Nosocomial blood-stream infection in patients with end-stage renal disease: excess length of hospital stay, extra cost and attributable mortality

Patients with end-stage renal disease undergoing haemodialysis are at high risk of nosocomial blood-stream infection (BSI), but data on the associated costs in this patient population are not available. Therefore, we conducted a retrospective matched (1:2) case-control study of such patients undergoing haemodialysis from January 1998 to December 1998 in a medical centre in southern Taiwan to determine the excess length of hospital stay, attributable mortality, and the extra cost caused by nosocomial BSI. The excess length of hospital stay was 30 days for cases vs. 16 days for controls (P<0.001), the mortality rate was 26.3% for cases vs. 0 for controls (P=0.003) (attributable mortality being 26.3%), and the median of overall costs was 131,584 dollars NT for cases vs. 65,282 dollars NT for controls (P<0.001). Based on these findings, we believe that an effective programme to minimize nosocomial BSI in this patient population would greatly reduce their medical and economic burdens.     

Attributable cost and length of stay for patients with central venous catheter-associated bloodstream infection in Mexico City intensive care units: a prospective, matched analysis.

BACKGROUND: No information is available about the financial impact of central venous catheter (CVC)-associated bloodstream infection (BSI) in Mexico. OBJECTIVE: To calculate the costs associated with BSI in intensive care units (ICUs) in Mexico City. DESIGN: An 18-month (June 2002 through November 2003), prospective, nested case-control study of patients with and patients without BSI. SETTING: Adult ICUs in 3 hospitals in Mexico City. PATIENTS AND METHODS: A total of 55 patients with BSI (case patients) and 55 patients without BSI (control patients) were compared with respect to hospital, type of ICU, year of hospital admission, length of ICU stay, sex, age, and mean severity of illness score. Information about the length of ICU stay was obtained prospectively during daily rounds. The daily cost of ICU stay was provided by the finance department of each hospital. The cost of antibiotics prescribed for BSI was provided by the hospitals' pharmacy departments. RESULTS: For case patients, the mean extra length of stay was 6.1 days, the mean extra cost of antibiotics was US dollars 598, the mean extra hospital cost was US dollars 11,591, and the attributable extra mortality was 20%. CONCLUSIONS: In this study, the duration of ICU stay for patients with central venous catheter-associated BSI was significantly longer than that for control patients, resulting in increased healthcare costs and a higher attributable mortality. These conclusions support the need to implement preventive measures for hospitalized patients with central venous catheters in Mexico.     

Outcomes of nosocomial bloodstream infections in adult neutropenic patients: a prospective cohort and matched case-control study.

OBJECTIVE: To examine the clinical and epidemiologic features, excess length of stay, extra costs, and mortality attributable to bloodstream infection (BSI) in neutropenic patients with hematologic malignancies. DESIGN: Prospective cohort and matched case-control study. PATIENTS: All adult neutropenic patients with hematologic malignancies admitted to Cologne University Hospital between May 1, 1997, and April 30, 1998, were prospectively observed. Case-patients were defined as patients with nosocomial BSI; control-patients were selected among patients without BSI. RESULTS: During the study period, the BSI rate in neutropenic patients was 14.3 per 100 neutropenic episodes. Eighty-four case-patients were included. Matching was successful for 96% of the cohort; 81 matched pairs were studied. The mean total length of stay was significantly longer for patients with BSI than for control-patients (37 vs 29 days; P = .002). Extra costs attributable to the infection averaged 3,200 dollars (U.S.) per patient. The crude mortality rates of case-patients and control-patients were 16% and 4%, respectively (P = .013), with an attributable mortality of 12% (odds ratio, 11). Eighty-seven percent of patients met the criteria for sepsis according to the American College of Chest Physicians/Society of Critical Care Medicine. Severe sepsis or septic shock occurred in 13% of patients and was correlated with mortality (55% vs 10% in patients without severe sepsis or septic shock; P = .01). CONCLUSIONS: Nosocomial BSI in neutropenic patients is significantly associated with an excess length of hospital stay, extra costs, and excess mortality. Severe sepsis and septic shock are closely correlated with an adverse outcome.     

Intensive-care-unit-acquired bloodstream infections in a regional critically ill population

Bloodstream infection (BSI) is a serious complication of critical illness but it is uncertain whether acquisition of BSI in the intensive care unit (ICU) increases the risk of death. A study was conducted among all Calgary health region (population approximately 1 million) adults admitted to ICUs for 48 h or more during a three-year period to investigate the occurrence, microbiology and risk factors for developing an ICU-acquired BSI and to determine whether these infections independently predict mortality. One hundred and ninety-nine ICU-acquired BSI episodes occurred during 4933 ICU admissions for a cumulative incidence of 4% and an incidence density of 5.4 per 1000 ICU days. The most common isolates were Staphylococcus aureus (18%), coagulase-negative staphylococci (11%), and Enterococcus faecalis (8%); 12% of infections were due to antimicrobial-resistant bacteria. Admission to the regional neurosurgery/trauma ICU [odds ratio (OR) 2.86; 95% confidence interval (CI) 2.10-3.90] and increasing Acute Physiology and Chronic Health Evaluation II (APACHE II) score (OR 1.05 per point, 95% CI 1.03-1.07) were associated with higher risk, whereas a surgical diagnosis (OR 0.69; 95% CI 0.52-0.93) was associated with lower risk of developing ICU-acquired BSI in logistic regression analysis. The crude in-hospital death rate was 45% for patients with ICU-acquired BSI compared with 21% for those without (P < 0.0001) Development of an ICU-acquired BSI was an independent risk factor for death (OR 1.79; 95% CI 1.3-2.5) and increases the risk of dying from critical illness.     

The impact of surgical-site infections in the 1990s: attributable mortality, excess length of hospitalization, and extra costs.

OBJECTIVE: To determine mortality, morbidity, and costs attributable to surgical-site infections (SSIs) in the 1990s. DESIGN: A matched follow-up study of a cohort of patients with SSI, matched one-to-one with patients without SSI. SETTING: A 415-bed community hospital. STUDY POPULATION: 255 pairs of patients with and without SSI were matched on age, procedure, National Nosocomial Infection Surveillance System risk index, date of surgery, and surgeon. OUTCOME MEASURES: Mortality, excess length of hospitalization, and extra direct costs attributable to SSI; relative risk for intensive care unit (ICU) admission and for readmission to the hospital. RESULTS: Of the 255 pairs, 20 infected patients (7.8%) and 9 uninfected patients (3.5%) died during the postoperative hospitalization (relative risk [RR], 2.2; 95% confidence interval [CI95], 1.1-4.5). Seventy-four infected patients (29%) and 46 uninfected patients (18%) required ICU admission (RR, 1.6; CI95, 1.3-2.0). The median length of hospitalization was 11 days for infected patients and 6 days for uninfected patients. The extra hospital stay attributable to SSI was 6.5 days (CI95, 5-8 days). The median direct costs of hospitalization were $7,531 for infected patients and $3,844 for uninfected patients. The excess direct costs attributable to SSI were $3,089 (CI95, $2,139-$4,163). Among the 229 pairs who survived the initial hospitalization, 94 infected patients (41%) and 17 uninfected patients (7%) required readmission to the hospital within 30 days of discharge (RR, 5.5; CI95, 4.0-7.7). When the second hospitalization was included, the total excess hospitalization and direct costs attributable to SSI were 12 days and $5,038, respectively. CONCLUSIONS: In the 1990s, patients who develop SSI have longer and costlier hospitalizations than patients who do not develop such infections. They are twice as likely to die, 60% more likely to spend time in an ICU, and more than five times more likely to be readmitted to the hospital. Programs that reduce the incidence of SSI can substantially decrease morbidity and mortality and reduce the economic burden for patients and hospitals.     

The impact of methicillin resistance in Staphylococcus aureus bacteremia on patient outcomes: mortality, length of stay, and hospital charges.

OBJECTIVE: To evaluate the impact of methicillin resistance in Staphylococcus aureus on mortality, length of hospitalization, and hospital charges. DESIGN: A cohort study of patients admitted to the hospital between July 1, 1997, and June 1, 2000, who had clinically significant S. aureus bloodstream infections. SETTING: A 630-bed, urban, tertiary-care teaching hospital in Boston, Massachusetts. PATIENTS: Three hundred forty-eight patients with S. aureus bacteremia were studied; 96 patients had methicillin-resistant S. aureus (MRSA). Patients with methicillin-susceptible S. aureus (MSSA) and MRSA were similar regarding gender, percentage of nosocomial acquisition, length of hospitalization, ICU admission, and surgery before S. aureus bacteremia. They differed regarding age, comorbidities, and illness severity score. RESULTS: Similar numbers of MRSA and MSSA patients died (22.9% vs 19.8%; P = .53). Both the median length of hospitalization after S. aureus bacteremia for patients who survived and the median hospital charges after S. aureus bacteremia were significantly increased in MRSA patients (7 vs 9 days, P = .045; 19,212 dollars vs 26,424 dollars, P = .008). After multivariable analysis, compared with MSSA bacteremia, MRSA bacteremia remained associated with increased length of hospitalization (1.29 fold; P = .016) and hospital charges (1.36 fold; P = .017). MRSA bacteremia had a median attributable length of stay of 2 days and a median attributable hospital charge of 6916 dollars. CONCLUSION: Methicillin resistance in S. aureus bacteremia is associated with significant increases in length of hospitalization and hospital charges.     

Hospital-acquired, laboratory-confirmed bloodstream infection: increased hospital stay and direct costs.

OBJECTIVES: To determine increased hospital stay and direct costs attributable to hospital-acquired, laboratory-confirmed bloodstream infection (BSI), and to evaluate the matching variable length of stay (LOS). DESIGN: Retrospective (historical) cohort study with 1:2 matching in intensive care units and surgical wards. SETTING: A 2,000-bed university hospital in Rome, Italy. PATIENTS: All patients admitted between January 1994 and June 1995 who had hospital-acquired, laboratory-confirmed BSI were considered cases; all others were eligible as controls. METHODS: Two controls (A and B) were selected per case in a stepwise fashion. Controls in group A were selected according to the following six criteria: ward, gender, age, diagnosis, central venous catheter, and LOS equal to the interval from admission to infection in a matched case +/- 20% (LOS +/- 20%). Controls in group B were selected according to the first five criteria, but excluded LOS +/- 20%. RESULTS: One hundred five of 108 patients were each matched with two controls. The matching appropriateness score was greater than 90%. With the use of controls in groups A and B, the case-fatality rates attributable to hospital-acquired, laboratory-confirmed BSI were 35.2% and 40.9%, respectively; the estimated risk ratios for death were 2.60 and 3.52 (P = .0001), respectively. The increased hospital stay per case attributable to hospital-acquired, laboratory-confirmed BSI was 19.1 (mean) and 13.0 (median) days for matched pairs in control group A and 19.9 (mean) and 15.0 (median) days for matched pairs in control group B. With controls in group A, the cost of increased hospital stay per patient attributable to hospital-acquired, laboratory-confirmed BSI was Euro 15,413. The additional cost per patient due to treatment was Euro 943, making the overall direct cost Euro 16,356 per case. CONCLUSIONS: This study should make it possible to estimate the cost of hospital-acquired, laboratory-confirmed BSI in most hospitals after adjusting for incidence rate. It also confirmed the use of LOS +/- 20% as a matching variable to limit overestimation of increased hospital stay. To our knowledge, this is among the first such studies in Europe.     

Invasive aspergillosis in critically ill patients: attributable mortality and excesses in length of ICU stay and ventilator dependence

Invasive aspergillosis is a rare disease in intensive care unit (ICU) patients and carries a poor prognosis. The aim of the present study was to determine the attributable mortality due to invasive aspergillosis in critically ill patients. In a retrospective, matched cohort study (July 1997-December 1999), 37 ICU patients with invasive aspergillosis were identified together with 74 control patients. Matching of control (1:2) patients was based on the acute physiology and chronic health evaluation (APACHE) II classification: an equal APACHE II score (+/-1 point) and diagnostic category. This matching procedure results in an equal expected in-hospital mortality for cases and controls. Additionally, control patients were required to have an ICU stay equivalent to or longer than the case before the first culture positive for Aspergillus spp. Patients with invasive aspergillosis were more likely to experience acute renal failure (43.2% versus 20.5%; P = 0.020). They also had a longer ICU stay (median: 13 days versus seven days; P < 0.001) as well as a more extended period of mechanical ventilator dependency (median: 13 days versus four days; P < 0.001). Hospital mortalities for cases and controls were 75.7% versus 56.8%, respectively (P=0.051). The attributable mortality was 18.9% (95% CI: 1.1-36.7). A multivariate survival analysis showed invasive aspergillosis [hazard ratio (HR): 1.9, 95% CI: 1.2-3.0; P = 0.004] and acute respiratory failure (HR: 6.5, 95%: 1.4-29.3; P < 0.016) to be independently associated with in-hospital mortality. In conclusion, it was found that invasive aspergillosis in ICU patients carries a significant attributable mortality of 18.9%. In a multivariate analysis, adjusting for other co-morbidity factors, invasive aspergillosis was recognized as an independent predictor of mortality.     

Risk factors and impact of nosocomial Acinetobacter baumannii bloodstream infections in the adult intensive care unit: a case–control study

During a nine-year study period, 96 episodes of nosocomial bloodstream infection (BSI) due to Acinetobacter baumannii were identified in the adult intensive care units (ICUs) of Shin Kong Wu Ho-Su Memorial Hospital. Seventy-seven (80.2%) of these were available for matching in terms of age, sex, primary diagnosis of ICU admission, ICU ward, and disease severity. Univariate analysis showed that central venous catheter use, ventilator use, prior A. baumannii colonisation, and respiratory and cardiovascular organ failure were significantly associated with acquiring A. baumannii BSI in the ICU. By multivariate analysis, only prior A. baumannii colonisation [odds ratio (OR): 3.81; P < 0.001] and cardiovascular failure (OR: 2.24; P = 0.04) were identified as independent risk factors. The lower respiratory tract (32/77; 41.6%) was the most frequent source of infection, followed by intravascular catheters (13/77; 16.9%). Cumulative survival curves for patients with A. baumannii BSI and control patients showed no significant difference (30 day crude mortality: 29.9% and 27.3%, respectively; P = 0.916). However, the mean length of ICU and hospital stay and mean hospital cost of patients with A. baumannii BSI significantly increased, with an estimated 8.7 days excess length of ICU stay, 19.1 days excess hospital stay, and US $8480 extra hospital costs. Imipenem and meropenem remained the most active antimicrobial agents, both with 95.5% susceptibility (MIC₅₀ = 0.25 and 0.5, respectively). Improving hand hygiene of healthcare workers and aseptic care of vascular catheters and endotracheal tubes are important measures to prevent A. baumannii colonisation and decrease the incidence of BSI.     

Length of Hospital Stay and Survival of Hospitalized COVID-19 Patients During the Second Wave of the Pandemic: A Single Centre Retrospective Study from Slovenia

BackgroundAs of writing, there are no publications pertaining to the prediction of COVID-19-related outcomes and length of stay in patients from Slovene hospitals.ObjectivesTo evaluate the length of regular ward and ICU stays and assess the survival of COVID-19 patients to develop better prediction models to forecast hospital capacity and staffing demands in possible further pandemic peaks.MethodsIn this retrospective, single-site study we analysed the length of stay and survival of all patients, hospitalized due to the novel coronavirus (COVID-19) at the peak of the second wave, between November 18th 2020 and January 27th 2021 at the University Clinic Golnik, Slovenia.ResultsOut of 407 included patients, 59% were male. The median length of stay on regular wards was 7.5 (IQR 5–13) days, and the median ICU length of stay was 6 (IQR 4–11) days. Age, male sex, and ICU stay were significantly associated with a higher risk of death. The probability of dying in 21 days at the regular ward was 14.4% (95% CI [10.9–18%]) and at the ICU it was 43.6% (95% CI [19.3-51.8%]).ConclusionThe survival of COVID-19 is strongly affected by age, sex, and the fact that a patient had to be admitted to ICU, while the length of hospital bed occupancy is very similar across different demographic groups. Knowing the length of stay and admission rate to ICU is important for proper planning of resources during an epidemic.     

Effect of nosocomial vancomycin-resistant enterococcal bacteremia on mortality, length of stay, and costs.

OBJECTIVE: To determine the impact of vancomycin-resistant enterococcal bacteremia on patient outcomes and costs by assessing mortality, excess length of stay, and charges attributable to it. DESIGN: A population-based, matched, historical cohort study. SETTING: A 1,025-bed, university-based teaching facility and referral hospital. PATIENTS: Two hundred seventy-seven vancomycin-resistant enterococcal bacteremia case-patients and 277 matched control-patients identified between 1993 and 2000. RESULTS: The crude mortality rate was 50.2% and 19.9% for case-patients and control-patients, respectively, yielding a mortality rate of 30.3% attributable to vancomycin-resistant enterococcal bacteremia. The excess length of hospital stay attributable to vancomycin-resistant enterococcal bacteremia was 17 days, of which 12 days were spent in intensive care units. On average, dollars 77,558 in extra charges was attributable to each vancomycin-resistant enterococcal bacteremia. To adjust for severity of illness, 159 pairs of case-patients and control-patients, who had the same severity of illness (All Patient Refined-Diagnosis Related Group complexity level), were further analyzed. When patients were stratified by severity of illness, the crude mortality rate was 50.3% among case-patients compared with 27.7% among control-patients, accounting for an attributable mortality rate of 22.6%. Attributable excess length of stay and charges were 17 days and dollars 81,208, respectively. CONCLUSION: Vancomycin-resistant enterococcal bacteremia contributes significantly to excess mortality and economic loss, once severity of illness is considered. Efforts to prevent these infections will likely be cost-effective.     

Contribution of acquired meticillin-resistant Staphylococcus aureus bacteraemia to overall mortality in a general intensive care unit

During a period of 11 years, 77 patients had meticillin-resistant Staphylococcus aureus (MRSA) bacteraemia > or =5 days after admission to the intensive care unit (ICU). Ten had no prior growth of MRSA, 13 had positive screens on admission and 54 initially tested negative for MRSA in ICU before positive blood culture. These 54 constituted 20.2% [95% confidence interval (CI): 15.6-25.0] of 267 who acquired MRSA > or =5 days after admission. Mortality among 77 patients with MRSA bacteraemia was 57.1% (46.0-68.2). Nineteen of these 77 patients with MRSA bacteraemia had growth of a second pathogen from blood. Those with only MRSA bacteraemia were each matched with five controls by diagnosis and initial Acute Physiological and Chronic Health Evaluation II score. Mortality was greater in bacteraemic patients [53.6% (40.5-66.7)] than in controls [31.8% (26.3-37.3)] [relative risk (RR) 1.69 (1.25-2.26), P < 0.01], implying an additional absolute mortality of 21.8% (8.0-40.1). Application of this estimate to all 77 patients suggests that ICU-acquired MRSA bacteraemia caused 17 (6-31) deaths, adding 0.3% (0.1-0.6) to the 30.1% hospital mortality of all admissions. Incidence of MRSA bacteraemia increased with length of stay, contributing an estimated 3.1% (1.1-5.7) towards 37.9% mortality of the 198 patients remaining > or =25 days. These data emphasise the importance of preventing initial MRSA colonisation/infection of long-stay patients.     

Excess Mortality, Length of Stay, and Costs Associated with Serious Fungal Infections among Elderly Cancer Patients: Findings from Linked SEER-Medicare Data

OBJECTIVE: To calculate the excess mortality, length of stay, and costs attributable to serious fungal infections in hospitalized elderly patients with selected cancers. Methods: This study involved a retrospective cohort analysis using linked data from the Surveillance, Epidemiology and End Results Program of the National Cancer Institute (SEER) and Medicare claims data. Study cohorts included patients aged 65 years and older who newly received a diagnosis of a selected cancer (acute myeloid leukemia [AML] or squamous cell carcinoma of the head and neck [SCCHN]) in a SEER registry between 1991 and 1996 and who had a subsequent diagnosis of a serious fungal infection during an inpatient hospitalization, and hospitalized controls without a fungal infection matched 1:1 by age, geographic region, receipt of recent chemotherapy, concomitant bacterial infection, timing of the index hospitalization, and cancer stage at diagnosis (for SCCHN patients only). RESULTS: Eighty AML patients and 52 SCCHN patients experienced a serious fungal infection involving hospitalization. Relative to matched controls, SCCHN patients with fungal infections had significantly higher all-cause mortality (40% vs. 14%, P = 0.002), while mortality rates did not differ between AML cohorts. Patients with fungal infections had significantly longer index hospitalizations regardless of cancer type (mean: 30 days vs. 19 days for AML patients; 20 days vs. 9 days for SCCHN patients), and correspondingly higher Medicare payments (mean +/- SD: 34,268 dollars +/- 31,811 dollars vs. 21,416 dollars +/- 22,449 dollars among AML patients, P < 0.0001; 25,942 dollars +/- 29,122 dollars vs. 10,131 dollars +/- 10,686 dollars among SCCHN patients, P < 0.0001). CONCLUSIONS: Efforts to prevent these infections and/or initiate early treatment may yield both clinical and economic benefits.     

Hospital economic impact of an outbreak of Pseudomonas aeruginosa infections

A total of 67 patients involved in an outbreak of Pseudomonas aeruginosa in the intensive care unit (ICU) were retrospectively followed to determine whether case patients experienced differences in cost, length of stay and survival rates when compared with non-affected patients. The method of microcosting, a technique that involves detailed identification and measurement of all care items and services offered by the hospital, was used to identify attributable costs related to diagnostic procedures, pharmacy and ICU stay of each patient. Seventeen patients developed nosocomial P. aeruginosa infection. On average, these patients incurred adjusted hospital costs of euro 27,917, 66% higher than non-case patients (P=0.002). The extra length of ICU stay attributable to P. aeruginosa infection was 70 days (P=0.0001). In multiple linear regression analysis, we found that P. aeruginosa infection was an independent predictor of increased hospital costs and length of hospital stay. On the basis of these findings, a conservative estimate of the extra cost attributable to P. aeruginosa infection in our ICU was euro 312,936 (95% confidence interval: 305,676-320,196).     

Reduction in central line-associated bloodstream infections among patients in intensive care units--Pennsylvania, April 2001-March 2005

Each year, an estimated 250,000 cases of central line-associated (i.e., central venous catheter-associated) bloodstream infections (BSIs) occur in hospitals in the United States, with an estimated attributable mortality of 12%-25% for each infection. The marginal cost to the health-care system is approximately 25,000 dollars per episode. In 2001, CDC was invited by the Pittsburgh Regional Healthcare Initiative (PRHI) to provide technical assistance for a hospital-based intervention to prevent central line-associated BSIs among intensive care unit (ICU) patients in southwestern Pennsylvania. During a 4-year period, BSI rates among ICU patients declined 68%, from 4.31 to 1.36 per 1,000 central line days. The results suggest that a coordinated, multi-institutional infection-control initiative might be an effective approach to reducing health-care-associated infections.     

Gender and hospital resource use. Unexpected differences

Several recent studies have explored gender differences in medical care that are not attributable to clinical characteristics. At an 880-bed teaching hospital between July 1987 and June 1990, we studied the importance of gender on two measures of hospital care: length of stay and ancillary service use. The latter was measured on a relative value unit (RVU) scale, based on an estimation of direct cost dollars. Neither mean age nor in-hospital mortality differed between the 9,102 women and 10,285 men. After case-mix adjustment, women stayed in the hospital 0.22 days longer than men (p = 0.01) but consumed 67 fewer RVUs (p = 0.01). This RVU difference dissolved when intensive care unit (ICU) stays were eliminated; men were 1.13 times more likely (95% confidence interval 1.07 to 1.19) to be placed in the ICU. Being married shortened length of stay and women were less likely to be married (51% vs. 68%; p < 0.001), but even within marital status subgroups women remained in the hospital longer than men. Whether this longer length of stay and less technologically intensive care for women reflects a difference in illness severity or physician gender bias requires further study.     

Burden of community-onset bloodstream infection: a population-based assessment

Although community-onset bloodstream infection (BSI) is recognized to be a major cause of morbidity and mortality, there is a paucity of population-based studies defining its overall burden. We conducted population-based laboratory surveillance for all community-onset BSI in the Calgary Health Region during 2000-2004. A total of 4467 episodes of community-onset BSI were identified for an overall annual incidence of 81.6/100,000. The three species, Escherichia coli, Staphylococcus aureus, and Streptococcus pneumoniae were responsible for the majority of community-onset BSI; they occurred at annual rates of 25.8, 13.5, and 10.1/100,000, respectively. Overall 3445/4467 (77%) episodes resulted in hospital admission representing 0.7% of all admissions to major acute care hospitals. The subsequent hospital length of stay was a median of 9 (interquartile range, 5-15) days; the total days of acute hospitalization attributable to community-onset BSI was 51,146 days or 934 days/100,000 annually. Four hundred and sixty patients died in hospital for a case-fatality rate of 13%. Community-onset BSI is common and has a major patient and societal impact. These data support further efforts to reduce the burden of community-onset BSI.     

Quantifying excess length of postoperative stay attributable to infections: a comparison of methods

To quantify the net effect of deep surgical site infection (DSSI) on postoperative stay (POS) among patients who had undergone open heart surgery, and to assess the comparability of two methods, two observational studies were conducted: one on a retrospective cohort of 701 operated patients, and the other on a cohort of 31 infected patients versus a cohort of uninfected patients, with 1:1 matching. In addition to DSSI, a further three factors were identified by multivariate analysis as independent POS-related predictor variables. After internal validation of the multivariate model, excess POS attributable to DSSI amounted to 20.7 days (95% confidence interval [CI] 16.7–24.9). In contrast, excess length of stay attributable to DSSI among the matched pairs who survived infection (22) totaled 14.3 days (95% CI 3.2–25.4) and 26.5 days (mean and median differences). Multivariate techniques may prove a more appropriate and reliable analysis than matched-pair comparisons for the purpose of evaluating the extra stay and cost attributable to the nosocomial infections.     

Risk factors for and influence of bloodstream infections on mortality: a 1-year prospective study in a Greek intensive-care unit

To determine the incidence, risk factors for, and the influence of bloodstream infections (BSIs) on mortality of patients in intensive-care units (ICUs), prospectively collected data from all patients with a stay in an ICU >48 h, during a 1-year period, were analysed. Of 572 patients, 148 developed a total of 232 BSI episodes (incidence 16.3 episodes/1000 patient-days). Gram-negative organisms with high level of resistance to antibiotics were the most frequently isolated pathogens (157 strains, 67.8%). The severity of illness on admission, as estimated by APACHE II score (OR 1.07, 95% CI 1.04-1.1, P<0.001), the presence of acute respiratory distress syndrome (OR 3.57, 95% CI 1.92-6.64, P<0.001), and a history of diabetes mellitus (OR 2.37, 95% CI 1.36-4.11, P=0.002) were risk factors for the occurrence of BSI whereas the development of an ICU-acquired BSI was an independent risk factor for death (OR 1.76, 95% CI 1.11-2.78, P=0.015). Finally, the severity of organ dysfunction on the day of the first BSI episode, as estimated by SOFA score, and the level of serum albumin, independently affected the outcome (OR 1.44, 95% CI 1.22-1.7, P<0.001 and OR 0.47, 95% CI 0.23-0.97, P=0.04 respectively).     

Influence of matching for exposure time on estimates of attributable mortality caused by nosocomial bacteremia in critically ill patients.

OBJECTIVE: To evaluate the influence of matching on exposure time on estimates of attributable mortality of nosocomial bacteremia as assessed by matched cohort studies. DESIGN: Two retrospective, pairwise-matched (1:2) cohort studies. SETTING: A 54-bed intensive care unit (ICU) in a university hospital. PATIENTS: Patients with nosocomial Escherichia coli bacteremia (n = 68) and control-patients without nosocomial bacteremia (n = 136 for each matched cohort study). INTERVENTION: In both matched cohort studies, the same set of bacteremic patients was matched with control-patients using the APACHE II system. In the first study, control-patients were required to have an ICU stay at least as long as the respective bacteremic patient prior to onset of bacteremia (matching on exposure time). In the second study, control-patients were required to have an ICU stay shorter than the stay prior to the development of bacteremia in the respective bacteremic patient (no matching on exposure time). RESULTS: For bacteremic patients, the mean ICU stay before onset of the bacteremia was 9 days (median, 6 days). In the first matched cohort study, hospital mortality was not different between bacteremic patients and control-patients (44.1% vs 43.4%; P = .999). In the second study, mortality of bacteremic patients and control-patients was also not different (44.1% vs 47.8%; P = .657). Mortality rates between control groups were not different (43.4% vs 47.8%; P = .543). CONCLUSION: Matching or not matching on exposure time did not alter the estimate of attributable mortality for ICU patients with E. coli bacteremia.