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Biomedical subjects

R M Centor

Publications and source records attributed to R M Centor.

18 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↗
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↗
PubMedDate not supplied

Underdocumentation of benzodiazepine prescriptions in a general medicine clinic.

During a three-month period the authors reviewed the charts of patients prescribed benzodiazepine and non-benzodiazepine medications by 73 housestaff practicing in an ambulatory medical clinic. Compared with non-benzodiazepine prescriptions, benzodiazepine name (p less than 0.001), instructions (p less than 0.001), and targeted problems (p less than 0.0001) were significantly underrecorded. In 11% of the records reviewed there was no indication that a mood disorder had been identified or a benzodiazepine prescribed (p less than 0.0001). Problems targeted for benzodiazepine management were found less frequently in the records of elderly patients than in those of patients less than 65 years of age (p less than 0.05). The authors conclude that many houseofficers significantly underdocument the prescriptions they write for benzodiazepine medications and that this may be a marker of their regard for managing mood disorders with benzodiazepines.

Ambulatory Care Facilities↗
PubMedDate not supplied

Rational decision making based on history: adult sore throats.

Primary care physicians are often required to make preliminary evaluations based only on the patient's history, especially during telephone encounters about sore throats. The authors studied adults with sore throats to determine whether patients can be stratified into higher and lower risks of strep throat by history alone. They first obtained data from 517 patients seen in an emergency room. Providers graded symptoms on a four-point scale (absent, mild, moderate, or severe). Initial analyses showed that prediction based on history should include three variables: fever, difficulty in swallowing, and cough. For ease of computation, these were consolidated into one score, "history" (= fever history + difficulty in swallowing - cough). This score was used to develop a model that predicts the probability of infection with group A beta-hemolytic streptococcus, and the model's performance was tested in two additional patient groups. The predictive accuracy of the "history" score was confirmed in all patient groups, despite differences in providers and disease prevalences. Primary care physicians may use this model to help them make decisions in situations such as telephone encounters without using additional data.

Adult↗
PubMedDate not supplied

What a difference a day makes: a decision analysis of adult streptococcal pharyngitis.

With the availability of group A beta-hemolytic streptococcal (GABHS) antigen detection tests, the management of adult pharyngitis is being reassessed. A decision analytic model was developed which considered four strategies: immediate treatment, no treatment, performing a rapid antigen test, or obtaining a bacterial culture. Patient outcomes were expressed in "well" days, which were reduced by the "sick" days associated with adverse reactions to treatment or complications of GABHS infection. When immediate test results are available, testing is the optimal strategy for probabilities of GABHS between 1 and 49 per cent. This range includes almost all patients, using probability estimates based on clinical criteria. The absolute benefit of testing was 0.1 days. The major advantage of a rapid test is the avoidance of penicillin reactions. Variations in the symptomatic benefits of treatment had minimal effects on the analysis. The analysis supports the use of an antigen test for adult patients with pharyngitis.

Acute Disease↗
PubMedDate not supplied

The use of nurses to evaluate houseofficers' humanistic behavior.

OBJECTIVES: 1) To determine whether nurse evaluations of humanistic behavior discriminate between houseofficers in an internal medicine training program, and 2) to compare nurse and attending physician evaluations. DESIGN: Prospective, six-month comparison of nurse and attending ratings of houseofficer humanistic behavior. PROCEDURE: Using a six-item, Likert-scale humanistic behavior rating form, nurses and ward attendings evaluated 76 PGY-1, PGY-2, and PGY-3 houseofficers over a six-month period. Nurses and attendings voluntarily evaluated houseofficers on all inpatient units in both university and Veterans Administration teaching hospitals. MEASUREMENTS AND MAIN RESULTS: Nurse ratings discriminated residents from one another throughout the six months of the study and over all units in both hospitals. Attending physician ratings were only moderately correlated with nurses' and were significantly more lenient. Exploratory analyses of the nursing evaluations revealed that female houseofficers received significantly more favorable evaluations than did men and that ward nurses were significantly more lenient than were critical care nurses. Nurse ratings did not differ by hospital, training year, or month of evaluation. CONCLUSIONS: Nurses can provide information about humanistic behavior that will allow program directors to discriminate among different levels of houseofficer behavior. Information from nurses differs from that provided by attending physicians. Nurse ratings are affected by gender and by the type of unit from which they are obtained.

Attitude of Health Personnel↗
PubMedDate not supplied

Evaluation of two ELISA's for detecting Chlamydia trachomatis from endocervical swabs.

Two enzyme immunoassays (EIAs) detecting Chlamydia trachomatis from endocervical swabs, Syva MicroTrak (MT) and Abbott Chlamydiazyme (CZ), were compared with a tissue culture (TC) standard. Initially, 8% (100 of 1250) of specimens were TC positive, yielding sensitivities of 94% (94 of 100) for MT and 79% (79 of 100) for CZ with identical 98% specificities (1129 of 1150 for MT and 1130 of 1150 for CZ). Discrepant specimens were retested by both EIAs and assayed for elementary bodies (EBs) by a fluorescent antibody test. After discrepancy analysis, 9.5% (118) of 1240 patients were either TC or EB positive, yielding sensitivities of 94.1% for MT (111 of 118) and 79.7% for CZ (94 of 118) with identical specificities of 100% (1122 of 1122). These results indicate that the MT is significantly more sensitive (p less than 0.05, McNemar test) than CZ in detecting C. trachomatis from endocervical swabs.

Adolescent↗
PubMedDate not supplied

Evaluating physicians' probabilistic judgments.

Physicians increasingly are challenged to make probabilistic judgments quantitatively. Their ability to make such judgments may be directly linked to the quality of care they provide. Many methods are available to evaluate these judgments. Graphic means of assessment include the calibration curve, covariance graph, and receiver operating characteristic (ROC) curve. Statistical tools can measure the significance of departures from ideal calibration, and measure the area under ROC curve. Modeling the calibration curve using linear or logistic regression provides another method to assess probabilistic judgments, although these may be limited by failure of the data to meet the model's assumptions. Scoring rules provide indices of overall judgmental performance, although their reliability is difficult to gauge for small sample sizes. Decompositions of scoring rules separate judgmental performance into functional components. The authors provide preliminary guidelines for choosing methods for specific research in this area.

Decision Theory↗
PubMedDate not supplied

Signal detectability: the use of ROC curves and their analyses.

Issues related to ROC curves are addressed. The original article on the subject by Lee Lusted, describing the "state of the art" 20 years ago, is reviewed. The concepts that Lusted addressed are then expanded, suggesting the current state of the art. New issues that have arisen with regard to ROC curves and their use in medicine are addressed. Finally, potential areas for future investigation are suggested.

Diagnosis, Computer-Assisted↗