Modifiable risk factors as predictors of all-cause mortality: the roles of genetics and childhood environment

The authors studied familial aggregation of mortality risk factors and their association with future deaths in the Finnish Twin Cohort. Cohort members (n = 15,904) aged 24-60 years and healthy at the end of 1981 who had responded to questionnaires in 1975 and 1981 were followed up for death through June 30, 2001. In individual-based analyses, the age- and sex-adjusted risk of death was higher among persons who were not participating in vigorous leisure physical activity in 1975 and 1981 than in those who were (p < 0.001), and risk was increased among smokers (p < 0.001) and heavy users of alcohol (p < 0.001). The study sample included data on both members of 3,551 dizygotic same-sex twin pairs and 1,772 monozygotic same-sex twin pairs. In pairwise analyses of discordant dizygotic pairs, risks of death were increased among co-twins who were not participating in vigorous activity (p = 0.05), co-twins who were smokers (p < 0.001), and co-twins who were heavy alcohol users (p < 0.001). Correspondingly, among monozygotic twin pairs, a difference in risk was seen only for smoking (p = 0.03). The authors conclude that, after adjustment for childhood environment, a low level of leisure physical activity, smoking, and heavy use of alcohol are associated with increased risks of death, but genetic selection may account for some of the association concerning physical activity and heavy use of alcohol.     

Staphylococcus aureus bacteremia in older adults: predictors of 7-day mortality and infection with a methicillin-resistant strain.

OBJECTIVES: To determine the predictors of 7-day mortality in older adult patients with Staphylococcus aureus bacteremia after controlling for comorbidity using the Charlson weighted index of comorbidity (WIC) and to identify the risk factors associated with bacteremia due to methicillin-resistant S. aureus (MRSA). DESIGN. Retrospective cohort study from January 2003 until December 2004. SETTING. Two tertiary care, university-affiliated hospitals. METHODS. One hundred thirty-five hospitalized patients with S. aureus bacteremia were included in the study. All patients who were 60 years or older and had 1 or more blood cultures positive for S. aureus were included in the study. The primary outcome was death 7 days after the onset of S. aureus bacteremia. RESULTS. Twenty-one patients (15.6%) died within 7 days after the onset of S. aureus bacteremia. Seventy-four patients (56.1%) had MRSA bacteremia. Multivariate analysis identified 3 independent determinants of 7-day mortality: Charlson WIC score greater than 5 (odds ratio [OR], 3.6 [95% confidence interval {CI}, 1.1-11.2]; P=.03), previous hospitalization in the past 3 months (OR, 5.0 [95% CI, 1.1-25.1]; P=.04), and altered mental status at the onset of S. aureus bacteremia (OR, 13.6 [95% CI, 2.9-64.6]; P=.001). Multivariate analysis identified previous hospitalization in the past 3 months (OR, 2.6 [95% CI, 1.1-5.9]; P=.02), residence in a long-term care facility (OR, 4.5 [95% CI, 1.7-12.3]; P=.003), and altered mental status at the onset of S. aureus bacteremia (OR, 2.5 [95% CI, 1.5-5.6]; P=.02) to be independently associated with the presence of MRSA. CONCLUSIONS: The Charlson WIC is significantly associated with increased mortality of S. aureus bacteremia in older adults. Previous hospitalization in the past 3 months, residence in a long-term care facility, and altered mental status should be used as a guidance for empirical vancomycin therapy and application of infection control measures in older adults with suspected S. aureus bacteremia.     

菌血症患者感染危险因素分析

目的探讨菌血症患者的相关危险因素,以降低菌血症的发生率。方法收集2012年12月-2013年8月菌血症患者174例,对其性别、基础疾病、科室、细菌种类、其他部位感染、是否进行中心静脉插管等资料进行回顾性分析,所有数据采用SPSS13.0软件进行统计分析。结果 174例菌血症患者的基础疾病主要为恶性血液病、实体肿瘤和淋巴瘤,分别占48.85%、20.69%和9.77%;居前5位的科室分别是移植科、血液科、消化道肿瘤区、淋巴头颈部肿瘤区、ICU,分别占35.63%、16.09%、10.34%、8.62%、6.90%;89例患者同时存在其他部位的感染,78例进行了中心静脉置管;在中心静脉置管的患者中16例同时进行了导管培养,送检率为20.51%,导管培养阳性12例,阳性率为75.00%;12例明确诊断为导管相关性血流感染;血标本及导管检出病原菌202株,大肠埃希菌居首位,占21.78%,所有标本共检出病原菌406株,血标本与所有标本分离细菌排序基本一致。结论恶性基础疾病、其他部位感染、中心静脉导管置入等为菌血症感染的高危因素,应加强对相关患者菌血症感染的预防与控制。     

Sociodemographic and psychosocial factors in childhood as predictors of adult mortality.

OBJECTIVES: Childhood sociodemographic, psychosocial, and environmental factors are often assumed to affect adult health and longevity. These relationships were prospectively tested by using the 7-decade Terman Life Cycle Study of Children With High Ability (n = 1285). METHODS: Parental socioeconomic status, childhood health, objective childhood stressors (e.g., death or divorce of parents), and childhood personality were considered as potential predictors in hazard regression analyses of longevity through 1991. RESULTS: Parental divorce during childhood predicted decreased longevity, with sex controlled. Other potential social predictors failed to show significant associations with longevity. Three dimensions of childhood personality--conscientiousness, lack of cheerfulness, and permanency of mood (males only)--predicted increased longevity. The effects of parental divorce and childhood personality were largely independent and did not account for any of the gender difference in mortality. CONCLUSIONS: A small number of childhood factors significantly predicted mortality across the life span in this sample. Further research should focus on how these psychosocial factors influence longevity.     

Protective factors and social risk factors for hospitalization and mortality among young men.

The association between presumed protective factors and social risk factors for hospitalization and mortality was studied during a 14-year follow-up period in a cohort of 8,168 Swedish men aged 18-20 years at baseline. Using Cox regression analysis, the authors found that five protective factors (high social class, home well-being, school well-being, good emotional control, and self-perceived good health) were associated with lower risks of hospitalization and death. Four social risk factors (contact with police or child welfare authorities, running away from home, having divorced parents, and ever using narcotics) were significantly associated with increased risk of hospitalization and mortality. The relative hazard decreased with the number of protective factors and increased with the number of social risk factors, almost linearly. The relative hazard was 0.24 for hospitalization among those with six protective factors and 0.24 for mortality for those with five or six protective factors. The relative hazard for hospitalization was 3.09 among those with five social risk factors compared with those with none, while for mortality the relative hazard among those with four or five social risk factors was 5.74 compared with those with none. While these results indicate strong cumulative effects for both the social risk factors and the protective factors, the associations of individual factors with the two outcome measures were generally reduced in models which simultaneously adjusted for all factors, which presumably indicates collinearity among the factors. There was only limited support for a buffering, or interacting, effect between the risk factors and the protective factors.     

Ventilator-associated pneumonia: risk factors and patient mortality

Among critically ill and mechanically ventilated patients, ventilator-associated pneumonia (VAP) is the most common nosocomial infection. Although VAP has a high mortality rate, it is unknown whether patients die from VAP or underlying illness. This article reviews the association between VAP and mortality, and discusses whether prevention of VAP will improve the outcome of mechanically ventilated patients.     

Comparison of mortality risk associated with bacteremia due to methicillin-resistant and methicillin-susceptible Staphylococcus aureus.

OBJECTIVE: To quantify the clinical impact of methicillin-resistance in Staphylococcus aureus causing infection complicated by bacteremia in adult patients, while controlling for the severity of patients' underlying illnesses. DESIGN: Retrospective cohort study from October 1, 1995, through December 31, 2003. PATIENTS AND SETTING: A total of 438 patients with S. aureus infection complicated by bacteremia from a single Veterans Affairs healthcare system. RESULTS: We found that 193 (44%) of the 438 patients had methicillin-resistant S. aureus (MRSA) infection and 114 (26%) died of causes attributable to S. aureus infection within 90 days after the infection was identified. Patients with MRSA infection had a higher mortality risk, compared with patients with methicillin-susceptible S. aureus (MSSA) infections (relative risk, 1.7 [95% confidence interval, 1.3-2.4]; P<.01), except for patients with pneumonia (relative risk, 0.7 [95% confidence interval, 0.4-1.3]). Patients with MRSA infections were significantly older (P<.01), had more underlying diseases (P=.02), and were more likely to have severe sepsis in response to their infection (P<.01) compared with patients with MSSA bacteremia. Patients who died within 90 days after S. aureus infection was identified were significantly older (P<.01) and more likely to have severe sepsis (P<.01) and pneumonia (P=.01), compared with patients who survived. After adjusting for age as a confounder, comorbidities, and pneumonia as an effect modifier, S. aureus infection-related mortality remained significantly higher in patients with MRSA infection than in those with MSSA infection, among those without pneumonia (hazard ratio, 1.8 [95% confidence interval, 1.2-3.0]); P<.01. CONCLUSIONS: The results of this study suggest that patients with MRSA infections other than pneumonia have a higher mortality risk than patients with MSSA infections other than pneumonia, independent of the severity of patients' underlying illnesses.     

Neonatal bacteremia: patterns of antibiotic resistance.

OBJECTIVE: To determine the incidence and evaluate the antimicrobial-susceptibility patterns of bacterial infections in our neonatal units. DESIGN: Retrospective surveillance study. SETTING: The neonatal units of the Hadassah University Hospitals, Jerusalem, Israel. PATIENTS: All newborns admitted from January 1994 through February 1999. METHODS: The records of all patients with positive blood and cerebrospinal fluid cultures were reviewed. Bacteremia was considered early-onset (vertical) when occurring within the first 72 hours of life and late-onset (nosocomial) when occurring later. The prevalence and antibiotic-resistance patterns of vertically transmitted and nosocomially acquired strains were compared and studied over time. RESULTS: 219 of 35,691 newborn infants had at least one episode of bacteremia (6.13/1,000 live births). There were 305 identified organisms, of which 21% (1.29/1,000 live births) were considered vertically transmitted and 79% nosocomially acquired. The most common organism causing early-onset disease (29.2%) was group B streptococcus (0.38/1,000 live births), whereas coagulase-negative staphylococci (51%) were the most prevalent in late-onset disease. All gram-positive bacteria were susceptible to vancomycin. Most gram-positive organisms other than staphylococci were susceptible to ampicillin. Gram-negative organisms represented 31% of all isolates. Generally, there was a trend of increasing resistance to commonly used antibiotics among nosocomially acquired gram-negative organisms, compared to those vertically transmitted, with statistically significant differences for ampicillin and mezlocillin (P<.05 and P<.01, respectively). Over the years, a trend toward an increasing resistance to antibiotics was observed among gram-negative organisms. CONCLUSIONS: The trend of increasing bacterial resistance to commonly used antibiotics necessitates the implementation of a rational empirical treatment strategy, based on local susceptibility data, reserving certain agents for emerging resistant pathogens.     

Colonization and bacteremia risk factors in parenteral nutrition catheterization

AIMS: 1) To establish the relationship between the kind of microorganism that colonizes parenteral nutrition catheters and several risk factors related to catheterization and patient characteristics. 2) To investigate the risk factors associated to bacteremia episodes originated in these colonized catheters. METHOD: An observational, non-controlled, retrospective and cohorts study of the parenteral nutrition catheters implanted between 1988 and 1994 in our hospital. Risk factors were studied in 6 multiple-logistic regression models. RESULTS: 3632 catheters were studied. Incidences of colonization and bacteremia per 1000 days of catheterization were 17.56 and 3.93, respectively. Coagulase-negative staphyloccoci (CNS) were the most frequently isolated microorganisms. The colonization risk factors were: insertion site for all the microorganisms except fungi, catheterization time for CNS and fungi, hospitalization area, sex and age for CNS model, the existence of other infectious foci for Gram negative bacilli (GNB), S. aureus and other microorganisms, hypoalbuminemia for GNB model, and neoplasm for other microorganisms. The bacteremia risk factors were jugular insertion site, catheterization time greater than 10 days, catheter's hub colonization, and catheter colonization by gram-negative bacilli, fungi and S. aureus. CONCLUSION: Risk factors for catheter colonization vary depending on the microorganism which colonizes the catheter.     

Attributable mortality of nosocomial Acinetobacter bacteremia.

OBJECTIVE: To determine the attributable mortality and outcome of nosocomial Acinetobacter bacteremia. DESIGN: Matched, retrospective cohort study. SETTING: Large, university-based, tertiary care center. PATIENTS: Of 219 patients with nosocomial Acinetobacter bacteremia identified by prospective surveillance during a 3-year period, 52 met the criteria for the study and were matched to a control patient by age, sex, primary and secondary diagnosis, operative procedures, and date of admission. RESULTS: A 100% success rate was achieved in the proportion of case patients and control patients matched for the compared criteria, except for major operative procedures (88%) and the presence of an important secondary underlying disease (54.5%). Twenty-nine (55.7%) of the case patients died, compared with 10 (19.2%) of the control patients (P<.001). The attributable mortality was 36.5% (95% CI, 27%-46%) and the risk ratio for death was 2.9 (95% CI, 1.58-5.32). In a multivariate survival analysis, older age, mechanical ventilation, renal failure, and Acinetobacter bacteremia (hazard ratio [HR], 4.41; 95% confidence interval [CI], 1.97-9.87; P<.001) were found to be independent predictors of mortality. There was a trend for a longer median duration of hospitalization among case patients, compared with control patients (11.5 vs. 6.5 days; P=.06). Three isolates were resistant to all but 1 antibiotic tested (colistin), and 45 isolates (86.5%) were resistant to 4 or more different antibiotic classes. CONCLUSIONS: When adjusted for risk-exposure time and severity of disease at admission, nosocomial Acinetobacter bacteremia is associated with mortality in excess of that caused by the underlying diseases alone.     

医院败血症相关危险因素及耐药性分析

目的探讨医院败血症的危险因素,减少医源性因素所致败血症风险。方法收集2006年1月至2009年12月期间在本院住院的菌血症患者资料。根据医院感染的定义将这些患者分为医院败血症组（83例）和社区获得性败血症组（119例）,对2组临床资料进行统计,对筛选出的可能危险因素进行多因素logistic回归分析。结果与社区获得性败血症相比较,医院败血症患者患恶性肿瘤的比例较高（21／83VS12／119,x2：8．2846,P〈0．01）,使用静脉留置导管比例高（28／83VS3／119,）（。=36．67,P〈0．01）,接受手术者比例高（37／83VS0／119,x2=68．226,P〈0．01）,既往使用抗生素比例较高（78／83VS10／119,x2=173．5657,P〈0．01）。多因素logistic回归分析示：伴有糖尿病者（P〈0．001,OR=4．821）、患恶性肿瘤者（P〈0．05,OR=3．186）、有静脉留置导管者（P〈0．05,OR=2．135）及既往不当抗生素治疗者（P〈0．05,OR=2．135）更易患医院败血症。且医院败血症感染细菌耐药率更高。结论医院内败血症严重威胁人类健康,糖尿病、恶性肿瘤、静脉留置导管及抗生素不当使用是相关危险因素。且医院内败血症感染细菌更具耐药性。     

Prediction model to identify patients with Staphylococcus aureus bacteremia at risk for methicillin resistance.

OBJECTIVES: To identify institution-specific risk factors for MRSA bacteremia and develop an objective mechanism to estimate the probability of methicillin resistance in a given patient with Staphylococcus aureus bacteremia (SAB). DESIGN: A cohort study was performed to identify institution-specific risk factors for MRSA. Logistic regression was used to model the likelihood of MRSA. A stepwise approach was employed to derive a parsimonious model. The MRSA prediction tool was developed from the final model. SETTING: A 279-bed, level 1 trauma center. PATIENTS: Between January 1, 1999, and June 30, 2001, 494 patients with clinically significant episodes of SAB were identified. RESULTS: The MRSA rate was 45.5%. Of 18 characteristics included in the logistic regression, the only independent features for MRSA were prior antibiotic exposure (OR, 9.2; CI95, 4.8 to 17.9), hospital onset (OR, 3.0; CI95, 1.9 to 4.9), history of hospitalization (OR, 2.5; CI95, 1.5 to 3.8), and presence of decubitus ulcers (OR, 2.5; CI95, 1.2 to 4.9). The prediction tool was derived from the final model, which was shown to accurately reflect the actual MRSA distribution in the cohort. CONCLUSION: Through multivariate modeling techniques, we were able to identify the most important determinants of MRSA at our institution and develop a tool to predict the probability of methicillin resistance in a patient with SAB. This knowledge can be used to guide empiric antibiotic selection. In the era of antibiotic resistance, such tools are essential to prevent indiscriminate antibiotic use and preserve the longevity of current antimicrobials.     

Prevalence and predictors of multiple behavioral risk factors for colon cancer

OBJECTIVES: This paper examines the prevalence of behavioral risk factors for colorectal cancer (CRC) (e.g., red meat consumption, fruit and vegetable intake, multivitamin intake, alcohol, smoking, and physical inactivity), co-occurrence among these behaviors, and motivation for change among patients at increased risk. METHODS: The study sample included 1,247 patients with recent diagnosis of adenomatous colorectal polyps. Within 4 weeks following the polypectomy, participants completed a baseline survey by telephone. RESULTS: Sixty-six percent of participants had not been diagnosed with polyps before. Fifty-eight percent of the sample had red meat as a risk factor, 63% had fruit and vegetable consumption as a risk factor, 54% did not take a daily multivitamin, and 44% had physical activity as a risk factor. In contrast, only 9% of the sample had alcohol consumption as a risk factor and only 14% were current smokers. The prevalence of the six individual risk factors was combined into an overall multiple risk factor score (MRF). The average number of risk factors was 2.43. Men, those with a high school education or below, those reporting fair or poor health status, and those with less self-efficacy about risk factor change had more risk factors. CONCLUSIONS: There is a need for multiple risk factor interventions that capitalize on natural intersections among intra- and interpersonal factors that maintain them.     

Enterobacteriaceae bacteremia: Risk factors for ESBLPE

Objectives

The increasing prevalence of extended spectrum beta-lactamase producing enterobacteriaceae (ESBLPE) requires defining the use of carbapenems in first intention. We analyzed the associations between enterobacteriaceae bacteremia (EbBact) and ESBLPE carriage during 10 years in a 950-bed teaching hospital.

Methods

We analyzed a 10-year (July 2001 to June 2011) prospective collection of bacteremia cases including 2 databases: (1) EbBact and (2) a computerized database of patients carrying EBLSE. Only one episode of EbBact was analyzed per patient and hospital stay. Factors associated with ESBLPE bacteremia were assessed by univariate and multivariate logistic regression analysis.

Results

Overall, 2355 cases of EbBact were identified, among which 135 (5.7%) were ESBLPE (2001–05: 1.4%, 2006–09: 7.6%, 2010–11: 14.2%). ESBLPE bacteremia was observed in 52 of the 88 (59%) patients carrying ESBLPE and in 83/2267 (3.7%) patients not known to be colonized with ESBLPE. Factors associated with ESBLPE bacteremia in patients not known to be colonized were: female gender (ORa = 0.56, CI95% [0.34–0.91]), hospitalization in the ICU (ORa = 2.51 [1.27–5.05]) or medical/surgical wards (ORa = 1.83 [1.04–3.38]), the period (2006–09, ORa = 4.08 [2.21–8.16]; 2010–11, ORa = 8.17 [4.14–17.06] compared to 2001–05), and history of EbBact (ORa = 2.29 [0.97–4.79]).

Conclusion

In case of EbBact, patients known to be colonized with ESBLPE present with ESBLPE bacteremia in more than half of the cases, requiring carbapenems as empirical antibiotic treatment. The global prevalence of ESBLPE among patients presenting with EbBact not known to be colonized with ESBLPE was 3.7%.     

Healthcare-associated Staphylococcus aureus bacteremia and the risk for methicillin resistance: is the Centers for Disease Control and Prevention definition for community-acquired bacteremia still appropriate?

OBJECTIVE: To evaluate a new classification for bloodstream infections that differentiates hospital acquired, healthcare associated, and community acquired in patients with blood cultures positive for Staphylococcus aureus. DESIGN: Prospective, observational study. SETTING: Three tertiary-care, university-affiliated hospitals in Dublin, Ireland, and Strasbourg, France. PATIENTS: Two hundred thirty consecutive patients older than 18 years with blood cultures positive for S. aureus. METHODS: S. aureus bacteremia (SAB) was defined as hospital acquired if the first positive blood culture was performed more than 48 hours after admission. Other SABs were classified as healthcare associated or community acquired according to the definition proposed by Friedman et al. When available, strains of methicillin-resistant Staphylococcus aureus (MRSA) were analyzed by pulsed-field gel electrophoresis (PFGE). RESULTS: Eighty-two patients were considered as having community-acquired bacteremia according to the Centers for Disease Control and Prevention (CDC) classification. Of these 82 patients, 56% (46) had healthcare-associated SAB. MRSA prevalence was similar in patients with hospital-acquired and healthcare-associated SAB (41% vs 33%; P > .05), but significantly lower in the group with community-acquired SAB (11%; P < .03). PFGE of MRSA strains showed that most community-acquired and healthcare-associated MRSA strains were similar to hospital-acquired MRSA strains. On multivariate analysis, Friedman's classification was more effective than the CDC classification for predicting MRSA. CONCLUSION: These results support the call for a new classification for community-acquired bacteremia that would account for healthcare received outside the hospital by patients with SAB.     

High vancomycin MIC and complicated methicillin-susceptible Staphylococcus aureus bacteremia

We conducted a retrospective study of 99 patients with methicillin-suseptible Staphylococcus aureus catheter-related bacteremia in which vancomycin MIC was determined by Etest. High vancomycin MIC (>1.5 ug/mL) was the only independent risk factor for development of complicated bacteremia caused by methicillin-susceptible S. aureus (odds ratio 22.9, 95% confidence interval 6.7-78.1).