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S V Williams

Publications and source records attributed to S V Williams.

At least 55 records · Page 3Linked to original sources
PubMed1988

Guiding individual decisions: a randomized, controlled trial of decision analysis.

In early 1983, all 1,280 faculty and resident physicians at one hospital who were eligible to be vaccinated against hepatitis B were divided randomly into three groups: Group 1 physicians received general information about the risks and benefits of alternative vaccine decisions; Group 2 physicians were additionally invited to provide personal information for an individualized decision analysis (12.6 percent responded); and Group 3 physicians, who served as controls, were not contacted. In one year's follow-up, 20 percent of physicians were screened for hepatitis B antibody or vaccinated. More Group 2 physicians whose decision analyses recommended screening or vaccination took these actions (39 percent) than any other group. Group assignment remained significantly associated with vaccine decisions after analyzing results by the "intention to treat" principle, and after adjusting for training status, exposure to blood and blood products, and pre-study intentions about the vaccine. Despite the low overall vaccine acceptance rate, it is concluded that individualized decision analysis can influence the clinical decisions taken by knowledgeable and interested patients.

Clinical Trials as Topic↗
PubMed1987

Gout and pseudogout of the temporomandibular joint.

The temporomandibular joint is rarely affected by gout or pseudogout. The following article presents two case reports that demonstrate gout and pseudogout of the temporomandibular joint. The surgical treatment and diagnostic criteria for these entities are presented and discussed.

Adult↗
PubMed1986

Comparing aggregate estimates of derived thresholds for clinical decisions.

Thresholds for medical decision making are the probabilities of disease at which clinicians choose to initiate testing or therapy. A descriptive analysis of clinicians' decision making can derive their test and test-treatment thresholds and has the potential to explain variations in test utilization. A previously described method summarizes thresholds for a group of clinicians by determining the range of probability which includes the maximum number of clinicians' individual thresholds. However, there is no statistical procedure to compare the summary measure of thresholds that is derived from the distribution of clinicians' thresholds. We describe two alternative methods of developing a summary measure of the thresholds for a group of clinicians. These alternative methods enable the analyst to apply standard statistical tests when analyzing the decision-making behavior of groups of clinicians. For the "Unweighted Mean of the Midpoints" method, confidence limits of means and standard t-tests can be used to compare different groups. For the "Weighted Mean of the Midpoints" method, a weighted standard error of the mean can be calculated to determine confidence intervals, and a weighted t-test or weighted regression can be used to compare weighted means of the midpoints of threshold ranges.

Angiography↗
PubMed1985

The impact of DRG-based prospective payment on clinical decision making.

The Medicare Prospective Payment System (PPS) and the financial incentives it creates are likely to influence physician practices, as well as to offer new opportunities for research into clinical decision making. Hospital managers and physicians alike will need to look increasingly to decision analysis for answers regarding technology assessment and the cost-effectiveness of clinical practices. Areas of research in which decision analysis might contribute significantly include: the compromise between cost and quality, the comparative advantages of outpatient versus inpatient procedures, and the appropriate timing of patient discharge or transfer.

Cost Control↗
PubMed1984

Teaching cost-effective diagnostic test use to medical students.

The purpose of this project was to develop and evaluate a program to teach medical students how to order diagnostic tests in a cost-effective manner. The 1-month educational program included a seminar, a simulated patient-care exercise, special case presentations by students, newsletters about diagnostic tests, and concurrent review of patients' bills. Content analysis of answers to open-ended questions and pretests and posttests were used to measure differences in the study and control groups. Although students said the program was useful, no significant differences were found in students' knowledge, attitudes, or simulated test-ordering behavior. The authors conclude that the lack of improvement in objective measures limits the potential effectiveness of restricted efforts such as this one and that the discrepancy between the subjective and objective measures reinforces the need for more rigorous evaluations of programs that teach cost-effective diagnostic test use.

Attitude of Health Personnel↗
PubMed1984

A course in clinical decision making adaptable to diverse audiences.

Faculty at the University of Pennsylvania have developed a prototype course in clinical decision making that can be adapted to the diverse backgrounds of a variety of medical audiences. The course was offered in its entirety to third and fourth-year medical students and in abbreviated form to two postgraduate audiences (community and university-based physicians) during 1982. Methods were developed for content, process, and outcome evaluation for the courses; the latter consisted of pretest and posttest comparisons of performance on a written examination. Ninety-four individuals attended one or more sessions of the three courses. All courses were very favorably received, although the postgraduate audiences perceived less clinical relevance than educational relevance in the material (p less than 0.05). The medical students performed better on the pretest than either group of physicians, with the student-university physician difference reaching statistical significance (p less than 0.01). Nevertheless, all groups performed better on the posttest than on the pretest (p less than 0.001) and the degree of improvement was no different among the groups (p greater than 0.29). We conclude that our course's concepts and skills can be effectively adapted to and assimilated by physicians at all levels of training and experience.

Curriculum↗
PubMed1984

Unrecognized redistributions of revenue in diagnosis-related group-based prospective payment systems.

The Medicare prospective payment system, which is based on the diagnosis-related group patient-classification system, identifies previously unrecognized redistributions of revenue among diagnosis-related groups and hospitals. The redistributions are caused by two artifacts. One artifact results from the use of labor market indexes to adjust costs for the different prices paid by hospitals in different labor markets. The other artifact results from the use of averages that are based on the number of hospitals, not the number of patients, to calculate payment rates from average costs. The effects of these artifacts in a sample data set have been measured, and it was concluded that they lead to discrepancies between costs and payments that may affect hospital incentives--the overall payment for each diagnosis-related group--and Medicare's total payment.

Costs and Cost Analysis↗
PubMed1984

Methodological limitations in case mix hospital reimbursement, with a proposal for change.

We have found five methodological limitations in the creation and implementation of the diagnosis related group (DRG) patient classification system, which is used to define a hospital's case mix. There are four methodological limitations in the system that Klastorin and Watts have proposed to identify hospital peer groups. We conclude that the effects of these limitations should be sought, and we propose studies to measure their extent. We also propose that these two approaches can be combined to create an improved hospital reimbursement program that accurately measures differences between hospitals caused by case mix and peer group characteristics.

Costs and Cost Analysis↗
PubMed1984

Health insurance under competition: would people choose what is expected?

To determine relative preferences for different cost-sharing options, we asked a 17% random sample of 2,754 nonunion employees to compare health insurance policies that differed in the level of 1) deductible amount, 2) coinsurance rate, 3) coinsurance limit, 4) maximum liability, and 5) price. Using conjoint analysis, we derived preference curves for each of the five components and measured preferences for the compromise between more coverage and the corresponding price increase. In contrast to other studies, our findings suggest that under fair market prices, respondents would choose policies with greater coverage for catastrophic illness, and they would as likely choose cost-sharing policies that contain incentives to reduce utilization as they would choose policies without these incentives.

Adult↗
PubMed1983

How many intensive care beds are enough?

Rapid changes in technology have forced many hospitals to consider changes in the size of their ICUs. One method of predicting intensive care bed needs creates a mathematical model of the unit which simulates the unit's operation. This report describes a model that provided information to a physician group charge with deciding how many beds to include in a proposed expansion of one hospital's ICU. As the total number of beds in the simulated unit increased from 7 to 15, the model predicted a linear increase in the number of empty beds and a nonlinear decrease in the number of prematurely discharged patients. Based on the results, the group chose to leave the unit's size unchanged at 11 beds. The immediate result was to facilitate planning by providing quantitative estimates of the consequences of different choices. The long-term result was an ICU whose size accommodated patient needs despite changing demand for services.

Hospital Bed Capacity↗
PubMed1983

A model of physicians' practice attributes determination.

This paper presents a conceptual framework for modelling physicians' styles of practice. It also develops and estimates a causal model of practice style determination. The method allows simultaneous analysis of different practice styles and their determinants. The paper provides new insights into physician decision-making and, in particular, the positive relationship between fees and the number of physicians.

Career Choice↗
PubMed1983

Limited usefulness of the proportion of tests with normal results in review of diagnostic services utilization.

We tested the hypothesis that the proportion of normal results in tests ordered by a physician correlates directly with the proportion of tests that are disapproved by a utilization review audit for inappropriate test use. Auditors reviewed 3497 charts for 13 067 repeated determinations of 10 diagnostic tests ordered by 81 medical residents to determine if test use had been appropriate, according to explicit criteria. By the Pearson product-moment correlation coefficient, there was a significant (p less than 0.001) correlation between the proportion of normal results in tests ordered by residents and the residents' audit-disapproval rates, a previously undocumented relationship. Although statistically significant, the correlation coefficient of 0.25 means that the proportion of normal tests results predicted only 6% of the variance in the audit-disapproval rates. This relationship is not strong enough to use the proportion of normal results as a measure of a physician's inappropriate test use, except to select physicians for utilization review.

Chemistry, Clinical↗
PubMed1982

Improved cost allocation in case-mix accounting.

Traditionally, many hospital costs have been allocated to patients using indirect measures that do not always reflect the value of the resources used to provide care. When, for example, costs are allocated by multiplying the patient's charges by the hospital's ratio of costs to charges, the allocated cost does not reflect actual cost because the hospital does not uniformly charge for services in proportion to their cost. The choice of method for cost allocation will be as important for the newly developed case-mix cost-accounting systems as it has been for traditional cost-accounting systems. To illustrate how the use of an indirect cost-allocation method might affect the output of a case-mix cost-accounting system, operating room, radiology and clinical laboratory costs were assigned to 106 hospitalized inguinal hernia patients in two diagnosis-related groups (DRGs) using both the hospital's existing cost-allocation method and a method that measures costs directly. Total costs and the costs in each department were significantly lower in each DRG using the direct method. It was concluded that patients in these two DRGs were being assigned more than the actual cost of their care with the existing cost-allocation method and, therefore, that the existing method prevented the case-mix accounting system from providing accurate management information.

Accounting↗
PubMed1982

The characteristics of stat laboratory tests.

We studied the use of stat (ie, statim--as soon as possible) laboratory tests at a university teaching hospital. For the 20 most frequently performed tests, 35.7% of the determinations were performed on a stat basis. The frequency with which a test was ordered on a stat basis ranged from 6.0% (for ESR) to 61.5% (amylase level). The proportion of laboratory test requests from a hospital service that were ordered stat ranged from 3.8% (orthopedic surgery) to 100% (emergency services). The daily number of regular laboratory test requests decreased significantly over the weekend, but the daily number of stat requests fell less sharply. The number of requests for routine tests decreased after 6 pm, but the number of requests for stat tests remained relatively constant until about midnight.

Blood Chemical Analysis↗