RESUMEN
BACKGROUND: Artificial neural networks (ANN) can be used to select sets of predictor variable that incorporate nonlinear interactions between variables. We used a genetic algorithm, with selection based on maximizing network accuracy and minimizing network input-layer cardinality, to evolve parsimonious sets of variables for predicting community-acquired pneumonia among patients with respiratory complaints. METHODS: ANN were trained on data from 1044 patients in a training cohort, and were applied to 116 patients in a testing cohort. Chromosomes with binary genes representing input-layer variables were operated on by crossover recombination, mutation, and probabilistic selection based on a fitness function incorporating both network accuracy and input-layer cardinality. RESULTS: The genetic algorithm evolved best 10-variable sets that discriminated pneumonia in the training cohort (ROC areas, 0.838 for selection based on average cross entropy (ENT); 0.954 for selection based on ROC area (ROC)), and in the testing cohort (ROC areas, 0.847 for ENT selection; 0.963 for ROC selection), with no significant differences between cohorts. Best variable sets based on the genetic algorithm using ROC selection discriminated pneumonia more accurately than variable sets based on stepwise neural networks (ROC areas, 0.954 versus 0.879, p = 0.030), or stepwise logistic regression (ROC areas, 0.954 versus 0.830, p = 0.000). Variable sets of lower cardinalities were also evolved, which also accurately discriminated pneumonia. CONCLUSION: Variable sets derived using a genetic algorithm for neural networks accurately discriminated pneumonia from other respiratory conditions, and did so with greater accuracy than variables derived using stepwise neural networks or logistic regression in some cases.
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Algoritmos , Intercambio Genético , Redes Neurales de la Computación , Neumonía/genética , Estudios de Cohortes , Infecciones Comunitarias Adquiridas/genética , Humanos , Modelos Logísticos , Curva ROC , Estados UnidosRESUMEN
OBJECTIVES: Artificial neural networks have proved to be accurate predictive instruments in several medical domains, but have been criticized for failing to specify the information upon which their predictions are based. We used methods of relevance analysis and sensitivity analysis to determine the most important predictor variables for a validated neural network for community-acquired pneumonia. METHODS: We studied a feed-forward, back-propagation neural network trained to predict pneumonia among patients presenting to an emergency department with fever or respiratory complaints. We used the methods of full retraining, weight elimination, constant substitution, linear substitution, and data permutation to identify a consensus set of important demographic, symptom, sign, and comorbidity predictors that influenced network output for pneumonia. We compared predictors identified by these methods to those identified by a weight propagation analysis based on the matrices of the network, and by logistic regression. RESULTS: Predictors identified by these methods were clinically plausible, and were concordant with those identified by weight analysis, and by logistic regression using the same data. The methods were highly correlated in network error, and led to variable sets with errors below bootstrap 95% confidence intervals for networks with similar numbers of inputs. Scores for variable relevance tended to be higher with methods that precluded network retraining (weight elimination) or that permuted variable values (data permutation), compared with methods that permitted retraining (full retraining) or that approximated its effects (constant and linear substitution). CONCLUSION: Methods of relevance analysis and sensitivity analysis are useful for identifying important predictor variables used by artificial neural networks.
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Infecciones Comunitarias Adquiridas/fisiopatología , Redes Neurales de la Computación , Neumonía Bacteriana/fisiopatología , Algoritmos , Infecciones Comunitarias Adquiridas/diagnóstico , Recolección de Datos , Humanos , Neumonía Bacteriana/diagnóstico , Sensibilidad y Especificidad , Estados UnidosRESUMEN
OBJECTIVE: Physician office laboratory regulations may decrease test availability. We examined the potential effects of regulations on test availability and whether the use of tests in diagnosing uncomplicated urinary tract infections is related to availability. STUDY DESIGN: We performed an analysis of a cross-sectional survey conducted in 1994 and 1995. Test availability and use were determined by physicians' reports. POPULATION: The survey respondents included practicing physicians in 3 specialties (family medicine, general internal medicine, and obstetrics and gynecology) from 4 states: Pennsylvania (which had longstanding office laboratory regulations), and Alabama, Minnesota, and Nebraska (states that were not regulated until the implementation of the Clinical Laboratory Improvement Amendment of 1988). OUTCOMES MEASURED: We determined whether 4 specific tests were available in the office and how the tests were used to diagnose uncomplicated urinary tract infections. RESULTS: Our analysis was based on the responses from the 1898 respondents to the survey. All tests were less commonly available in Pennsylvania; this included the dipstick, microscopic urinalysis, wet prep, and urine culture (odds ratio [OR]=0.20-0.34; all P values < .05). The availability of the microscopic urinalysis and culture increased their use (OR = 4.37 and 2.03, respectively; P=.001). The availability of microscopic urinalysis was associated with a decrease in ordering urine cultures (OR=0.42; P=.001), and the availability of the dipstick was associated with a decrease in the use of both the microscopic urinalysis (OR=0.36; P=.02) and the culture (OR=0.48; P=.05). CONCLUSIONS: We found lower test availability in the state with office laboratory regulations and a decrease in testing when availability is reduced, suggesting that laboratory regulations may influence physicians&rsquo diagnostic approach to urinary tract infections. Further study will be required to determine the level of testing that maximizes patient welfare.
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Laboratorios/legislación & jurisprudencia , Urinálisis/estadística & datos numéricos , Infecciones Urinarias/diagnóstico , Adulto , Alabama , Estudios Transversales , Recolección de Datos , Técnicas de Diagnóstico Urológico/estadística & datos numéricos , Femenino , Humanos , Minnesota , Nebraska , PennsylvaniaRESUMEN
To determine practicing physicians' strategies for diagnosing and managing uncomplicated urinary tract infection, we surveyed physicians in general internal medicine, family practice, obstetrics and gynecology, and emergency medicine in four states. Responses differed significantly by respondents' specialty. For example, nitrofurantoin was the antibiotic of first choice for 46% of obstetricians, while over 80% in the other specialties chose trimethoprim-sulfamethoxazole. Most surveyed said they do not usually order urine culture, but the percentage who do varied by specialty. Most use a colony count of 10(5) colony-forming units or more for diagnosis although evidence favors a lower threshold, and 70% continue antibiotic therapy even if the culture result is negative. This survey found considerable variation by specialty and also among individual physicians regarding diagnosis and treatment of urinary tract infection and also suggests that some of the new information from the literature has not been translated to clinical practice.
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Antiinfecciosos Urinarios/uso terapéutico , Pautas de la Práctica en Medicina/estadística & datos numéricos , Infecciones Urinarias/tratamiento farmacológico , Adulto , Recolección de Datos , Femenino , Humanos , Medicina , Nitrofurantoína/uso terapéutico , Especialización , Combinación Trimetoprim y Sulfametoxazol/uso terapéutico , Estados Unidos , Infecciones Urinarias/diagnósticoRESUMEN
To be successful, the system will need to be easily modified. Do not dissolve the tailoring team when the clinician screens are "done." Anticipate constant change in how patients are cared for and plan to change the system accordingly. Communicate with the vendor so that the company understands your changing needs and so you can keep current with new functionality. Above all, listen to your clinician users--"The customer is always right."
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Centros Médicos Académicos/organización & administración , Sistemas de Información en Hospital/estadística & datos numéricos , Pautas de la Práctica en Medicina , Conflicto Psicológico , Humanos , Nebraska , Negociación , Técnicas de Planificación , Poder Psicológico , Interfaz Usuario-ComputadorRESUMEN
Policy capturing was used to provide insight into those factors that people consider important in the decision of whether to accept life-sustaining medical treatment. First, open-ended interviews with community-dwelling elderly persons (n = 30) were conducted to determine the factors they would consider when drafting an advance directive. College students (n = 53) then made judgments as to whether they would accept life-sustaining treatment for each of 100 hypothetical vignettes comprising a similar set of factors. Results revealed that 1) students made consistent judgments, 2) there was considerable variability in their mean judgments, 3) the most influential factors were mental and physical functioning, 4) mental and physical functioning had an interactive effect on judgments, and 5) subjective estimates of importance were significantly related to policy-capturing weights. This approach for studying the relationship of individuals' values to their acceptance of life-sustaining therapy may be useful in future studies of patient and surrogate decision making.
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Directivas Anticipadas , Toma de Decisiones , Estado de Salud , Cuidados para Prolongación de la Vida , Competencia Mental , Anciano , Actitud Frente a la Salud , Conflicto Psicológico , Humanos , Juicio , Modelos Psicológicos , Análisis de Regresión , Valores Sociales , Estudiantes/psicología , Encuestas y CuestionariosRESUMEN
We surveyed pulmonologists to determine which procedures they do in practice, where they learned the procedures, and how much training they recommend to attain and maintain clinical competence in each. We mailed a survey to a random sample of 1,000 members of the American College of Physicians who were identified as practicing pulmonologists; 755 (75%) responded. Respondents performed a variety of pulmonary procedures, an average of 17 of the 29 listed. Pulmonologists who were more recent graduates, who worked longer hours, and who were involved in critical care did a greater variety of procedures. Only 26% of practicing pulmonologists currently do all the procedures required for board certification in pulmonary medicine. For each of 13 specific procedures, the number reported done in the past year was generally unrelated to practice factors. Many respondents who learned procedures in practice did so without formal training or supervision. Respondents' recommendations regarding numbers of procedures required to attain or maintain competence did not vary greatly. Pulmonologists vary considerably in the types of procedures they do. Their opinions about the training needed for competence help to better define requirements for training programs. More attention should be focused on training and certifying practicing pulmonologists in procedures learned after formal fellowship training.
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Competencia Clínica/estadística & datos numéricos , Neumología/normas , Adulto , Certificación/estadística & datos numéricos , Humanos , Persona de Mediana Edad , Neumología/educación , Neumología/estadística & datos numéricos , Enfermedades Respiratorias/diagnóstico , Sociedades Médicas , Encuestas y Cuestionarios , Estados UnidosRESUMEN
Before establishing the utility of ambulatory blood pressure monitoring during pregnancy, we evaluated the accuracy of a small, easily concealed monitor. The 59 normotensive pregnant patients were between 13 and 26 gestational weeks. For each monitor reading, two trained observers independently and simultaneously recorded blood pressures using a mercury manometer connected to the monitor cuff. Seven readings in three positions (sitting upright, semirecumbent, standing) were performed on each patient. Averaged differences between the observers' and monitor readings varied from -2.2 to -0.9 mm Hg (systolic) and from -2.8 to -0.6 (fifth-phase diastolic), indicating slight but clinically unimportant overestimation by the monitor. Correlations between averaged observers' readings and the monitor ranged from 0.79 to 0.92 (systolic) and from 0.85 to 0.92 (fifth-phase diastolic). Overall, the observers agreed with the monitor within 5 mm Hg on 94% of systolic readings and 99% of fifth-phase diastolic readings. There was no statistically significant difference in accuracy with changes in body position. We conclude that this small, quiet, noninvasive device accurately determined blood pressures during pregnancy.
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Monitoreo Ambulatorio de la Presión Arterial/instrumentación , Presión Sanguínea/fisiología , Embarazo/fisiología , Adolescente , Adulto , Determinación de la Presión Sanguínea/instrumentación , Determinación de la Presión Sanguínea/estadística & datos numéricos , Monitoreo Ambulatorio de la Presión Arterial/estadística & datos numéricos , Femenino , Humanos , Persona de Mediana Edad , PosturaRESUMEN
PURPOSE: A prospective study to determine the usefulness of quantitative bacterial cultures of fluid obtained via fiberoptic bronchoscopy and bronchoalveolar lavage as an aid in the diagnosis of bacterial pneumonia. PATIENTS AND METHODS: All patients undergoing fiberoptic bronchoscopy with bronchoalveolar lavage during a 6 1/2-month period. Presence of pneumonia was determined using clinical, radiographic, laboratory, and histologic data. Quantitative bacterial cultures of bronchoalveolar lavage fluid were determined using a 1-microL culture loop. RESULTS: Quantitative bacterial cultures of bronchoalveolar lavage (BAL) fluid were sensitive and specific predictors of bacterial pneumonia. Using 10(3) colony-forming units (cfu)/mL as the threshold value for a positive culture, we determined the sensitivity and specificity to be 90% and 97%, respectively. The data were also analyzed for the subgroups of patients who were intubated or were receiving antibiotics. The sensitivity and specificity were 78% and 96% for the group of patients receiving antibiotics and 100% and 82% for the group of patients intubated for more than 24 hours at the time of BAL. Values for the area under the receiver operating characteristic curve for the 3 groups were 0.94, 0.88, and 0.96, respectively. CONCLUSIONS: Quantitative bacterial cultures of BAL fluid are sensitive and specific in the diagnosis of bacterial pneumonia. The use of antibiotics at the time of BAL reduces the sensitivity of the test, and prolonged intubation reduces the specificity of the test.
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Infecciones Bacterianas/diagnóstico , Líquido del Lavado Bronquioalveolar/microbiología , Neumonía/diagnóstico , Infecciones Bacterianas/microbiología , Broncoscopía , Recuento de Colonia Microbiana , Femenino , Humanos , Masculino , Neumonía/microbiología , Estudios Prospectivos , Curva ROC , Sensibilidad y EspecificidadRESUMEN
OBJECTIVE: To study the effect of a computerized medical record and other practice factors on the delivery of preventive health care. DESIGN: Prospective, controlled trial. SETTING: University general internal medicine teaching clinic. PARTICIPANTS: Forty-five internal medicine residents and their 4 supervising attending physicians. INTERVENTION: The study group used a computerized ambulatory medical record system that included health care maintenance reminders. The control group used a conventional paper record with a health care maintenance flow sheet. MEASUREMENTS AND MAIN RESULTS: The computer reminders significantly increased health care maintenance recommendations made to patients for proctosigmoidoscopy, tetanus vaccination, influenza vaccination, and pneumococcal vaccination, but not for fecal occult blood testing, mammography, Pap smears, or serum thyroxine screening in the elderly. First-year residents were nearly twice as successful as third-year residents in overall health care maintenance. Success scores varied markedly depending on which attending physician was supervising the residents. We found a strong interaction among group assignment, supervising attending, and level of training such that the reminders doubled success scores among first-year residents supervised by two of the attending physicians but had little effect on other subgroups. The time of year and the format of the reminder also had important effects for some of the maneuvers. CONCLUSIONS: Although computerized medical records markedly improved the performance of prevention maneuvers by committed physicians, many physicians using computer systems failed to make use of the resource. The reasons for this were complex. Future work in this area should carefully control for personal behaviors and focus upon administrative changes that more effectively implement these potentially powerful tools.
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Sistemas de Información en Atención Ambulatoria , Sistemas de Registros Médicos Computarizados , Servicios Preventivos de Salud , Anciano , Correspondencia como Asunto , Femenino , Hospitales Universitarios/organización & administración , Humanos , Masculino , Persona de Mediana Edad , Nebraska , Estudios ProspectivosRESUMEN
Predictor variables for multivariate rules are frequently selected by methods that maximize likelihood rather than information. We compared the discrimination and reproducibility of a prediction rule for pneumonia derived using extended dependency analysis (EDA), an information maximizing variable selection program, with that of a validated rule derived using logistic regression. Discrimination was measured by receiver-operating characteristic (ROC) analysis, and reproducibility by rederivation of the rule on 200 replicate samples of size 250 and 500, generated from a training cohort of 905 patients using Monte Carlo techniques. Four of the five predictor variables selected by EDA were identical to those selected by logistic regression. With each variable weighted by its conditional contribution to total information transmission, EDA discriminated pneumonia and nonpneumonia in the training cohort with an ROC area of 0.800 (vs 0.816 for logistic regression, p = 0.60), and in the validation cohort with an area of 0.822 (vs 0.821 for logistic regression, p = 0.98). EDA demonstrated reproducibility comparable to that of logistic regression according to most criteria for replicability. Replicate EDA models showed good discrimination in the training and testing cohorts, and met statistical criteria for validation (no significant difference in ROC areas at a one-tailed alpha level of 0.05) in 80.8% to 94.2% of cases. We conclude that extended dependency analysis selected the most important variables for predicting pneumonia, based on a validated logistic regression model. The information-theoretic model showed good discriminatory power, and demonstrated reproducibility according to clinically reasonable criteria. Information-theoretic variable selection by extended dependency analysis appears to be a reasonable basis for developing clinical prediction rules.
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Teoría de la Información , Modelos Logísticos , Aplicaciones de la Informática Médica , Computación en Informática Médica , Análisis Multivariante , Neumonía/epidemiología , Estudios de Cohortes , Humanos , Oportunidad Relativa , Neumonía/etiología , Reproducibilidad de los Resultados , Factores de RiesgoRESUMEN
OBJECTIVE: To determine whether the wording of the descriptions of life-sustaining interventions would affect the choices elderly patients make when completing advance directives. METHODS: Survey. SETTING: General community in Omaha, Nebraska. PATIENTS: Two hundred one community-dwelling elderly were selected from a population-based sample. MAIN OUTCOME MEASURES: Subjects were asked whether they would accept or reject three life-sustaining interventions: cardiopulmonary resuscitation, mechanical ventilation, or tube feeding in three separate hypothetical case scenarios. The three life-sustaining interventions were each described positively, negatively, and exactly as they are worded in a widely used advance directive. Subjects reviewed each scenario three times with three different descriptions of the three interventions. RESULTS: For the three interventions presented in three scenarios, subjects opted for the intervention 12 percent of the time when it was presented negatively, 18 percent of the time when it was phrased as in an advance directive already in use and 30 percent of the time it was phrased positively. One hundred fifty-five of the 201 subjects (77 percent) changed their minds at least once when given the same scenario but a different description of the intervention. Of these 155, 33 percent changed decisions one to three times, 33 percent changed decisions four to seven times, and another 34 percent changed decisions eight to seventeen times based solely on the description of the intervention. CONCLUSION: The decisions patients make about whether to accept or reject life-sustaining treatments are affected by the descriptions of the treatments. These findings emphasize the critical importance of doctor-patient consultation when patients execute advance directives.
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Directivas Anticipadas , Aceptación de la Atención de Salud , Privación de Tratamiento , Anciano , Anciano de 80 o más Años , Formularios de Consentimiento , Toma de Decisiones , Femenino , Humanos , Voluntad en Vida , Masculino , Nebraska , Medición de Riesgo , Encuestas y Cuestionarios , Terminología como Asunto , EscrituraRESUMEN
It has been suggested that clinical prediction rules are not reproducible, and that the most important variables frequently do not appear in replicate models. The authors studied the reproducibility of a validated rule for predicting radiographic evidence of pneumonia (ROC areas for the training and validation cohorts, 0.816 and 0.821, respectively). Two hundred replicate samples of size 250 and size 500 were generated by sampling without replacement from the original training cohort of 905 patients with a 14.6% prevalence of pneumonia. Forward selection was performed among 31 candidate variables by stepwise logistic regression. Using as reproducibility criteria: 1) inclusion of all five variables from the original model in the original order; 2) inclusion of all five variables in any order; 3) inclusion of the first three variables; 4) inclusion of the first two variables; 5) inclusion of the first variable; and 6) inclusion of any of the five variables: 2.5%, 13.5%, 48.5%, 85.5%, 98.0%, and 100% of replicate models of sample size 500, respectively, met the criteria, whereas 0%, 0%, 16.5%, 49.0%, 71.5%, and 97.5% of models of sample size 250 met the criteria (all comparisons by sample size p < .0001 except for criteria 1 and 6, p = 0.07). Mean ROC areas in the training and validation samples were 0.829 and 0.791 for replicate models of sample size 500, and 0.831 and 0.779 for models of sample size 250. There was no significant difference in ROC areas between training and validation cohorts for 80.5% of models of sample size 500, and for 75.3% of models of sample size 250.(ABSTRACT TRUNCATED AT 250 WORDS)
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Protocolos Clínicos , Modelos Estadísticos , Reproducibilidad de los Resultados , Atención Ambulatoria , Humanos , Funciones de Verosimilitud , Modelos Logísticos , Neumonía/diagnóstico por imagen , Pronóstico , Curva ROC , Radiografía , Análisis de Regresión , Trastornos Respiratorios/diagnósticoRESUMEN
Feedback to physicians about how they use information in making judgments can improve the quality of their judgments, but questions remain about which types of feedback are most effective. The authors conducted a controlled study of feedback in 60 medical students learning to predict the risk of cardiovascular death based on the presence or absence of five risk factors. After a pretest of 40 cases abstracted from patient records, the students worked through 173 computer-simulated cases and a posttest of 40 patient cases. The students received no feedback, probability feedback (correct probability of cardiac death for each case), cognitive feedback (the correct cue weights compared with their own weights derived from the previous set of cases), or both types of feedback. Students who received probability feedback markedly improved both base rate calibration and discrimination. Those who received only cognitive feedback showed no improvement over control on any of the measures of learning. All subjects were highly consistent in their weightings. The superiority of probability feedback differed from previous findings that cognitive feedback was essential for mastery of multiple-cue-probability learning tasks. The information on cue-outcome relationships given by cognitive feedback may be more useful when these relationships are complex and the combining rule is not known, while the precise outcome information provided by probabilistic feedback is more useful when the combining rule is known and the cue-outcome relationships are straightforward. Thus, the optimal method of learning depends on the nature of the task.
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Simulación por Computador , Cardiopatías/mortalidad , Pronóstico , Adulto , Retroalimentación , Cardiopatías/diagnóstico , Humanos , Masculino , Probabilidad , Factores de Riesgo , Estudiantes de MedicinaRESUMEN
As we understand the process of ambulatory care better, the need to effectively implement standards of practice becomes more apparent. To facilitate successful use of practice guidelines, we have integrated an artificial intelligence system of Medical Logic Modules into our computerized medical record. A rule shell allows rapid development and prototyping of rules which can be practice reminders, information gathering utilities, or standing orders. A set of utilities allows non-programmer clinicians to develop and maintain the rule set. We will demonstrate these enhancements in the context of the comprehensive patient record.
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Atención Ambulatoria , Inteligencia Artificial , Guías de Práctica Clínica como Asunto , Prescripciones de Medicamentos , Sistemas de Registros Médicos Computarizados , EnfermeríaRESUMEN
To investigate the relation between physicians' predicted probabilities of pneumonia and their utilities for ordering chest x-rays to detect pneumonia, the authors studied 52 physicians who ordered chest x-rays of 886 patients presenting to an emergency department with fever or respiratory complaints. Physicians estimated the probability of pneumonia prior to obtaining the results of the chest x-ray. Utilities were assessed by asking physicians to consider a hypothetical patient presenting with acute respiratory symptoms, with unknown chest x-ray status, and to rank on a scale from +50 ("best thing I could do") to -50 ("worst thing I could do") their rating scale utilities for not diagnosing pneumonia and not ordering a chest x-ray when the patient had pneumonia (i.e., missing a pneumonia), and for diagnosing pneumonia and ordering a chest x-ray when the patient did not have pneumonia (i.e., ordering an unnecessary x-ray). The utility for ordering an unnecessary x-ray was negatively correlated with average predicted probability (r = -0.1495, p = 0.29), whereas the utility for missing a pneumonia was positively correlated with average predicted probability (r = 0.2254, p = 0.11), although the correlations were not statistically significant. Relative chagrin, defined as the difference in these utilities, was significantly inversely correlated with average predicted probability (r = -0.2992, p less than 0.035), even after adjusting for the prevalence of pneumonia seen by each physician (partial r = -0.42, p less than 0.0027). It is concluded that physicians who experienced greater regret over missing a pneumonia than over ordering an unnecessary x-ray estimated lower probabilities of pneumonia for patients for whom they ordered x-rays.(ABSTRACT TRUNCATED AT 250 WORDS)
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Cuerpo Médico de Hospitales/psicología , Neumonía/diagnóstico por imagen , Pautas de la Práctica en Medicina/normas , Radiografía Torácica/estadística & datos numéricos , Análisis Costo-Beneficio , Toma de Decisiones , Servicio de Urgencia en Hospital , Hospitales Universitarios , Humanos , Illinois/epidemiología , Neumonía/economía , Neumonía/epidemiología , Valor Predictivo de las Pruebas , Radiografía Torácica/economía , Radiografía Torácica/normas , Encuestas y CuestionariosRESUMEN
The authors sought to explain regional differences in physicians' accuracies in diagnosing pneumonia by prospectively studying emergency department patients at three sites and analyzing differences in physicians' diagnostic strategies and patient characteristics. They enrolled 1,119 Illinois patients, 150 Nebraska patients, and 142 Virginia patients presenting with fever or respiratory symptoms for whom physicians ordered a chest radiograph because of suspicion of pneumonia. Emergency department physicians recorded patients' clinical findings and estimated the probability that a chest radiograph would show pneumonia. A measure of accuracy, the correlation between physicians' probability estimates and actual outcomes, was 0.41 (95% CI 0.36-0.46) at Illinois, 0.66 (95% CI 0.54-0.75) at Nebraska, and 0.55 (95% CI 0.42-0.65) at Virginia. Physicians' strategies at the three sites differed markedly in their weightings of asthma, signs of consolidation, cough, tachypnea, age, and gender. These differences in weighting paralleled differences in the optimal clinical strategies derived from patient data at the three sites. Differences in diagnostic accuracy were best explained by differences in the difficulties of diagnosing pneumonia in the populations. Physicians at each site used clinical findings in a way that was close to optimal for their location. This type of analysis provides a new tool for understanding the sources of regional variations in clinical practice.
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Competencia Clínica , Técnicas de Apoyo para la Decisión , Medicina de Emergencia/métodos , Juicio , Neumonía/diagnóstico por imagen , Pautas de la Práctica en Medicina/normas , Adulto , Medicina de Emergencia/normas , Humanos , Illinois/epidemiología , Modelos Psicológicos , Nebraska/epidemiología , Neumonía/diagnóstico , Neumonía/epidemiología , Radiografía , Virginia/epidemiologíaRESUMEN
Because physicians have been reluctant to accept computerized medical records systems, we sought to identify the barriers to acceptance and redesigned our ambulatory records system accordingly. We identified several problems physicians encounter in using our computerized medical record system (COSTAR), including physicians' hesitation to use a computer in front of their patients, physicians' poor keyboard skills, and the structural organization of the computerized medical record. We formed a users group to educate users and the group has helped identify solutions to these problems. We equipped the exam room terminals with a user-friendly, patient-specific menu. We created a new physician interface for COSTAR that was organized to function similarly to a patient's chart and features user-friendly menus that provide cues to the unsophisticated user. Physician use of exam room terminals tripled after the installation of the exam room menu. The new physician interface doubled physician use of COSTAR's scheduling features. Acceptance of the new interface as gauged by a user survey was excellent, with the majority stating it improved their patient care.
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Sistemas de Información en Atención Ambulatoria/estadística & datos numéricos , Actitud del Personal de Salud , Actitud hacia los Computadores , Sistemas de Registros Médicos Computarizados/estadística & datos numéricos , Interfaz Usuario-Computador , Centros Médicos Académicos , Nebraska , Médicos , Programas InformáticosRESUMEN
OBJECTIVE: To derive and validate a clinical rule for predicting pneumonic infiltrates in adult patients with acute respiratory illness. DESIGN: Prevalence studies in three settings. SETTING: Emergency departments of the University of Illinois Hospital at Chicago, the University of Nebraska Medical Center at Omaha, and the Medical College of Virginia at Richmond. PATIENTS: Symptoms, signs, comorbidity data, and chest roentgenogram results were recorded for 1134 patients from Illinois (the derivation set), 150 patients from Nebraska, and 152 patients from Virginia (the validation sets). All patients presented to the emergency department and had a chest roentgenogram to evaluate fever or respiratory complaints. MEASUREMENTS AND MAIN RESULTS: Within the training set, temperature greater than 37.8 degrees C, pulse greater than 100 beats/min, rales, decreased breath sounds, and the absence of asthma were identified as significant predictors of radiographically proved pneumonia in a stepwise logistic regression model (P = 0.001). The logistic rule discriminated patients with and without pneumonia in the training set with a receiver operating characteristic (ROC) area of 0.82. In the validation sets, the rule discriminated pneumonia and nonpneumonia with ROC areas of 0.82 and 0.76 after adjusting for differences in disease prevalence (P greater than 0.2 compared with the training set). The predicted probability of having pneumonia for patients with different clinical findings corresponded closely with the incidence of pneumonia among patients with such findings in the three settings. CONCLUSIONS: Among adults presenting with acute respiratory illness, a prediction rule based on clinical findings accurately discriminated patients with and without radiographic pneumonia, and was used in two other samples of patients without significant decrement in discriminatory ability. This rule can be used by physicians to develop more effective strategies for detecting pneumonia and for helping to determine the need for radiologic study among patients with acute respiratory disease.
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Pulmón/metabolismo , Enfermedades Respiratorias/metabolismo , Enfermedad Aguda , Humanos , Persona de Mediana Edad , Neumonía/complicaciones , Pronóstico , Curva ROC , Radiografía , Análisis de Regresión , Enfermedades Respiratorias/complicaciones , Enfermedades Respiratorias/diagnóstico por imagenRESUMEN
OBJECTIVE: To determine which procedures nephrologists do in practice, where they learned the procedures, and how much training they recommend to achieve and maintain clinical competence in each. DESIGN: Mailed survey. PARTICIPANTS: A random sample of 700 members of the American College of Physicians who were identified as practicing nephrologists; 516 (74%) responded. RESULTS: Acute peritoneal dialysis, acute hemodialysis, continuous arteriovenous hemofiltration, and percutaneous renal biopsy were done by 95%, 97%, 87%, and 91% of the respondents, respectively. Except for hemofiltration, procedures were learned by most respondents during fellowship training. Compared with general internists, fewer nephrologists did most of the 19 general procedures included in the survey. The number of nephrology procedures done during the past year varied considerably among respondents, as did the minimum number of procedures they recommended for achieving and maintaining competence. Neither the variation in number of procedures done nor recommendations regarding certification were explained by differences in practice characteristics. Median recommendations remained relatively constant among subgroups. CONCLUSIONS: Nearly all nephrologists do the four nephrology procedures included in the survey. Their opinions about the training needed for competence help to better define requirements for training programs. More attention should be focused on training and certifying practicing nephrologists in procedures learned after formal fellowship training.