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Biomedical subjects

J L Wagner

Publications and source records attributed to J L Wagner.

At least 73 records · Page 4Linked to original sources
PubMed1991

Cost effectiveness of colorectal cancer screening in the elderly.

OBJECTIVE: To assess the cost effectiveness of a periodic program of colorectal cancer screening in the elderly. DESIGN: A model was constructed of four strategies for the periodic screening of persons 65 to 85 years of age. The effect of each strategy on life expectancy and health care costs was estimated under assumptions that were uniformly unfavorable to screening. Cost and added years of life were discounted at 5% per year. Cost per year of life gained from screening was calculated for each screening strategy. DATA SOURCES: Assumptions used in the model were based on a review of pertinent studies; those studies with results more unfavorable to screening were given more weight. Strengths and weaknesses of studies are discussed. MAIN RESULTS: A program of annual fecal occult blood testing (FOBT) in the elderly would detect at least 17% of the expected cases of cancer and could cost $35,000 per year of life saved. Screening schedules that include periodic sigmoidoscopy would prevent more cases of cancer but could cost between $43,000 and $47,000 per year of life gained. These estimates are based on uncertain assumptions, but results were not extremely sensitive to further relaxation of the values of the most uncertain assumptions. In no case did the cost per year of life gained from annual FOBT exceed $55,000 or did the cost per year of life gained from FOBT with sigmoidoscopy every 5 years exceed $61,000. CONCLUSIONS: Although colorectal cancer screening is costly in the aggregate, its potential medical benefits make it a reasonably cost-effective preventive intervention for the elderly.

Aged↗
PubMed1991

An experimental evaluation of a prototype public access nutrition information system for supermarkets.

Located the Nutrition for a Lifetime System (NLS-1), a prototype interactive information system, in a large supermarket to help users decrease high-fat food purchases and increase high-fiber food purchases. Study participants were randomly assigned to control (n = 23; used the NLS-1 to enter food purchases only) or experimental (n = 26; viewed videodisc instructional programs, received prompts, made commitments, received feedback from the NLS-1) conditions. According to data entered in the NLS-1 and actual food shopping receipts, experimental participants significantly reduced higher fat purchases. Increases in higher fiber purchases favored the experimental group but were not significant.

Adult↗
PubMed1991

A divided attention analysis of the effects of methylphenidate on the arithmetic performance of children with attention-deficit hyperactivity disorder.

Thirteen boys with Attention-Deficit Hyperactivity Disorder (ADHD) completed 80 arithmetic problems presented on a computer screen by typing a two digit answer. On half the trials, a foot press was required to terminate a computer-generated tone presented 2 seconds before, 1 second before, 1 second after, and 2 seconds after arithmetic problem presentation. Compared to placebo, methylphenidate resulted in significantly faster reaction times (RTs) to tone probes and faster answers to arithmetic problems when the two tasks did not overlap in time, but not when simultaneous processing was required when the probe was presented 2 seconds after arithmetic problems. When dual processing taxed cognitive capacity, methylphenidate still improved accuracy on the primary arithmetic task relative to placebo, but at the expense of speed of performance on the secondary RT task. When ADHD children fail to allocate available resources to a primary cognitive task, treatment with methylphenidate may result in reallocation of existing cognitive capacity from a secondary task to the primary task.

Attention↗
PubMed1991

Altering shoppers' supermarket purchases to fit nutritional guidelines: an interactive information system.

This study reports the results of one effort to help supermarket shoppers alter food purchases to make purchases (and meals) that are lower in fat and higher in fiber. A prototype interactive information system using instructional video programs, feedback on purchases with specific goals for change, weekly programs, and the ability to track user interactions and intended purchases was evaluated. The major dependent measure was users' actual food purchases as derived from participants' highly detailed supermarket receipts. After a 5- to 7-week baseline phase, participants were randomly assigned to an experimental or control condition for the 7- to 8-week intervention phase. A follow-up phase began 5 to 8 weeks after participants completed the intervention and discontinued use of the system. The results indicated that experimental participants, when compared to control participants, decreased high fat purchases and increased high fiber purchases during intervention, with evidence for some maintenance of effect in follow-up. Plans for increasing the use and impact of the system are discussed.

Dietary Fats↗
PubMed1991

Costs and health consequences of cholesterol screening for asymptomatic older Americans.

To predict the consequences of cholesterol screening among elderly Americans who do not have symptoms of heart disease, we explore the cost implications of a cholesterol screening program, evaluate evidence linking hypercholesterolemia to coronary heart disease and mortality in the elderly, and describe the likely effects of therapy of hypercholesterolemia. According to our calculations, if all Americans 65 years of age and older adhered to a cholesterol screening program similar to the one proposed by the National Cholesterol Education Program, minimum annual expenditures for screening and treatment would be between $1.6 billion and $16.8 billion, depending on the effectiveness of diet and the cost of the medications used to treat hypercholesterolemia. There is no direct evidence that this program would lessen overall morbidity or extend the lives of elderly Americans.

Aged↗
PubMed1990

The competitive solution and the health care problems of today.

Mark Pauly claims that a "competitive" health care system will solve the health care cost crisis. This article examines how well the competitive solution deals with the five central problems of the health care system: (1) almost universal lack of adequate health insurance for nursing homes and home care; (2) Medicaid's penurious approach to payment for health services for the poor; (3) the emergence of a dual health care system, especially for children; (4) the entrenched waste and inefficiency of the health care system; and (5) consumers' inability to judge the quality of health care. The competitive solution does not eliminate any of these problems--and may not even improve some of them.

Economic Competition↗
PubMed1989

The release of C5a in complement-activated serum does not require C6.

The influence of terminal complement components on the generation and release of the complement C5a fragment was investigated by comparing the levels of C5a in complement-activated serum with the levels of C5a produced in serum depleted of complement C6. In order to investigate the release of C5a, a modified C5a assay was developed that utilizes an anti-C5b monoclonal antibody to remove C5, C5b, and C5b-C5a complexes from samples prior to C5a assay. The modified assay was developed because the standard methodology, which includes an acid-precipitation step designed to dissociate C5a and C5b, cannot distinguish free C5a from the C5a that is bound to C5b. Therefore, the standard methodology is not capable of monitoring the influence of terminal components on C5a/C5b dissociation. Levels of C5a were measured in complement-activated whole human serum, in serum depleted of C6, and in serum containing inhibitory levels of anti-C6 Fab using both the modified C5a assay and the standard methodology. Sera were complement-activated with either zymosan to activate the alternative complement pathway or with antibody-coated sheep erythrocytes to activate the classical pathway. The levels of free C5a in C6-depleted sera after activation were equivalent to the C5a levels in activated whole serum, indicating that C6 is not required for the release of C5a from C5b. In addition, the quantity of C5a detected in zymosan-activated sera using the standard acid-precipitation methodology was greater than C5a levels when assayed using the modified immunoadsorption technique, confirming that acid-treatment enhances the C5a dissociation and promotes C5a recovery. Since the other terminal components, C7, C8, and C9, bind to C5b only after C5b only after C6 is bound, these results indicate that none of the terminal components are required for the release of C5a. Although the terminal components could influence the rate of C5a release, the quantity of C5a released in serum was entirely independent of terminal components.

Animals↗
PubMed1989

Changing prognosis for very low birth weight infants.

Obstetric decisions regarding extremely premature infants are based in part on their long-term prognosis. This review pools data from perinatal center reports to update mortality and morbidity trends for each subgroup of very low birth weight infants. Throughout the last 10 years, there has been steady and statistically significant improvement in neonatal mortality rates among inborn very low weight infants (1500 g or less). The most substantial improvement of the 1980s over the late 1970s is in the 750-1000-g birth weight group, in which today's infants have about a 70% chance of surviving if they have access to neonatal intensive care. Mortality in infants born weighing less than 750 g is still very high; overall about two-thirds die, but results are highly variable across centers, with several centers reporting 50-70% survival. The rate of serious long-term disability increases with decreasing birth weight, but within each birth weight group, the proportion of survivors who have serious handicaps has not changed significantly since the introduction of neonatal intensive care. For infants born between 1975-1985, 26% of surviving infants with birth weights below 800 g, 17% of survivors with birth weights between 750-1000 g, and 11% of survivors with birth weights between 1000-1500 g have major handicaps at 1 or 2 years of age. Because many very sick newborns who previously would have died are now surviving, an increasing rate of handicap might have been expected.

Humans↗
PubMed1988

Sleeping on a wedge diminishes exposure of the esophagus to refluxed acid.

In a randomized crossover study, we compared the effect on gastroesophageal reflux of three sleeping positions: elevation of the head of the bed on standard eight-inch bed blocks; elevation by a foam wedge; or a flat position. Fifteen subjects with moderate to severe reflux symptoms were studied in each position on consecutive nights using continuous intraesophageal pH monitoring. We found no difference in reflux frequency among the positions. The wedge caused a statistically significant decrease in the time that distal esophageal pH was less than 4 as compared to the flat position. The wedge also decreased the longest episode experienced by the subjects. Elevation on blocks caused a similar improvement in parameters but failed in this study to achieve statistical significance. Both elevation by a wedge and on blocks showed a trend towards a decrease in clearance time as compared to the flat position. The patients did not always prefer elevation on a wedge, but for some it is a valuable alternative to elevation by bed blocks.

Aged↗
PubMed1988

Prompting one low-fat, high-fiber selection in a fast-food restaurant.

Evidence increasingly links a high-fat, low-fiber diet to coronary heart disease and certain site cancers, indicating a need for large-scale dietary change. Studies showing the effectiveness of particular procedures in specific settings are important at this point. The present study, using an A-B-A-B design and sales data from computerized cash registers, replicated and extended previous work by showing that inexpensive prompts (i.e., signs and fliers) in a national fast-food restaurant could increase the sales of salads, a low-fat, high-fiber menu selection. Suggestions also are made pertinent to more widespread use of the procedures.

Behavior Therapy↗
PubMed1987

Cost containment and computerized medical imaging. Meeting one another's needs?

Today, computers are used in several important and fast-growing medical imaging modalities, such as digital subtraction angiography, positron emission tomography, magnetic resonance imaging, nuclear medicine, and diagnostic ultrasound. The ultimate test for the computer in medical imaging will be its ability to replace traditional film-based radiography as the mechanism for displaying, communicating, and storing imaging information. This transition will require radiologists and other imagers to accept information in digital form. The speed of that acceptance depends on the economic incentives of the health care system. These are changing as a result of cost containment, which is moving away from fee-for-service toward bundled payment. The increase in capitated health plans will encourage the development of digital radiography systems that realistically trade-off the perceived quality needs of radiologists with the costs of producing and operating such systems.

Cost Control↗