Patients with Lemierre syndrome have a high risk of new thromboembolic complications, clinical sequelae and death: an analysis of 712 cases.

BACKGROUND: Lemierre syndrome is characterized by head/neck vein thrombosis and septic embolism usually complicating an acute oropharyngeal bacterial infection in adolescents and young adults. We described the course of Lemierre syndrome in the contemporary era. METHODS: In our individual-level analysis of 712 patients (2000-2017), we included cases described as Lemierre syndrome if these criteria were met: (i) primary site of bacterial infection in the head/neck; (ii) objectively confirmed local thrombotic complications or septic embolism. The study outcomes were new or recurrent venous thromboembolism or peripheral septic lesions, major bleeding, all-cause death and clinical sequelae. RESULTS: The median age was 21 (Q1-Q3: 17-33) years, and 295 (41%) were female. At diagnosis, acute thrombosis of head/neck veins was detected in 597 (84%) patients, septic embolism in 582 (82%) and both in 468 (80%). After diagnosis and during in-hospital follow-up, new venous thromboembolism occurred in 34 (5.2%, 95% CI 3.8-7.2%) patients, new peripheral septic lesions became evident in 76 (11.7%; 9.4-14.3%). The rate of either was lower in patients who received anticoagulation (OR: 0.59; 0.36-0.94), higher in those with initial intracranial involvement (OR: 2.35; 1.45-3.80). Major bleeding occurred in 19 patients (2.9%; 1.9-4.5%), and 26 died (4.0%; 2.7-5.8%). Clinical sequelae were reported in 65 (10.4%, 8.2-13.0%) individuals, often consisting of cranial nerve palsy (n = 24) and orthopaedic limitations (n = 19). CONCLUSIONS: Patients with Lemierre syndrome were characterized by a substantial risk of new thromboembolic complications and death. This risk was higher in the presence of initial intracranial involvement. One-tenth of survivors suffered major clinical sequelae.

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.

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.

Physicians' survival predictions for patients with acute congestive heart failure.

BACKGROUND: Current guidelines suggest that patients with low likelihoods of survival may be excluded from intensive care. Patients with new or exacerbated congestive heart failure are frequently but not inevitably admitted to critical care units. OBJECTIVE: To assess how well physicians could predict the probability of survival for acutely ill patients with congestive heart failure, and in particular how well they could identify patients with small chances of survival. METHODS: This was a prospective cohort study done in the emergency departments of a university hospital, a Veterans Affairs medical center, and a community hospital. The study population was consecutive adults for whom new or exacerbated congestive heart failure, diagnosed clinically, was a major reason for the emergency department visit. Physicians caring for the study patients in the emergency departments recorded their judgments of the numeric probability that each patient would survive for 90 days and for 1 year. The patients vital status at 90 days and 1 year was ascertained by multiple means, including interview, chart review, and review of hospital and state databases. RESULTS: By calibration curve analysis, the physicians underestimated survival probability at both 90 days and 1 year, particularly for patients they judged to have the lowest probabilities of survival. Their predictions had modest discriminating ability (receiver operating characteristic curve areas, 0.66 [SE = 0.020] for 90 days; 0.63 [SE = 0.017] for 1 year). The physicians identified only 15 patients they judged to have a 90-day survival probability of 10% or less, whose survival rate was actually 33.3%. CONCLUSIONS: Physicians have great difficulty predicting survival for patients with acute congestive heart failure and cannot identify patients with poor chances of survival. Current triage guidelines that suggest patients with poor chances of survival may be excluded from critical care may be impractical or harmful.

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.

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.

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.

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.

An intervention to increase physicians' use of adherence-enhancing strategies in managing hypercholesterolemic patients.

PURPOSE: Patients' lack of adherence to medical regimens frustrates many practicing physicians. This study was conducted to determine the effectiveness of a combined continuing medical education intervention in increasing physicians' adherence-enhancing skills and improving hypercholesterolemic patients' health. METHOD: A prospective, randomized, controlled trial was designed using a nested cohort of 28 community physicians throughout Alabama and 222 of their hypercholesterolemic outpatients. The intervention, carried out in 1998, consisted of three interactive case audio-conferences plus chart reminders. Physicians' learning was measured by unannounced standardized patients, and patients' health by serum cholesterol levels, weight, knowledge of hypercholesterolemia, self-reported dietary habits, and health status. RESULTS: No significant difference was found in the numbers of physician adherence-enhancing strategies, although the number did increase within the treatment group. There were significant differences in the intervention group's patients' knowledge of cholesterol management (p = .008) and significant reductions in their self-reported consumption of dietary fats (p = .002). A significant difference was found in the serum cholesterol level of men in the intervention group nine months after the intervention (p = .02). CONCLUSION: Combining a series of interactive case audio-conferences with chart reminders shows promise in increasing physicians' adherence-enhancing strategies. In chronic disease management, the problem of enhancing adherence remains complex.

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.

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.

Treating sore throats in the emergency room. The importance of follow-up in decision making.

Evaluation and treatment of emergency room patients complaining of sore throats are complicated by an unknown probability of follow-up. Tompkins' analysis of cost-effective sore throat management strategies was modified by adding an expression for variable follow-up rate. The original analysis specified a culture range when the probability of streptococcal infection was between 0.05 and 0.20, while the expanded analysis demonstrates that this range decreases with decreasing follow-up. For follow-up rates of 0.70 or less, all patients would be in either the treatment or no treatment group. This analysis demonstrates the importance of follow-up in out-patient decision making, and illustrates the methodology for including follow-up (and similar factors) in our analyses.

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.

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.

The diagnosis of strep throat in adults in the emergency room.

Adult patients who presented to an urban emergency room complaining of a sore throat had cultures and clinical information recorded. Models were constructed, using logistic regression analysis, of both a positive culture for Group A beta streptococcus and a positive guess by a resident. The model of a positive culture consisted of four variables--tonsillar exudates, swollen tender anterior cervical nodes, lack of a cough, and history of fever. Patients with all 4 variables had a 56% probability of a positive culture; 3 variables, 32%; 2 variables, 15%; 1 variable, 6.5%; and 0 variables, 2.5%. The model of a positive guess by a resident demonstrated an over-reliance on physical exam and an underuse of history. The model of a positive culture allows stratification of patients to assist clinicians in the management strategies.

Practice variation in the management of pharyngitis: the importance of variability in patients' clinical characteristics and in physicians' responses to them.

The objective of this study was to assess whether geographic differences in antibiotic-prescribing rates for patients with pharyngitis could be explained by intersite differences in patients' clinical characteristics and in how physicians responded to these clinical cues when making decisions. As part of the initial phase of a prospective controlled trial to improve physicians' diagnostic ability, the authors enrolled cohorts of consecutive patients seen at staff-model--HMO student health services in Pennsylvania and Nebraska. Physicians' decisions whether to prescribe antibiotics for 310 consecutive patients presenting with pharyngitis to the former and 214 such patients presenting to the latter at the time of the initial visit were examined. There was a large discrepancy between the antibiotic-prescribing rates at the student health services in Pennsylvania, 106/310, 32.4%, and Nebraska, 156/214, 72.9%. The clinical variables significantly independently associated with treatment at both sites in a logistic regression model were fever, adjusted odds ratio = 2.1 (95% CI = 1.1, 3.8); exudates, 5.4 (2.8, 10); palatine petechiae, 6.5 (1.5, 28); rhinorrhea, 0.46, (0.25, 0.85); and high risk of complications, 3.8 (1.04, 14). There was a significant interaction between site and anterior cervical adenopathy, 5.5 (1.6, 19); and a borderline interaction between site and rhinorrhea, 2.4 (0.89, 6.7). Site was not a significant independent predictor of treatment, 1.8 (0.45, 6.6.). Practice variation was related to geographic differences in patients' clinical characteristics and in how physicians responded to these factors when prescribing antibiotics. How physicians weight patients' clinical characteristics when making decisions may be an important element of their "practice styles."

An international comparison of physicians' judgments of outcome rates of cardiac procedures and attitudes toward risk, uncertainty, justifiability, and regret.

OBJECTIVE: Compare U.K. and U.S. physicians' judgments of population probabilities of important outcomes of invasive cardiac procedures; and values held by them about risk, uncertainty, regret, and justifiability relevant to utilization of cardiac treatments. DESIGN: Cross-sectional study. SETTING: University hospital and VA medical center in the United States; two teaching hospitals in the United Kingdom. PARTICIPANTS: 171 housestaff and attendings at U.S. teaching hospitals; 51 physician trainees and consultants at U.K. hospitals. MEASURES: Judgments of probabilities of severe complications and deaths due to Swan-Ganz catheterization, cardiac catheterization, percutaneous transluminal coronary angioplasty (PTCA), and coronary artery bypass grafting (CABG); judgments of malpractice risks for case vignettes; Nightingale's risk-aversion instrument; Gerrity's reaction-to-uncertainty instrument; questions about need to justify decisions; responses to case vignettes regarding regret. RESULTS: The U.S. physicians judged rates of two bad outcomes of cardiac procedures (complications due to cardiac catheterization; death due to CABG) to be significantly higher (p < or = 0.01) than did the U.K. physicians (U.S. medians, 5 and 3.5, respectively; U.K. medians 3 and 2). The median ratio of (risk of malpractice suit I error of omission)/(risk of suit I error of commission) judged by U.K. physicians, 3, was significantly (p=0.0006) higher than that judged by U.S. physicians, 1.5. The U.K. physicians were less often risk-seeking in the context of possible losses than the U.S. physicians (odds ratio for practicing in the U.K. as a predictor of risk seeking 0.3, p=0.003). The U.K. physicians had significantly more discomfort with uncertainty than did the U.S. physicians, as reflected by higher scores on the stress scale (U.K. median 48, U.S. 42, p=0.0001) and the reluctance-to-disclose-uncertainty scale (U.K. 40, U.S. 37, p < 0.0001) of the Gerrity instrument. There was no clear international difference in perceived need to justify decisions, or in regret. CONCLUSIONS: The results were not clearly consistent with the uncertainty hypothesis that international practice variation is due to differences in judged rates of outcomes of therapy or with the imperfect-agency hypothesis that practice variation is due to differences in physicians' personal values. The causes and implications of practice variations remain unclear.

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.