Evolution of hospital participation in the National Nosocomial Infections Surveillance System, 1986 to 1993

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

Objective.

To determine the feasibility of estimating the number of central line-days at a hospital from a sample of months or individual days in a year, for surveillance of healthcare-associated bloodstream infections.

Design.

We used data reported to the National Nosocomial Infections Surveillance system in the adult and pediatric intensive care unit component for 1995-2003 and data from a sample of hospitals' daily counts of device use for 12 consecutive months. We calculated the percentile error as the central line-associated bloodstream infection percentile based on rates per line-days minus the percentile based on rates per estimated line-days.

Setting and Participants.

A total of 247 hospitals were used for sampling whole months and 12 hospitals were used for sampling individual days.

Results.

For a 1-month sample of central line–days data, the median percentile error was 3.3 (75th percentile, 7.9; 90th percentile, 15.4). The percentile error decreased with an increase in the number of months sampled. For a 3-month sample, the median percentile error was 1.4 (75th percentile, 4.3; 95th percentile, 8.3). Sampling individual days throughout the year yielded lower percentile errors than sampling an equivalent fraction of whole months. With 1 weekday sampled per week, the median percentile error ranged from 0.65 to 1.40, and the 90th percentile ranged from 2.8 to 5.0. Thus, for 90% of units, collecting data on line-days once a week provides an estimate within ± 5 percentile points of the true line-day rate.

Conclusion.

Sample-based estimates of central line-days can yield results that are acceptable for surveillance of healthcare-associated bloodstream infections.

[Healthcare-associated infection rates: measuring and comparing. Experiences from the German National Nosocomial Infection Surveillance System (KISS) and from other surveillance systems]

Surveillance of nosocomial infections is meanwhile a cornerstone of infection prevention activities in hospitals. The objective of this article is to compare healthcare-associated infection rates in intensive care patients, neonatal intensive care patients and operated patients (ICU-KISS, OP-KISS, NEO-KISS) of the German nosocomial infection surveillance system (KISS) with the corresponding data of the US American National Healthcare Safety Network (NHSN) and the European Centre for Disease Prevention and Control (ECDC). In general, the methodological differences among the three surveillance systems are minor but there are some exceptions. Therefore, differences between countries have to be interpreted very carefully as they may be due to differences in diagnostics, patient mix, types of interventions, length of stay, selection of participating hospitals, post-discharge surveillance activities and interpretation of case definitions. Organizational aspects, such as mandatory participation with public disclosure on infection rates may also have an impact.

Prevalence of nursing home-associated infections in the Department of Veterans Affairs nursing home care units

BACKGROUND

The Department of Veterans Affairs (VA) is the largest single provider of long-term care in the United States. The prevalence of nursing home-associated infections (NHAIs) among residents of VA nursing home care units (NHCUs) is not known.

METHODS

A Web-based point prevalence survey of NHAIs using modified Centers for Disease Control and Prevention definitions for health care-associated infections was conducted in the VA's 133 NHCUs on November 9, 2005.

RESULTS

From a total population of 11,475 NHCU residents, 591 had at least 1 NHAI for a point prevalence rate of 5.2%. Urinary tract infection, asymptomatic bacteriuria, pneumonia, skin infection, gastroenteritis, and soft tissue infection were most prevalent, constituting 72% of all NHAIs. A total of 2817 residents (24.5%) had 1 or more indwelling device. Of these 2817 residents with an indwelling device(s), 309 (11.0%) had 1 or more NHAI. In contrast, the prevalence of NHAIs in residents without an indwelling device was 3.3%. Indwelling urinary catheter, percutaneous gastrostomy tube, intravenous peripheral line, peripherally inserted central catheter, and suprapubic urinary catheter were most common, accounting for 79.3% of all devices used.

CONCLUSION

There are effective infection surveillance and control programs in VA NHCUs with a point prevalence of NHAIs of 5.2%.

Estimating health care-associated infections and deaths in U.S. hospitals, 2002

OBJECTIVE

The purpose of this study was to provide a national estimate of the number of healthcare-associated infections (HAI) and deaths in United States hospitals.

METHODS

No single source of nationally representative data on HAIs is currently available. The authors used a multi-step approach and three data sources. The main source of data was the National Nosocomial Infections Surveillance (NNIS) system, data from 1990-2002, conducted by the Centers for Disease Control and Prevention. Data from the National Hospital Discharge Survey (for 2002) and the American Hospital Association Survey (for 2000) were used to supplement NNIS data. The percentage of patients with an HAI whose death was determined to be caused or associated with the HAI from NNIS data was used to estimate the number of deaths.

RESULTS

In 2002, the estimated number of HAIs in U.S. hospitals, adjusted to include federal facilities, was approximately 1.7 million: 33,269 HAIs among newborns in high-risk nurseries, 19,059 among newborns in well-baby nurseries, 417,946 among adults and children in ICUs, and 1,266,851 among adults and children outside of ICUs. The estimated deaths associated with HAIs in U.S. hospitals were 98,987: of these, 35,967 were for pneumonia, 30,665 for bloodstream infections, 13,088 for urinary tract infections, 8,205 for surgical site infections, and 11,062 for infections of other sites.

CONCLUSION

HAIs in hospitals are a significant cause of morbidity and mortality in the United States. The method described for estimating the number of HAIs makes the best use of existing data at the national level.

Infection surveillance and control programs in the Department of Veterans Affairs nursing home care units: a preliminary assessment

A survey was conducted to assess the capacity and current practices of the infection surveillance and control programs at the Department of Veterans Affairs' 130 nursing home care units (VA NHCUs) covering a total of 15,006 beds in 2003. All 130 VA NHCUs responded to the survey, although not all NHCUs answered every question. The majority of the VA NHCUs provided specialized services that might pose increased risks of infection. For every 8 to 10 VA NHCU beds, there was 1 regular-pressure or negative-pressure infection control room available. Each VA NHCU had an active ongoing infection surveillance and control program managed by highly educated infection control personnel (ICP), of which 96% had a minimum of a bachelor degree. A median of 12 hours per week of these ICP efforts was devoted to the infection surveillance and control activities. The most frequently used surveillance methods were targeted surveillance for specific infections and for specific organisms. Most VA NHCUs conducted surveillance for antibiotic-resistant organisms. However, VA NHCUs did not use a uniform set of definitions for nosocomial infections for their infection surveillance and control purposes. We conclude that VA NHCUs have a considerable infrastructure and capacity for infection surveillance and control. This information can be used to develop a nationwide VA NHCU nosocomial infection surveillance system.

Does using a laparoscopic approach to cholecystectomy decrease the risk of surgical site infection?

OBJECTIVE

To assess the impact of laparoscopy on surgical site infections (SSIs) following cholecystectomy in a large population of patients.

SUMMARY BACKGROUND DATA

Previous investigations have demonstrated that laparoscopic cholecystectomy is associated with a shorter postoperative stay and fewer overall complications. Less is known about the impact of laparoscopy on the risk for SSIs.

METHODS

Epidemiologic analysis was performed on data collected during a 7-year period (1992-1999) by participating hospitals in the National Nosocomial Infections Surveillance (NNIS) System in the United States.

RESULTS

For 54,504 inpatient cholecystectomy procedures reported, use of the laparoscopic technique increased from 59% in 1992 to 79% in 1999. The overall rate of SSI was significantly lower for laparoscopic cholecystectomy than for open cholecystectomy. Overall, infecting organisms were similar for both approaches. Even after controlling for other significant factors, the risk for SSI was lower in patients undergoing the laparoscopic technique than the open technique.

CONCLUSIONS

Laparoscopic cholecystectomy is associated with a lower risk for SSI than open cholecystectomy, even after adjusting for other risk factors. For interhospital comparisons, SSI rates following cholecystectomy should be stratified by the type of technique.

Characteristics of hospitals and infection control professionals participating in the National Nosocomial Infections Surveillance System 1999

The National Nosocomial Infections Surveillance (NNIS) system is the oldest and largest monitoring system for health care-acquired infections in the United States. This report describes both the characteristics of NNIS hospitals compared with those of US hospitals with 100 beds or more and their infection control programs. Overall, NNIS hospitals tend to have more hospital beds than the average for-comparable US hospitals. The majority of NNIS hospitals have affiliations with academic medical centers, and most have substantial intensive care units. Even though infection control professionals in NNIS hospitals spend most of their time in inpatient settings, 40% of their time is also spent in a variety of other settings, including home health, outpatient surgery or clinics, extended care facilities, employee health and quality management, and other clinical or administrative activities. As described in this report, the infrastructure of the NNIS system offers a national resource on which to build improved voluntary patient safety monitoring efforts, as outlined in the recent Institute of Medicine report on medical errors.

Nosocomial infections in the intensive care units at a university hospital in a developing country: comparison with National Nosocomial Infections Surveillance intensive care unit rates

OBJECTIVE

As a measure of the quality of care provided to patients in the intensive care unit, comparison of nosocomial infection rates with those of the National Nosocomial Infection surveillance was completed during a 3-year observation period.

DESIGN

The study design was a prospective study during 3 years between 1993 and 1995. During that period, patients at the medical/surgical and neurosurgical intensive care units and the high-risk nursery were surveyed for nosocomial infections. Device use, bloodstream infection, urinary tract infection, and ventilator-associated pneumonia nosocomial infection rates were calculated and compared with the National Nosocomial Infection Surveillance published rates for the same period.

SETTING

The study setting was the medical/surgical intensive care unit, the neurosurgical intensive care unit, and the high-risk nursery at the Jordan University Hospital.

RESULTS

Overall infection rates were 17.2 per 100 patients in the medical/surgical intensive care unit, 14.2 to 18.5 per 100 patients in the neurosurgical intensive care unit, and 13.4 to 73.5 per 100 patients in the high-risk nursery. When compared with the weight of the infants, these rates were 61.9 to 94 per 100 in infants weighing <1500 g, 26 to 30.8 per 100 patients in infants weighing >1500 g to 2500 g, and 11.7 to 14.4 per 100 in infants weighing >2500 g. Whereas device use was moderate, bloodstream infection and ventilator-associated pneumonia rates were >90th percentile for National Nosocomial Infection Surveillance in the high-risk nursery, and urinary tract infection was >90th percentile in the medical/surgical and neurosurgical intensive care units. Nosocomial infections at the intensive care units in developing countries need further investigation and control.

Passive surveillance for Kawasaki disease in San Diego County

BACKGROUND

Kawasaki disease (KD) is the most common cause of acquired heart disease in children in the United States. Epidemiologic surveillance is conducted to monitor baseline incidence of the disease and to identify epidemics. The aim of this study was to evaluate a passive surveillance system for reporting cases of KD in San Diego County to the local, state and national health authorities.

METHODS

We performed a retrospective review of a 2-year period to identify the number of patients who met criteria of the Centers for Disease Control and Prevention for diagnosis of KD and who were successfully reported to the county, state and national databases.

RESULTS

The total number of KD patients for 1994 and 1995 was determined by retrospective review of medical record discharge diagnosis codes. Of the 28 San Diego County residents diagnosed with KD in 1994, 24 (86%) met CDC criteria and 15 (63%) of these eligible patients were reported to the county and state health authorities. Of the 41 residents in 1995, 34 (83%) met CDC criteria and 22 (65%) were reported to the above agencies. No patient in either 1994 or 1995 was reported by local or state health authorities to the CDC.

CONCLUSION

Passive surveillance for KD in San Diego County resulted in the reporting of approximately two-thirds of the eligible patients at the county and state levels but completely failed to report any documented cases to the CDC. Implementation of a sentinel hospital reporting system should be considered as a preferred alternative to national passive surveillance in the effort to track total numbers of patients and to follow disease trends over time.

Improving hospital-acquired infection rates: the CDC experience

BACKGROUND

The National Nosocomial Infections Surveillance (NNIS) System, begun in 1970 by the Centers for Disease Control to collect data on hospital-acquired infections, is one of the oldest continuously operating clinical performance indicator systems in the United States. Growth of the system, from 19 to 230 hospitals, has been accompanied by developments such as the evolution from hospitalwide to targeted surveillance, improved data processing and telecommunications for data collection and reporting, and risk adjustment.

ELEMENTS OF A SUCCESSFUL SYSTEM

The NNIS System provides specific, standardized methods for data collection and uses device-associated, device-day rates to risk adjust the data and make it meaningful for interhospital comparison. The system has been used as a tool for improving quality of care through prevention of nosocomial infections. For example, an 800-bed teaching hospital's rate of ventilator-associated nosocomial pneumonia in the surgical intensive care unit-49.5 infections per 1,000 ventilator days-was in excess of the 90th percentile. Improvements in care, including changing tubing and cascades every 48 hours and Ambu bags every 24 hours, as well as increased clinical evaluation of patients, was followed 12 months later by a decrease to 25.8 infections, well below the 90th percentile.

INFORMATION DISSEMINATION

Since 1992, staff from NNIS hospitals have met in a biennial conference to learn about advances in nosocomial infection surveillance and to share information with one another on infection control and quality improvement programs.

CONCLUSIONS

The NNIS experience can be used as a source of guidance for assessing the effectiveness and utility of other indicator systems.