Utility of the Chronic Disease Score and Charlson Comorbidity Index as comorbidity measures for use in epidemiologic studies of antibiotic-resistant organisms

Association between contact precautions and delirium at a tertiary care center

OBJECTIVE

To investigate the relationship between contact precautions and delirium among inpatients, adjusting for other factors.

DESIGN

Retrospective cohort study.

SETTING

A 662-bed tertiary care center.

PATIENTS

All nonpyschiatric adult patients admitted to a tertiary care center from 2007 through 2009.

METHODS

Generalized estimating equations were used to estimate the association between contact precautions and delirium in a retrospective cohort of 2 years of admissions to a tertiary care center.

RESULTS

During the 2-year period, 60,151 admissions occurred in 45,266 unique nonpsychiatric patients. After adjusting for comorbid conditions, age, sex, intensive care unit status, and length of hospitalization, contact precautions were significantly associated with delirium (as defined by International Classification of Diseases, Ninth Revision), medication, or restraint exposure (adjusted odds ratio [OR], 1.40 [95% confidence interval {CI}, 1.24-1.51]). The association between contact precautions and delirium was seen only in patients who were newly placed under contact precautions during the course of their stay (adjusted OR, 1.75 [95% CI, 1.60-1.92]; P < .01) and was not seen in patients who were already under contact precautions at admission (adjusted OR, 0.97 [95% CI, 0.86-1.09]; P = .06).

CONCLUSIONS

Although delirium was more common in patients who were newly placed under contact precautions during the course of their hospital admission, delirium was not associated with contact precautions started at hospital admission. Patients newly placed under contact precautions after admission but during hospitalization appear to be at a higher risk and may benefit from proven delirium-prevention strategies.

Prolactin levels independently predict major cardiovascular events in patients with erectile dysfunction

The physiological role of prolactin (PRL) in men is not completely clarified. We previously reported that in subjects consulting for sexual dysfunction, lower PRL plasma levels were associated with worse lipid and glycaemic profile, as well as with a higher prevalence of metabolic syndrome and arteriogenic erectile dysfunction (ED). The aim of this study was to assess possible associations between PRL levels and incident major cardiovascular events (MACE) in subjects with ED. When only subjects without pathological hyperprolactinaemia (PRL < 735 mU/L or 35 ng/mL) and pituitary diseases were considered, both unadjusted and adjusted analyses showed a significantly lower incidence of MACE in subjects with PRL levels in the highest PRL quintile (246-735 mU/L or 12-35 ng/mL) when compared with the rest of the sample. In particular, the risk of MACE was reduced by 5% (1-9%; p = 0.03) for each 10 ng/mL increment of PRL. Conversely, comparing patients with hyperprolactinaemia with matched controls, no significant difference was detected between cases and controls in MACE. In subjects at high risk for cardiovascular diseases, such as those with ED, a relatively high PRL plasma level is associated with an overall decreased chance of MACE, independently from other known risk factors.

Poor response to alprostadil ICI test is associated with arteriogenic erectile dysfunction and higher risk of major adverse cardiovascular events

INTRODUCTION

Intracavernous alprostadil injection (ICI) test has been considered useless in assessing the vascular status of subjects with erectile dysfunction (ED).

AIM

To analyze the clinical correlates of ICI test in patients with ED and to verify the value of this test in predicting major adverse cardiovascular events (MACE).

METHODS

A consecutive series of 2,396 men (mean age 55.9 ± 11.9 years) attending our outpatient clinic for sexual dysfunction was retrospectively studied. A subset of this sample (N = 1,687) was enrolled in a longitudinal study.

MAIN OUTCOME MEASURES

Several clinical, biochemical, and instrumental (penile color Doppler ultrasound; PCDU) factors were evaluated. All patients underwent an ICI test, and responses were recorded on a four-point scale ranging from 1 = no response to 4 = full erection.

RESULTS

Among the patients studied, 16.4%, 41.2%, 40.2% and 2.2% showed grade 4, 3, 2, and 1 ICI test response, respectively. After adjusting for confounders, subjects with grade 1 ICI test response showed reduced perceived sleep-related, masturbation-related, and sexual-related erections when compared with the rest of the sample. In addition, a worse response to ICI test was associated with a higher prevalence of hypogonadism-related symptoms and signs along with lower testosterone levels. The prevalence of both diabetes mellitus and metabolic syndrome was inversely related to ICI test response. Accordingly, dynamic and basal peak systolic velocity (PSV), as well as acceleration at PCDU, decreased as a function of ICI test response. In the longitudinal study, after adjusting for confounders, grade 1 response was independently associated with a higher incidence of MACE (hazard ratio = 2.745 [1.200-6.277]; P < 0.05). These data were confirmed even when only subjects with normal PSV (>25 cm/s) were considered.

CONCLUSIONS

Our results demonstrate that poor ICI test response is associated with several metabolic disturbances and higher incidence of MACE. We strongly recommend performing ICI test with alprostadil in all ED subjects.

Validity of ICD-9-CM coding for identifying incident methicillin-resistant Staphylococcus aureus (MRSA) infections: is MRSA infection coded as a chronic disease?

BACKGROUND AND OBJECTIVE

Investigators and medical decision makers frequently rely on administrative databases to assess methicillin-resistant Staphylococcus aureus (MRSA) infection rates and outcomes. The validity of this approach remains unclear. We sought to assess the validity of the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) code for infection with drug-resistant microorganisms (V09) for identifying culture-proven MRSA infection.

DESIGN

Retrospective cohort study.

METHODS

All adults admitted to 3 geographically distinct hospitals between January 1, 2001, and December 31, 2007, were assessed for presence of incident MRSA infection, defined as an MRSA-positive clinical culture obtained during the index hospitalization, and presence of the V09 ICD-9-CM code. The κ statistic was calculated to measure the agreement between presence of MRSA infection and assignment of the V09 code. Sensitivities, specificities, positive predictive values, and negative predictive values were calculated.

RESULTS

There were 466,819 patients discharged during the study period. Of the 4,506 discharged patients (1.0%) who had the V09 code assigned, 31% had an incident MRSA infection, 20% had prior history of MRSA colonization or infection but did not have an incident MRSA infection, and 49% had no record of MRSA infection during the index hospitalization or the previous hospitalization. The V09 code identified MRSA infection with a sensitivity of 24% (range, 21%-34%) and positive predictive value of 31% (range, 22%-53%). The agreement between assignment of the V09 code and presence of MRSA infection had a κ coefficient of 0.26 (95% confidence interval, 0.25-0.27).

CONCLUSIONS

In its current state, the ICD-9-CM code V09 is not an accurate predictor of MRSA infection and should not be used to measure rates of MRSA infection.

Presence of central nervous system, cardiovascular and overall co-morbidity burden in patients with overactive bladder disorder in a real-world setting

OBJECTIVE

•  To determine the proportion of patients with overactive bladder (OAB) potentially at risk for adverse events by assessing their pre-existing central nervous system (CNS), cardiovascular (CV) and other co-morbidities.

PATIENTS AND METHODS

•  The GE Centricity Electronic Medical Record database was utilized to identify patients with a diagnosis of OAB using International Classification of Diseases, Ninth Revision (ICD-9) codes or a prescription between 1 January 1996 and 30 March 2007 for an OAB anti-muscarinic agent. •  Matched non-OAB patients were assigned the same index date as the corresponding OAB patient. Based on the presence of ≥ one pharmacy claim for an OAB anti-muscarinic agent, the OAB cohort was stratified as treated or untreated. A random sample of age- and gender-matched patients formed a non-OAB control cohort. •  An additional and separate analysis focusing on all co-morbidities was performed examining non-OAB patients who were matched to OAB patients on 1:1 propensity score matching, based on age, body mass index (BMI) and gender at baseline. •  Charlson Comorbidity Index (CCI), using ICD-9 codes, and the Chronic Disease Score (CDS), using prescribed drugs, were calculated.

RESULTS

•  When compared with non-OAB patients (N= 77,272; 83.2% women; median age 64 years), OAB patients (N= 41,440; 83.6% women; median age 65 years) had more overall CNS co-morbidities (45.4 vs 29.0%; P < 0.001). •  In addition, OAB patients had a higher use of medications with anti-muscarinic effects (39.6 vs 25.4%; P < 0.001). OAB patients were also more likely to have CV co-morbidities (57.6 vs 44.6%; P < 0.001). •  CNS co-morbidities were slightly more common in untreated (n= 8 106) than in treated (n= 33 334) OAB patients (47.2 vs 45.0%; P < 0.001). CV co-morbidities were higher in treated OAB patients (58.8 vs 53.7%; P < 0.001). •  In the additional separate analysis, which focused on all co-morbidities, patients with OAB had higher mean CCI and CDS scores than patients without OAB (CCI: 1.17 vs 1.11 [P < 0.001]; CDS: 2.95 vs 1.74 [P < 0.001]). •  After controlling for other covariates, the linear regressions (n= 22,544) showed that OAB patients had higher CCI and CDS than patients without OAB.

CONCLUSIONS

•  Among OAB patients, CNS, CV and all co-morbidities were more prevalent than in non-OAB patients. •  Prior exposure to CNS medications was more prevalent in OAB patients who received anti-muscarinic treatment than in those who did not. •  Co-morbidities and concomitant medications affecting the CNS and the CV system should be taken into account when making the decision on the most appropriate OAB treatment option for each individual patient.

Do contact precautions cause depression? A two-year study at a tertiary care medical centre

Contact precautions, used to reduce the transmission of infectious diseases, include the wearing of gowns and gloves for room entry. Previous small studies have shown an association between contact precautions and increased symptoms of depression and anxiety. A retrospective cohort of all patients admitted to a tertiary care centre over two years was studied to assess the relationship between contact precautions and depression or anxiety. During the two-year period, there were 70,275 admissions including 28,564 unique non-intensive-care-unit (ICU), non-psychiatric admissions. After adjusting for potential confounders, contact precautions were associated with depression [odds ratio (OR) 1.4, 95% confidence interval (CI) 1.2-1.5] but not with anxiety (OR 0.8, 95% CI 0.7-1.1) in the non-ICU population. Depression was 40% more prevalent among general inpatients on contact precautions.

Body mass index regulates hypogonadism-associated CV risk: results from a cohort of subjects with erectile dysfunction

INTRODUCTION

Obesity is an independent cardiovascular (CV) risk factor. Testosterone (T) is inversely related to body mass index (BMI) in males. There is substantial evidence suggesting that low T could play a role as a moderator of CV mortality in men.

AIM

This study is designed to assess the possible interaction between T and obesity in predicting major CV events (MACE) in a sample of subjects with erectile dysfunction.

METHODS

A consecutive series of 1,687 patients were studied. Different clinical, biochemical, and instrumental parameters were evaluated. According to BMI, subjects were divided into normal weight (BMI = 18.5-24.9 kg/m(2) ), overweight (BMI = 25.0-29.9 kg/m(2) ), and obese (BMI ≥ 30.0 kg/m(2) ). Hypogonadism was defined as total T below 10.4 nmol/L. Information on MACE was obtained through the City of Florence Registry Office.

MAIN OUTCOME MEASURES

Information on MACE was obtained through the City of Florence Registry Office.

RESULTS

Among the patients studied, 39.8% had normal weight, whereas 44.1% and 16.1% were overweight and obese, respectively. Unadjusted analysis in the whole sample showed that while hypogonadism and obesity were significantly associated with an increased risk of MACE, their interaction term was associated with a protective effect. In a Cox regression model, adjusting for confounders, hypogonadism showed a significant increased risk of MACE in normal weight subjects, whereas it was associated with a reduced risk in obese patients.

CONCLUSIONS

Hypogonadism-associated CV risk depends on the characteristics of subjects, being more evident in normal weight than in obese patients. Further studies are advisable to clarify if low T in obese patients is a (positive) consequence of a comorbid condition (i.e., to save energy) or if it represents a pathogenetic issue of the same illness. Hence, possible misuse/abuse of T treatment in obese subjects must be avoided.

Assessment of Association of Increased Heart Rates to Cardiovascular Events among Healthy Subjects in the United States: Analysis of a Primary Care Electronic Medical Records Database

Objective. To determine whether increases in heart rates (HRs) over time leads to adverse cardiovascular (CV) events among “healthy subjects.” Methods. This retrospective cohort study used the GE Centricity EMR database. “Healthy subjects” were defined as those with Charlson Comorbidity Index (CCI) score = 0 and Chronic Disease Score (CDS) = 0 at baseline. Subjects were followed for 3 years post the first date of a clinical encounter between the patient and provider. Those aged ≥18 years old with baseline HR and ≥2 post-index HR readings were identified between 01/01/1996 to 03/30/2007. Results. There were 93,952 “healthy subjects” at baseline (median age 42 years; 67.2% women; mean HR was 75.8 (SD: 11) bpm); 20.7% with a mean HR at baseline of 76.3 (SD: 11.3) bpm (median age 45; 63 women) experienced a CV event during 3 years of follow-up. The mean HR was higher among those with a CV event (76.3 bmp) compared to those without a CV event (75.7 bpm). A Cox regression model indicated that an increase in HR by 5 bpm was associated with a 1% increase in CV event risk. Conclusions. Elevated HRs are associated with an increased likelihood of CV events among “healthy subjects”.

Emergence in Spain of a multidrug-resistant Enterobacter cloacae clinical isolate producing SFO-1 extended-spectrum beta-lactamase

Between February 2006 and October 2009, 38 patients in different wards at the A Coruña University Hospital (northwest Spain) were either infected with or colonized by an epidemic, multidrug-resistant (MDR), and extended-spectrum-β-lactamase (ESBL)-producing strain of Enterobacter cloacae (EbSF), which was susceptible only to carbapenems. Semiautomated repetitive extragenic palindromic sequence-based PCR (rep-PCR) and pulsed-field gel electrophoresis (PFGE) analysis revealed that all of the E. cloacae isolates belonged to the same clone. Cloning and sequencing enabled the detection of the SFO-1 ESBL in the epidemic strain and the description of its genetic environment. The presence of the ampR gene was detected upstream of bla(SFO-1), and two complete sequences of IS26 surrounding ampR and ampA were detected. These IS26 sequences are bordered by complete left and right inverted repeats (IRL and IRR, respectively), which suggested that they were functional. The whole segment flanked by two IS26 copies may be considered a putative large composite transposon. A gene coding for aminoglycoside acetyltransferase (gentamicin resistance gene [aac3]) was found downstream of the 3' IS26. Despite the implementation of strict infection control measures, strain EbSF spread through different areas of the hospital. A case-control study was performed to assess risk factors for EbSF acquisition. A multivariate analysis revealed that the prior administration of β-lactam antibiotics, chronic renal failure, tracheostomy, and prior hospitalization were statistically associated with SFO-1-producing E. cloacae acquisition. This study describes for the first time an outbreak in which an SFO-1-producing E. cloacae strain was involved. Note that so far, this β-lactamase has previously been isolated in only a single case of E. cloacae infection in Japan.

Increased mortality with accessory gene regulator (agr) dysfunction in Staphylococcus aureus among bacteremic patients

Accessory gene regulator (agr) dysfunction in Staphylococcus aureus has been associated with a longer duration of bacteremia. We aimed to assess the independent association between agr dysfunction in S. aureus bacteremia and 30-day in-hospital mortality. This retrospective cohort study included all adult inpatients with S. aureus bacteremia admitted between 1 January 2003 and 30 June 2007. Severity of illness prior to culture collection was measured using the modified acute physiology score (APS). agr dysfunction in S. aureus was identified semiquantitatively by using a δ-hemolysin production assay. Cox proportional hazard models were used to measure the association between agr dysfunction and 30-day in-hospital mortality, statistically adjusting for patient and pathogen characteristics. Among 814 patient admissions complicated by S. aureus bacteremia, 181 (22%) patients were infected with S. aureus isolates with agr dysfunction. Overall, 18% of patients with agr dysfunction in S. aureus died, compared to 12% of those with functional agr in S. aureus (P = 0.03). There was a trend toward higher mortality among patients with S. aureus with agr dysfunction (adjusted hazard ratio [HR], 1.34; 95% confidence interval [CI], 0.87 to 2.06). Among patients with the highest APS (scores of >28), agr dysfunction in S. aureus was significantly associated with mortality (adjusted HR, 1.82; 95% CI, 1.03 to 3.21). This is the first study to demonstrate an independent association between agr dysfunction and mortality among severely ill patients. The δ-hemolysin assay examining agr function may be a simple and inexpensive approach to predicting patient outcomes and potentially optimizing antibiotic therapy.

Prevalence and acquisition of MRSA amongst patients admitted to a tertiary-care hospital in Brazil

BACKGROUND

There are few studies in Brazil that address baseline prevalence of MRSA colonization and associated risk factors at hospital admission, or the incidence of nosocomial colonization. We report a prospective study in a tertiary-care, university-affiliated hospital to implement a new MRSA control policy at the institution.

METHODS

A cohort of randomly selected patients admitted to emergency and clinical wards at our hospital was followed until discharge. Nasal swabs were taken for identification of MRSA-colonized patients and detection of SCCmecA in positive cultures, at admission and weekly thereafter. Multivariate analysis using a log-binomial analysis was used to identify risk factors for colonization.

RESULTS

After screening 297 adult patients and 176 pediatric patients, the prevalence of MRSA at admission was 6.1% (95%CI, 3.6% to 9.4%), in the adult population and 2.3% (95%CI, 0.6% to 5.7%), for children. From multivariate analysis, the risk factors associated with colonization in adults were: age above 60 years (P = 0.019) and hospitalization in the previous year (P = 0.022). Incidence analysis was performed in 276 MRSA-negative patients (175 adults and 101 children). Acquisition rate was 5.5/1,000 patient-days for adults (95%CI, 3.4 to 8.5/1,000 patients-days), and 1.1/1,000 patient-days for children (95%CI, 0.1 to 4.0/1,000 patients-days).

CONCLUSIONS

The identification of MRSA carriers is a step towards establishing a control policy for MRSA, and helps to identify measures needed to reduce colonization pressure and to decrease the high acquisition rate in hospitalized patients.

Pulse pressure independently predicts major cardiovascular events in younger but not in older subjects with erectile dysfunction

INTRODUCTION

Pulse pressure (PP; i.e., the arithmetic difference between systolic and diastolic blood pressure) has been suggested to be an independent cardiovascular risk (CV) factor in the general population. We previously also reported a negative association between PP and arteriogenic erectile dysfunction (ED). This finding has recently been questioned.

AIM

To verify the association of PP with ED severity and to evaluate its role in predicting forthcoming CV events.

METHODS

This is an observational prospective cohort study evaluating a consecutive series of 1,687 patients attending our Andrological Unit for ED.

MAIN OUTCOME MEASURES

Several hormonal and biochemical parameters were studied, along with SIEDY structured interviews and penile Doppler ultrasound.

RESULTS

Subjects with PP in the lowest quartile (I: 20-45; II: 46-55; III: 56-62; IV: 63-115 mm Hg) had a significant reduction in the risk of severe ED (RR = 0.60[0.47-0.76]; P < 0.0001). When the same analysis was repeated as a function of age quartile (I = 17-44, II = 45-55, III = 56-62, and IV = 63-88 years old), after adjusting for testosterone levels, mean blood pressure, Chronic Disease Score, and body mass index, PP was inversely related to ED only in the youngest age group. During a mean follow up of 4.4 ± 2.6 years, 147 major cardiovascular events (MACE) were observed. In a Cox regression model, after adjusting for possible confounding factors, a lower PP was associated with a lower risk of MACE in the whole sample and in younger subjects, but not in the older ones.

CONCLUSIONS

Checking for blood pressure in ED subjects and calculating PP should become a routine practice in sexual medicine. In younger individuals, low PP reflects not only sexual health (better erection) but also cardiovascular health (less prevalence of MACE).

Priapus is happier with Venus than with Bacchus

INTRODUCTION

The relationship between alcohol consumption and erectile function is still not completely clarified.

AIM

Aims of the present study are to explore a number of biological and clinical correlates of alcohol consumption in a sample of men consulting for sexual dysfunction, and to verify possible associations with the incidence of major adverse cardiovascular events (MACEs).

METHODS

A consecutive series of 1956 (mean age 55 ± 11.9 years old) attending our outpatient clinic for sexual dysfunction was retrospectively studied. A subset of the previous sample (N = 1687) was enrolled in a longitudinal study.

MAIN OUTCOME MEASURES

Different clinical, biochemical, instrumental (penile Doppler ultrasound [PCDU]), and intrapsychic (Middlesex Hospital Questionnaire [MHQ]) were evaluated. We considered alcohol abuse more than three drinks per day.

RESULTS

Among the patients studied 81% reported no or mild (<4 drinks/day) alcohol consumption whereas 14.3% and 3.9% declared a moderate (4-6 drinks/day) or severe (>6 drinks/day) alcohol abuse, respectively. After adjustment for confounders, both moderate or severe alcohol abuse was associated with low perceived partner's sexual desire, worse couple relationship, and smoking abuse. Furthermore, moderate and severe alcohol abuse was associated with low prolactin and thyroid-stimulating hormone levels, as well as an increase in triglycerides and total cholesterol levels. Penile blood flow was reduced in moderate and severe alcohol drinkers even after adjustment for confounders. In the longitudinal study, after adjusting for confounding factors, any kind of alcohol abuse was independently associated with a higher incidence of MACE (hazard ratio = 2.043 [1.059-3.943]; P < 0.0001).

CONCLUSIONS

Our findings demonstrate that, in subjects consulting for erectile dysfunction, severe alcohol consumption is associated with a worse sexual function and a higher incidence of MACE.

Empiric antibiotic therapy for Staphylococcus aureus bacteremia may not reduce in-hospital mortality: a retrospective cohort study

Background

Appropriate empiric therapy, antibiotic therapy with in vitro activity to the infecting organism given prior to confirmed culture results, may improve Staphylococcus aureus outcomes. We aimed to measure the clinical impact of appropriate empiric antibiotic therapy on mortality, while statistically adjusting for comorbidities, severity of illness and presence of virulence factors in the infecting strain.

Methodology

We conducted a retrospective cohort study of adult patients admitted to a tertiary-care facility from January 1, 2003 to June 30, 2007, who had S. aureus bacteremia. Time to appropriate therapy was measured from blood culture collection to the receipt of antibiotics with in vitro activity to the infecting organism. Cox proportional hazard models were used to measure the association between receipt of appropriate empiric therapy and in-hospital mortality, statistically adjusting for patient and pathogen characteristics.

Principal Findings

Among 814 admissions, 537 (66%) received appropriate empiric therapy. Those who received appropriate empiric therapy had a higher hazard of 30-day in-hospital mortality (Hazard Ratio (HR): 1.52; 95% confidence interval (CI): 0.99, 2.34). A longer time to appropriate therapy was protective against mortality (HR: 0.79; 95% CI: 0.60, 1.03) except among the healthiest quartile of patients (HR: 1.44; 95% CI: 0.66, 3.15).

Conclusions/Significance

Appropriate empiric therapy was not associated with decreased mortality in patients with S. aureus bacteremia except in the least ill patients. Initial broad antibiotic selection may not be widely beneficial.

Is obesity a further cardiovascular risk factor in patients with erectile dysfunction?

INTRODUCTION

Erectile dysfunction (ED) and, in particular, arteriogenic ED have been proposed as new markers of risk for incident major adverse cardiovascular events (MACE). Reduced penile blood flow is more common in obese people than in leaner ED subjects.

AIM

To explore the interaction of overweight/obesity and penile blood flow in the prediction of incident MACE.

METHODS

This is an observational prospective cohort study evaluating a consecutive series of 1,687 patients attending our andrological unit for ED. Different clinical, biochemical, and instrumental (penile flow at color Doppler ultrasound: PCDU) parameters were evaluated.

MAIN OUTCOMES MEASURES

According to body mass index (BMI), subjects were divided into three groups: normal weight (BMI = 18.5-24.9 kg/m(2)), overweight (BMI = 25.0-29.9 kg/m(2)), and obese (BMI >or= 30.0 kg/m(2)). Information on MACE was obtained through the City of Florence Registry Office.

RESULTS

Among patients studied, 39.8% were normal weight, while 44.1% and 16.1% showed BMI 25-29.9 and 30 kg/m(2) or higher, respectively. During a mean follow-up of 4.3 +/- 2.6 years, 139 MACE, 15 of which were fatal, were observed. Cox regression model, after adjusting for age and Chronic Diseases Score, showed that obesity classes along with the presence of arteriogenic ED (peak systolic velocity at PCDU <25 cm/second) were significantly and independently associated with incident MACE (hazard ratio = 1.47 [1.1-1.95], P < 0.05 and 2.58 [1.28-5.09], P < 0.001, respectively). When a separate analysis was performed for classes of obesity, reduced peak systolic velocity at PCDU (<25 cm/second) was significantly associated with incident MACE in obese (BMI >or= 30 kg/m(2)), but not in leaner, subjects.

CONCLUSIONS

In obese subjects, more than in leaner ED subjects, impaired penile blood flow is associated with an increased risk of incident cardiovascular disease. The interaction with concomitant risk factors, such as obesity, should be taken into account when assessing the predictive value of penile blood flow for cardiovascular diseases.

Psychobiological correlates of women's sexual interest as perceived by patients with erectile dysfunction

INTRODUCTION

We have recently reported that the perceived loss of a partner's sexual desire is independently associated with an increased incidence of major cardiovascular events in patients with erectile dysfunction (ED). No study has ever evaluated the specific impact of men's perception of women's sexual desire on male sexual function and lifestyle attitudes in ED subjects.

AIM

To evaluate the clinical correlates of the perception of a partner's sexual desire [hypoactive sexual desire (HSD)] in a consecutive series of subjects seeking medical care for ED.

METHODS

A consecutive series of 2,303 heterosexual male patients (mean age 58.1 ± 10.5) was studied.

MAIN OUTCOME MEASURES

Patients were interviewed with the Structured Interview on Erectile Dysfunction (SIEDY) structured interview. They also completed the Middlesex Hospital Questionnaire, a brief questionnaire for the screening of the symptoms of mental disorders.

RESULTS

Among the patients studied, 458 (19.9%) reported a mild loss of their partner's desire, 302 (13.1%) a moderate reduction of libido, while 118 (5.1%) complained of a complete absence of sexual interest on the part of their partner. After adjustment for confounding factors, the perceived women's HSD was associated with different sexual, lifestyle, and relational factors. In particular, more extra-marital affairs, a longer and more hostile couple relationship, as well as a stressful job and both alcohol and smoking abuse were all significantly associated with perceived women's HSD. In addition, the perceived women's moderate to severe HSD was significantly associated with severe ED and less frequent sexual intercourse. Finally, partner HSD was significantly associated with a stepwise increase of free-floating anxiety and depressive symptoms (adj. r = 0.081, P < 0.05 and 0.158, P < 0.0001, respectively).

CONCLUSIONS

Perceived sexual interest (éros) on the part of the woman can be seen for men not only as a fun and enjoyable behavior, but also a safe strategy for improving a man's overall health and life expectancy.

Health costs in patients treated for depression, in patients with depressive symptoms treated for another chronic disorder, and in non-depressed patients: a two-year prospective cohort study in anthroposophic outpatient settings

We studied costs of healthcare and productivity loss in 487 German outpatients starting anthroposophic treatment: Group 1 was treated for depression, Group 2 had depressive symptoms but were treated for another chronic disorder, while Group 3 did not have depressive symptoms. Costs were adjusted for socio-demographics, comorbidity, and baseline health status. Total costs in groups 1-3 averaged euro7,129, euro4,371, and euro3,532 in the pre-study year (P = 0.008); euro6,029, euro3,522, and euro3,353 in the first year (P = 0.083); and euro4,929, euro3,792, and euro4,031 in the second year (P = 0.460). In the 2nd year, costs were significantly reduced in Group 1. This study underlines the importance of depression for health costs, and suggests that treatment of depression could be associated with long-term cost reductions.

Risks factors for infections with extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae at a tertiary care university hospital in Switzerland

BACKGROUND

There are considerable geographical differences in the occurrence of extended-spectrum beta-lactamase(ESBL)-producing bacteria, both in the community and in the hospital setting. Our aim was to assess risk factors for blood stream, urinary tract, and vascular catheter-associated infections with ESBL-producing Escherichia coli and Klebsiella pneumoniae at a tertiary care hospital in a low-prevalence country.

METHODS

We performed a case-control study comparing 58 patients with infections due to ESBL-producing E. coli orK. pneumoniae vs 116 controls with infections due to non-ESBL producing organisms at the University Hospital Zurich, Switzerland, between 1 July 2005 and 30 June 2007.

RESULTS

Cases included 15 outpatients and 43 inpatients. Multivariable analyses found three risk factors for ESBL-producing isolates: begin of symptoms or recent antibiotic pre-treatment in a foreign country (odds ratio [OR] 27.01,95% confidence interval [CI] 2.38-1,733.28], p = 0.042),antibiotic therapy within the year preceding the isolation of the ESBL-producing strain (OR 2.88, 95% CI 1.13-8.49,p = 0.025), and mechanical ventilation (OR 10.56, 95% CI 1.06-579.10, p = 0.042).

CONCLUSIONS

The major risk factors for infections due to ESBL-producing bacteria were travel in high-prevalence countries, prior antibiotic use, and mechanical ventilation during a stay in the intensive care unit. Community-acquired infections were documented in 17% of the patients.An early identification of risk factors is crucial to providing the patients an optimal empiric antibiotic therapy and to keep the use of carbapenems to a minimum.

Predictors of dropout from a multidisciplinary heart failure program: a nested case study

BACKGROUND

Chronic heart failure is a growing public health issue that is reaching epidemic proportions. In the last few years, multidisciplinary management programs have been developed to improve its management. Yet, some patients take advantage of these programs, whereas others do not.

METHODS

Several demographic, medical, and social variables were evaluated as contributors to dropout after enrollment into a multidisciplinary heart failure program using a nested case-control design. A total of 14 patients and 42 controls were interviewed using a standardized questionnaire. Possible associations were explored by means of chi Mantel-Haenszel test and a binary logistic regression model.

RESULTS

The only significant factor associated with dropout was social isolation. Patients who lived alone, without family support, had a significantly greater dropout risk (odds ratio, 12.5; 95% confidence interval, 1.35-11.6).

CONCLUSIONS

For patients who live alone, an individualized approach may be better than a multidisciplinary management program, but this hypothesis should be investigated in future studies.

Vancomycin and oritavancin have different modes of action in Enterococcus faecium

The increasing frequency of Enterococcus faecium isolates with multidrug resistance is a serious clinical problem given the severely limited number of therapeutic options available to treat these infections. Oritavancin is a promising new alternative in clinical development that has potent antimicrobial activity against both staphylococcal and enterococcal vancomycin-resistant pathogens. Using solid-state NMR to detect changes in the cell-wall structure and peptidoglycan precursors of whole cells after antibiotic-induced stress, we report that vancomycin and oritavancin have different modes of action in E. faecium. Our results show the accumulation of peptidoglycan precursors after vancomycin treatment, consistent with transglycosylase inhibition, but no measurable difference in cross-linking. In contrast, after oritavancin exposure, we did not observe the accumulation of peptidoglycan precursors. Instead, the number of cross-links is significantly reduced, showing that oritavancin primarily inhibits transpeptidation. We propose that the activity of oritavancin is the result of a secondary binding interaction with the E. faecium peptidoglycan. The hypothesis is supported by results from (13)C{(19)F} rotational-echo double-resonance (REDOR) experiments on whole cells enriched with l-[1-(13)C]lysine and complexed with desleucyl [(19)F]oritavancin. These experiments establish that an oritavancin derivative with a damaged d-Ala-d-Ala binding pocket still binds to E. faecium peptidoglycan. The (13)C{(19)F} REDOR dephasing maximum indicates that the secondary binding site of oritavancin is specific to nascent and template peptidoglycan. We conclude that the inhibition of transpeptidation by oritavancin in E. faecium is the result of the large number of secondary binding sites relative to the number of primary binding sites.

Controlling for severity of illness in outcome studies involving infectious diseases: impact of measurement at different time points

BACKGROUND

Severity of illness is an important confounder in outcome studies involving infectious diseases. However, it is unclear whether the time at which severity of illness is measured is important.

METHODS

We performed a retrospective study of 328 episodes of gram-negative bacteremia in adult patients to assess the impact of the time of measurement of severity of illness on the association between empirical antimicrobial therapy received and in-hospital mortality. Using a modified Acute Physiology Score (APS), severity of illness was measured at 2 time points: (1) hospital admission and (2) 24 hours before the first culture-positive blood sample was collected. Multivariate logistic regression was used to estimate the impact of adjusting for the APS on the relationship between empirical therapy received (ie, the exposure) and in-hospital mortality (ie, the outcome).

RESULTS

The mean APS (+/- standard deviation) of patients with bacteremia increased during their hospital stay (from 19.2 +/- 11.6 at admission to 24.2 +/- 13.6 at the second time point; P < .01). When examining the association between empirical antimicrobial therapy received and in-hospital mortality, and controlling for the APS, there was a trend toward a decreased impact of appropriate therapy received on in-hospital mortality. The unadjusted odds ratio (OR) for the association between appropriate therapy received and in-hospital mortality was 0.83 (95% confidence interval [CI], 0.51-1.34). After controlling for the APS at admission, this association was attenuated (OR, 0.94 [95% CI, 0.57-1.55]), and when a change in the APS was also included in the multivariate logistic regression model, the association was further attenuated (OR, 0.99 [95% CI, 0.58-1.69]).

CONCLUSIONS

The magnitude of the association between appropriate antimicrobial therapy received and in-hospital mortality among patients with gram-negative bacteremia was sensitive to the timing of adjustment for severity of illness.

Clinical and economic burden of antimicrobial resistance

Knowledge of the clinical and economic impact of antimicrobial resistance is useful to influence programs and behavior in healthcare facilities, to guide policy makers and funding agencies, to define the prognosis of individual patients and to stimulate interest in developing new antimicrobial agents and therapies. There are a variety of important issues that must be considered when designing or interpreting studies into the clinical and economic outcomes associated with antimicrobial resistance. One of the most misunderstood issues is how to measure cost appropriately. Although imperfect, existing data show that there is an association between antimicrobial resistance in Staphylococcus aureus, enterococci and Gram-negative bacilli and increases in mortality, morbidity, length of hospitalization and cost of healthcare. Patients with infections due to antimicrobial-resistant organisms have higher costs (US $6,000-30,000) than do patients with infections due to antimicrobial-susceptible organisms; the difference in cost is even greater when patients infected with antimicrobial-resistant organisms are compared with patients without infection. Given limited budgets, knowledge of the clinical and economic impact of antibiotic-resistant bacterial infections, coupled with the benefits of specific interventions targeted to reduce these infections, will allow for optimal control and improved patient safety. In this review, the authors discuss a variety of important issues that must be considered when designing or interpreting studies of the clinical and economic outcomes associated with antimicrobial resistance. Representative literature is reviewed regarding the associations between antimicrobial resistance in specific pathogens and adverse outcomes, including increased mortality, length of hospital stay and cost.

Delay in filling the initial prescription for a statin: a potential early indicator of medication nonpersistence

BACKGROUND

Identification of early predictors of medication nonpersistence may allow timely adherence-promoting interventions and potentially reduce the risk of negative health outcomes.

OBJECTIVE

This study was conducted to determine whether delay in filling an initial statin prescription predicts subsequent nonpersistence with medication.

METHODS

This observational study of a cohort of adult patients (>18 years) who newly initiated statin therapy between December 1997 and June 2000 employed data from the administrative claims database of a large US managed care organization. Patients initiating statin therapy had to have at least 18 months of continuous eligibility and no statin use in the 6-month period before the index prescription. A new measure, dispensation delay, was measured as the gap between the most recent physician or hospital visit and the fill date of the index prescription. Five categories of dispensation delay were created--no delay, 1 to 7 days, 8 to 30 days, 31 to 183 days, and >183 days. Nonpersistence was defined as a gap of >or=30 days in the statin prescription supply during the follow-up period. Cox proportional hazards regression was used to model the risk of the initial dispensation delay on the time to discontinuation, controlling for such variables as demographic characteristics, comorbidities, physician specialty, and previous health care utilization.

RESULTS

The final sample included 19,038 patients. Among all variables studied, the dispensation-delay variables were the most significant predictors of non-persistence, with a longer delay predicting a higher risk of early discontinuation. Patients with delays in filling the initial prescription of >30 days but <183 days were 30% more likely to discontinue therapy than those without delays (hazard ratio=1.30; 95% CI=1.20-1.40).

CONCLUSIONS

The delay in filling the first statin prescription significantly predicted future non-persistence. Use of this measure may allow early identification of patients at high risk for early discontinuation.

Impact of empiric antimicrobial therapy on outcomes in patients with Escherichia coli and Klebsiella pneumoniae bacteremia: a cohort study

BACKGROUND

It is unclear whether appropriate empiric antimicrobial therapy improves outcomes in patients with bacteremia due to Escherichia coli or Klebsiella. The objective of this study is to assess the impact of appropriate empiric antimicrobial therapy on in-hospital mortality and post-infection length of stay in patients with Escherichia coli or Klebsiella bacteremia while adjusting for important confounding variables.

METHODS

We performed a retrospective cohort study of adult patients with a positive blood culture for E. coli or Klebsiella between January 1, 2001 and June 8, 2005 and compared in-hospital mortality and post-infection length of stay between subjects who received appropriate and inappropriate empiric antimicrobial therapy. Empiric therapy was defined as the receipt of an antimicrobial agent between 8 hours before and 24 hours after the index blood culture was drawn and was considered appropriate if it included antimicrobials to which the specific isolate displayed in vitro susceptibility. Data were collected electronically and through chart review. Survival analysis was used to statistically assess the association between empiric antimicrobial therapy and outcome (mortality or length of stay). Multivariable Cox proportional hazards models were used to calculate hazard ratios (HR) and 95% confidence intervals (CI).

RESULTS

Among 416 episodes of bacteremia, 305 (73.3%) patients received appropriate empiric antimicrobial therapy. Seventy-one (17%) patients died before discharge from the hospital. The receipt of appropriate antimicrobial agents was more common in hospital survivors than in those who died (p = 0.04). After controlling for confounding variables, there was no association between the receipt of appropriate empiric antimicrobial therapy and in-hospital mortality (HR, 1.03; 95% CI, 0.60 to 1.78). The median post-infection length of stay was 7 days. The receipt of appropriate antimicrobial agents was not associated with shortened post-infection length of stay, even after controlling for confounding (HR, 1.11; 95% CI 0.86 to 1.44).

CONCLUSION

Appropriate empiric antimicrobial therapy for E. coli and Klebsiella bacteremia is not associated with lower in-hospital mortality or shortened post-infection length of stay. This suggests that the choice of empiric antimicrobial agents may not improve outcomes and also provides data to support a randomized trial to test the hypothesis that use (and overuse) of broad-spectrum antibiotics prior to the availability of culture results is not warranted.

The estimation power of alternative comorbidity indices

OBJECTIVE

Health-care expenditures are strongly influenced by overall illness burden. Appropriate risk adjustment is required for correct policy analysis. We compared three risk adjustment methods: the Charlson comorbidity index (CCI), the chronic disease score (CDS), and the Agency for Healthcare Research and Quality's comorbidity index (AHRQCI) in terms of their estimation power in analyzing health-care expenditures.

METHOD

Data from the Thomson MarketScan Research Databases (Thomson Healthcare, Ann Arbor, MI) were used to estimate total health-care expenditures of migraine patients treated by a triptan. Seven distinct multivariate models were evaluated for model fit (CCI only, CDS only, AHRQCI only, CCI + CDS, CCI + AHRQCI, CDS + AHRQCI, and CCI + CDS + AHRQCI). The estimation power of these indices (alone and in combination) was evaluated using Bayesian and Akaike information criteria, log-likelihood scores, and pseudo R(2) values.

RESULTS

Confirming results from previous studies, when comorbidity indices were considered individually the results were inconclusive. Statistically the best performance was observed in the model that included all three of the comorbidity measures (CCI + CDS + AHRQCI); however, the practical differences in the estimated values were small.

CONCLUSION

Low correlation between these comorbidity indices shows that it is possible to have potential risk factors that are not captured in the single comorbidity index. Each comorbidity measure considers different risks, and the collinearity of the three measures is not strong enough to preclude using them simultaneously in the same model.

Quality of colon cancer outcomes in hospitals with a high percentage of Medicaid patients

BACKGROUND

There is evidence that patients with Medicaid insurance suffer worse outcomes from surgical conditions; but there is little research about whether this reflects clustering of such patients at hospitals with worse outcomes. We assess the outcomes of patients with colon and rectal cancers at hospitals with a high proportion of Medicaid patients.

STUDY DESIGN

California Cancer Registry patient-level records were linked to discharge abstracts from California's Office of Statewide Health Planning and Development. All operative California Cancer Registry patients from 1998 and 1999 were included. Hospitals with > 40% Medicaid patients were labeled high Medicaid hospitals (HMH). We analyzed the odds of mortality at 30 days, 1, and 5 years for colon cancer and rectal cancer separately. Multilevel logistic regression models were constructed, using MLwiN 2.0, to include patient and hospital-level characteristics.

RESULTS

Thirty-day mortality after colon operation was worse in HMH (1% versus 0.6%; p = 0.04); as was 1-year mortality (3.4% versus 2.4%; p = 0.001). There was no substantial difference in rates of 5-year mortality. Individuals who were insured by Medicaid had worse outcomes at 5 years. Adjustment for surgical volume eliminated the effect of HMH at 30 days (1% versus 0.7%; p = 0.45) but not at 1 year (3.4% versus 2.5%; p = 0.01). Adjustment for academic affiliation did not alter these results. There were an insufficient number of rectal cancer patients to detect any differences by hospital type.

CONCLUSIONS

HMH have higher postoperative colon cancer mortality rates at 30 days and 1 year but not at 5 years. The early effect can be explained by surgical volume, but additional research is needed to determine which factors contribute to differences in intermediate outcomes after operations in HMH settings.

Raising standards while watching the bottom line: making a business case for infection control

While society would benefit from a reduced incidence of nosocomial infections, there is currently no direct reimbursement to hospitals for the purpose of infection control, which forces healthcare institutions to make economic decisions about funding infection control activities. Demonstrating value to administrators is an increasingly important function of the hospital epidemiologist because healthcare executives are faced with many demands and shrinking budgets. Aware of the difficulties that face local infection control programs, the Society for Healthcare Epidemiology of America (SHEA) Board of Directors appointed a task force to draft this evidence-based guideline to assist hospital epidemiologists in justifying and expanding their programs. In Part 1, we describe the basic steps needed to complete a business-case analysis for an individual institution. A case study based on a representative infection control intervention is provided. In Part 2, we review important basic economic concepts and describe approaches that can be used to assess the financial impact of infection prevention, surveillance, and control interventions, as well as the attributable costs of specific healthcare-associated infections. Both parts of the guideline aim to provide the hospital epidemiologist, infection control professional, administrator, and researcher with the tools necessary to complete a thorough business-case analysis and to undertake an outcome study of a nosocomial infection or an infection control intervention.

Tae Kwon Do: an effective exercise for improving balance and walking ability in older adults

BACKGROUND

Age-related declines in balance and walking ability are major risk factors for falls. Older adults reduce the dynamic components of walking in an effort to achieve a more stable walking pattern. Tae Kwon Do is an exercise that trains dynamic components of balance and walking that diminish with age.

METHODS

Twenty participants from a Tae Kwon Do exercise class (average age 72.7 years) and 20 nonexercising controls (average age 73.8 years) participated. Balance and walking ability for all participants were pretested and posttested using the following measures: single-leg stance (SLS), Multidirectional Reach Test (MDRT), Timed Up-and-Go (TUG), walking velocity, cadence, gait stability ratio (GSR), and sit-and-reach (S&R). Analysis of variance for a mixed design was used to assess differences at the 0.05 level of significance.

RESULTS

For nonexercising controls, no differences were found between pretest and posttest measures. Tae Kwon Do participants showed significant improvements on the MDRT when reaching backward, right, and left. TUG, walking velocity, GSR, and S&R also showed significant improvement in this exercising group.

CONCLUSIONS

Tae Kwon Do exercise was effective for improving balance and walking ability in community-dwelling older adults. These improvements were attributed to Tae Kwon Do movements that emphasize dynamic movement components typically deficient in the older adult walking pattern. Improving balance and walking ability through Tae Kwon Do exercise may serve to restore function that has declined with age and preserve mobility for older adults.

Value of performing active surveillance cultures on intensive care unit discharge for detection of methicillin-resistant Staphylococcus aureus

OBJECTIVE

To quantify the value of performing active surveillance cultures for detection of methicillin-resistant Staphylococcus aureus (MRSA) on intensive care unit (ICU) discharge.

DESIGN

Prospective cohort study.

SETTING

Medical ICU (MICU) and surgical ICU (SICU) of a tertiary care hospital.

PARTICIPANTS

We analyzed data on adult patients who were admitted to the MICU or SICU between January 17, 2001, and December 31, 2004. All participants had a length of ICU stay of at least 48 hours and had surveillance cultures of anterior nares specimens performed on ICU admission and discharge. Patients who had MRSA-positive clinical cultures in the ICU were excluded.

RESULTS

Of 2,918 eligible patients, 178 (6%) were colonized with MRSA on ICU admission, and 65 (2%) acquired MRSA in the ICU and were identified by results of discharge surveillance cultures. Patients with MRSA colonization confirmed by results of discharge cultures spent 853 days in non-ICU wards after ICU discharge, which represented 27% of the total number of MRSA colonization-days during hospitalization in non-ICU wards for patients discharged from the ICU.

CONCLUSIONS

Surveillance cultures of nares specimens collected at ICU discharge identified a large percentage of MRSA-colonized patients who would not have been identified on the basis of results of clinical cultures or admission surveillance cultures alone. Furthermore, these patients were responsible for a large percentage of the total number of MRSA colonization-days during hospitalization in non-ICU wards for patients discharged from the ICU.

Surveillance cultures and duration of carriage of multidrug-resistant Acinetobacter baumannii

Isolating carriers of multidrug-resistant (MDR) Acinetobacter baumannii is the main measure to prevent its spread. Identification of carriers accompanied by contact precautions is essential. We aimed to determine the appropriate surveillance sampling sites and the duration of carriage of MDR A. baumannii. We studied prospectively two groups of patients from whom MDR A. baumannii was previously isolated: (i) those with recent clinical isolation (<or=10 days) and (ii) those with remote clinical isolation (>or=6 months). Screening for carriage was conducted from six sites: nostrils, pharynx, skin, rectum, wounds, and endotracheal aspirates. Strains recovered concurrently from different sites were genotyped using pulsed-field gel electrophoresis. Twelve of 22 with recent clinical isolation of MDR A. baumannii had >or=1 positive screening culture, resulting in a sensitivity of 55% when six body sites were sampled. Sensitivities of single sites ranged from 13.5% to 29%. Among 30 patients with remote clinical isolation, screening cultures were positive in 5 (17%), with a mean duration of 17.5 months from the last clinical culture. Remote carriers had positive screening cultures from the skin and pharynx but not from nose, rectum, wounds, or endotracheal aspirates. Eleven strains from five patients were genotyped. In all but one case, isolates from different sites in a given patient were clonal. Current methodology is suboptimal to detect MDR A. baumannii carriage. The sensitivity of surveillance cultures is low, even when six different body sites are sampled. The proportion of individuals with previous MDR A. baumannii isolation who remain carriers for prolonged periods is substantial. These data should be considered when designing measures to limit the spread of MDR A. baumannii.

A checklist for medication compliance and persistence studies using retrospective databases

The increasing number of retrospective database studies related to medication compliance and persistence (C&P), and the inherent variability within each, has created a need for improvement in the quality and consistency of medication C&P research. This article stems from the International Society of Pharmacoeconomics and Outcomes Research (ISPOR) efforts to develop a checklist of items that should be either included, or at least considered, when a retrospective database analysis of medication compliance or persistence is undertaken. This consensus document outlines a systematic approach to designing or reviewing retrospective database studies of medication C&P. Included in this article are discussions on data sources, measures of C&P, results reporting, and even conflict of interests. If followed, this checklist should improve the consistency and quality of C&P analyses, which in turn will help providers and payers understand the impact of C&P on health outcomes.

Impact of empiric antibiotic therapy on outcomes in patients with Pseudomonas aeruginosa bacteremia

The impact of appropriate empirical antimicrobial therapy for Pseudomonas aeruginosa bacteremia on patient outcomes has not been clearly established. We assessed the effect of appropriate empirical therapy on in-hospital mortality and length of stay (LOS) among patients with P. aeruginosa bacteremia. This was a retrospective cohort study of inpatients with a positive blood culture for P. aeruginosa between January 2001 and June 2005. Empirical therapy was defined as appropriate if the patient received an antibiotic the organism was susceptible to between 8 h before culture collection and the time the susceptibility results were available. The severity of the illness was measured 24 h before culture collection. The data were analyzed using logistic regression (in-hospital mortality) and linear regression (LOS). Overall, there were 167 episodes of P. aeruginosa bacteremia, 123 (86%) of which received appropriate empirical antibiotics. Sixty-one patients died (36.5%). The median time from culture collection to susceptibility results was 3.4 days. After we adjusted for age, severity of illness, and time at risk, we found that the appropriate empirical therapy was not significantly associated with mortality (odds ratio = 0.96; 95% confidence interval = 0.31 to 2.93). There was a 7% reduction in the mean LOS for patients who had received appropriate therapy at the time susceptibility results were available compared to those who did not (P = 0.74). These data suggest that the use of appropriate empirical therapy, i.e., before susceptibility results are known may not be as critical to patient outcomes as other studies have suggested.

Comorbidity risk-adjustment measures were developed and validated for studies of antibiotic-resistant infections

OBJECTIVES

Comorbidities are often included in risk-factor models for nosocomial antibiotic-resistant bacterial infections, and aggregate comorbidity measures are valuable because they allow one variable to represent many. This study aimed to develop new aggregate comorbidity measures based upon the Chronic Disease Score (CDS) for assessing the comorbidity-attributable risk of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) nosocomial infections.

STUDY DESIGN AND SETTING

For each outcome, two retrospective cohort studies of hospitalized patients were conducted. Outcomes were a first MRSA or VRE positive clinical culture obtained 48 hours or more postadmission. Each cohort was divided into development (July 1998-2001) and validation (August 2001-2003) samples. New comorbidity measures were created for MRSA (CDS-MRSA), VRE (CDS-VRE), or any nosocomial infection outcome (CDS-ID) using logistic regression and subsequently validated. Model discrimination was measured using the c-statistic.

RESULTS

Discrimination of the CDS-MRSA (c=0.60), CDS-VRE (c=0.65), and CDS-ID (MRSA: c=0.57; VRE: c=0.64) was greater than that of the original CDS (MRSA: c=0.52; VRE: c=0.57).

CONCLUSION

The CDS-MRSA, CDS-VRE, and CDS-ID are new infectious disease specific comorbidity risk-adjustment measures that will be useful for the quality of future epidemiologic studies of MRSA, VRE, and other infectious diseases.

Clinical outcomes of bacteremic pneumococcal infections in an area with high resistance

In a retrospective study designed to gather information in a region with high antimicrobial resistance, the outcomes of 216 episodes of laboratory-confirmed pneumococcal bacteremia treated in Hong Kong between 1995 and 2001 were assessed. The patients had a mean age (+/-standard deviation) of 40+/-33.7 years. In all patients, the clinical diagnosis was confirmed by isolation of Streptococcus pneumoniae from blood (n=216), cerebrospinal fluid (n=7) and/or other sterile sites (n=12). Penicillin nonsusceptibility was found in 37.5% of the isolates (20.8% intermediate and 16.7% resistant). Penicillin nonsusceptibility was not a risk factor for inpatient mortality (p=0.7), nor did it affect duration of fever (p=0.4), requirement for intensive care unit admission (p=0.4) or development of suppurative complications (p=0.2). Advanced age (OR 11.3, 95%CI 4.5-28.2, p<0.01), critical illness (OR 11.3, 95%CI 4.5-28.2, p<0.001) and discordant therapy (OR 4.3, 95%CI 1.7-10.9, p<0.002) involving agents with poor anti-pneumococcal activity (but not penicillins and broad-spectrum beta-lactam agents) were significantly associated with mortality.

Methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci co-colonization

High prevalence of co-colonization increases risk for colonization or infection by vancomycin-resistant Staphylococcus aureus.

We assessed the prevalence, risk factors, and clinical outcomes of patients co-colonized with vancomycin-resistant enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) upon admission to the medical and surgical intensive care units (ICUs) of a tertiary-care facility between January 1, 2002, and December 31, 2003. Co-colonization was defined as a VRE-positive perirectal surveillance culture with an MRSA-positive anterior nares surveillance culture collected concurrently. Among 2,440 patients, 65 (2.7%) were co-colonized. Independent risk factors included age (odds ratio [OR] 1.03, 95% confidence interval [CI] 1.01–1.05), admission to the medical ICU (OR 4.38, 95% CI 2.46–7.81), male sex (OR 1.93, 95% CI 1.14–3.30), and receiving antimicrobial drugs on a previous admission within 1 year (OR 3.06, 95% CI 1.85–5.07). None of the co-colonized patients would have been identified with clinical cultures alone. We report a high prevalence of VRE/MRSA co-colonization upon admission to ICUs at a tertiary-care hospital.