Biomedical subjects

Warren B Bilker

Publications and source records attributed to Warren B Bilker.

At least 37 records · Page 2Linked to original sources

PubMed2006

Effectiveness of a two-part educational intervention to improve hypertension control: a cluster-randomized trial.

STUDY OBJECTIVE: To measure the effectiveness of a multifaceted educational intervention to improve ambulatory hypertension control. DESIGN: Cluster-randomized trial. SETTING: Academic health system using an ambulatory electronic medical record. SUBJECTS: A total of 10,696 patients with a diagnosis of hypertension cared for by 93 primary care providers. INTERVENTION: Academic detailing, provision of provider-specific data about hypertension control, provision of educational materials to the provider, and provision of educational and motivational materials to patients. MEASUREMENTS AND MAIN RESULTS: The primary outcome was blood pressure control, defined as a blood pressure measurement below 140/90 mm Hg, and was ascertained from electronic medical records over 6 months of follow-up. We determined the adjusted odds ratio for the association between the intervention and the achievement of controlled blood pressure. When we accounted for clustering by provider, this adjusted odds ratio was 1.13 (95% confidence interval 0.87-1.47). Adjusted odds ratios were 1.03 (95% confidence interval 0.78-1.36) in patients whose blood pressure was controlled at baseline and 1.25 (95% confidence interval 0.94-1.65) in those whose blood pressure was not. These odds ratios were not significantly different (p=0.11). CONCLUSIONS: These results were consistent with no effect or, at best, a relatively modest effect of the intervention among patients with hypertension. Had we not included a concurrent control group, the data would have provided an unduly optimistic view of the effectiveness of the program. The effectiveness of future interventions may be improved by focusing on patients whose blood pressure is uncontrolled at baseline.

Antihypertensive Agents↗

PubMed2005

Association between fluoroquinolone resistance and mortality in Escherichia coli and Klebsiella pneumoniae infections: the role of inadequate empirical antimicrobial therapy.

BACKGROUND: The prevalence of fluoroquinolone (FQ) resistance among Escherichia coli and Klebsiella pneumoniae has increased markedly in recent years. However, the impact of FQ resistance on mortality remains unknown. METHODS: To identify the association between FQ resistance and mortality, we conducted a retrospective cohort study of hospitalized patients with infections due to FQ-resistant strains and FQ-susceptible strains of E. coli and K. pneumoniae between 1 January 1998 and 30 June 1999. RESULTS: Of 123 patients with FQ-resistant infection, 16 (13.0%) died, compared with 4 (5.7%) of 70 patients with FQ-susceptible infection (odds ratio [OR], 2.47; 95% confidence interval [CI], 0.75-10.53). After adjustment for other significant risk factors and confounders, there remained an independent association between FQ-resistant infection and mortality (adjusted OR, 4.41; 95% CI, 1.03-18.81). Patients with FQ-resistant infection were significantly less likely to have received antimicrobial therapy with activity against the infecting pathogen within the first 24 h and 48 h of infection (P=.002 and P<.001, respectively). The association between FQ resistance and mortality was no longer significant, after adjusting for inadequate empirical therapy. CONCLUSIONS: FQ resistance is an independent risk factor for mortality in patients with health care-acquired E. coli and K. pneumoniae infections. This may be explained, at least in part, by a delay in the initiation of appropriate antimicrobial therapy in patients with FQ-resistant infection. These results highlight the grave clinical consequences of FQ resistance and emphasize the importance of efforts designed to curb the increase in the prevalence of resistance to these agents.

Adult↗

PubMed2005

Impact of inadequate initial antimicrobial therapy on mortality in infections due to extended-spectrum beta-lactamase-producing enterobacteriaceae: variability by site of infection.

BACKGROUND: Infections due to extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella species (ESBL-EK) have increased markedly in recent years. Risk factors for mortality among ESBL-EK infections have not been studied. METHODS: This retrospective cohort study was conducted in a 625-bed tertiary care medical center and a 344-bed urban community hospital to determine whether inadequate initial antimicrobial therapy (IIAT) (>48 hours between the time a culture was obtained and initiation of an agent to which the infecting organism was susceptible) is associated with mortality in ESBL-EK infections. All hospitalized patients with an ESBL-EK infection between June 1, 1997, and December 31, 2002, were eligible for inclusion. Subsequently, we conducted a nested case-control study to identify risk factors for IIAT. RESULTS: Of 187 subjects, 32 (17.1%) died while in the hospital. Clinical site of infection was a significant effect modifier in the association between IIAT and mortality. The presence of IIAT was an independent risk factor for mortality, but only for nonurinary ESBL-EK infections (adjusted odds ratio [95% confidence interval], 10.04 [1.90-52.96]). Independent risk factors for IIAT were (1) infection with a multidrug-resistant ESBL-EK (ie, resistant to sulfamethoxazole-trimethoprim, aminoglycosides, and quinolones) (14.58 [1.91-111.36]) and (2) health care-acquired ESBL-EK infection (4.32 [1.49-12.54]). CONCLUSIONS: Inadequate initial antimicrobial therapy is an independent risk factor for mortality in ESBL-EK infections, but only among nonurinary infections. Multidrug resistance was a strong risk factor for IIAT.

Aged↗

PubMed2005

Risk factors for increasing multidrug resistance among extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella species.

BACKGROUND: The importance of infections due to extended-spectrum beta -lactamase-producing Escherichia coli and Klebsiella species (ESBL-EK) has been increasingly recognized in recent years. ESBL-EK infections are of clinical concern, because few antimicrobials are available as therapeutic options. Increased reliance on carbapenems has led to increasing carbapenem resistance. Efforts to maintain current therapeutic options for ESBL-EK infections are essential. METHODS: We conducted a case-control study to identify risk factors for multidrug resistance (MDR) among ESBL-EK. All patients at our institution who had an inpatient clinical culture result positive for an ESBL-EK during the period of 1 June 1997 through 31 December 2002 were eligible for inclusion. An MDR ESBL-EK was defined as ESBL-EK demonstrating resistance to trimethoprim-sulfamethoxazole, aminoglycosides, and quinolones. All available ESBL-EK isolates were characterized by pulsed-field gel electrophoresis (PFGE). RESULTS: Of 361 total ESBL-EK isolates, 68 (18.8%) were MDR. During the study period, the prevalence of MDR among ESBL-EK isolates increased from 12.5% to 26.9%. The only independent risk factor for MDR ESBL-EK was the infecting organism (i.e., Klebsiella pneumoniae; adjusted odds ratio, 11.7; 95% confidence interval, 4.77-28.51; P < .001). Prior antibiotic use was not independently associated with MDR ESBL-EK. PFGE patterns from K. pneumoniae isolates indicated close genetic relatedness among a substantial proportion of isolates. CONCLUSIONS: The emergence of MDR among ESBL-EK has important implications for the future ability to treat these infections. The strong association between the species of infecting organism and MDR suggests that the epidemiology in K. pneumoniae may be unique. PFGE results suggest that horizontal spread is important in the emergence of MDR ESBL-EK.

Adolescent↗

PubMed2005

Telling truth from lie in individual subjects with fast event-related fMRI.

Deception is a clinically important behavior with poorly understood neurobiological correlates. Published functional MRI (fMRI) data on the brain activity during deception indicates that, on a multisubject group level, lie is distinguished from truth by increased prefrontal and parietal activity. These findings are theoretically important; however, their applied value will be determined by the accuracy of the discrimination between single deceptive and truthful responses in individual subjects. This study presents the first quantitative estimate of the accuracy of fMRI in conjunction with a formal forced-choice paradigm in detecting deception in individual subjects. We used a paradigm balancing the salience of the target cues to elicit deceptive and truthful responses and determined the accuracy of this model in the classification of single lie and truth events. The relative salience of the task cues affected the net activation associated with lie in the superior medial and inferolateral prefrontal cortices. Lie was discriminated from truth on a single-event level with an accuracy of 78%, while the predictive ability expressed as the area under the curve (AUC) of the receiver operator characteristic curve (ROC) was 85%. Our findings confirm that fMRI, in conjunction with a carefully controlled query procedure, could be used to detect deception in individual subjects. Salience of the task cues is a potential confounding factor in the fMRI pattern attributed to deception in forced choice deception paradigms.

Adolescent↗

PubMed2005

Antidepressant studies in Parkinson's disease: a review and meta-analysis.

The objective of this study was to determine effect sizes for both antidepressant treatment and placebo for depression in Parkinson's disease (PD), and to compare the findings with those reported in elderly depressed patients without PD. Recent reviews have concluded that there is little empiric evidence to support the use of antidepressants in PD; however, available data has not been analyzed to determine the effect size for antidepressant treatment in PD depression. A literature review identified antidepressant studies in PD. Suitable studies were analyzed using meta-analytic techniques, and effect sizes were compared with those from antidepressant studies in elderly patients without PD. Large effect sizes were found for both active treatment and placebo in PD, but there was no difference between the two groups. In contrast, active treatment was superior to placebo in depressed elderly patients without PD. In PD, increasing age and a diagnosis of major depression were associated with better treatment response. Results also suggest that newer antidepressants are well tolerated in PD. Despite the high prevalence of depression and antidepressant use in PD, controlled treatment research has been almost nonexistent. Meta-analysis results suggest a large but nonspecific effect for depression treatment in PD. In addition, PD patients may benefit less from antidepressant treatment, particularly selective serotonin reuptake inhibitors, than do elderly patients without PD.

Antidepressive Agents↗

PubMed2005

The relationship between time since registration and measured incidence rates in the General Practice Research Database.

BACKGROUND: The General Practice Research Database (GPRD) is widely used to study incidence rates. This study examines whether incidence rates are overestimated during the first year after registration, how long one needs to wait to obtain accurate incidence rates, and whether the time period of overestimation differs among disease types. METHODS: We measured incidence rates of nine acute, eight chronic, and eight neoplastic outcomes in 3-month intervals through month 36 after enrollment in GPRD. The incidence rates in months 13-36 were used to estimate baseline incidence rates for each diagnosis. RESULTS: For patients registering with practices that were already UTS, incidence rates were highest in the first 3 months after registration. In eight of nine acute diagnoses, the incidence rate was within 20% of baseline by months 4-6; and in seven of eight cancers, the incidence rate was within 20% of baseline by months 7-9. For chronic conditions, the incidence rate in months 10-12 differed from baseline by more than 20% for five of the eight outcomes, respectively. For patients registering prior to UTS, incidence rates during the first quarter were within 20% of baseline for all acute and cancer diagnoses and six of eight chronic diagnoses. CONCLUSIONS: Reported incidence rates are highest in the first 3 months after registration with an UTS practice and decline to baseline over the first year, more quickly for acute conditions than chronic conditions. For patients who registered prior to UTS, incidence rates are near the baseline level at the start of follow-up.

Cohort Studies↗

PubMed2005

Antibiotic use and the risk of flare of inflammatory bowel disease.

BACKGROUND & AIMS: Intestinal microbial flora participate in the pathogenesis of inflammatory bowel disease. Because antibiotic therapy alters intestinal microbial flora, we hypothesized that use of antibiotics might decrease the risk of flare. METHODS: We conducted a case-crossover study by using the General Practice Research Database from 1989-1997. Flares of disease were identified by receipt of a new prescription for either corticosteroids or mesalamine medications after an interval of at least 4 months without prescriptions for either class of medication. The primary exposure was receipt of any antibiotics in the 60 days preceding the index date. RESULTS: Among 1205 patients with Crohn's disease, exposure to antibiotics was associated with a reduced risk of flare (adjusted odds ratio [OR], 0.78; 95% confidence interval [CI], 0.64-0.96; P = .019). The effect was strongest with more recent exposure (test for trend, P < .05). Among 2230 patients with ulcerative colitis, use of any antibiotics within 60 days was not associated with flare of disease (adjusted OR, 0.96; 95% CI, 0.82-1.12; P = .581), although a potentially protective effect was observed in those patients with very recent exposure (exposure within 15 days: OR, 0.66; 95% CI, 0.51-0.85). CONCLUSIONS: Antibiotic use within 60 days was associated with a lower risk of flare of Crohn's disease, but not ulcerative colitis. The strength of the protective effect of antibiotics in Crohn's disease wanes over time.

Adrenal Cortex Hormones↗

PubMed2005

Longitudinal trends in antimicrobial susceptibilities across long-term-care facilities: emergence of fluoroquinolone resistance.

BACKGROUND: Antibiotic resistance in the longterm-care facility (LTCF) setting is of increasing concern due to both the increased morbidity and mortality related to infections in this debilitated population and the potential for transfer of resistant organisms to other healthcare settings. Longitudinal trends in antibiotic resistance in LTCFs have not been well described. DESIGN: Correlational longitudinal survey study. SETTING: Four LTCFs in Pennsylvania. SUBJECTS: All clinical cultures of residents of the participating LTCFs (700 total beds) from 1998 through 2003. We assessed the annual prevalence of resistance to various antimicrobials of interest for the following organisms: Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Staphylococcus aureus, and enterococcus species. RESULTS: A total of 4,954 clinical isolates were obtained during the study. A high prevalence of antimicrobial resistance was noted for many organism-drug combinations. This was especially true for fluoroquinolone susceptibility among the Enterobacteriaceae (susceptibility range, 51.3% to 92.2%). In addition, the prevalence of resistance to various agents differed significantly across study sites. Finally, significant increasing trends in resistance were noted over time and were most pronounced for fluoroquinolone susceptibility among the Enterobacteriaceae. CONCLUSIONS: The prevalence of antimicrobial resistance has increased significantly in LTCFs, although trends have varied substantially across different institutions. These trends have been particularly pronounced for fluoroquinolone resistance among the Enterobacteriaceae. These findings demonstrate that antimicrobial resistance is widespread and increasing in LTCFs, highlighting the need for future studies to more clearly elucidate the risk factors for, and potential interventions against, emerging resistance in these settings.

Aged↗

PubMed2005

Staphylococcus aureus as a risk factor for bloodstream infection in children with postoperative mediastinitis.

Bloodstream infection (BSI) complicates postoperative mediastinitis in >50% of cases. In this retrospective cohort study from 1995-2003, postoperative mediastinitis caused by Staphylococcus aureus was an independent risk factor for the development of BSI (adjusted odds ratio, 6.4; 95% confidence interval, 1.4-29.3). Postoperative mediastinitis caused by S. aureus has a higher intrinsic risk of being complicated by BSI than mediastinitis caused by other pathogens.

Adolescent↗

PubMed2005

Embryo culture does not affect the longevity of offspring in mice.

The oldest assisted reproductive technologies (ART)-conceived child is only 27 years old. Thus, the effects of ART on longevity are unknown, and it will be many years before this can be assessed in humans. We recently reported that culturing preimplantation mouse embryos under suboptimal conditions results in differences in how the offspring perform in behavioral assays that reflect anxiety (elevated zero maze) and spatial memory (Morris hidden water maze; Ecker et al. 2004). Here we monitored the mice generated in our previous study and found no difference in their longevity.

Aging↗

PubMed2005

Risk factors for and outcomes of bloodstream infection caused by extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella species in children.

OBJECTIVE: The increasing prevalence of infections caused by extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella species (ESBL-EK) has become a growing concern in the hospitalized patient population. Previous studies on risk factors for infection with ESBL-EK have mainly focused on adult populations, and these findings may not be relevant among the pediatric population that experiences a unique set of health care exposures and underlying conditions. The objective of this study was to define the risk factors and outcomes associated with ESBL-EK bloodstream infections in children. METHODS: We conducted a nested case-control study using data from the Children's Hospital of Philadelphia from May 1, 1999, to September 30, 2003. Eligible patients were identified from the hospital database of microbiology laboratory records. All patients with ESBL-EK bloodstream infections were compared to a random sample of patients with non-ESBL-EK bloodstream infections. Risk factors analyzed included prior antimicrobial use, comorbid conditions, and demographic characteristics. Pulsed-field gel electrophoresis was performed to determine genetic relatedness of the ESBL-EK isolates. RESULTS: Thirty-five cases and 105 control subjects were included in the study. The median age among the cases was 2 years (interquartile range: 0-11), compared with 1 year (interquartile range: 0-8) among control subjects. Patients with ESBL-EK infections were 5.8 times (95% confidence interval: 1.9-17.7) more likely to have had exposure to an extended-spectrum cephalosporin in the 30 days before infection than those with non-ESBL-EK infections. Other independent predictors of ESBL-EK infection were being female, infection with a Klebsiella species, and steroid use in the 30 days before infection. All ESBL-EK isolates were susceptible to carbapenem antibiotics. Pulsed-field gel electrophoresis analysis revealed that the ESBL-EK isolates were polyclonal. Although a substantially higher proportion of children with ESBL-EK died (in-hospital mortality: 36% vs 13%), this difference was not statistically significant. CONCLUSIONS: Receipt of extended-spectrum cephalosporins in the 30 days before infection by an Escherichia coli or Klebsiella species is significantly associated with having an ESBL-EK infection in hospitalized children. Curtailed use of cephalosporins among high-risk groups may reduce the occurrence of ESBL-EK infections. Future studies on identifying high-risk children and investigating the impact of curtailed third-generation cephalosporin use to limit additional emergence of ESBL-EK infections should be undertaken.

Analysis of Variance↗

PubMed2004

Differences in facial expressions of four universal emotions.

The facial action coding system (FACS) was used to examine recognition rates in 105 healthy young men and women who viewed 128 facial expressions of posed and evoked happy, sad, angry and fearful emotions in color photographs balanced for gender and ethnicity of poser. Categorical analyses determined the specificity of individual action units for each emotion. Relationships between recognition rates for different emotions and action units were evaluated using a logistic regression model. Each emotion could be identified by a group of action units, characteristic to the emotion and distinct from other emotions. Characteristic happy expressions comprised raised inner eyebrows, tightened lower eyelid, raised cheeks, upper lip raised and lip corners turned upward. Recognition of happy faces was associated with cheek raise, lid tightening and outer brow raise. Characteristic sad expressions comprised furrowed eyebrow, opened mouth with upper lip being raised, lip corners stretched and turned down, and chin pulled up. Only brow lower and chin raise were associated with sad recognition. Characteristic anger expressions comprised lowered eyebrows, eyes wide open with tightened lower lid, lips exposing teeth and stretched lip corners. Recognition of angry faces was associated with lowered eyebrows, upper lid raise and lower lip depression. Characteristic fear expressions comprised eyes wide open, furrowed and raised eyebrows and stretched mouth. Recognition of fearful faces was most highly associated with upper lip raise and nostril dilation, although both occurred infrequently, and with inner brow raise and widened eyes. Comparisons are made with previous studies that used different facial stimuli.

Adolescent↗

PubMed2004

Symptom and demographic profiles in first-episode schizophrenia.

First-episode schizophrenia (FE-SZP) presents a diagnostic challenge because of symptomatic overlap between the various causes of psychosis. An early and accurate diagnosis is important for the implementation of appropriate treatment, for determining prognosis and for identifying research participants. In an effort to facilitate early diagnosis, we followed a group of first-episode psychosis patients with a presumptive diagnosis of schizophrenia who were subsequently diagnosed at 6-month follow-up with either schizophrenia (n=104) or other psychiatric diagnoses (n=19). The two groups-first-episode schizophrenia and first-episode non-schizophrenia-were compared on measures of demographics, symptoms, quality of life, premorbid adjustment and lateral dominance. Odds ratios were calculated for each variable and all significant variables were entered into a multivariate prediction model. The model showed that higher levels of anhedonia and hallucinations increased the odds of a final diagnosis of schizophrenia. This predictive model was validated in a smaller group of patients.

Adolescent↗

PubMed2004

A sexually dimorphic ratio of orbitofrontal to amygdala volume is altered in schizophrenia.

BACKGROUND: Neuroanatomic sexual dimorphisms have been correlated with behavioral differences between healthy men and women. We have reported higher orbitofrontal cortex to amygdala ratio (OAR) in women than men. Although gender differences in schizophrenia are evident clinically and correlate with neuroanatomic measures, their relationship to OAR has not been examined. METHODS: Magnetic resonance imaging was performed in 31 neuroleptic-naïve schizophrenic patients (16 men) and 80 healthy volunteers (34 men), aged less than 50 years. An automated tissue segmentation procedure was combined with expert-guided parcellation of orbitofrontal and amygdala volumes. RESULTS: Men with schizophrenia had increased OAR relative to healthy men, whereas women had decreased OAR. Increased OAR in men with schizophrenia reflected abnormally low amygdala volumes, whereas decreased OAR in women reflected abnormally low orbitofrontal volumes. Less severe negative symptoms were associated with increased OAR in men but with decreased OAR in women. In men, increased amygdala volume was associated with greater symptom severity, whereas in women higher volumes of both amygdala and orbitofrontal regions were associated with lesser severity of negative symptoms. CONCLUSIONS: These opposite OAR abnormalities, whereby men show feminization and women masculinization, suggest gender-mediated effects of the underlying neuropathologic processes. The correlations with symptom severity suggest that neuroanatomic abnormalities in OAR reflect compensatory brain changes.

Adult↗

PubMed2004

Longitudinal trends in fluoroquinolone resistance among Enterobacteriaceae isolates from inpatients and outpatients, 1989-2000: differences in the emergence and epidemiology of resistance across organisms.

We conducted a 12-year study to identify and compare trends in annual prevalence of fluoroquinolone (FQ) resistance among Enterobacteriaceae isolates obtained from inpatients and outpatients in our health care system. A total of 46,070 clinical Enterobacteriaceae isolates underwent susceptibility testing. Although there were significant increases in inpatient FQ resistance for all Enterobacteriaceae, FQ resistance trends differed significantly across Enterobacteriaceae (P<.001). For isolates obtained from outpatients, only Escherichia coli and Proteus mirabilis demonstrated significant increases in FQ resistance (P<.001 for each). Trends in outpatient FQ resistance also differed significantly across Enterobacteriaceae (P<.001). There were significant differences between inpatient and outpatient FQ resistance trends for all Enterobacteriaceae except P. mirabilis and Enterobacter cloacae. Although hospital-wide use of certain antibiotics correlated significantly with inpatient FQ resistance, these correlations differed substantially across organisms. Efforts to elucidate the epidemiology of FQ resistance and identify targets for intervention must recognize and account for the variability of FQ resistance across organisms and clinical settings.

Anti-Infective Agents↗

PubMed2004

Long-term effects of culture of preimplantation mouse embryos on behavior.

Many procedures used in assisted reproductive technologies (ART) to treat human infertility entail culture of preimplantation embryos. Moreover, there is an increasing trend to culture embryos for longer periods of time before uterine transfer to identify the "best" embryos for transfer and to minimize multiple pregnancies. Embryo culture, however, can perturb embryo metabolism and gene expression, and the long-term consequences of culture are unknown. We have explored the behavioral consequences of embryo culture by using a 129S6/SvEvTac/C57BL/6J F(1) mouse model and find that adults derived from cultured embryos exhibit specific behavioral alterations in the elevated zero maze and Morris water maze tasks.

Animals↗

PubMed2004

Quality of care indicators for gout management.

OBJECTIVE: Despite the significant health impact of gout, there is no consensus on management standards. To guide physician practice, we sought to develop quality of care indicators for gout management. METHODS: A systematic literature review of gout therapy was performed using the Medline database. Two abstractors independently reviewed each of the articles for relevance and satisfaction of minimal inclusion criteria. Based on the review of the literature, 11 preliminary quality indicators were developed and then reviewed and refined by an initial feasibility panel of community and academic rheumatologists. A twelfth indicator was added at the request of the first panel. Using a modification of the RAND/University of California at Los Angeles appropriateness method (bridging teleconference and white-board Internet technology were added), a second expert panel rated each of the proposed indicators for validity using a 9-point scale, in which ratings of 1-3, 4-6, and 7-9 were considered "invalid," "indeterminate," and "highly valid," respectively. Indicators were considered valid if the median panel rating was > or =7 and there was no evidence of panel disagreement (defined to occur when 2 of 6 panelists provided a validity rating of 1-3 and 2 panelists provided a validity rating of 7-9). RESULTS: Ten of the 12 draft indicators were rated to be valid by our second expert panel. Validated indicators pertained to 1) the use of urate-lowering medications in chronic gout, 2) the use of antiinflammatory drugs, and 3) counseling on lifestyle modifications. CONCLUSION: Using a combination of evidence and expert opinion, 10 indicators for quality of gout care were developed. These indicators represent an important initial step in quality improvement initiatives for gout care.

Gout↗