BACKGROUND: Surveillance of health care-associated, catheter-associated urinary tract infections (CAUTI) are the corner stone of infection prevention activity. The Centers for Disease Control and Prevention's National Healthcare Safety Network provides standard definitions for CAUTI surveillance, which have been updated periodically to increase objectivity, credibility, and reliability of urinary tract infection definitions. Several state health departments have validated CAUTI data that provided insights into accuracy of CAUTI reporting and adherence to CAUTI definition. METHODS: Data accuracy measures included pooled mean sensitivity, specificity, positive predictive value, and negative predictive value. Total CAUTI error rate was computed as proportion of mismatches among total records. The impact of 2015 CAUTI definition changes were tested by comparing pooled accuracy estimates of validations prior to 2015 with post-2015. RESULTS: At least 19 state health departments conducted CAUTI validations and indicated pooled mean sensitivity of 88.3%, specificity of 98.8%, positive predictive value of 93.6%, and negative predictive value of 97.6% of CAUTI reporting to the National Healthcare Safety Network. Among CAUTIs misclassified (121), 66% were underreported and 34% were overreported. CAUTI classification error rate declined significantly from 4.3% (pre-2015) to 2.4% (post-2015). Reasons for CAUTI misclassifications included: misapplication of CAUTI definition, misapplication of general health care-associated infection definitions, and clinical judgement over surveillance definition. CONCLUSIONS: CAUTI underreporting is a major concern; validations provide transparency, education, and relationship building to improve reporting accuracy.

BACKGROUND: A point-prevalence survey that was conducted in the United States in 2011 showed that 4% of hospitalized patients had a health care-associated infection. We repeated the survey in 2015 to assess changes in the prevalence of health care-associated infections during a period of national attention to the prevention of such infections. METHODS: At Emerging Infections Program sites in 10 states, we recruited up to 25 hospitals in each site area, prioritizing hospitals that had participated in the 2011 survey. Each hospital selected 1 day on which a random sample of patients was identified for assessment. Trained staff reviewed medical records using the 2011 definitions of health care-associated infections. We compared the percentages of patients with health care-associated infections and performed multivariable log-binomial regression modeling to evaluate the association of survey year with the risk of health care-associated infections. RESULTS: In 2015, a total of 12,299 patients in 199 hospitals were surveyed, as compared with 11,282 patients in 183 hospitals in 2011. Fewer patients had health care-associated infections in 2015 (394 patients [3.2%; 95% confidence interval {CI}, 2.9 to 3.5]) than in 2011 (452 [4.0%; 95% CI, 3.7 to 4.4]) (P<0.001), largely owing to reductions in the prevalence of surgical-site and urinary tract infections. Pneumonia, gastrointestinal infections (most of which were due to Clostridium difficile [now Clostridioides difficile]), and surgical-site infections were the most common health care-associated infections. Patients' risk of having a health care-associated infection was 16% lower in 2015 than in 2011 (risk ratio, 0.84; 95% CI, 0.74 to 0.95; P=0.005), after adjustment for age, presence of devices, days from admission to survey, and status of being in a large hospital. CONCLUSIONS: The prevalence of health care-associated infections was lower in 2015 than in 2011. To continue to make progress in the prevention of such infections, prevention strategies against C. difficile infection and pneumonia should be augmented. (Funded by the Centers for Disease Control and Prevention.).

This case study is part of a series centered on the Centers for Disease Control and Prevention's National Healthcare Safety Network's (NHSN) health care-associated infection (HAI) surveillance definitions. The intent of the case study series is to foster standardized application of the NHSN's HAI surveillance definitions among infection preventionists and accurate determination of HAI events. This specific case study focuses on the definitions found within the surgical site infection (SSI) protocol. It aims to reflect the real life and complex patient scenario surrounding a bloodstream infection that is secondary to an SSI and the application of the Present at the Time of Surgery event detail. An online survey link is provided where participants may confidentially answer questions related to the case study and receive immediate feedback in the form of correct answers and explanations and rationales. Details of the case study, answers, and explanations have been reviewed and approved by NHSN staff. We hope that participants take advantage of this educational offering and thereby gain a greater understanding of the NHSN's HAI surveillance definitions.

This is the first case study published in a series in the American Journal of Infection Control (AJIC) since the Centers for Disease Control and Prevention/ National Healthcare Safety Network (NHSN) surveillance definition update of 2016. These cases represent some of the complex patient scenarios IPs have encountered in their daily surveillance of healthcare-associated infections (HAI) using NHSN procedural approach and definitions. Case study objectives have been previously published. (1) | With each case, a link to an online survey is provided, where you may enter answers to questions and receive immediate feedback in the form of correct answers and explanations. All individual participant answers will remain confidential, although it is the authors' intention to share a summary of the survey responses at a later date. Cases, answers, and explanations have been reviewed and approved by NHSN staff. We hope that you will take advantage of this offering, and we look forward to your active participation.