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Warren B Bilker

Publications and source records attributed to Warren B Bilker.

67 records · Page 4Linked to original sources

Prevalence of erectile dysfunction and active depression: an analytic cross-sectional study of general medical patients.

Erectile dysfunction is a common problem, affecting more than half of all men between the ages of 40 and 70 years. The authors' goal was to quantify the prevalence of concomitant erectile dysfunction and active depression among patients seen in a general medical setting between September 1998 and September 1999. Simple random sampling techniques were used to select a subset of 334 patients from 73 general medical practices affiliated with an academic tertiary referral center in Pennsylvania. Of the 334 patients sampled, the authors received responses from 268 subjects (80.2%) and completed questionnaires from 199 subjects (59.6%) with a mean age of 59 years. The survey instrument consisted of three major sections: demographic and health history information, the Center for Epidemiologic Studies Depression (CES-D) Scale, and the five-item version of the International Index of Erectile Function Scale. The prevalence of moderate or complete erectile dysfunction in this sample was 36.4% (95% confidence interval (CI): 29.6, 43.1). The prevalence of current depression by CES-D Scale criteria was 12.1% (95% CI: 7.5, 16.7), and the prevalence of concomitant erectile dysfunction and depression was 5.1% (95% CI: 2.0, 8.1). Using logistic regression, the authors found that current depressive symptoms were not associated with moderate or complete erectile dysfunction (odds ratio = 1.3, 95% CI: 0.5, 3.1; p = 0.565). Concomitant erectile dysfunction and depression represent a significant public health problem.

Adult↗

Risk factors for fluoroquinolone resistance in nosocomial Escherichia coli and Klebsiella pneumoniae infections.

BACKGROUND: The incidence of fluoroquinolone (FQ) resistance has increased markedly in recent years. Even in the common nosocomial pathogens Escherichia coli and Klebsiella pneumoniae, in which the emergence of FQ resistance was believed to be unlikely, increasing resistance to these agents has been noted. Risk factors for FQ resistance in these pathogens remain unknown. Although FQs are important components of the present antimicrobial arsenal, their continued usefulness is threatened by rising FQ resistance. OBJECTIVE: To identify risk factors for nosocomial FQ resistance. METHODS: A case-control study of hospitalized patients with infections due to FQ-resistant and FQ-susceptible E coli and K pneumoniae occurring between January 1, 1998, and June 30, 1999. RESULTS: We included 123 patients with nosocomial FQ-resistant infections and 70 randomly selected patients with nosocomial FQ-susceptible infections. Independent risk factors (adjusted odds ratio [95% confidence interval]) for FQ resistance were (1) recent FQ use (5.25 [1.81-15.26]); (2) residence in a long-term care facility (3.65 [1.64-8.15]); (3) recent aminoglycoside use (8.86 [1.71-45.99]); and (4) older age (1.03 [1.01-1.06]). CONCLUSIONS: Recent FQ use, residence in a long-term care facility, recent aminoglycoside use, and older age were all noted to be independent risk factors for FQ resistance among patients with nosocomial E coli and K pneumoniae infections. Efforts should be directed at recognition and modification of these risk factors to curb the rise in FQ resistance and preserve the utility of these agents in the treatment of common nosocomial gram-negative infections.

Adult↗

Cardiac arrest and ventricular arrhythmia in patients taking antipsychotic drugs: cohort study using administrative data.

OBJECTIVE: To examine the rates of cardiac arrest and ventricular arrhythmia in patients with treated schizophrenia and in non-schizophrenic controls. DESIGN: Cohort study of outpatients using administrative data. SETTING: 3 US Medicaid programmes. PARTICIPANTS: Patients with schizophrenia treated with clozapine, haloperidol, risperidone, or thioridazine; a control group of patients with glaucoma; and a control group of patients with psoriasis. MAIN OUTCOME MEASURE: Diagnosis of cardiac arrest or ventricular arrhythmia. RESULTS: Patients with treated schizophrenia had higher rates of cardiac arrest and ventricular arrhythmia than controls, with rate ratios ranging from 1.7 to 3.2. Overall, thioridazine was not associated with an increased risk compared with haloperidol (rate ratio 0.9, 95% confidence interval 0.7 to 1.2). However, thioridazine showed an increased risk of events at doses > or =600 mg (2.6, 1.0 to 6.6; P=0.049) and a linear dose-response relation (P=0.038). CONCLUSIONS: The increased risk of cardiac arrest and ventricular arrhythmia in patients with treated schizophrenia could be due to the disease or its treatment. Overall, the risk with thioridazine was no worse than that with haloperidol. Thioridazine may, however, have a higher risk at high doses, although this finding could be due to chance. To reduce cardiac risk, thioridazine should be prescribed at the lowest dose needed to obtain an optimal therapeutic effect.

Adult↗

Development of an abbreviated schizophrenia quality of life scale using a new method.

The goal of the study was to develop and apply a predictive model approach to reduce the number of items collected for scales that yield a total summary score. A parsimonious subset of items from the 21-item Quality of Life Scale (QLS) that can accurately predict the total scale score was sought and evaluated in 198 patients with schizophrenia, using a statistical modeling approach. Two additional data sets were used for model validation: the subset of 101 patients used in the model construction who had the QLS administered approximately 1 year later and a new sample of 37 patients. Using only seven QLS items as predictors, the correlation was 0.9831 between the predicted and true QLS totals. Applying the model based for these seven QLS items, the correlations from the first and second validation data sets were 0.9791 and 0.9637, respectively. The study demonstrates that a small subset of items of the QLS predicts the entire 21-item scale with high accuracy. Two validation samples have confirmed the finding. This reduces the effort associated with scale administration and is likely to increase the assessment of an important functional domain. Such models can guide efforts for item reduction in other rating instruments.

Adolescent↗

Effects of strain, novelty, and NMDA blockade on auditory-evoked potentials in mice.

People with schizophrenia exhibit impaired ability to modify electroencephalographic event-related potential (ERP) responses to novel stimuli. These deficits serve as a window into the abnormalities of neuronal organization and function and are thought to reflect a component of genetic vulnerability for schizophrenia. We describe differences among inbred mouse strains for ERPs following a novelty detection paradigm, as a model for genetic contributions to disease vulnerability. Auditory-evoked potentials were recorded during an auditory oddball task in nonanesthetized C57BL/6J, C3H/HeJ, and DBA/2J mice prior to and following ketamine (10 mg/kg). Stimuli consisted of 80 sets of 24 standard tones followed by one novel tone. Principal component analysis yielded four temporal components that contribute to the auditory ERP responses to standard and novel stimuli. Two principal components that varied between standard and novel stimuli also differed among inbred mouse strains. Post hoc analyses indicate that strain effects on novelty detection are due to a significant difference between the response to novel and standard tones in C3H/HeJ mice that is absent in the other two strains. Inbred strains of mice vary in their ability to perform neuronal detection of change in the auditory environment. The ability to model novelty detection deficits in mice will aid in identifying genetic contributions to abnormal neuronal organization in people with schizophrenia.

Acoustic Stimulation↗

Provider inaccuracy in assessing adherence and outcomes with newly initiated antiretroviral therapy.

We studied the ability of providers to predict and estimate patient adherence to newly initiated highly active antiretroviral therapy (HAART). Nineteen providers referring 40 patients into an adherence study were surveyed. Widespread inaccuracy was found in providers' adherence predictions and estimates. Therefore, HAART should not be withheld solely on provider predictions of adherence. Providers should not rely on their own assessments when attempting to determine if patients are adhering to therapy.

Adult↗

Surgically implantable long-term antipsychotic delivery systems for the treatment of schizophrenia.

Non-adherence with medication remains a major correctable cause for poor outcome in schizophrenia. We describe a surgically implantable preparation of haloperidol with the aim that patients will have superior outcomes with improved medication adherence from implants. In contrast to depot formulations, implantable pellets could last many months, providing symptomatic improvement for periods of time never before possible. Additionally, in the event of unacceptable side effects, implants could be removed, offering a degree of reversibility not available with depot formulations. A surgically-implantable formulation of haloperidol has been created using biodegradable polymers. Implants have been characterized for in-vitro kinetics, as well as in-vivo bioactivity in rodents. Haloperidol implants demonstrate steady release of drug for 5 months. Animals treated with haloperidol implants display increased striatal D2 receptor expression as well as increased apomorphine stimulated locomotion. Surgically-implantable formulations are a viable approach to provide long-term delivery of antipsychotic medications to patients with psychotic disorders.

Animals↗

Sex differences in temporo-limbic and frontal brain volumes of healthy adults.

Sex differences have been observed in neurobehavioral measures and in neuroanatomic studies. Men and women differ in emotion processing, including perception, experience and expression, most notably reflected in greater male aggression. We examine temporo-limbic and prefrontal structures volumetrically in a large well-characterized sample of healthy adults, applying morphometric methods across cerebral regions that regulate emotions. Quantitative magnetic resonance imaging (MRI) was performed in 116 healthy adults, 57 men and 59 women, age range 18-49 years. We used reliable methods of region of interest identification to examine sex differences in volume of temporo-limbic and frontal regions. An automated tissue segmentation procedure was used to obtain separate measurements for gray and white matter. After correcting for cranial volume, men and women had identical volumes of amygdala and hippocampus, as well as dorsal prefrontal cortex. However, women had larger orbital frontal cortices than men, resulting in highly significant difference in the ratio of orbital gray to amygdala volume (P = 0.002). The larger volume of cortex devoted to emotional modulation may relate to behavioral evidence for sex differences in emotion processing.

Adolescent↗

Hospitalization and mortality rates from peptic ulcer disease and GI bleeding in the 1990s: relationship to sales of nonsteroidal anti-inflammatory drugs and acid suppression medications.

OBJECTIVES: Nonsteroidal anti-inflammatory drugs (NSAIDs) can cause peptic ulcer disease and upper GI bleeding. Acid suppression medications effectively treat NSAID-induced ulcers. However, it is unknown what effect the availability of proton pump inhibitors and over-the-counter preparations of NSAIDs and histamine type 2 receptor antagonists have had on population rates of hospitalization and mortality from GI toxicity. This study examines trends in hospitalization and mortality rates from GI toxicity during the 1990s. METHODS: We performed an analysis of secular trends of hospitalization and mortality rates from peptic ulcer disease, upper GI bleeding, and any GI bleeding using data from the National Hospital Discharge Survey, comparing them with sales of NSAIDs, aspirin, and acid suppression medications from 1992 to 1999. RESULTS: From 1992 to 1999, annual rates of hospitalization and mortality per 100,000 population for peptic ulcer disease declined from 205 to 165 and 7.7 to 6.0, respectively; calendar year was negatively correlated with both peptic ulcer disease hospitalization rates (p = -0.88, p = 0.007) and mortality rates (p = -0.71, p = 0.058). In contrast, these correlations did not reach statistical significance for upper or any GI bleeding (p > 0.1 for all comparisons). Sales of acid suppression medications were negatively correlated with peptic ulcer disease hospitalization rates (p = -0.76, p = 0.037) and mortality rates (p = -0.83, p = 0.015). Sales of NSAIDs were not positively correlated with hospitalization or mortality rates from peptic ulcer disease or GI bleeding (p > 0.2 for all comparisons). CONCLUSIONS: Despite changing patterns of use of NSAIDs and acid suppression medications during the 1990s, mortality rates from GI bleeding and peptic ulcer disease have been relatively stable, with an apparent decline in hospitalization rates and mortality from peptic ulcer disease. Changing rates of peptic ulcer disease morbidity and mortality were temporally related to increasing sales of antiulcerants but not to change in sales of NSAIDs.

Antacids↗

Validity and completeness of the General Practice Research Database for studies of inflammatory bowel disease.

PURPOSE: The objective of this study was to evaluate the validity and completeness of the General Practice Research Database (GPRD) as a tool for research into inflammatory bowel disease epidemiology. METHODS: Patients diagnosed with inflammatory bowel disease were identified from GPRD. Mailed surveys were sent to the general practitioner caring for a stratified random sample of 170 of these patients and collected information on the diagnosis of inflammatory bowel disease and the most recent surgery and hospitalization. RESULTS: Usable surveys were returned for 157 patients (92%). The inflammatory bowel disease diagnosis was highly probable or probable in 144 (92%, 95% CI 86 to 96%). Among the 53 patients with a potentially incident inflammatory bowel disease diagnosis, 33 (62%) had the first recorded diagnosis in GPRD within 30 days of the date reported in the survey (median difference -8 days; interquartile range 0 to -81 days). Of 12 surgeries and 25 hospitalizations reported in the survey, 11 (92%) and 19 (76%) were identified in GPRD, respectively. CONCLUSIONS: The diagnosis of inflammatory bowel disease in GPRD appears reliable for most patients. Important medical events such as hospitalizations and surgery are recorded at a high rate, although algorithms to identify these events are complex.

Cohort Studies↗

Relationship between clock-drawing and neuropsychological and functional status in elderly institutionalized patients with schizophrenia.

OBJECTIVE: The authors sought to examine the usefulness of the clock-drawing test (CDT) as a measure of general cognitive and adaptive functioning in elderly patients with schizophrenia. METHODS: CDT performance of elderly institutionalized patients with schizophrenia were contrasted with a comparison group, similar in age. Cognitive and functional status was examined using an expanded battery from the Consortium to Establish a Registry for Alzheimer's disease and the Psychogeriatric Dependency Rating Scale. RESULTS: Patients (N=21) performed more poorly overall on the CDT than the comparison group (N=21), with greater clock number and hand errors. Production of the clock's gestalt did not differ between groups. In patients, overall CDT performance and clock hand placement were significantly correlated with general cognitive functioning, memory, visuoconstruction, and word-list generation. CDT global and hand placement performances corresponded to patients' general orientation. CONCLUSIONS: Impaired CDT performance in elderly patients with schizophrenia is not attributable to normal aging. Also, the CDT uniquely relates to an array of cognitive abilities in this population, validating its multicognitive character and implicating multiple brain regions. The CDT's tolerability and brevity make it attractive for use in geriatric schizophrenia.

Adaptation, Psychological↗

Brain region and sex differences in age association with brain volume: a quantitative MRI study of healthy young adults.

There is evidence that some brain regions show age-associated volume decline and that men undergo more accelerated cerebral aging than women. However, limited information is available on age-associated changes during young adulthood. The authors performed quantitative magnetic resonance imaging in 116 healthy young adults (57 men, 59 women; age range: 18-49 years) to evaluate the relationship of age and sex with volumes of frontal and temporal regions, including selected limbic structures and the basal ganglia. Regardless of sex, increasing age was moderately associated with decrease in total gray matter (GM) and mildly with increase in sulcal cerebrospinal fluid (CSF). Associations of age with reduced GM volume were observed in all frontal and temporal cortical regions and some basal ganglia structures, but were generally less prominent in subcortical regions. The associations were stronger for men than women in the dorsolateral prefrontal cortex. Thus, in young, healthy adults, age-associated changes are selective as well as sex-specific, with men experiencing greater volume decrement across age-groups than women, particularly in the dorsolateral prefrontal regions. Reduced GM and increased CSF in this age range suggests that the aging process is a continuum, with changes evident before senescence. Thus, the biological changes commonly attributed to "aging" do, in fact, begin much earlier in the life-cycle.

Adult↗