Automated methods for surveillance of surgical site infections

Establishing semi-automated infection surveillance in obstetrics and gynaecology

BACKGROUND

Surveillance is an acknowledged method to decrease nosocomial infections, such as surgical site infections (SSIs). Electronic healthcare records create the opportunity for automated surveillance. While approaches for different types of surgeries and indicators already exist, there are very few for obstetrics and gynaecology.

AIM

To analyse the sensitivity and workload reduction of semi-automated surveillance in obstetrics and gynaecology.

METHODS

In this retrospective, single-centre study at a 1438-bed tertiary care hospital in Germany, semi-automated SSI surveillance using the indicators 'antibiotic prescription', 'microbiological data' and 'administrative data' (diagnosis codes, readmission, post-hospitalization care) was compared with manual analysis and categorization of all patient files. Breast surgeries (BSs) conducted in 2018 and caesarean sections (CSs) that met the inclusion criteria between May 2013 and December 2019 were included. Indicators were analysed for sensitivity, number of analysed procedures needed to identify one case, and potential workload reduction in detecting SSIs in comparison with the control group.

FINDINGS

The reference standard showed nine SSIs in 416 BSs (2.2%). Sensitivities for the indicators 'antibiotic prescription', 'diagnosis code', 'microbiological sample taken', and the combination 'diagnosis code or microbiological sample' were 100%, 88.9%, 66.7% and 100%, respectively. The reference standard showed 54 SSIs in 3438 CSs (1.6%). Sensitivities for the indicators 'collection of microbiological samples', 'diagnosis codes', 'readmission/post-hospitalization care', and the combination of all indicators were 38.9%, 27.8%, 85.2% and 94.4%, respectively.

CONCLUSIONS

Semi-automated surveillance systems may reduce workload by maintaining high sensitivity depending on the type of surgery, local circumstances and thorough digitalization.

Epidemiologic characteristics of orthopedic surgical site infections and under-reporting estimation of registries using capture-recapture analysis

Background

Surgical Site Infections (SSIs) are among the leading causes of the postoperative complications. This study aimed at investigating the epidemiologic characteristics of orthopedic SSIs and estimating the under-reporting of registries using the capture-recapture method.

Methods

This study, which was a registry-based, cross-sectional one, was conducted in six educational hospitals in Tehran during a one-year period, from March, 2017 to March, 2018. The data were collected from two hospital registries (National Nosocomial Infection Surveillance System (NNIS) and Health Information Management database (HIM)). First, all orthopedic SSIs registered in these sources were used to perform capture-recapture (N = 503). Second, 202 samples were randomly selected to assess patients` characteristics.

Results

Totally, 76.24% of SSIs were detected post-discharge. Staphylococcus aureus (11.38%) was the most frequently detected bacterium in orthopedic SSIs. The median time between the detection of a SSI and the discharge was 17 days. The results of a study done on 503 SSIs showed that the coverage of NNIS and HIM was 59.95 and 65.17%, respectively. After capture-recapture estimation, it was found that about 221 of orthopedic SSIs were not detected by two sources among six hospitals and the real number of SSIs were estimated to be 623 ± 36.58 (95% CI, 552–695) and under-reporting percentage was 63.32%.

Conclusion

To recognize the trends of SSIs mortality and morbidity in national level, it is significant to have access to a registry with minimum underestimated data. Therefore, according to the weak coverage of NNIS and HIM among Iranian hospitals, a plan for promoting the national Infection Prevention and Control (IPC) programs and providing updated protocols is recommended.

Advanced Loss Eventuality Assessment and Technical Estimates: An Integrated Approach for Management of Healthcare-Associated Infections

BACKGROUND

Healthcare Associated Infections (HAIs) represent a crucial issue in health and patient safety management due to the persistent nature, economic impact and possible preventability of the phenomenon. Compensation claims for damages resulting from HAI could provide insights that can improve the understanding of suboptimal steps in the therapeutic process, enable an estimate of costs related to infectious complications, and guide the development of planning tools for implementation of the quality of care.

OBJECTIVE

This paper analyzes all the HAI claims received at the Umberto I General Hospital of Rome across a five-year period with the aim of outlining a methodological approach to the litigation management and of characterizing the economic impact of infections on health facilities resources.

METHODS

All claims received during the study period have been classified according to the International Classification for Patient Safety (ICPS) system. Subsequently, claims related to Healthcare Associated Infections were evaluated through an innovative tool for determination of the risk of loss, the Advanced Loss Eventuality Assessment (ALEA) score.

RESULTS

The results obtained demonstrate the relevance of a correct management of HAI claims in the administration of a health care system. Specifically, the cases examined during the study highlighted the significant impact of infectious diseases of a nosocomial nature in terms of frequency and economic exposure.

CONCLUSION

The proposed methodological approach allows a productive analysis of the internal processes, providing fundamental data for the refinement of the preventive strategies and for the rationalization of the resources through the expenditure forecasts. Article Highlights Box: Healthcare-Associated Infections represent an essential element to consider in the management of health facilities. • Many studies highlight the economic burden of Healthcare-Associated Infections in health policies. • Litigation management represents a useful resource in the prevention of Healthcare Associated Infections. • Appropriate clinical risk management policies in the field of Healthcare-Associated Infections allow the implementation of preventive measures, the reduction of the incidence of the phenomenon and the quality of care. • The costs of Healthcare-Associated Infections can be limited through a systematic methodological approach based on Advanced Loss Eventuality Assessment and technical estimate of the value of each case. • The application of a standardized system would be desirable in any health facility despite the potential methodological, technical, behavioral and financial issues.

Surgical Site Infection (SSI) Rates Among Patients Who Underwent Mastectomy After the Introduction of SSI Prevention Policies

Objective.

To describe the results of an intervention program to reduce the rate of surgical site infection (SSI) in the breast tumor department of a referral teaching hospital for patients with cancer.

Methods.

Preventive measures introduced in the Breast Tumor Department of the study hospital included the following: starting in July 2000, use of sterile technique for wound care; starting in 2001, use of closed antireflux silicone evacuation systems, use of perioperative antimicrobial prophylaxis, provision of feedback to surgeons, and remodeling of the ambulatory wound care clinic. We conducted surveillance of all patients who underwent mastectomy between February 1 and December 31, 2001, and the SSI rate was calculated. A case-control analysis was performed for risk factors known to be associated with SSI. Results were compared with the data from 2000.

Results.

The study included data on 385 surgeries. SSIs were registered in 52 (13.7%) of these 385, which was a rate 58.6% less than the 2000 infection rate (33.1%). Risk factors associated with SSI included concomitant chemotherapy and radiation therapy (OR, 3.6 [95% confidence interval {CI}, 1.9-7.1]), surgery performed during an evening shift (OR, 1.9 [95% CI, 1.1-3.6]), and insertion of a second drainage tube during the late postoperative period (OR, 2.8 [95% CI, 1.4-5.7]). The mean number (± SD) of postoperative visits to the outpatient wound care clinic was reduced from 11.6 ± 7.1 in 2000 to 9.2 ± 4.4 in 2001 (P< .001, Student's t test). The mean number of days that the evacuation systems were used was reduced from 19.0 to 16.0 days (P =.001, Student's t test).

Conclusions.

Continuous wound surveillance, along with feedback to surgeons, use of closed antireflux evacuation systems, and standardized practices in wound and drainage-tube care, decreased by 58.6% the rate of SSI in a breast surgical department with high rates of infection.

Surgical-Site Infections Following Cesarean Section in an Estonian University Hospital: Postdischarge Surveillance and analysis of Risk Factors

Objectives:

To evaluate a multi-method approach to postdischarge surveillance of surgical-site infections (SSIs) and to identify infection rates and risk factors associated with SSI following cesarean section.

Design:

Cross-sectional survey.

Setting:

Academic tertiary-care obstetric and gynecology center with 54 beds.

Patients:

All women who delivered by cesarean section in Tartu University Women's Clinic during 2002.

Methods:

Infections were identified during hospital stay or by postdischarge survey using a combination of telephone calls, healthcare worker questionnaire, and outpatient medical records review. SSI was diagnosed according to the criteria of the Centers for Disease Control and Prevention National Nosocomial Infections Surveillance System.

Results:

The multi-method approach gave a follow-up rate of 94.8%. Of 305 patients, 19 (6.2%; 95% confidence interval [CI95)], 3.8-9.6) had SSIs. Forty-two percent of these SSIs were detected during postdischarge surveillance. We found three variables associated with increased risk for developing SSI: internal fetal monitoring (odds ratio [OR], 16.6; CI95, 2.2-125.8; P = .007), chorioamnionitis (OR, 8.8; CI95, 1.1-69.6; P = .04), and surgical wound classes III and IV (OR, 3.8; CI95, 1.2-11.8; P=.02).

Conclusions:

The high response rate validated the effectiveness of this kind of surveillance method and was most suitable in current circumstances. A challenge exists to decrease the frequency of internal fetal monitoring and to treat chorioamnionitis as soon as possible (Infect Control Hosp Epidemiol 2005;26:449-454).

Guidance on Public Reporting of Healthcare-Associated Infections: Recommendations of the Healthcare Infection Control Practices Advisory Committee

Consumer demand for healthcare information, including data about the performance of healthcare providers, has increased steadily during the past decade. Many state and national initiatives are under way to mandate or induce healthcare organizations to publicly disclose information regarding institutional and physician performance. Mandatory public reporting of healthcare performance is intended to enable stakeholders, including consumers, to make more informed choices on healthcare issues.

Public reporting of healthcare performance information has taken several forms. Healthcare performance reports (report cards and honor rolls) typically describe the outcomes of medical care in terms of mortality, selected complications, or medical errors and, to a lesser extent, economic outcomes. Increasingly, process measures (ie, measurement of adherence to recommended healthcare practices, such as hand hygiene) are being used as an indicator of how well an organization adheres to established standards of practice with the implicit assumption that good processes lead to good healthcare outcomes. National healthcare quality improvement initiatives, notably those of the Joint Commission on the Accreditation of Healthcare Organizations (JCAHO), the Centers for Medicare & Medicaid Services (CMS), and the Hospital Quality Alliance, use process measures in their public reporting initiatives.

An electronic surveillance tool for catheter-associated urinary tract infection in intensive care units

BACKGROUND

Traditional methods of surveillance of catheter-associated urinary tract infections (CAUTIs) are error-prone and resource-intensive. To resolve these issues, we developed a highly sensitive electronic surveillance tool.

OBJECTIVE

To develop an electronic surveillance tool for CAUTIs and assess its performance.

METHODS

The study was conducted at a 947-bed tertiary care center. Patients included adults aged ≥18 years admitted to an intensive care unit between January 10 and June 30, 2012, with an indwelling urinary catheter during their admission. We identified CAUTIs using 4 methods: traditional surveillance (TS) (ie, manual chart review by ICPs), an electronic surveillance (ES) tool, augmented electronic surveillance (AES) (ie, ES with chart review on a subset of cases), and reference standard (RS) (ie, a subset of CAUTIs originally ascertained by TS or ES, confirmed by review). We assessed performance characteristics to RS for reviewed cases.

RESULTS

We identified 417 candidate CAUTIs in 308 patients; 175 (42.0%) of these candidate CAUTIs were selected for review, yielding 32 confirmed CAUTIs in 22 patients (RS). Compared with RS, the sensitivities of TS, ES, and AES were 43.8% (95% confidence interval [CI], 26.4%-62.3%), 100.0% (95% CI, 89.1%-100.0%), and 100.0% (95% CI, 89.1%-100.0%). Specificities were 82.5% (95% CI, 75.3%-88.4%), 2.8% (95% CI, 0.8%-7.0%), and 100.0% (95% CI, 97.5%-100.0%).

CONCLUSIONS

Electronic CAUTI surveillance offers a streamlined approach to improve reliability and resource burden of surveillance.

Use of Medicare Claims to Rank Hospitals by Surgical Site Infection Risk following Coronary Artery Bypass Graft Surgery

Objective.

To evaluate whether longitudinal insurer claims data allow reliable identification of elevated hospital surgical site infection (SSI) rates.

Design.

We conducted a retrospective cohort study of Medicare beneficiaries who underwent coronary artery bypass grafting (CABG) in US hospitals performing at least 80 procedures in 2005. Hospitals were assigned to deciles by using case mix–adjusted probabilities of having an SSI-related inpatient or outpatient claim code within 60 days of surgery. We then reviewed medical records of randomly selected patients to assess whether chart-confirmed SSI risk was higher in hospitals in the worst deciles compared with the best deciles.

Participants.

Fee-for-service Medicare beneficiaries who underwent CABG in these hospitals in 2005.

Results.

We evaluated 114,673 patients who underwent CABG in 671 hospitals. In the best decile, 7.8% (958/12,307) of patients had an SSI-related code, compared with 24.8% (2,747/11,068) in the worst decile (P<.001). Medical record review confirmed SSI in 40% (388/980) of those with SSI-related codes. In the best decile, the chart-confirmed annual SSI rate was 3.2%, compared with 9.4% in the worst decile, with an adjusted odds ratio of SSI of 2.7 (confidence interval, 2.2–3.3; P<.001) for CABG performed in a worst-decile hospital compared with a best-decile hospital.

Conclusions.

Claims data can identify groups of hospitals with unusually high or low post-CABG SSI rates. Assessment of claims is more reproducible and efficient than current surveillance methods. This example of secondary use of routinely recorded electronic health information to assess quality of care can identify hospitals that may benefit from prevention programs.

Postdischarge Surgical Site Infection Surveillance Practices in Washington Acute Care Hospitals

Little is known about postdischarge surveillance practices currently in place among American hospitals. This survey describes practices used by acute care hospitals covered by Washington State's legislated mandate for public reporting of surgical site infections. While the vast majority of facilities use multiple techniques, wide variation in practices was discovered.

Infect Control Hosp Epidemiol 2012;33(1):8

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

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.

Leveraging Electronic Medical Records for Surveillance of Surgical Site Infection in a Total Joint Replacement Population

Objective.

TO evaluate whether a hybrid electronic screening algorithm using a total joint replacement (TJR) registry, electronic surgical site infection (SSI) screening, and electronic health record (EHR) review of SSI is sensitive and specific for SSI detection and reduces chart review volume for SSI surveillance.

Design.

Validation study.

Setting.

A large health maintenance organization (HMO) with 8.6 million members.

Methods.

Using codes for infection, wound complications, cellullitis, procedures related to infections, and surgeon-reported complications from the International Classification of Diseases, Ninth Revision, Clinical Modification, we screened each TJR procedure performed in our HMO between January 2006 and December 2008 for possible infections. Flagged charts were reviewed by clinical-content experts to confirm SSIs. SSIs identified by the electronic screening algorithm were compared with SSIs identified by the traditional indirect surveillance methodology currently employed in our HMO. Positive predictive values (PPVs), negative predictive values (NPVs), and specificity and sensitivity values were calculated. Absolute reduction of chart review volume was evaluated.

Results.

The algorithm identified 4,001 possible SSIs (9.5%) for the 42,173 procedures performed for our TJR patient population. A total of 440 case patients (1.04%) had SSIs (PPV, 11.0%; NPV, 100.0%). The sensitivity and specificity of the overall algorithm were 97.8% and 91.5%, respectively.

Conclusion.

An electronic screening algorithm combined with an electronic health record review of flagged cases can be used as a valid source for TJR SSI surveillance. The algorithm successfully reduced the volume of chart review for surveillance by 90.5%.

Measurement of the Impact of Risk Adjustment for Central Line–Days on Interpretation of Central Line–Associated Bloodstream Infection Rates

Objective.

To describe methods to assess the practical impact of risk adjustment for central line-days on the interpretation of central line–associated bloodstream infection (BSI) rates, because collecting these data is often burdensome.

Methods.

We analyzed data from 247 hospitals that reported to the adult and pediatric intensive care unit component of the National Nosocomial Infections Surveillance System from 1995 through 2003. For each unit each year, we calculated the percentile error as the absolute value of the difference between the percentile based on a risk-adjusted or more-sophisticated measure (eg, the central line–day rate) and the percentile based on a crude or less-sophisticated measure (eg, the patient-day rate). Using rate per central line–day as the “gold standard,” we calculated performance characteristics (eg, sensitivity and predictive values) of rate per patient-day for finding central line–associated BSI rates higher or lower than the mean. Greater impact of risk adjustment is indicated by higher values for percentile error and lower values for performance characteristics.

Results.

The median percentile error was ± 7 (ie, the percentile based on central line-days could be 7% higher or lower than the percentile based on patient-days). This error was less than 10 percentile points for 62% of the unit-years, was between 10 and 19 percentile points for 22% of the unit-years, and was 20 percentile points or more for 15% of the unit-years. Use of the rate based on patient-days had a sensitivity of 76% and a positive predictive value of 61% for detecting a significantly high or low central line–associated BSI rate.

Conclusions.

We found that risk adjustment for central line–days has an important impact on the calculated central line–associated BSI percentile for some units. Similar methods can be used to evaluate the impact of other risk adjustment methods. Our results support current recommendations to use central line–days for surveillance of central line–associated BSI when comparisons are made among facilities.

The evolving landscape of healthcare-associated infections: recent advances in prevention and a road map for research

This white paper identifies knowledge gaps and new challenges in healthcare epidemiology research, assesses the progress made toward addressing research priorities, provides the Society for Healthcare Epidemiology of America (SHEA) Research Committee's recommendations for high-priority research topics, and proposes a road map for making progress toward these goals. It updates the 2010 SHEA Research Committee document, "Charting the Course for the Future of Science in Healthcare Epidemiology: Results of a Survey of the Membership of SHEA," which called for a national approach to healthcare-associated infections (HAIs) and a prioritized research agenda. This paper highlights recent studies that have advanced our understanding of HAIs, the establishment of the SHEA Research Network as a collaborative infrastructure to address research questions, prevention initiatives at state and national levels, changes in reporting and payment requirements, and new patterns in antimicrobial resistance.

Matching bacteriological and medico-administrative databases is efficient for a computer-enhanced surveillance of surgical site infections: retrospective analysis of 4,400 surgical procedures in a French university hospital

OBJECTIVE

Our goal was to estimate the performance statistics of an electronic surveillance system for surgical site infections (SSIs), generally applicable in French hospitals.

METHODS

Three detection algorithms using 2 different data sources were tested retrospectively on 9 types of surgical procedures performed between January 2010 and December 2011 in the University Hospital of Nantes. The first algorithm was based on administrative codes, the second was based on bacteriological data, and the third used both data sources. For each algorithm, sensitivity, specificity, and positive and negative predictive values (PPV and NPV) were calculated. The reference method was the hospital's routine surveillance: a comprehensive review of the computerized medical charts of the patients who underwent one of the targeted procedures during the study period.

SETTING

A 3,000-bed teaching hospital in western France.

POPULATION

We analyzed 4,400 targeted surgical procedures.

RESULTS

Sensitivity results varied significantly between the three algorithms, from 25% (95% confidence interval, 17-33) when using only administrative codes to 87% (80%-93%) with the bacteriological data and 90% (85%-96%) with the combined algorithm. Fewer variations were observed for specificity (91%-98%), PPV (21%-25%), and NPV (98% to nearly 100%). Overall, performance statistics were higher for deep SSIs than for superficial infections.

CONCLUSIONS

A reliable computer-enhanced SSI surveillance can easily be implemented in French hospitals using common data sources. This should allow infection control professionals to spend more time on prevention and education duties. However, a multicenter study should be conducted to assess the generalizability of this method.

An automated algorithm to preselect patients to be assessed individually in point prevalence surveys for hospital-acquired infections in surgery

In this pilot study, we evaluate an algorithm that uses predictive clinical and laboratory parameters to differentiate between patients with hospital-acquired infection (HAI) and patients without HAI. Seventy-four percent of the studied population of surgical patients could be reliably (negative predictive value of 98%) excluded from detailed assessment by the infection control practitioner.

Assessing surgical site infection risk factors using electronic medical records and text mining

Text mining techniques to detect surgical site infections (SSI) in unstructured clinical notes were used to improve SSI detection. In conjuction with data from an integrated electronic medical record, all of the 22 SSIs detected by traditional hospital-based surveillance were found using text mining, along with an additional 37 SSIs not detected by traditional surveillance.

Data use and effectiveness in electronic surveillance of healthcare associated infections in the 21st century: a systematic review

OBJECTIVE

As more electronic health records have become available during the last decade, we aimed to uncover recent trends in use of electronically available patient data by electronic surveillance systems for healthcare associated infections (HAIs) and identify consequences for system effectiveness.

METHODS

A systematic review of published literature evaluating electronic HAI surveillance systems was performed. The PubMed service was used to retrieve publications between January 2001 and December 2011. Studies were included in the review if they accurately described what electronic data were used and if system effectiveness was evaluated using sensitivity, specificity, positive predictive value, or negative predictive value. Trends were identified by analyzing changes in the number and types of electronic data sources used.

RESULTS

26 publications comprising discussions on 27 electronic systems met the eligibility criteria. Trend analysis showed that systems use an increasing number of data sources which are either medico-administrative or clinical and laboratory-based data. Trends on the use of individual types of electronic data confirmed the paramount role of microbiology data in HAI detection, but also showed increased use of biochemistry and pharmacy data, and the limited adoption of clinical data and physician narratives. System effectiveness assessments indicate that the use of heterogeneous data sources results in higher system sensitivity at the expense of specificity.

CONCLUSIONS

Driven by the increased availability of electronic patient data, electronic HAI surveillance systems use more data, making systems more sensitive yet less specific, but also allow systems to be tailored to the needs of healthcare institutes' surveillance programs.

Variations in identification of healthcare-associated infections

OBJECTIVE

Little is known about whether those performing healthcare-associated infection (HAI) surveillance vary in their interpretations of HAI definitions developed by the Centers for Disease Control and Prevention's National Healthcare Safety Network (NHSN). Our primary objective was to characterize variations in these interpretations using clinical vignettes. We also describe predictors of variation in responses.

DESIGN

Cross-sectional study.

SETTING

United States.

PARTICIPANTS

A sample of US-based members of the Society for Healthcare Epidemiology of America (SHEA) Research Network.

METHODS

Respondents assessed whether each of 6 clinical vignettes met criteria for an NHSN-defined HAI. Individual- and institutional-level data were also gathered.

RESULTS

Surveys were distributed to 143 SHEA Research Network members from 126 hospitals. In total, 113 responses were obtained, representing at least 61 unique hospitals (30 respondents did not identify a hospital); 79.2% (84 of 106 nonmissing responses) were infection preventionists, and 79.4% (81 of 102 nonmissing responses) worked at academic hospitals. Among the 6 vignettes, the proportion of respondents correctly characterizing the vignettes was as low as 27.3%. Combining all 6 vignettes, the mean percentage of correct responses was 61.1% (95% confidence interval, 57.7%-63.8%). Percentage of correct responses was associated with presence of a clinical background (ie, nursing or physician degrees) but not with hospital size or infection prevention and control department characteristics.

CONCLUSIONS

Substantial heterogeneity exists in the application of HAI definitions in this survey of infection preventionists and hospital epidemiologists. Our data suggest a need to better clarify these definitions, especially when comparing HAI rates across institutions.

Methodology of the Norwegian Surveillance System for Healthcare-Associated Infections: the value of a mandatory system, automated data collection, and active postdischarge surveillance

BACKGROUND

Surveillance is a primary component of systems for the prevention of health care-associated infections (HCAI). Feedback to surgeons from these surveillance systems may reduce rates of surgical site infections (SSIs) by approximately 20%.

OBJECTIVE

Our objective was to describe the Norwegian Surveillance System for Healthcare-Associated Infections' (NOIS) module for SSI (NOIS-SSI) and to evaluate the completeness of hospital participation, the effectiveness of automated data collection, and the added value of follow-up after hospital discharge during 2005 to 2009.

METHODS

NOIS was introduced by regulation in 2005. Hospital participation is described through adherence to the mandatory requirements and participation in the voluntary aspects of the system. Automated data collection is evaluated through the completeness of reporting of explanatory and administrative variables. The impact of active postdischarge surveillance is assessed through the completeness of follow-up and the proportion of infections detected after hospital discharge.

RESULTS

The system has achieved 95% (52/55) hospital participation, with 65% (34/52) of the hospitals submitting more data than the required minimum. The completeness of patient and procedure-related background data is satisfactory, with 23.3% (5,079/21,772) of the records having at least 1 missing value. The completeness of 30-day follow-up of patients is 90.7% (19,747/21,772), and 81% (765/948) of the infections were detected after discharge from hospital.

CONCLUSION

Implementation of a new surveillance system for SSI has been successful evaluated through hospital participation, the completeness of reporting of explanatory and administrative variables, and the completeness of postdischarge follow-up. Important success factors are a mandatory system, automated data-harvesting systems in hospitals, and active postdischarge surveillance.

Advances in electronic surveillance for healthcare-associated infections in the 21st Century: a systematic review

BACKGROUND

Traditional methodologies for healthcare-associated infection (HCAI) surveillance can be resource intensive and time consuming. As a consequence, surveillance is often limited to specific organisms or conditions. Various electronic databases exist within the healthcare setting and may be utilized to perform HCAI surveillance.

AIM

To assess the utility of electronic surveillance systems for monitoring and detecting HCAI.

METHODS

A systematic review of published literature on surveillance of HCAI was performed. Databases were searched for studies published between January 2000 and December 2011. Search terms were divided into infection, surveillance and data management terms, and combined using Boolean operators. Studies were included for review if they demonstrated or proposed the use of electronic systems for HCAI surveillance.

FINDINGS

In total, 44 studies met the inclusion criteria. For the majority of studies, emphasis was on the linkage of electronic databases to provide automated methods for monitoring infections in specific clinical settings. Twenty-one studies assessed the performance of their method with traditional surveillance methodologies or a manual reference method. Where sensitivity and specificity were calculated, these varied depending on the organism or condition being surveyed and the data sources employed.

CONCLUSIONS

The implementation of electronic surveillance was found to be feasible in many settings, with several systems fully integrated into hospital information systems and routine surveillance practices. The results of this review suggest that electronic surveillance systems should be developed to maximize the efficacy of abundant electronic data sources existing within hospitals.

Automated surveillance for healthcare-associated infections: opportunities for improvement

Surveillance of healthcare-associated infections is a cornerstone of infection prevention programs, and reporting of infection rates is increasingly required. Traditionally, surveillance is based on manual medical records review; however, this is very labor intensive and vulnerable to misclassification. Existing electronic surveillance systems based on classification algorithms using microbiology results, antibiotic use data, and/or discharge codes have increased the efficiency and completeness of surveillance by preselecting high-risk patients for manual review. However, shifting to electronic surveillance using multivariable prediction models based on available clinical patient data will allow for even more efficient detection of infection. With ongoing developments in healthcare information technology, implementation of the latter surveillance systems will become increasingly feasible. As with current predominantly manual methods, several challenges remain, such as completeness of postdischarge surveillance and adequate adjustment for underlying patient characteristics, especially for comparison of healthcare-associated infection rates across institutions.

Use of Medicare claims to identify US hospitals with a high rate of surgical site infection after hip arthroplasty

OBJECTIVE

To assess the ability of Medicare claims to identify US hospitals with high rates of surgical site infection (SSI) after hip arthroplasty.

DESIGN

Retrospective cohort study.

SETTING

Acute care US hospitals.

PARTICIPANTS

Fee-for-service Medicare patients 65 years of age and older who underwent hip arthroplasty in US hospitals from 2005 through 2007.

METHODS

Hospital rankings were derived from claims codes suggestive of SSI, adjusted for age, sex, and comorbidities, while using generalized linear mixed models to account for hospital volume. Medical records were obtained for validation of infection on a random sample of patients from hospitals ranked in the best and worst deciles of performance. We then calculated the risk-adjusted odds of developing a chart-confirmed SSI after hip arthroplasty in hospitals ranked by claims into worst- versus best-performing deciles.

RESULTS

Among 524,892 eligible Medicare patients who underwent hip arthroplasty at 3,296 US hospitals, a patient who underwent surgery in a hospital ranked in the worst-performing decile based on claims-based evidence of SSI had 2.9-fold higher odds of developing a chart-confirmed SSI relative to a patient with the same age, sex, and comorbidities in a hospital ranked in the best-performing decile (95% confidence interval, 2.2-3.7).

CONCLUSIONS

Medicare claims successfully distinguished between hospitals with high and low SSI rates following hip arthroplasty. These claims can identify potential outlier hospitals that merit further evaluation. This strategy can also be used to validate the completeness of public reporting of SSI.

Hospital-acquired infections

Health-acquired infection (HAI) is defined as a localized or systemic condition resulting from an adverse reaction to the presence of infectious agents or its toxins. This article focuses on HAIs that are well studied, common, and costly (direct, indirect, and intangible). The HAIs reviewed are catheter-related bloodstream infection, ventilator-associated pneumonia, surgical site infection, and catheter-associated urinary tract infection. This article excludes discussion of Clostridium difficile infections and vancomycin-resistant Enterococcus.

Automated detection of nosocomial infections: evaluation of different strategies in an intensive care unit 2000-2006

The aim of this study was to evaluate seven different strategies for the automated detection of nosocomial infections (NIs) in an intensive care unit (ICU) by using different hospital information systems: microbiology database, antibiotic prescriptions, medico-administrative database, and textual hospital discharge summaries. The study involved 1,499 patients admitted to an ICU of the University Hospital of Lyon (France) between 2000 and 2006. The data were extracted from the microbiology laboratory information system, the clinical information system on the ward and the medico-administrative database. Different algorithms and strategies were developed, using these data sources individually or in combination. The performances of each strategy were assessed by comparing the results with the ward data collected as a national standardised surveillance protocol, adapted from the National Nosocomial Infections Surveillance system as the gold standard. From 1,499 patients, 282 NIs were reported. The strategy with the best sensitivity for detecting these infections using an automated method was the combination of antibiotic prescription or microbiology, with a sensitivity of 99.3% [95% confidence interval (CI): 98.2-100] and a specificity of 56.8% (95% CI: 54.0-59.6). Automated methods of NI detection represent an alternative to traditional monitoring methods. Further study involving more ICUs should be performed before national recommendations can be established.

Assessing specific secondary ICD-9-CM codes as potential predictors of surgical site infections

BACKGROUND

Public reporting and reduced Medicare payments because of health care-associated infections have resulted in the consideration of administrative discharge codes as markers of health care-associated infections. This study aims to determine whether specific secondary ICD-9-CM infection codes linked to cases from a large data set of surgical procedures are predictors of surgical site infections (SSIs).

METHODS

All patients undergoing 1 of 9 surgical procedures from January 1, 2005, through December 31, 2005, at a large academic medical center and who were assigned a secondary ICD-9-CM infection code at discharge were eligible for study inclusion. All cases were reviewed to determine the presence of SSIs. Logistic regression was used to determine which secondary codes were predictors of SSIs.

RESULTS

Among 75 secondary infection codes applied at discharge to 454 patients, only 1 code (998.59) appeared to be reliably associated with SSIs. Two other general infection codes (996.63 and 996.67) and 1 specific infection code (320.3) may also have utility.

CONCLUSION

Administrative coding data do not perform well to identify SSIs. Some general secondary infection codes, however, may have the potential to be utilized in screening algorithms of electronic health data to assist in SSI surveillance.

Does aspirin have a role in venous thromboembolism prophylaxis in total knee arthroplasty patients?

The objectives of this study were to compare the risk of venous thromboembolism (VTE), bleeding, surgical site infection, and mortality in patients receiving aspirin or guideline-approved VTE prophylactic therapies (warfarin, low-molecular-weight heparins, synthetic pentasaccharides) in total knee arthroplasty (TKA). We analyzed clinical and administrative data from 93,840 patients who underwent primary TKA at 307 US hospitals over a 24-month period. Fifty-one thousand nine hundred twenty-three (55%) patients received warfarin, 37,198 (40%) received injectable agents, and 4719 (5%) received aspirin. After adjustment for patient and hospital factors, patients who received aspirin VTE prophylaxis (VTEP) had lower odds for thromboembolism compared to warfarin patients but with similar odds compared with injectable VTEP; there were no differences in risk of bleeding, infection, or mortality after adjustment. Our results suggest that aspirin, when used in conjunction with other clinical care protocols, may be effective VTEP for certain TKA patients.

Predictive ability of positive clinical culture results and International Classification of Diseases, Ninth Revision, to identify and classify noninvasive Staphylococcus aureus infections: a validation study

OBJECTIVE

To develop and validate an algorithm to identify and classify noninvasive infections due to Staphylococcus aureus by using positive clinical culture results and administrative data.

DESIGN

Retrospective cohort study.

SETTING

Veterans Affairs Maryland Health Care System.

METHODS

Data were collected retrospectively on all S. aureus clinical culture results from samples obtained from nonsterile body sites during October 1998 through September 2008 and associated administrative claims records. An algorithm was developed to identify noninvasive infections on the basis of a unique S. aureus-positive culture result from a nonsterile site sample with a matching International Classification of Diseases, Ninth Revision (ICD-9-CM), code for infection at time of sampling. Medical records of a subset of cases were reviewed to find the proportion of true noninvasive infections (cases that met the Centers for Disease Control and Prevention National Healthcare Safety Network [NHSN] definition of infection). Positive predictive value (PPV) and negative predictive value (NPV) were calculated for all infections and according to body site of infection.

RESULTS

We identified 4,621 unique S. aureus-positive culture results, of which 2,816 (60.9%) results met our algorithm definition of noninvasive S. aureus infection and 1,805 (39.1%) results lacked a matching ICD-9-CM code. Among 96 cases that met our algorithm criteria for noninvasive S. aureus infection, 76 also met the NHSN criteria (PPV, 79.2% [95% confidence interval, 70.0%-86.1%]). Among 98 cases that failed to meet the algorithm criteria, 80 did not meet the NHSN criteria (NPV, 81.6% [95% confidence interval, 72.8%-88.0%]). The PPV of all culture results was 55.4%. The algorithm was most predictive for skin and soft-tissue infections and bone and joint infections.

CONCLUSION

When culture-based surveillance methods are used, the addition of administrative ICD-9-CM codes for infection can increase the PPV of true noninvasive S. aureus infection over the use of positive culture results alone.

Surgical site infection following hip fracture surgery - the role of wound surveillance

In a prospective study we assessed 440 patients, sequentially admitted to the trauma unit with hip fracture. The superficial infection rate was 7.7% and the deep infection was 1.8%. The commonest organism responsible for surgical site infection was MRSA (47.6%). 45.2% of the patients with SSI and 50 % of the patients with MRSA wound infection were admitted from institutional care or other hospital. The high prevalence of MRSA wound infection and increased mortality rate in this subgroup highlights the need for a good surveillance programme in place, to monitor trends and identify risk factors with an emphasize on minimising infection rates. Using the National Hip Fracture Database (NHFD) to make surveillance for surgical site infection a routine part of hip fracture care would be best practice in monitoring the trend and comparing care and outcomes against national benchmarks and quality standards. We recommend a close surveillance of wound in this vulnerable group.

Postoperative infection rates in foot and ankle surgery: a clinical audit of Australian podiatric surgeons, January to December 2007

Background.Surgical site infections are one of the most common post-operative complications encountered by foot and ankle surgeons. The incidence reported in the literature varies between 0.5 and 6.5%. The results of a 12-month Australia-wide clinical audit analysing the rates of postoperative infections in association with podiatric surgery are presented. Methods.De-identified patient data was collected from nine podiatric surgeons Australia-wide. Infections were identified according to Australian Council on Health Care Standards (ACHS) definitions and data was entered no earlier than thirty days post procedure. Results.A total of 1339 patient admissions and 2387 surgical procedures were reported using the International Classification of Diseases (ICD-10) and Medicare Benefit Schedule (MBS) coding systems. The overall infection rate was 3.1% and the rate of infection resulting in hospital re-admission was 0.25%. Conclusions.The benchmark results presented in this paper suggest that infection rates associated with podiatric surgery are well within accepted industry standards as stated in recent literature. What is known about the topic?The rates of infection in foot and ankle surgery have been reported in international literature to vary between 0.5 and 6.5%. No such data has been published to date, which describes the rate of infection following podiatric surgery in Australia. What does this paper add?This paper provides benchmark data on complication rates associated with Australian podiatric surgeons. Such data also informs health and hospital managers who may be considering podiatric surgery as an option for providing foot surgery services within the public hospital system. What are the implications for practitioners?This paper challenges podiatric surgeons to consider their own practice and whether it is a reflection of best practice.

Automated surveillance for central line-associated bloodstream infection in intensive care units

OBJECTIVE

To develop and evaluate computer algorithms with high negative predictive values that augment traditional surveillance for central line-associated bloodstream infection (CLABSI).

SETTING

Barnes-Jewish Hospital, a 1,250-bed tertiary care academic hospital in Saint Louis, Missouri.

METHODS

We evaluated all adult patients in intensive care units who had blood samples collected during the period from July 1, 2005, to June 30, 2006, that were positive for a recognized pathogen on culture. Each isolate recovered from culture was evaluated using the definitions for nosocomial CLABSI provided by the National Healthcare Safety Network of the Centers for Disease Control and Prevention. Using manual surveillance by infection prevention specialists as the gold standard, we assessed the ability of various combinations of dichotomous rules to determine whether an isolate was associated with a CLABSI. Sensitivity, specificity, and predictive values were calculated.

RESULTS

Infection prevention specialists identified 67 cases of CLABSI associated with 771 isolates recovered from blood samples. The algorithms excluded approximately 40%-62% of the isolates from consideration as possible causes of CLABSI. The simplest algorithm, with 2 dichotomous rules (ie, the collection of blood samples more than 48 hours after admission and the presence of a central venous catheter within 48 hours before collection of blood samples), had the highest negative predictive value (99.4%) and the lowest specificity (44.2%) for CLABSI. Augmentation of this algorithm with rules for common skin contaminants confirmed by another positive blood culture result yielded in a negative predictive value of 99.2% and a specificity of 68.0%.

CONCLUSIONS

An automated approach to surveillance for CLABSI that is characterized by a high negative predictive value can accurately identify and exclude positive culture results not representing CLABSI from further manual surveillance.

Administrative coding data, compared with CDC/NHSN criteria, are poor indicators of health care-associated infections

BACKGROUND

ICD-9-CM coding alone has been proposed as a method of surveillance for health care-associated infections (HAIs). The accuracy of this method, however, relative to accepted infection control criteria is not known.

METHODS

Retrospective analysis of patients at an academic medical center in 2005 who underwent surgical procedures or who were at risk for catheter-associated bloodstream infections or ventilator-associated pneumonia was performed. Patients previously identified with HAIs by Centers for Disease Control and Prevention's National Healthcare Safety Network surveillance methods were compared with those of the same risk group identified by secondary infection ICD-9-CM codes. Discordant cases identified by only coding were all rereviewed and adjusted prior to final analysis. When coding and surveillance were both negative, a sample of patients was used to estimate the proportion of false negatives in this group.

RESULTS

The positive predictive values (PPVs) ranged from 0.14 to 0.51 with an aggregate of 0.23, even after adjustment for additional cases detected on subsequent medical record review. The negative predictive values (NPVs) ranged from 0.91 to 1.00, with an aggregate of 0.96. The estimates of the true variance of PPVs and NPVs across surgical procedures were small (0.0129, standard error, 0.009; 0.000145, standard error, 0.00019, respectively) and could be mostly explained by variation in prevalence of surgical site infections.

CONCLUSION

Administrative coding alone appears to be a poor tool to be used as an infection control surveillance method. Its proposed use for routine HAI surveillance, public reporting of HAIs, interfacility comparisons, and nonpayment for performance should be seriously questioned.

Comparison of the National Surgical Site Infection surveillance data between The Netherlands and Germany: PREZIES versus KISS

As there has been increasing interest in comparing surgical site infection (SSI) rates between countries, we compared the SSI surveillance data for The Netherlands ('PREZIES') and Germany ('KISS'). Both surveillance systems have comparable protocols with many similar risk factors, including SSI definitions developed by the Centers for Disease Control and Prevention and optional postdischarge surveillance. Nine surgical procedure categories from several specialities were included, the reporting of which were similar, with respect to content and with enough data for proper comparison. Differences for the SSI data were found between PREZIES and KISS for duration of surgery, wound contamination class, American Society of Anesthesiologists physical status classification and the postoperative duration of hospitalization. A significantly higher superficial SSI rate was found for seven surgical procedures according to PREZIES and a higher deep SSI rate for five procedures. When considering only deep SSI during hospitalization, the differences in SSI rates were much smaller. Differences in intensity of postdischarge surveillance led to 34% of SSI being detected after discharge for PREZIES and 21% for KISS. In conclusion, even though similar infection surveillance protocols are used in The Netherlands and Germany, differences occurred in the implementation. Comparisons between countries are most reliable if only deep SSIs during hospitalization are taken into account, since these SSI are not affected by postdischarge surveillance and the diagnostic sensitivity for deep SSI is probably more alike between countries than for superficial SSI.

Developing algorithms for healthcare insurers to systematically monitor surgical site infection rates

BACKGROUND

Claims data provide rapid indicators of SSIs for coronary artery bypass surgery and have been shown to successfully rank hospitals by SSI rates. We now operationalize this method for use by payers without transfer of protected health information, or any insurer data, to external analytic centers.

RESULTS

We performed a descriptive study testing the operationalization of software for payers to routinely assess surgical infection rates among hospitals where enrollees receive cardiac procedures. We developed five SAS programs and a user manual for direct use by health plans and payers. The manual and programs were refined following provision to two national insurers who applied the programs to claims databases, following instructions on data preparation, data validation, analysis, and verification and interpretation of program output. A final set of programs and user manual successfully guided health plan programmer analysts to apply SSI algorithms to claims databases. Validation steps identified common problems such as incomplete preparation of data, missing data, insufficient sample size, and other issues that might result in program failure. Several user prompts enabled health plans to select time windows, strata such as insurance type, and the threshold number of procedures performed by a hospital before inclusion in regression models assessing relative SSI rates among hospitals. No health plan data was transferred to outside entities. Programs, on default settings, provided descriptive tables of SSI indicators stratified by hospital, insurer type, SSI indicator (inpatient, outpatient, antibiotic), and six-month period. Regression models provided rankings of hospital SSI indicator rates by quartiles, adjusted for comorbidities. Programs are publicly available without charge.

CONCLUSION

We describe a free, user-friendly software package that enables payers to routinely assess and identify hospitals with potentially high SSI rates complicating cardiac procedures.

Catheter-related bloodstream infections in hematology

Central venous catheters are essential in the management of many malignant disorders, but catheter-related bloodstream infections (CR-BSIs) are significant complications in terms of morbidity, mortality, and healthcare expenditure. These outcome measures are useful for monitoring of infection control practice and the effect of preventive strategies. Unlike intensive care unit (ICU) populations, surveillance for CR-BSIs in the hematology population is not standardized, despite the potential value of detecting changes in rate, etiology, and changes in risk for infective complications in association with increasingly intensive chemotherapeutic regimens in this immunocompromised population. Essential components of a successful surveillance strategy include selection of a health outcome of significance, definition of goals of the surveillance system, involvement of key stakeholders in planning and development, application of valid case definitions, allocation of resources and trained personnel, risk stratification, and use of appropriate statistical methods for analysis. These are discussed with reference to patients with hematologic malignancy, together with review of previous surveillance strategies in this population. Only when these issues are addressed can a surveillance strategy reliably assess trends and compare data, leading to improved patient outcomes and a reduction in healthcare expenditure for patients with hematologic malignancy.

Impact of postdischarge surveillance on the rate of surgical site infection after orthopedic surgery

OBJECTIVE

To evaluate the impact of postdischarge surveillance on surgical site infection (SSI) rates after orthopedic surgery.

SETTING

Nine hospitals participating in the Finnish Hospital Infection Program.

PATIENTS

All patients who underwent hip or knee arthroplasty or open reduction of a femur fracture during 1999-2002.

RESULTS

The date of discharge was available for 11,812 procedures (90%). The median length of hospital stay was 8 days (range per hospital, 6-9 days). The overall SSI rate was 3.3% (range, 0.8%-6.4%). Of 384 SSIs detected, 216 (56%; range, 28%-90%) were detected after discharge: 93 (43%) were detected on readmission to the hospital, 73 (34%) at completion of a postdischarge questionnaire, and 23 (11%) at a follow-up visit. For 27 postdischarge SSIs (13%), the location of detection was unknown. Altogether, 32 (86%) of 37 of organ/space SSIs, 57 (80%) of 71 deep incisional SSIs, and 127 (46%) of 276 superficial incisional SSIs were detected after discharge. Most SSIs (70%) detected on readmission were severe (organ/space or deep incisional), whereas most SSIs (86%) detected at follow-up visits or at completion of a postdischarge questionnaire were superficial. Of all SSIs, 78% (range, 48%-100%) were microbiologically confirmed. Microbiologic confirmation was less common after discharge than during postoperative hospital stay (66% vs 93%; P<.001).

CONCLUSIONS

Postdischarge surveillance had a large impact on the rate of SSI detected after orthopedic surgery. However, postdischarge surveillance conducted by means of a questionnaire detected only a minority of deep incisional and organ/space SSIs.

Surgical site infection (SSI) rates among patients who underwent mastectomy after the introduction of SSI prevention policies

OBJECTIVE

To describe the results of an intervention program to reduce the rate of surgical site infection (SSI) in the breast tumor department of a referral teaching hospital for patients with cancer.

METHODS

Preventive measures introduced in the Breast Tumor Department of the study hospital included the following: starting in July 2000, use of sterile technique for wound care; starting in 2001, use of closed antireflux silicone evacuation systems, use of perioperative antimicrobial prophylaxis, provision of feedback to surgeons, and remodeling of the ambulatory wound care clinic. We conducted surveillance of all patients who underwent mastectomy between February 1 and December 31, 2001, and the SSI rate was calculated. A case-control analysis was performed for risk factors known to be associated with SSI. Results were compared with the data from 2000.

RESULTS

The study included data on 385 surgeries. SSIs were registered in 52 (13.7%) of these 385, which was a rate 58.6% less than the 2000 infection rate (33.1%). Risk factors associated with SSI included concomitant chemotherapy and radiation therapy (OR, 3.6 [95% confidence interval {CI}, 1.9-7.1]), surgery performed during an evening shift (OR, 1.9 [95% CI, 1.1-3.6]), and insertion of a second drainage tube during the late postoperative period (OR, 2.8 [95% CI, 1.4-5.7]). The mean number (+/- SD) of postoperative visits to the outpatient wound care clinic was reduced from 11.6+/-7.1 in 2000 to 9.2+/-4.4 in 2001 (P<.001, Student's t test). The mean number of days that the evacuation systems were used was reduced from 19.0 to 16.0 days (P=.001, Student's t test).

CONCLUSIONS

Continuous wound surveillance, along with feedback to surgeons, use of closed antireflux evacuation systems, and standardized practices in wound and drainage-tube care, decreased by 58.6% the rate of SSI in a breast surgical department with high rates of infection.

Surgical site infection in patients submitted to digestive surgery: risk prediction and the NNIS risk index

BACKGROUND

Some problems have been reported with the power of the National Nosocomial Infection Surveillance (NNIS) risk index to predict the risk of surgical site infections (SSI) for specific procedures.

OBJECTIVES

To develop an alternative risk prediction index for SSI and to compare the performance with the NNIS index.

METHODS

A prospective cohort study was carried out with all (609) patients submitted to digestive tract surgery in 2 general teaching hospitals in the city of São Paulo, Brazil, from August 2001 through March 2002.

RESULTS

The final incidence rate of SSI was 24.5%; 149 cases of SSI were identified: 33 (22.1%) during hospitalization and 116 (77.9%) after discharge. Logistic multivariate analysis was used for construction of the model. Obesity, surgery risk, adjusted duration, and video laparoscopic surgery were statistically significant (P < .05) for all previous procedures. The performance of the NNIS model in this study showed a low predictive capacity for the occurrence of SSI as determined by the receiver operating characteristic (ROC) curve (0.627; 95% CI: 0.575-0.678) compared with the alternative model developed with this population (0.732; 95% CI: 0.685-0.779).

CONCLUSION

The presence of obesity, adjusted duration, and surgery risk significantly increased the risk for SSI. The NNIS risk index was not significant for SSI in the sample studied, and laparoscopic access was associated with a significant reduction in the risk for SSI. Although the NNIS index is a well-known and simple index, other models depicting variables related to SSI with a better sensitivity and specificity can be developed. Additional studies are required to confirm our results.

Automatic detection of patients with nosocomial infection by a computer-based surveillance system: a validation study in a general hospital

OBJECTIVE

To validate an automated system for the detection of patients with nosocomial infection (NI) in an intensive care unit (ICU).

DESIGN

Retrospective analysis of data from the hospital information system. We applied 3 different NI suspicion criteria (positive microbiology reports, antibiotic administration, and diagnosis of clinical infection) and compared the results to those of a prospective NI incidence study done in the ICU during the same period (1999-2002).

SETTING

A 250-bed general hospital in Barcelona, Spain.

PATIENTS

From April 15, 1999, through June 30, 2002, 1380 patients were admitted to the ICU. Of these, 1043 had an ICU stay of more than 24 hours and were included in the study.

RESULTS

At least one NI suspicion criterion was present for 242 patients (23.2%); 2 criteria were present for 184 patients (17.6%); and all 3 criteria were present for 112 (11.7%). Comparison of hospital information system data to the results of the prospective study indicated that the combination of 2 criteria demonstrated the most satisfactory sensitivity (94.3%; 95% confidence interval [CI], 79.5%-99.0%) and specificity (83.6%; 95% CI, 76.8%-88.9%). The positive predictive value was 55.9% (95% CI, 42.5%-68.6%); the negative predictive value was 98.5% (95% CI, 94.2%-99.7%). The system could assign a site of infection for 90.4% of the NIs detected.

CONCLUSION

The hospital information system was a useful tool for retrospectively detecting patients with an NI during the ICU stay. Given its high sensitivity, it may be useful as an alert for the NI team.

Linkage of microbiology reports and hospital discharge diagnoses for surveillance of surgical site infections

Surveillance of surgical site infections (SSIs) with feedback to surgical personnel is pivotal in decisions regarding infection control. Prospective surveillance is time and resource consuming, so we aimed to evaluate a method based on data collected routinely during care delivery. The study was carried out at three acute hospitals in North-eastern Italy, from 1 January 2001 to 31 December 2001. Hospital discharge diagnoses (selected codes from the International Classification of Diseases, 9th Revision--Clinical Modification) and electronic microbiology reports (positive cultures from surgical wounds and drainages) were linked to identify suspected SSIs. A random sample of tracked events was submitted to total chart review in order to confirm the presence of SSIs retrospectively according to Centers for Disease Control and Prevention definitions. Of 865 suspected SSIs, 64.5% were identified from the microbiological database, 27.1% from discharge codes, and 8.4% from both. Four hundred and three admissions were sampled for review; the overall positive predictive value was 72% (95%CI=69-76%). Since inpatient individual antibiotic exposure is not registered in Italy, the combined use of discharge codes and microbiology reports represents the most feasible automated method for surveillance of SSIs developing during hospital stay.

Improved detection of orthopaedic surgical site infections occurring in outpatients

To test the hypothesis that a simple method of text searching of standard dictated outpatient clinic notes could be used to detect postoperative infections that otherwise were undetected by the traditional hospital-based infection surveillance methods, a retrospective analysis of all clinical notes from the orthopaedic surgery service of a tertiary care medical center without an electronic medical record system was done. Text-searching algorithms were used to screen all outpatient clinic notes for patients seen between September, 2000 and May, 2001. Clinic notes were screened using specific search terms indicative of surgical site infection, to yield a subset of notes that then were manually reviewed. The identified 18,887 notes were reduced to 558 screen-positive notes, of which 347 notes (197 patients) had confirmed surgical site infections on manual review (positive predictive value, 62.2%). Eighty percent of the total joint infections and 54% of the spine infections were not detected through standard hospital-based surveillance. This simple, inexpensive, method for screening clinic notes is effective in improving detection of postdischarge surgical site infections (and, therefore, quality assessment for surgery). It can be implemented in most current clinical settings.

LEVEL OF EVIDENCE

Diagnostic study, Level II-1 (development of diagnostic criteria on basis of consecutive patients--with universally applied reference gold standard). See the Guidelines for Authors for a complete description of levels of evidence.

Computer algorithms to detect bloodstream infections

We compared manual and computer-assisted bloodstream infection surveillance for adult inpatients at two hospitals. We identified hospital-acquired, primary, central-venous catheter (CVC)-associated bloodstream infections by using five methods: retrospective, manual record review by investigators; prospective, manual review by infection control professionals; positive blood culture plus manual CVC determination; computer algorithms; and computer algorithms and manual CVC determination. We calculated sensitivity, specificity, predictive values, plus the kappa statistic (kappa) between investigator review and other methods, and we correlated infection rates for seven units. The kappa value was 0.37 for infection control review, 0.48 for positive blood culture plus manual CVC determination, 0.49 for computer algorithm, and 0.73 for computer algorithm plus manual CVC determination. Unit-specific infection rates, per 1,000 patient days, were 1.0-12.5 by investigator review and 1.4-10.2 by computer algorithm (correlation r = 0.91, p = 0.004). Automated bloodstream infection surveillance with electronic data is an accurate alternative to surveillance with manually collected data.

The Changing Face of Surveillance for Health Care--Associated Infections

Surveillance of health care-associated infections and antimicrobial resistance is an important aspect of prevention. In 2004, the Centers for Disease Control and Prevention had 3 national health care surveillance systems. During 2004-2005, these will be combined into a single Internet-based system, the National Healthcare Safety Network (NHSN). The NHSN will feature a number of enhancements, and ultimately, all US hospitals and other health care facilities will be encouraged to participate. Health care surveillance using standard methods has been very useful and is cited as a model for prevention. However, alternative approaches may improve health care surveillance by reducing complexity, decreasing the burden of data collection, and improving accuracy. These alternative approaches include adopting simpler methods and more-objective definitions, using sampling and estimation, substituting information in computer databases for manually collected data, and increasing surveillance for process measures with known prevention efficacy. Maintaining successful features of standard systems, adopting alternate surveillance approaches, and exploiting new technologies, such as the Internet, will make health care surveillance an even better tool for prevention.

Can hospital discharge diagnoses be used for surveillance of surgical-site infections?

The aim of this study was to assess the data quality of postoperative infections in a hospital discharge registry in the Emilia-Romagna region of Italy. Data from a prospective regional study of postoperative infections in 6158 patients from 31 of the 36 public hospitals of the region were compared with data from the regional hospital discharge registry, using different classes of ICD-9-CM codes. The sensitivity of the hospital discharge database for postoperative surgical infections was 10% when ICD-9-CM codes directly indicative of postoperative infectious complications were used. When non-specific codes of postoperative complications, not necessarily of infectious origin, were added, the sensitivity reached 21%. At present, the hospital discharge registry is not suited for surveillance of hospital-acquired infection.

Electronic Reporting of Pelvic Inflammatory Disease From an Emergency Department

BACKGROUND AND OBJECTIVES

Pelvic inflammatory disease (PID) is a clinically diagnosed condition that is preventable and underreported. We developed an electronic emergency department (ED) PID reporting system by using an automatic and secure system to send computerized clinician PID diagnoses to the state health department.

GOAL

The goal of this study was to assess if electronic transmission of ED PID data could enhance the completeness and timeliness of PID surveillance.

STUDY DESIGN

We conducted a retrospective chart review.

METHODS

To validate electronic ED diagnoses, we reviewed charts of 157 women with 7 clinicians' diagnoses compatible with PID. We determined which women met the Centers for Disease Control and Prevention (CDC) PID surveillance case definition and determined the positive predictive values of electronic ED diagnoses of PID. We compared completeness of electronic PID reporting with state sexually transmitted disease surveillance.

RESULTS

Three diagnoses were appropriate for electronic PID surveillance. Information on women with these diagnoses is sent daily to the health department with no extra effort needed from ED clinicians. Less than 10% of women who met the CDC PID case definition were reported within 6 months through conventional methods.

CONCLUSIONS

Electronic ED surveillance will improve completeness and timeliness of PID reporting.

Syndromic Surveillance for Measleslike Illnesses in a Managed Care Setting

Surveillance for measles must be enhanced to support the objective of measles elimination in the United States. Many conditions produce febrile rash illnesses that are clinically similar to measles; investigations of measleslike illnesses (MLIs) should occur regardless of the incidence of measles. Few data exist regarding the incidence of MLI in the United States, and it is unknown how providers evaluate patients with such conditions. We searched databases at a large managed care organization to obtain complete ascertainment of MLI during 1994-1998. Among 6000000 patient encounters, 68 records were identified that met the study case definition. The incidence of MLI was 4.5 cases/100000 persons/year. Measles diagnoses were considered by physicians for 9 patients (13.2%); 2 were laboratory-tested and reported to the state health department and the other 7 were given alternative diagnoses. It was not possible to determine for the remaining MLI patients whether measles was ruled out on clinical grounds or whether the possibility was not considered. Provider education regarding evaluation and reporting of measles is warranted. Databases at health care plans can be used to address public health issues and to establish syndromic surveillance for communicable diseases.