Bloodstream Infections in a Community Hospital: A 25-Year Follow-Up

Objective:

To examine the current status of bloodstream infections (BSIs) in a community hospital as part of a 25-year longitudinal study.

Design:

Retrospective descriptive epidemiologic study.

Setting:

Community teaching hospital.

Patients:

All inpatients in 1998 with a positive blood culture who met the CDC NNIS System case definition of BSI.

Methods:

Cases were stratified by underlying illness category using case mix adjustment categories (after McCabe) and reviewed for associations among mortality, underlying illness severity, and multiple clinical and laboratory parameters.

Results:

Of 19,289 patients discharged in 1998,185 had an episode of infection documented by blood culture (96 cases per 10,000 inpatients). BSI was twice as frequent in patients 65 years and older compared with younger patients. BSIs caused or contributed to the deaths of 22 patients for an overall case-fatality rate of 11.9% compared with 20.7% in 1982 (P = .02). Striking decreases were noted for in-hospital patient mortality in 1998 for BSIs with ultimately and rapidly fatal underlying illnesses (P = .02 and P < .10, respectively). Primary bacteremia decreased compared with 1982. Antibiotic use was vigorous, but resistance was modest in both nosocomial and community-acquired organisms and had changed little from 1982 and 1987.

Conclusions:

Compared with previous studies, case-fatality rates in patients with BSI were substantially lower in rapidly fatal and ultimately fatal underlying illness categories. Antibiotic use was extensive but prompt and appropriate. Microorganism resistance to antibiotics changed little from the 1980s.

The Effect of Frequency of Chart Review on the Sensitivity of Nosocomial Infection Surveillance in General Surgery

Objective:

To assess the sensitivity of different frequencies of nosocomial infection surveillance (NIS) in general surgery.

Design:

Data obtained with a prospective daily NIS are compared with those of hypothetical cross-sectional studies carried out with different frequencies (from one weekly visit up to one visit every other day).

Setting:

General surgery services at three hospitals.

Main Outcome Measure:

Sensitivity in the detection of nosocomial infection (overall and stratified by site), compared to a gold standard of prospective surveillance of every patient's complete medical record daily from the first day after surgery until discharge and once more after discharge.

Patients:

5,859 patients.

Results:

837 nosocomial infections were detected by the gold standard (58.8% were surgical-site infections [SSI]). The sensitivity of weekly NIS for all infections was 74.5% (95% confidence interval [CI95], 71.4%-77.5%) and varied from 65.1% (CI95, 56.2%-73.3%) for urinary tract infection to 83.3% (CI95, 62.6%-95.3%) for respiratory tract infection; it was 76.4% (CI95, 72.4%-80.1%) for SSI. As expected, sensitivity increased with the frequency of NIS. Performing NIS every 4 days improved sensitivity significantly, to 82.3% (CI95, 79.5%-84.8%) for all infections and 83.3% (CI95, 79.7%-86.5%) for SSI. One visit every other day increased the sensitivity for all infections by another 4.9%, mainly due to increased detection of urinary tract and other less severe infections.

Conclusions:

The sensitivity of two visits a week exceeded that of one weekly visit by approximately 8%, and one visit every other day added another 5% increase. Results varied according to duration of infection and postdischarge hospital stay.

Can quality circles improve hospital-acquired infection control?

It is a fundamental principle of continuous quality improvement (CQI) that processes should be the objects of quality improvement. The objective of this study was to improve process quality concerning the prevention of hospital-acquired infections in surgical departments and intensive care units by a continuous quality improvement (CQI) approach based mainly on quality circles. This approach was evaluated in a prospective controlled intervention study in medium-size acute care hospitals (four intervention and four control hospitals). During two intervention periods (each 10 months) four external physicians with training in hospital epidemiology and infection control introduced and supervised quality circles in the intervention hospitals. Process quality was assessed by interviewing senior staff members before the first and after the second intervention period using standardized questionnaires. The gold standard process quality was defined on the basis of the CDC/HICPAC-guidelines for the prevention of hospital-acquired infections. Most of the evaluated aspects of process quality belonged to the HICPAC-categories IA and IB respectively, the CDC category I. Fifty quality circle sessions were performed in the four intervention hospitals of which 28 were dealing directly with key subjects in infection control. In the intervention hospitals, 19.8% of evaluated aspects of process quality which concerned the prevention of hospital-acquired infections were improved compared to only 6.9% in the control hospitals (P<0.05). Sixty-six point seven percent of positive changes in process quality were initiated by the results of the quality circles. Our study demonstrates that a CQI approach based on infection control quality circles can lead to a substantial improvement of process quality regarding the prevention of hospital-acquired infections.

The effect of frequency of chart review on the sensitivity of nosocomial infection surveillance in general surgery

OBJECTIVE

To assess the sensitivity of different frequencies of nosocomial infection surveillance (NIS) in general surgery.

DESIGN

Data obtained with a prospective daily NIS are compared with those of hypothetical cross-sectional studies carried out with different frequencies (from one weekly visit up to one visit every other day).

SETTING

General surgery services at three hospitals.

MAIN OUTCOME MEASURE

Sensitivity in the detection of nosocomial infection (overall and stratified by site), compared to a gold standard of prospective surveillance of every patient's complete medical record daily from the first day after surgery until discharge and once more after discharge.

PATIENTS

5,859 patients.

RESULTS

837 nosocomial infections were detected by the gold standard (58.8% were surgical-site infections [SSI]). The sensitivity of weekly NIS for all infections was 74.5% (95% confidence interval [CI95], 71.4%-77.5%) and varied from 65.1% (CI95, 56.2%-73.3%) for urinary tract infection to 83.3% (CI95, 62.6%-95.3%) for respiratory tract infection; it was 76.4% (CI95, 72.4%-80.1%) for SSI. As expected, sensitivity increased with the frequency of NIS. Performing NIS every 4 days improved sensitivity significantly, to 82.3% (CI95, 79.5%-84.8%) for all infections and 83.3% (CI95, 79.7%-86.5%) for SSI. One visit every other day increased the sensitivity for all infections by another 4.9%, mainly due to increased detection of urinary tract and other less severe infections.

CONCLUSIONS

The sensitivity of two visits a week exceeded that of one weekly visit by approximately 8%, and one visit every other day added another 5% increase. Results varied according to duration of infection and postdischarge hospital stay.

The affinity between continuous quality improvement and epidemic surveillance

OBJECTIVE

To discuss the close affinity between the continuous quality improvement (CQI) concept of monitoring a process for the introduction of special causes and epidemic surveillance.

DESIGN

A case study of a CQI tool for infection control epidemic surveillance.

SETTING AND PATIENTS

A 668-bed acute care hospital with 5 intensive care units supporting heart, liver transplant, and trauma teams. The infection control department consists of 2.5 full-time employee nurse epidemiologists and a medical director who is an infectious disease specialist.

RESULTS

The outbreak investigation illustrates principles of CQI and their relationship to epidemic surveillance through the use of applied statistical methods.

CONCLUSIONS

The expanding role of hospital epidemiology is enhanced by applying CQI concepts to improving health care. The application of epidemiologic tools and principles to the problems of nosocomial infections is strongly connected to the CQI concept of using dependable data to improve processes.