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R M Centor

Publications and source records attributed to R M Centor.

At least 19 recordsLinked to original sources
PubMed1992

Controlled trial using computerized feedback to improve physicians' diagnostic judgments.

The goal of this study was to test an innovative method to improve physicians' diagnostic judgments by integrating the use of a computer program (employing cognitive feedback to teach a clinical rule that predicts the probability of streptococcal pharyngitis), a traditional lecture, and periodic disease-prevalence reports. In a controlled trial using pre- and postintervention measures involving 885 patients, the authors compared the effects of the integrated method on the diagnostic judgments of seven experienced physicians at a university health service (from 1982 to 1985) with the effects of the lecture alone on the judgments of seven experienced physicians at a different university health service (1986 to 1987). The integrated method significantly improved the quality of the physicians' judgments as measured by calibration curves and Brier scores, and increased the level of agreement between the physicians' judgments and those made by the clinical prediction rule. The lecture alone produced less improvement in the quality of the physicians' judgments, and decreased the level of agreement with the rule. The authors conclude that this method, based on cognitive psychology, is a promising educational tool.

Computer-Assisted Instruction↗
PubMed1992

Screening for drinking disorders in the elderly using the CAGE questionnaire.

OBJECTIVE: To assess the performance of the CAGE questionnaire in identifying elderly medicine outpatients with drinking problems. DESIGN: Cross-sectional design, with the alcohol module of the Diagnostic Interview Schedule as the criterion standard. SETTING: The outpatient medical practice of an urban university teaching hospital. PATIENTS: Consecutive patients 18 years or older who signed a consent form approved by the university's institutional review board. For this study, 323 patients greater than or equal to 60 years old. MAIN OUTCOME MEASURES: Sensitivity, specificity, receiver operating characteristics (ROC) curve and positive predictive value for CAGE scores of 0-4 for patients 60 years or older. RESULTS: Thirty-three percent of the sample group met study criteria for a history of drinking problems, including 63% of the male patients and 22% of the female patients. The sensitivity and specificity for a cut-off score of one for all patients was 86% and 78%, respectively, and 70% and 91% for a cut-off of two. The calculation of the area under the ROC curve was .86, and the positive predictive value of CAGE scores of 0-4 were 33%, 66%, 79%, 82%, and 94%, respectively. The predictive value for any score was higher in males than females, reflecting the higher prevalence of problems in the male population. CONCLUSIONS: The CAGE can effectively discriminate elderly patients with a history of drinking problems from those without such a history. The chosen cut-off score should consider the prevalence of drinking problems in the population being tested.

Aged↗
PubMed1991

Screening for alcohol abuse using CAGE scores and likelihood ratios.

OBJECTIVE: To assess the performance of the CAGE (acronym referring to four questions, see below) questionnaire in discriminating between medicine outpatients with and without an alcohol abuse or dependence disorder. DESIGN: A cross-sectional design of a sample of consecutive patients who received both the alcohol module of the diagnostic interview schedule and the CAGE (Cut down, Annoyed, Guilty, Eye-opener) screening questionnaire. SETTING: The outpatient medical practice of an urban university teaching hospital. PATIENTS: All patients 18 years or older who signed a consent form approved by the university's institutional review board. MEASUREMENT: Calculation of the sensitivity, specificity, receiver operating characteristic (ROC) curve, and likelihood ratio for CAGE scores of 0 to 4. RESULTS: Thirty-six percent of the sample group met criteria for a history of alcohol abuse or dependence. A CAGE score of 2 or more was associated with a sensitivity and specificity of 74% and 91%. The calculated area under the ROC curve was 0.89, whereas the likelihood ratios for CAGE scores of 0 to 4 were 0.14, 1.5, 4.5, 13, and 100, respectively. These ratios were associated with posterior probabilities for an abuse or dependence disorder of 7%, 46%, 72%, 88%, and 98%, respectively. CONCLUSION: Clinicians can improve their ability to estimate a patient's risk for an alcohol abuse or dependence disorder using likelihood ratios for CAGE scores.

Adult↗
PubMed1990

Clinical and microbiological evidence for endemic pharyngitis among adults due to group C streptococci.

Group C beta-hemolytic streptococci cause rare epidemic outbreaks of pharyngitis, but their role in sporadic endemic pharyngitis has been uncertain. We addressed the question of whether non-group A beta-hemolytic streptococci are associated with endemic pharyngitis in two ways. First, we compared rates of isolation from throat swabs of group A, B, C, and G and ungrouped beta-hemolytic streptococci ("culture negative") in adult patients vs those rates in controls. Second, we collected in standardized form clinical indexes of patients with pharyngitis: signs and symptoms graded for severity, the examining physician's subjective estimate of the probability of streptococcal pharyngitis, a logistic regression score predicting streptococcal pharyngitis, and whether antibiotic therapy was prescribed. After collecting data and cultures on 1425 patients with sore throats and cultures on 284 controls, we found the following: group C streptococci were isolated significantly more frequently in patients with sore throats than in controls (6% vs 1.4%); four clinical signs and two symptoms distinguished group C-associated pharyngitis as more severe than culture-negative pharyngitis; and six clinical signs and one symptom distinguished group C-associated pharyngitis as less severe than group A pharyngitis. Physicians' subjective estimates, logistic regression scores, and antibiotic treatment all characterized group C-associated pharyngitis as more severe than culture-negative sore throats but less severe than group A pharyngitis. From these data we present the first definitive evidence that group C streptococci are associated with endemic pharyngitis, show that clinical presentation distinguishes a group of patients with group C-associated pharyngitis from populations with culture-negative sore throats and from those with group A pharyngitis. Physicians' response to that presentation merits consideration in the context of rapid group-specific diagnosis of streptococcal pharyngitis by group A antigen tests.

Adult↗
PubMed1989

Risk factors for attempted suicide during adolescence.

It is unknown whether adolescents can provide the information necessary to identify their risk for attempted suicide. The present study was designed to determine whether data collected directly from adolescents can be used to develop a simple model for differentiating suicidal from nonsuicidal adolescents. Patients aged 13 to 19 years hospitalized for medical complications of serious suicide attempts (n = 56) or for acute illnesses unrelated to injuries or ingestions (n = 248) completed self-administered questionnaires pertaining to psychosocial function, recent stress, alcohol and drug use, and health care use. Compared with ill adolescents, suicidal adolescents had poorer mental health, impulse control, family relationships, and school performance; higher 3-month stress scores and alcohol-use scores; and more use of 7 of 12 drugs (P less than .05). Compared with ill adolescents, suicidal adolescents were more likely to report previous suicide attempts (39% vs 10%, P less than .001) and previous mental health care (27% vs 8%, P less than .001) but were less likely to identify a primary care site (61% vs 87%, P less than .001). In a logistic regression model based on previous suicide attempts, previous mental health care, poor school performance, marijuana use, and dependence on the emergency room for primary care, 84% of the suicidal and 55% of the ill adolescents were correctly identified. If validated prospectively, these five self-administered questions may constitute a helpful screen for the rapid identification of suicidal adolescents.

Adolescent↗
PubMed1988

Effects of low dose oral iodide supplementation on thyroid function in normal men.

Previous studies have demonstrated that short-term oral iodide administration, in doses ranging from 1500 micrograms to 250 mg/day, has an inhibitory effect on thyroid hormone secretion in normal men. As iodide intake in the USA may be as high as 800 micrograms/d, we investigated the effects of very low dose iodide supplementation on thyroid function. Thirty normal men aged 22-40 years were randomly assigned to receive 500, 1500, and 4500 micrograms iodide/day for 2 weeks. Blood was obtained on days 1 and 15 for measurement of serum T4, T3, T3-charcoal uptake, TSH, protein-bound iodide (PBI) and total iodide, and 24 h urine samples were collected on these days for measurement of urinary iodide excretion. TRH tests were performed before and at the end of the period of iodide administration. Serum inorganic iodide was calculated by subtracting the PBI from the serum total iodide. We found significant dose-related increases in serum total and inorganic iodide concentrations, as well as urinary iodide excretion. The mean serum T4 concentration and free T4 index values decreased significantly at the 1500 micrograms/day and 4500 micrograms/day doses. No changes in T3-charcoal uptake or serum T3 concentration occurred at any dose. Administration of 500 micrograms iodide/day resulted in a significant increase (P less than 0.005) in the serum TSH response to TRH, and the two larger iodide doses resulted in increases in both basal and TRH-stimulated serum TSH concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

The adult respiratory distress syndrome. Cell populations and soluble mediators in the air spaces of patients at high risk.

In order to better understand the modulation of polymorphonuclear neutrophil influx into the lung during the development of the adult respiratory distress syndrome (ARDS), we evaluated bronchoalveolar lavage fluids from control subjects (n = 9), patients at high risk of developing ARDS (n = 12), and patients with ARDS (n = 11) for cellular and protein content and capacity to promote neutrophil adhesion to tissue culture plastic. Analysis of the lavage fluids from high risk patients and patients with ARDS showed an 8- to 10-fold increase in the total number of cells, an increase in the percentage of neutrophils present (control subjects = 1 +/- 0.4%, high risk = 53 +/- 8%, ARDS = 70 +/- 7%), and a 10- to 40-fold increase in protein content. The adherence of normal neutrophils to plastic surfaces after pretreatment with either concentrated lavage fluid, ultrafiltrates of BALF, or plasma samples was determined to evaluate the neutrophil adherence-promoting activity of each. Lavage fluid from high risk patients and patients with ARDS promoted an approximate 3-fold increase in neutrophil adherence when compared with control lavage fluid. Neutrophil adhesion-promoting activity of the plasma and lavage filtrates (mw less than 500 daltons) was not significantly different from that of control subjects. The adherence-promoting activity found in ARDS lavage was stable at 56 degrees C for 30 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Assessing the responsiveness of functional scales to clinical change: an analogy to diagnostic test performance.

One characteristic of newer health or functional status scales which has received little attention is their responsiveness over time to clinical change. In part, this is because methods for assessing this characteristic are crude and not well standardized. We suggest that scales be viewed as "diagnostic tests" for discriminating between improved and unimproved patients. With this perspective, one may construct receiver operating characteristic (ROC) curves describing a scale's ability to detect improvement (or failure to improve) using some external criterion. This method is illustrated using data from a study of acute low back pain, comparing the Sickness Impact Profile, its major subscales, and a shorter, more disease-specific scale. The results demonstrate an advantage of the ROC approach over simple pre- and post-treatment score comparisons in assessing scale responsiveness. They also suggest some advantage for a brief disease-specific scale over the lengthier "generic" SIP.

Adult↗
PubMed1986

Effect of medium and cultivation conditions on comparisons between latex agglutination and culture detection of group A streptococci.

In the laboratory diagnosis of pharyngitis, results from latex agglutination tests (LAT) performed directly on throat swabs are often compared with the isolation of group A beta-hemolytic streptococci (GABHS) from simultaneously obtained swabs cultivated on a variety of media under different atmospheric conditions. In this study, results of an LAT, Directigen, were compared with those of two different media: sheep blood agar (SBA) and group A selective strep agar (ssA). Specimens inoculated on SBA were incubated in three different atmospheres: air, 3 to 5% CO2, and anaerobically. Those inoculated on ssA were incubated in 3 to 5% CO2 only. Isolation of GABHS was confirmed by coagglutination. The standard for true positivity was the isolation of GABHS from at least one of the simultaneous cultures. Comparisons were made with samples from 693 adult patients. GABHS was isolated on at least one of the three cultures in 143 patients, demonstrating an isolation rate of 20.6%. LAT exhibited a sensitivity of 95.1%. SBA incubated in air, in CO2, or anaerobically had sensitivities of 86.2, 85.9, and 93.7%, respectively. The ssA detected 99.3% of the positive specimens. Single SBA culture proved to be inferior to LAT and therefore was a poor standard for measuring LAT performance. Single ssA cultures demonstrated the greatest sensitivity in GABHS detection and therefore could serve as a standard for measuring LAT performance.

Aerobiosis↗
PubMed1986

Throat cultures and rapid tests for diagnosis of group A streptococcal pharyngitis.

This article reviews the use of diagnostic tests to guide management of adults with sore throats. Pharyngitis due to group A beta-hemolytic streptococci represents the major diagnostic concern in these patients. Organisms other than group A streptococci can cause pharyngitis, but their clinical importance and their diagnostic tests have not yet been established. For many years, physicians have used routine throat cultures to diagnose group A streptococcal pharyngitis. Rapid tests have recently been introduced that detect the group A streptococcal antigen on throat swab specimens. Because both tests have high sensitivity and specificity, the choice of tests may depend on test turnaround time. Rapid tests should improve management by decreasing both short-term morbidity and inappropriate use of antibiotics.

Antigens, Bacterial↗
PubMed1986

Transportability of a decision rule for the diagnosis of streptococcal pharyngitis.

Use of existing decision rules could improve management of streptococcal pharyngitis, but the validity of such rules outside their original patient population is not known. We applied a four-item decision rule derived at the Medical College of Virginia, Richmond, to 516 patients at the University of Nebraska, Omaha, to test how accurately it would predict outcome of throat culture. After correction for differences in the prevalence of a positive culture (17% in Virginia, 26% in Nebraska), the rule closely predicted the frequency of positive cultures in five subgroups based on the presence of clinical findings. We conclude that this rule transported well to a different patient population and would have been useful in identifying patients with pharyngitis who had a high likelihood of throat cultures positive for group A streptococci.

Adult↗
PubMed1985

A Visicalc program for estimating the area under a receiver operating characteristic (ROC) curve.

The area under the ROC curve interests us as a method for analyzing discrimination or detectability. One can assess a diagnostic test or probability assessor with respect to its degree of discrimination. The area under the ROC curve gives us the probability of correctly identifying abnormal from normal in a forced-choice, two-alternative problem. Previous methods used for calculating the area involved maximum likelihood estimation on a mainframe or minicomputer. This paper demonstrates an adaptation of a recently published nonparametric method for estimating the area. This adaptation takes advantage of electronic spreadsheet software and may be used on most (if not all) microcomputers. The paper develops the construction of the program needed for the necessary calculations.

Computers↗
PubMed1985

An evaluation of methods for estimating the area under the receiver operating characteristic (ROC) curve.

The area under the receiver operating characteristic (ROC) curve serves as one means for evaluating the performance of diagnostic and predictive test systems. The most commonly used method for estimating the area under an ROC curve utilizes the maximum-likelihood-estimation technique, and a nonparametric method to calculate the area under an ROC curve was recently described. We compared the performance of these two methods. The results for the area under the ROC curve and the standard error of the estimate as calculated by each of the two methods exhibited high correlation. Generally, the nonparametric method yields lower area estimates than the maximum-likelihood-estimation technique. However, these differences generally were small, particularly with ROC curves derived from five or more cutoff points. Consistent results of hypothesis testing of the significance of differences between two ROC curves will be similar, regardless of which method is used, as long as one uses the same estimation technique on the two curves and as long as the two ROC curves being compared are of similar shape.

Computers↗
PubMed1984

Development of the adult respiratory distress syndrome: progressive alteration of neutrophil chemotactic and secretory processes.

Chemotaxis and lysosomal enzyme release in peripheral blood neutrophils taken from patients before, during, and after recovery from the adult respiratory distress syndrome (ARDS) were studied. This allowed for correlation of cellular function with changes in a patient's clinical status. It was found that neutrophils from 8 of 9 patients with the fully developed syndrome exhibited a profound depression of chemotaxis (63% depressed, P = 0.0001) and a fourfold elevation of basal lysosomal enzyme release relative to neutrophils from healthy controls (P = 0.0001). These findings of depression of chemotaxis and enhanced basal enzyme release were also detected in neutrophils taken from 7 of 11 patients in whom clinical risk factors (eg, sepsis, pneumonia) for the syndrome had developed. Following resolution of the adult respiratory distress syndrome, the above changes in neutrophil function resolved in the four patients studied during convalescence. Healthy neutrophils exposed to plasma samples (untreated or zymosan-activated) from control subjects and patients with ARDS could not be distinguished with respect to chemotaxis and enzyme secretion. It is concluded that patients in whom ARDS develops show profound but reversible changes in peripheral neutrophil activity which can be measured following the development of a clinical predisposition for the syndrome. Further, the presence of a humoral substance capable of promoting chemotaxis or enzyme secretion from healthy neutrophils in the untreated plasma of patients suffering from ARDS was not demonstrated. This suggests that alteration of neutrophil activity measured in patients with the fully developed syndrome may be cellular in origin.

Acetylglucosaminidase↗