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Biomedical subjects

N V Dawson

Publications and source records attributed to N V Dawson.

At least 19 recordsLinked to original sources
PubMed1991

A risk-benefit analysis of elective bilateral oophorectomy: effect of changes in compliance with estrogen therapy on outcome.

A bilateral oophorectomy at the time of elective hysterectomy is often performed to prevent ovarian cancer. The assumption that endogenous estrogen can be easily replaced with supplemental medication fosters the decision for routine oophorectomy. Published reports on the use of postmenopausal estrogen indicate that compliance is less than perfect. This fact could affect the overall outcome. Decision analysis techniques with Markov cohort modeling were used to evaluate the policy of elective bilateral oophorectomy. Results from studies judged methodologically sound were combined to determine values representing the influence of estrogen on coronary heart disease, breast cancer, and osteoporotic fracture. The decision tree also explicitly incorporated patient compliance. When compliance with estrogen therapy is assumed to be perfect, oophorectomy yields longer life expectancy than retaining the ovaries. When actual drug-taking behavior is considered, retaining the ovaries results in longer survival. This analysis highlights the importance of including the effects of patient compliance with treatment recommendations when the impact of a health policy decision such as prophylactic surgery is assessed.

Adult↗
PubMed1991

Organizing the Metro Firm System for research.

During the mid-1970s, four similar groups of patients and providers were created with the institution of the Firm System at Cleveland Metropolitan General Hospital (Metro). In the early 1980s, ongoing randomization was initiated for patients and physicians, setting the stage for the performance of randomized controlled trials. Techniques such as stratification and blocking are used with randomization to ensure that equivalent numbers and characteristics of patients and physicians are distributed among the firms. Comparability of key patient and physician features across firms has been documented during the baseline periods of several recent firm studies. Dissimilarities among firms can occur secondary to differential drop-out of patients (residue cohort effect), or to administrative decisions that adversely affect the structural or operational integrity of the system. Prestudy evaluations of equivalence and vigilant system maintenance programs are methods to identify and minimize important differences among firms.

Female↗
PubMed1990

Hemodynamic status in critically ill patients with and without acute heart disease.

Physicians have been urged to reduce the use of the pulmonary artery catheter. However, there are no guidelines to help the clinician make the decision to use or withhold invasive monitoring in the individual patient. This study was designed to examine the accuracy of physician estimates of cardiac function in a spectrum of patients with hemodynamic instability to determine whether differences in accuracy among subgroups would suggest subgroups of patients who could be managed without invasive measurements. Physician estimates of cardiac index were found to be sufficiently accurate in patients without acute heart disease that initial management without invasive monitoring may be appropriate in selected cases. However, due to the general inaccuracy of physician estimates, efforts to improve the accuracy of clinical judgments of cardiac function and hemodynamic status should be pursued with vigor in patients both with and without acute cardiac dysfunction.

Aged↗
PubMed1988

Occult proximal deep vein thrombosis: its prevalence among patients admitted to a rehabilitation hospital.

This study was designed first to determine the prevalence of occult proximal deep vein thrombosis (DVT) in stroke patients admitted to rehabilitation hospital using the technique of impedance plethysmography (IPG), and second, to identify clinical findings which may be indicators of an increased risk for the development of proximal DVT. Impedance plethysmography was performed on 105 consecutive stroke patients within one week of admission to our hospital. It was found that 34 out of 100 patients with adequate studies had abnormal IPG, two out of the 34 had known DVT, leaving 32 out of 98 with undiagnosed DVT (19 on the paretic side alone, nine bilateral, and four on the nonparetic side). Using logistic regression analysis, it was determined that profound weakness, male gender, interval between the stroke and IPG, edema, and leg hyperpigmentation were independently associated with positive IPG. Since IPG has a high positive predictive value for proximal DVT, one must assume that most of our patients with positive IPG have proximal DVT. Routine screening of stroke patients for DVT seems indicated and probably should include noninvasive venous studies such as serial IPG. The most efficient screening protocol needs to be determined.

Adult↗
PubMed1987

Resident knowledge of charges: are we asking the right questions?

Physician knowledge of costs and charges for medical services is thought to have substantial relevance for cost containment. Unfortunately, numerous studies have demonstrated the difficulties in using educational techniques to improve knowledge and reduce charges. Furthermore, reductions in charges, when achieved, have not correlated with improved physician knowledge. The authors examined several methods of ascertaining physician knowledge of charges and they suggest that previous methods may have been too insensitive. Previous reports may have underestimated physician knowledge of costs and charges.

Educational Measurement↗
PubMed1987

Effect of an academic group practice on patient show rates: a randomized controlled trial.

Ambulatory medical clinics at academic centers are reputed to be expensive, inefficient, and poorly regarded by the medical residents who staff them. In an effort to address these problems, some centers have reorganized their traditional clinics into group practices. These group practices are thought to be more effective for teaching and providing services than are the traditional clinics. This is a report on the results of a study in which the authors reorganized two of four firm clinics into group practices in order to test the influence of the organizational changes on the various aspects of ambulatory care. During this controlled prospective trial of the group practice model, higher show rates were observed for patients in the group practices than in the traditional clinics (70% vs 65%, P less than 0.0005). The possible reasons for the higher rates are discussed.

Academic Medical Centers↗
PubMed1987

Should all pregnant women be screened for hepatitis B?

To assess the sensitivity of historical risk factors for identification for hepatitis B surface antigen (HBsAg)-positive parturients, 4399 pregnant women were consecutively screened for HBsAg. Information regarding risk for hepatitis B infection was obtained from each HBsAg-positive parturient. Twenty-three HBsAg-positive subjects were identified (5.2/1000 deliveries). The HBsAg carrier rate (18/2231, or 8.1/1000 deliveries) was significantly higher in women of black, Asian, or Hispanic origin than in the remaining ethnic groups (non-Hispanic whites plus all others, 5/2168, or 2.3/1000 deliveries) (chi square, 5.95; p = 0.016). Risk factors for identification of HBsAg-positive women were present in 10 of 22 asymptomatic subjects (sensitivity, 45%; 95% confidence interval, 24% to 68%). Much of the information required to assess one of these risk factors, previous infection, involved detailed questioning and is unlikely to be obtained in the context of conventional obstetrical care. Routine maternal HBsAg screening programs may be needed if transmission of hepatitis B from mother to infant is to be prevented.

Carrier State↗
PubMed1986

The cost implications of academic group practice. A randomized controlled trial.

We evaluated the reorganization of a general medical clinic into several group practices, using equivalent groups of patients and physicians in a randomized controlled trial. The group practice, unlike the traditional clinic, provided decentralized registration, clinic coverage five days a week, and telephone coverage at night and on weekends. Residents worked in small groups with an attending physician, nurse practitioner, and receptionist. All financial activity involving a sample of 2299 patients was followed during the 11-month intervention. The total hospital charges per patient were 26 percent lower for the patients seen in the group practice than for those seen in the traditional clinic (P = 0.003). This difference was primarily attributable to inpatient charges, which were 27 percent lower per patient hospitalized (P = 0.004). The mean length of stay was 8.3 days among group-practice patients and 10.5 days among traditional-clinic patients (P = 0.011). We conclude that organizational changes to improve outpatient access and to integrate inpatient and outpatient services can decrease medical charges.

Academic Medical Centers↗
PubMed1986

Academic group practice. The patient's perspective.

The effect upon patient satisfaction of a reorganization of a traditional medical clinic into a group practice model was examined in a controlled trial in which both patients and physicians were randomized. The group practice model, unlike the traditional clinic, provided decentralized registration, 5 days/week clinic coverage, and night/weekend phone coverage. Residents worked in small groups with an attending physician, a nurse practitioner, and a receptionist. This reorganization resulted in a substantial decrease in charges and utilization for patients in the experimental group. A panel of 302 patients was interviewed prior to the reorganization and 1 year later. Patients in the experimental groups perceived improvements in access to their physicians as well as decreases in clinic waiting time and decreases in the lag time between requesting and obtaining an appointment. General health perceptions and other satisfaction measures were unchanged. The authors conclude that a group practice organization can result in decreased patient charges without substantially altering patient satisfaction.

Academic Medical Centers↗
PubMedDate not supplied

Systematic errors in medical decision making: judgment limitations.

Much of medical practice involves the exercise of such basic cognitive tasks as estimating probabilities and synthesizing information. Scientists studying cognitive processes have identified impediments to accurate performance on these tasks. Together the impediments foster "cognitive bias." Five factors that can detract from accurate probability estimation and three that impair accurate information synthesis are discussed. Examples of all eight factors are illustrated by reference to published articles. The authors suggest ways to minimize the negative influences of these factors.

Cognition↗
PubMedDate not supplied

The effect of patient gender on the prevalence and recognition of alcoholism on a general medicine inpatient service.

OBJECTIVES: 1) to determine the rate of alcoholism among general internal medicine inpatients, 2) to assess the recognition and referral rates of these patients by their physicians, 3) to determine the effect of patient gender on physician recognition of alcoholism, and 4) to compare the observed alcoholism rates with rates reported in frequently cited studies, controlling for gender distribution. DESIGN: Cross-sectional study, face-to-face interviews. SETTING: A large, county-owned metropolitan teaching hospital. PATIENTS/PARTICIPANTS: Adult patients admitted to an inpatient general medical firm. From among 95 consecutive admissions, 78 patients (81%) entered the study. INTERVENTION: The Michigan Alcoholism Screening Test (MAST) was administered to all study subjects. Chart reviews provided evidence of physician recognition and referral of patients with alcoholism. The observed rate of alcoholism was compared with rates reported in frequently cited studies after stratifying by type of service sampled and alcoholism assessment method used. Rates were then standardized for gender using the direct method. MEASUREMENTS AND MAIN RESULTS: Twenty-two patients (28%) were found to be alcoholic by MAST criteria (scores of 5 or higher). Scores in the range indicative of alcoholism were observed more frequently among the 36 men than among the 42 women (p = 0.002) and varied by age group. Only the interaction between gender and age group was significant (p = 0.023). Sixteen of the 22 patients (73%) with alcoholism by MAST criteria were identified as alcoholic by physician evaluation. Physicians were significantly more likely to identify as alcoholic those patients with MAST scores higher than 29 and tended to more readily identify men who had alcoholism than women. Among physician-identified patients, only about one in five was referred for rehabilitation. The standardized alcoholism rate found (291/1,000) ranked about halfway between the highest and the lowest standardized rates from nine other studies of medicine inpatient services (465/1,000 and 112/1,000). CONCLUSIONS: Patient gender affected the prevalence of alcoholism and influenced its recognition by physicians. Alcoholism by MAST criteria was found in one in eight female and nearly one in two male inpatients. Physician recognition was higher for men and for more severely affected patients. An understanding of gender effects is essential to the appropriate interpretation of the results of screening tests for alcoholism and to understanding differences in reported crude rates of alcoholism among studies. Supplementing clinical impressions with the routine use of standardized methods for detecting alcoholism is recommended.

Adult↗
PubMedDate not supplied

Hindsight bias: an impediment to accurate probability estimation in clinicopathologic conferences.

Although clinicopathologic conferences (CPCs) have been valued for teaching differential diagnosis, their instructional value may be compromised by hindsight bias. This bias occurs when those who know the actual diagnosis overestimate the likelihood that they would have been able to predict the correct diagnosis had they been asked to do so beforehand. Evidence for the presence of the hindsight bias was sought among 160 physicians and trainees attending four CPCs. Before the correct diagnosis was announced, half of the conference audience estimated the probability that each of five possible diagnoses was correct (foresight subjects). After the correct diagnosis was announced the remaining (hindsight) subjects estimated the probability they would have assigned to each of the five possible diagnoses had they been making the initial differential diagnosis. Only 30% of the foresight subjects ranked the correct diagnosis as first, versus 50% of the hindsight subjects (p less than 0.02). Although less experienced physicians consistently demonstrated the hindsight bias, more experienced physicians succumbed only on easier cases.

Clinical Competence↗