Validation of a Modified Version of the National Nosocomial Infections Surveillance System Risk Index for Health Services Research

2009 ◽  
Vol 30 (6) ◽  
pp. 563-569 ◽  
Author(s):  
Nick Daneman ◽  
Andrew E. Simor ◽  
Donald A. Redelmeier
Keyword(s):  
Surgical Site Infection ◽  
Nosocomial Infections ◽  
Surveillance System ◽  
Elective Surgery ◽  
Risk Index ◽  
Surgical Site Infections ◽  
Population Based ◽  
Site Infection ◽  
Services Research ◽  
System Risk

Objective.To validate the National Nosocomial Infections Surveillance system risk index through administrative data to predict surgical site infections.Design.Retrospective cohort study.Setting.Population-based analysis in Ontario, Canada.Patients.All elderly patients who underwent elective surgery from April 1, 1992, through March 31, 2006 (n = 469,349).Methods.Data on procedural and patient outcomes were gathered from linked population-wide hospital discharge records and physician claims. The 75th percentile of surgical duration was estimated through anesthesiologist billing fees recorded in 15-minute increments; the American Society of Anesthesiology score of at least 3 out of 5 was estimated by diagnostic codes for severe systemic illness; and all surgeries were classified as clean or clean-contaminated because of their elective nature (thus, the maximum score on the modified index was 2).Results.A total of 147,216 surgeries (31%) had a score of 0;246,592 (53%) had a score of 1; and 75,541 (16%) had a score of 2 on the modified index. The 30-day risk of surgical site infection increased with each increment in the modified index (score of 0, 5.4%; score of 1, 8.0%; score of 2, 14.3%; P < .001). The association was evident for surgical site infection diagnosed during the index admission (score of 0, 2.0%; score of 1, 3.7%; score of 2, 8.9%; P < .001), as well as that associated with reoperation or death (score of 0, 0.04%; score of 1, 0.23%; score of 2, 0.73%; P < .001). The modified index predicted increases in surgical site infection risk within each of 11 surgical subgroups. In accord with past research, the modified index had modest discrimination (C statistic, 0.59), and the majority of surgical site infections (72%) occurred within lower risk strata.Conclusions.The modified index predicts surgical site infection in population-based analyses and is associated with incremental increases in risk.

scholarly journals Applicability of the national nosocomial infections surveillance system risk index for the prediction of surgical site infections: a review

2007 ◽  
Vol 11 (1) ◽  
pp. 134-141 ◽  
Author(s):  
Flávia Falci Ercole ◽  
Carlos Ernesto Ferreira Starling ◽  
Tânia Couto Machado Chianca ◽  
Mariângela Carneiro
Keyword(s):  
Nosocomial Infections ◽  
Surveillance System ◽  
Risk Index ◽  
Surgical Site Infections ◽  
System Risk

scholarly journals Surgical Site Infection (SSI) Rates in the United States, 1992–1998: The National Nosocomial Infections Surveillance System Basic SSI Risk Index

2001 ◽  
Vol 33 (s2) ◽  
pp. S69-S77 ◽  
Author(s):  
Robert P. Gaynes ◽  
David H. Culver ◽  
Teresa C. Horan ◽  
Jonathan R. Edwards ◽  
Chesley Richards ◽  
...  
Keyword(s):  
United States ◽  
Surgical Site Infection ◽  
Nosocomial Infections ◽  
Surveillance System ◽  
Risk Index ◽  
The United States ◽  
Site Infection

Surgical-Site Infection After Cardiac Surgery: Incidence, Microbiology, and risk Factors

2005 ◽  
Vol 26 (5) ◽  
pp. 466-472 ◽  
Author(s):  
Didier Lepelletier ◽  
Stéphanie Perron ◽  
Philippe Bizouarn ◽  
Jocelyne Caillon ◽  
Henri Drugeon ◽  
...  
Keyword(s):  
Risk Factors ◽  
Surgical Site Infection ◽  
Artery Bypass ◽  
Risk Index ◽  
Bypass Graft ◽  
Surgical Site Infections ◽  
Incidence Rates ◽  
Site Infection ◽  
Internal Mammary ◽  
System Risk

AbstractObjective:To identify risk factors associated with surgical-site infection according to the depth of infection, the cardiac procedure, and the National Nosocomial Infections Surveillance System risk index.Design:Prospective survey conducted during a 12-month period.Setting:A 48-bed cardiac surgical department in a teaching hospital.Patients:Patients admitted for cardiac surgery between February 2002 and January 2003.Results:Surgical-site infections were diagnosed in 3% of the patients (38 of 1,268). Of the 38 surgical-site infections, 20 were superficial incisional infections and 18 were mediastinitis for incidence rates of 1.6% and 1.4%, respectively. Cultures were positive in 28 cases and the most commonly isolated pathogen wasStaphylococcus. A National Nosocomial Infections Surveillance System risk index score of 2 or greater was associated with a risk of surgical-site infection (relative risk, 2.4;P< .004). Heart transplantation, mechanical circulatory assistance, coronary artery bypass graft with the use of internal mammary artery, and reoperation for cardiac tamponade or pericard effusion were independent risk factors associated with surgical-site infection.Conclusions:Data surveillance using incidence rates stratified by cardiac procedure and type of infection is relevant to improving infection control efforts. Risk factors in patients who developed superficial infection were different from those in patients who developed mediastinitis. Coronary artery bypass graft using internal mammary artery was associated with a high risk of surgical-site infection, and independent factors such as reoperation for cardiac tamponade or pericard effusion increased the risk of infection.

Accounting for Incomplete Postdischarge Follow-Up During Surveillance of Surgical Site Infection by Use of the National Nosocomial Infections Surveillance System's Risk Index

2009 ◽  
Vol 30 (5) ◽  
pp. 433-439 ◽  
Author(s):  
Fernando Martín Biscione ◽  
Renato Camargos Couto ◽  
Tânia M. G. Pedrosa
Keyword(s):  
Surgical Site Infection ◽  
Nosocomial Infections ◽  
Goodness Of Fit ◽  
Risk Index ◽  
Operative Procedures ◽  
Site Infection ◽  
Goodness Of Fit Test ◽  
Simple Method ◽  
Genitourinary System

Objective.We examined the usefulness of a simple method to account for incomplete postdischarge follow-up during surveillance of surgical site infection (SSI) by use of the National Nosocomial Infections Surveillance (NNIS) system's risk index.Design.Retrospective cohort study that used data prospectively collected from 1993 through 2006.Setting.Five private, nonuniversity healthcare facilities in Belo Horizonte, Brazil.Patients.Consecutive patients undergoing the following NNIS operative procedures: 20,981 operations on the genitourinary system, 11,930 abdominal hysterectomies, 7,696 herniorraphies, 6,002 cholecystectomies, and 6,892 laparotomies.Methods.For each operative procedure category, 2 SSI risk models were specified. First, a model based on the NNIS system's risk index variables was specified (hereafter referred to as the NNIS-based model). Second, a modified model (hereafter referred to as the modified NNIS-based model), which was also based on the NNIS system's risk index, was specified with a postdischarge surveillance indicator, which was assigned the value of 1 if the patient could be reached during follow-up and a value of 0 if the patient could not be reached. A formal comparison of the capabilities of the 2 models to assess the risk of SSI was conducted using measures of calibration (by use of the Pearson goodness-of-fit test) and discrimination (by use of receiver operating characteristic curves). Goodman-Kruskal correlations (G) were also calculated.Results.The rate of incomplete postdischarge follow-up varied between 29.8% for abdominal hysterectomies and 50.5% for cholecystectomies. The modified NNIS-based model for laparotomy did not show any significant benefit over the NNIS-based model in any measure. For all other operative procedures, the modified NNIS-based model showed a significantly improved discriminatory ability and higher G statistics, compared with the NNIS-based model, with no significant impairment in calibration, except if used to assess the risk of SSI after operations on the genitourinary system or after a cholecystectomy.Conclusions.Compared with the NNIS-based model, the modified NNIS-based model added potentially useful clinical information regarding most of the operative procedures. Further work is warranted to evaluate this method for accounting for incomplete postdischarge follow-up during surveillance of SSI.

Impact of Postdischarge Surveillance on Surgical-Site Infection Rates for Coronary Artery Bypass Procedures

2002 ◽  
Vol 23 (7) ◽  
pp. 364-367 ◽  
Author(s):  
Joan L Avato ◽  
Kwan Kew Lai
Keyword(s):  
Coronary Artery ◽  
Surgical Site Infection ◽  
Coronary Artery Bypass ◽  
Artery Bypass ◽  
Risk Index ◽  
Surgical Site Infections ◽  
Site Infection ◽  
Infection Rates ◽  
Surgical Site Infection Rate ◽  
Harvest Site

Objective:To assess the influence of postdischarge infection surveillance on risk-adjusted surgical-site infection rates for coronary artery bypass graft (CABG) procedures.Design:Prospective surveillance of surgical-site infections after CABG.Setting:Tertiary-care referral hospital.Methods:Data on surgical-site infections were collected for 1,324 CABG procedures during 27 months. They were risk adjusted and analyzed according to the surgical surveillance protocol of the National Nosocomial Infections Surveillance (NNIS) System of the Centers for Disease Control and Prevention, with and without postdischarge data.Results:Data were available for 96% of the patients. Of the 88 surgical-site infections, 28% were identified prior to discharge and 72% postdischarge. More chest than harvest-site infections were identified (46% vs 11%) prior to discharge, and more harvest-site than chest infections were identified in the outpatient setting (42% vs 14%). The surgical-site infection rate for patients stratified under risk index 1, calculated without postdischarge surveillance, was 2.9%; when compared with that of the NNIS System, the P value was .29. When postdischarge surveillance was included, the surgical-site infection rate was 4.9% and statistically significant when compared with that of the NNIS System (P = .007). For patients stratified under risk index 2, the rates with and without postdischarge surveillance were 11.7% and 10.0%, respectively; when compared with the NNIS System rates, the P values were .000008 and .0006, respectively.Conclusions:Only 28% of the surgical-site infections would have been detected if surveillance had been limited to hospital stay. Postdischarge surveillance identified more surgical-site infections among risk index 1 patients. Hospitals with comprehensive postdischarge surveillance after CABG procedures are likely to record higher surgical-site infection rates than those that do not perform such surveillance.

scholarly journals Prospective Nationwide Surveillance of Surgical Site Infections after Gastric Surgery and Risk Factor Analysis in the Korean Nosocomial Infections Surveillance System (KONIS)

2012 ◽  
Vol 33 (6) ◽  
pp. 572-580 ◽  
Author(s):  
Eu Suk Kim ◽  
Hong Bin Kim ◽  
Kyoung-Ho Song ◽  
Young Keun Kim ◽  
Hyung-Ho Kim, ◽  
...  
Keyword(s):  
Risk Factors ◽  
Nosocomial Infections ◽  
Surveillance System ◽  
Demographic Data ◽  
Risk Index ◽  
Operation Time ◽  
Surgical Site Infections ◽  
Gastric Surgery ◽  
Increased Risk ◽  
Male Sex

Objective.To evaluate the risk factors for surgical site infection (SSI) after gastric surgery in patients in Korea.Design.A nationwide prospective multicenter study.Setting.Twenty university-affiliated hospitals in Korea.Methods.The Korean Nosocomial Infections Surveillance System (KONIS), a Web-based system, was developed. Patients in 20 Korean hospitals from 2007 to 2009 were prospectively monitored for SSI for up to 30 days after gastric surgery. Demographic data, hospital characteristics, and potential perioperative risk factors were collected and analyzed, using multivariate logistic regression models.Results.Of the 4,238 case patients monitored, 64.9% (2,752) were male, and mean age (±SD) was 58.8 (±12.3) years. The SSI rates were 2.92, 6.45, and 10.87 per 100 operations for the National Nosocomial Infections Surveillance system risk index categories of 0, 1, and 2 or 3, respectively. The majority (69.4%) of the SSIs observed were organ or space SSIs. The most frequently isolated microorganisms were Staphylococcus aureus and Klebsiella pneumoniae. Male sex (odds ratio [OR], 1.67 [95% confidence interval (CI), 1.09–2.58]), increased operation time (1.20 [1.07–1.34] per 1-hour increase), reoperation (7.27 [3.68–14.38]), combined multiple procedures (1.79 [1.13–2.83]), prophylactic administration of the first antibiotic dose after skin incision (3.00 [1.09–8.23]), and prolonged duration (≥7 days) of surgical antibiotic prophylaxis (SAP; 2.70 [1.26–5.64]) were independently associated with increased risk of SSI.Conclusions.Male sex, inappropriate SAP, and operation-related variables are independent risk factors for SSI after gastric surgery.

The Standardized Incidence Ratio as a Reliable Tool for Surgical Site Infection Surveillance

2006 ◽  
Vol 27 (08) ◽  
pp. 817-824 ◽  
Author(s):  
Christophe Rioux ◽  
Bruno Grandbastien ◽  
Pascal Astagneau
Keyword(s):  
Surgical Site Infection ◽  
Incidence Rate ◽  
Surveillance System ◽  
Risk Index ◽  
Temporal Trends ◽  
Site Infection ◽  
Standardized Incidence Ratio ◽  
Surveillance Network ◽  
Reliable Tool ◽  
Number Of Patients

Objective.To evaluate whether the standardized incidence ratio (SIR) is a more reliable tool for comparing rates and temporal trends of surgical site infection (SSI) in surgery wards than the incidence rate among patients with an National Nosocomial Infections Surveillance system (NNIS) risk index category of 0.Design.Observational, prospective cohort study in a sequential SSI surveillance system.Setting.Volunteer surgery wards in a surveillance network in northern France that annually conducted SSI surveillance for 3 months from 1998 to 2000.Methods.The incidence rate was the number of SSIs divided by the number of patients included, stratified by the NNIS risk index category. SIR was the observed number of SSIs divided by the expected number computed using a multiple regression model.Results.Overall, 26,904 patients in 67 surgery wards were enrolled. Between 1998 and 2000, the SSI incidence rate among patients with NNIS risk index category 0 decreased from 2.1% to 1.4%, which was a 33% reduction (P= .002). The SIR decreased from 1.2 (95% confidence interval [CI], 1.1-1.3) to 0.8 (95% CI, 0.7-0.9), which was a 20% decrease per year and an overall 33% reduction. The number of SSIs was significantly higher than expected in 17 of 201 surveillance periods over the 3 years. The classification of the wards according to the 2 indicators over the 3 years showed that wards with a high SIR did not consistently have the highest SSI incidence rate among patients with NNIS risk index category 0, partly because the type of surgical procedure and the duration of follow-up are not taken into account in the NNIS risk index.Conclusion.SIR should be considered a reliable indicator to estimate the reduction in SSI incidence that results from implementation of infection control policies and for comparison of SSI rates between wards.

Finding a Method for Optimizing Risk Adjustment When Comparing Surgical-Site Infection Rates

2004 ◽  
Vol 25 (4) ◽  
pp. 313-318 ◽  
Author(s):  
Christian Brandt ◽  
Sonja Hansen ◽  
Dorit Sohr ◽  
Franz Daschner ◽  
Henning Rüden ◽  
...  
Keyword(s):  
Risk Factors ◽  
Logistic Regression ◽  
Surgical Site Infection ◽  
Regression Models ◽  
Predictive Power ◽  
Risk Index ◽  
Significant Risk ◽  
Site Infection ◽  
Logistic Regression Models ◽  
System Risk

AbstractObjective:To investigate whether stratification of the risk of developing a surgical-site infection (SSI) is improved when a logistic regression model is used to weight the risk factors for each procedure category individually instead of the modified NNIS System risk index.Design and Setting:The German Nosocomial Infection Surveillance System, based on NNIS System methodology, has 273 acute care surgical departments participating voluntarily. Data on 9 procedure categories were included (214,271 operations).Methods:For each of the procedure categories, the significant risk factors from the available data (NNIS System risk index variables of ASA score, wound class, duration of operation, and endoscope use, as well as gender and age) were identified by multiple logistic regression analyses with stepwise variable selection. The area under the receiver operating characteristic (ROC) curve resulting from these analyses was used to evaluate the predictive power of logistic regression models.Results:For most procedures, at least two of the three variables contributing to the NNIS System risk index were shown to be independent risk factors (appendectomy, knee arthroscopy, cholecystectomy, colon surgery, herniorrhaphy, hip prosthesis, knee prosthesis, and vascular surgery). The predictive power of logistic regression models (including age and gender, when appropriate) was low (between 0.55 and 0.71) and for most procedures only slightly better than that of the NNIS System risk index.Conclusion:Without the inclusion of additional procedure-specific variables, logistic regression models do not improve the comparison of SSI rates from various hospitals.

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