Development and Testing of Tools to Detect Ambulatory Surgical Adverse Events.
ABSTRACT OBJECTIVES: Numerous health-care systems in the United States, including the Veterans Health Administration (VA), use the National Surgical Quality Improvement Program (NSQIP) to detect surgical adverse events (AEs). VASQIP sampling methodology excludes many routine ambulatory surgeries from review. Triggers, algorithms derived from clinical logic to flag cases where AEs have most likely occurred, could complement VASQIP by detecting a higher yield of ambulatory surgeries with a true surgical AE. METHODS: We developed and tested a set of ambulatory surgical AE trigger algorithms using a sample of fiscal year 2008 ambulatory surgeries from the VA Boston Healthcare System. We used VA Boston VASQIP-assessed cases to refine triggers and VASQIP-excluded cases to test how many trigger-flagged surgeries had a nurse chart review-detected surgical AE. Chart review was performed using the VA electronic medical record. We calculated the ratio of cases with a true surgical AE over flagged cases (i.e., the positive predictive value [PPV]), and the 95% confidence interval for each trigger. RESULTS: Compared with the VASQIP rate (9 AEs, or 2.8%, of the 322 charts assessed), nurse chart review of the 198 trigger-flagged surgeries yielded more cases with at least 1 AE (47 surgeries with an AE, or 6.0%, of the 782 VASQIP-excluded ambulatory surgeries). Individual trigger PPVs ranged from 12.4% to 58.3%. CONCLUSIONS: In comparison with VASQIP, our set of triggers identified a higher rate of surgeries with AEs in fewer chart-reviewed cases. Because our results are based on a relatively small sample, further research is necessary to confirm these findings.
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ABSTRACT: Clostridium difficile colitis is the predominant hospital-acquired gastrointestinal infection in the United States and has emerged as an important nosocomial cause of morbidity and death. Although several institutional studies have examined the effects of C. difficile on hospitalized patients, its nationwide impact on surgical patients has yet to be defined. To provide a national estimate of the burden of C. difficile, we performed a five-year retrospective analysis of the Agency for Healthcare Research and Quality's National Inpatient Sample Database, which represents a stratified 20% sample of hospitals in the United States, from 1999 to 2003. All surgical inpatient discharge data from 997 hospitals in 37 states were analyzed to determine the association of C. difficile infections with patient demographics, hospital characteristics, surgical procedure, length of stay (LOS), total charges, and in-hospital mortality rate. Univariate analysis was performed to identify any association between the presence of C. difficile infection and the outcome variables using chi-square contingency table analysis or the Student t-test following the exclusion of patients with other medical complications. Multivariate regression analysis was used to determine whether the presence of C. difficile infection was an independent predictor of increased LOS, total charges, and in-hospital mortality rate when controlling for surgery type, age, sex, payor, and hospital characteristics. Clostridium difficile infection was reported as a discharge diagnosis for 8,113 (0.52%) of all 1,553,597 inpatients who had undergone a general surgical procedure. The incidence increased significantly in 2002 (34% higher than in 2001; p < 0.0001). The following patient and hospital characteristics were associated with the highest incidence of C. difficile infection (all p < 0.0001): Age > 64 years (0.95%); Medicare beneficiary status (0.94%); north-eastern hospital location (0.73%); and large (0.55%), urban (0.56%), or teaching hospital (0.61%). Patients undergoing an emergency operation were at higher risk than those having operations performed electively (0.8% vs. 0.3%; p < 0.0001). Colectomy, small-bowel resection, and gastric resection were associated with the highest risk of C. difficile infection (incidence after colectomy 1.11%; odds ratio [OR] 2.77, 95% confidence interval [CI] 2.65, 2.89, p < 0.0001; small-bowel resection 1.17%, OR 2.40, 95% CI 2.26, 2.54, p < 0.0001; gastric resection 1.02%, OR 2.26, 95% CI 2.03, 2.52, p < 0.0001). Patients undergoing cholecystectomy and appendectomy had the lowest risk of C. difficile infection (cholecystectomy 0.41%, OR 0.37, 95% CI 0.35, 0.39, p < 0.0001; appendectomy 0.20%, OR 0.45, 95% CI 0.42, 0.49, p < 0.0001). Multivariable analysis demonstrated that C. difficile was an independent predictor of LOS, which increased by 16.0 days (95% CI 15.6, 16.4 days; p < 0.0001) in the presence of infection. Total charges increased by $77,483 (95% CI $75,174, $79,793; p < 0.0001), and there was a 3.4-fold increase in the mortality rate (95% CI 3.02, 3.77; p < 0.0001) compared with patients who did not acquire C. difficile. Epidemiologic data suggest that the incidence of C. difficile infection is increasing in U.S. surgical patients and that the infection is most prevalent after emergency operations and among patients having intestinal tract resections. Infection with C. difficile is an independent predictor of increased LOS, total charges, and mortality rate after surgery and represents a considerable burden to both patients and hospitals. Preventing C. difficile infection offers a potentially significant improvement in patient outcomes, as well as a reduction in hospital costs and resource expenditures.Surgical Infections 12/2007; 8(6):557-66. DOI:10.1089/sur.2006.062 · 1.72 Impact Factor