of units, collecting data on line-days once a week provides an estimate within +/-5 percentile points of the true line-day rate. Sample-based estimates of central line-days can yield results that are acceptable for surveillance of healthcare-associated bloodstream infections.