The concept of prevention: a good idea gone astray?

Over time, the definition of prevention has expanded so that its meaning in the context of health services is now unclear. As risk factors are increasingly considered to be the equivalent of "diseases" for purposes of intervention, the concept of prevention has lost all practical meaning. This paper reviews the inconsistencies in its utility, and suggests principles that it should follow in the future: a population orientation with explicit consideration of attributable risk, the setting of priorities based on reduction in illness and avoidance of adverse effects, and the imperative to reduce inequities in health.

Identifying efficient dairy producers using data envelopment analysis.

The objective of this research was to calculate the efficiency of a group of Pennsylvania dairy farms to determine factors that contributed to efficiency in production and business management. Data envelopment analysis (DEA) was used to estimate the efficiency. Two models were developed to measure the efficient use of physical (land, cows, and labor) inputs to produce physical (milk and butterfat) outputs, and the use of physical and economic (debt capital) inputs to produce physical and economic (income) outputs. The results showed that about 29% of the producers in our sample were DEA-efficient and demonstrated that there was no combination of inputs used by efficient producers that was best. In addition, the method of analysis illustrated the benefits of DEA in that it is possible to identify the set of efficient producers that inefficient producers can benchmark to in an effort to achieve similar levels of efficiency. Finally, the analysis demonstrated that producers should not benchmark to the highest level of production, but rather should combine resources in land, labor, cows, and debt capital to achieve an efficient level of production, which indeed may be less than the maximum production level of the group.

Relationships between selected human resource management practices and dairy farm performance.

The objectives were to identify relationships between human resource management (HRM) practices used by dairy farm businesses and the productivity and profitability of the dairies. Explanatory variables were the following practices: training, job descriptions, standard operating procedures, milk quality incentives, and the employment of Spanish-speaking employees. The dependent variables were return on assets, return on equity, rolling herd average, and somatic cell count. The effects of individual HRM practices were analyzed to test for means separation between groups that "used" and those that "did not use" HRM practices. The results did not support expectations that differences exist between the groups. However, a significant positive relationship was found between return on equity and the use of continued training (used = 10.61%; did not use = -62.38%), and a significant negative relationship was found between the use of standard operating procedures for feeding and somatic cell count (used = 263,000; did not use = 214,000). Profitability and productivity did not seem to be major factors in producers' decisions to use or not use HRM practices.

Investing in a robotic milking system: a Monte Carlo simulation analysis.

This paper uses Monte Carlo simulation methods to estimate the breakeven value for a robotic milking system (RMS) on a dairy farm in the United States. The breakeven value indicates the maximum amount that could be paid for the robots given the costs of alternative milking equipment and other important factors (e.g., milk yields, prices, length of useful life of technologies). The analysis simulates several scenarios under three herd sizes, 60, 120, and 180 cows. The base-case results indicate that the mean breakeven values are $192,056, $374,538, and $553,671 for each of the three progressively larger herd sizes. These must be compared to the per-unit RMS cost (about $125,000 to $150,000) and the cost of any construction or installation of other equipment that accompanies the RMS. Sensitivity analysis shows that each additional dollar spent on milking labor in the parlor increases the breakeven value by $4.10 to $4.30. Each dollar increase in parlor costs increases the breakeven value by $0.45 to $0.56. Also, each additional kilogram of initial milk production (under a 2x system in the parlor) decreases the breakeven by $9.91 to $10.64. Finally, each additional year of useful life for the RMS increases the per-unit breakeven by about $16,000 while increasing the life of the parlor by 1 yr decreases the breakeven value by between $5,000 and $6,000.

Maternity leave, women's employment, and marital incompatibility.

This research investigated the relationship between the length of women's maternity leave and marital incompatibility, in the context of other variables including the woman's employment, her dissatisfaction with the division of household labor, and her sense of role overload. Length of leave, work hours, and family salience were associated with several forms of dissatisfaction, which in turn predicted role overload. Role overload predicted increased marital incompatibility for experienced mothers but did not for first-time mothers, for whom discrepancies between preferred and actual child care were more important. Length of maternity leave showed significant interactions with other variables, supporting the hypothesis that a short leave is a risk factor that, when combined with another risk factor, contributes to personal and marital distress.

Environmental management of asthma at Massachusetts managed care organizations.

Asthma management staff at eight Massachusetts managed care organizations (MCOs) were interviewed to learn the extent of inclusion of environmental prevention strategies in their asthma disease management policies. Six of the plans had formal asthma disease management programs, all reported to be based on the National Heart Lung and Blood Institute guidelines, but none followed these guidelines in their entirety. Three MCOs provided for home visits that included addressing environmental factors for severe asthmatics. Despite the limited role that MCOs appear to play in environmental prevention of asthma, the authors identify opportunities and encourage efforts to expand these programs.

Economic considerations for the adoption of transgenic crops: the case of bt corn.

Biotechnology is offering farmers new crop production opportunities and challenges. Prior to selecting a transgenic variety, farmers must consider the cost of the technology fee, possible yield drag, potential pest infestations, possible reductions in pesticide costs, refuge requirements to minimize the development of insect resistance, and adjustments in cultural practices. Moreover, crop segregation in the field, storage, and shipment may be necessary to capture potential price premiums for nontransgenic varieties. As farmers consider these various production and marketing factors, they find that Bt corn is a more profitable control method for European corn borer in the Western Corn Belt relative to the Eastern Corn Belt. This is primarily due to higher infestation probabilities in the Western Corn Belt, coupled with greater demand for manufacturing and export uses in the Eastern Corn Belt where several buyers do not accept transgenic corn.

Gender differences in moral orientation: a meta-analysis.

C. Gilligan's (1982) critique of L. Kohlberg's theory of moral reasoning and her assertion that two modes of moral reasoning (justice and care) exist have been the subject of debate within the field of psychology for more than 15 years. This meta-analysis was conducted to review quantitatively the work on gender differences in moral orientation. The meta-analysis revealed small differences in the care orientation favoring females (d = -.28) and small differences in the justice orientation favoring males (d = .19). Together, the moderator variables accounted for 16% of the variance in the effect sizes for care reasoning and 17% of the variance in the effect sizes for justice reasoning. These findings do not offer strong support for the claim that the care orientation is used predominantly by women and that the justice orientation is used predominantly by men.

Getting off the bandwagon: an academic health center takes a different strategic path.

Focusing on one state university academic health center (AHC) located in a rural setting in the southeastern United States, this case study investigates the strategic response to the increasingly turbulent and competitive environment in the healthcare industry. The qualitative research reported here involved a review of pertinent documents and archival data and interviews with key informants including AHC executives and staff, community leaders, and others. Additional information was obtained from published sources, including a literature review that covers a five-year period ending in 1997 and searches conducted using the key words "academic medical or health center." The AHC in this case study demonstrates how it is possible to respond proactively to changes in the environment without sacrificing the multiple missions of the institution. This AHC implemented strategies that ensure access for both inner city and rural underserved populations while providing venues for primary care training and educational programs. In addition, the AHC positioned itself to compete more effectively by implementing a continuous quality improvement program that is aimed at maximizing quality while controlling costs. Administrators in not only AHCs but also other healthcare organizations, such as community hospitals and competing systems, should consider the findings from this case study useful in evaluating existing strategies and possible alternatives. In particular, the use of an affiliation strategy for growth in a resource-poor environment may encourage organizations located in rural areas to consider innovative expansion strategies to develop integrated systems of care.

Academic health centers in turbulent times: strategies for survival.

Given the increasingly turbulent health care environment, the strategic adaptation of academic health centers (AHCs) provides an opportunity to investigate the effects of drastic change on a population of organizations. This article identifies and categorizes the adaptive behavior using existing strategic typologies, while exploring the implications for hospital managers.

Special care team: a welcome choice.

What happens when a patient isn't ready to accept hospice care? Or when curative rather than palliative care is needed? Some patients need the skills of a hospice nurse in a curative setting--which calls for a special care team.

Simultaneous assessment of flow and BOLD signals in resting-state functional connectivity maps.

We have recently demonstrated using functional magnetic resonance imaging the presence of synchronous low-frequency fluctuations of signal intensities from the resting human brain that have a high degree of temporal correlation (p < 0.0001) both within and across the sensorimotor cortex. A statistically significant overlap between the resting-state functional connectivity map and the task-activation map due to bilateral finger tapping was obtained. Similar results have been obtained in the auditory and visual cortex. Because the pulse sequence used for collecting data was sensitive to blood flow and blood oxygenation, these low-frequency fluctuations of signal intensity may have arisen from variations of both. The objective of this study was simultaneously to determine the contribution of the blood oxygenation level signal and the flow signal to physiological fluctuations in the resting brain using the flow-sensitive alternating inversion recovery pulse sequence. In all subjects, the functional connectivity maps obtained from BOLD had a greater coincidence with task-activation maps than the corresponding functional connectivity maps obtained from blood-flow signals at the same level of statistical significance. Results of this study suggest that while variations in blood flow might contribute to functional connectivity maps, BOLD signals play a dominant role in the mechanism that gives rise to functional connectivity in the resting human brain.

Determinants of physician vacancy rates in rural hospitals.

This study examines the determinants of physician vacancy rates in rural hospitals from the perspective of the rural hospital administrator. Data on community characteristics, hospital characteristics, and hospital recruitment strategies are examined for 50 rural hospitals in Kentucky using questionnaire and archival data. Physician vacancy rates in this sample were quite high (mean of 37 percent). Results indicate lower physician vacancy rates in hospitals with a chain affiliation. In addition, the "job shopping" model for physicians decisions on where to practice (Johnson, 1978) is supported. Hospitals that target physician candidates with more work experience display lower physician vacancy rates. Generally, hospital characteristics were more significant predictors of physician vacancy rates than were community characteristics. Implications for rural hospital physician recruitment/retention strategies are discussed.

Coil optimization for MRI by conjugate gradient descent.

A flexible iterative algorithm is presented for optimizing gradient and radio frequency coils for MRI. It is based on a model using discrete current elements and direct Biot-Savart calculation of the fields. An error function is defined over a region of interest (ROI) and is minimized by conjugate gradient descent. The choice of error function allows optimization of the field uniformity, the inductance, and the efficiency of the coil in any combination. Neither the coil nor the ROI is restricted to any particular geometry. A 40-turn cylindrical z-gradient coil of radius a and length 4a, designed for ROI of radius 0.7a and length 2a has an average error in the gradient fields generated of 0.85%, an inductance of 0.014a mH/cm, and an efficiency of 6.65a-2 Gcm/A. A 16-turn birdcage-like RF coil of radius 5 cm, designed for a ROI of radius 4 cm has an average error of 0.79%.

A clinical diagnostic model for the assessment of asbestosis: a new algorithmic approach.

Asbestosis, one of the pneumoconioses that is defined by a set of clinical, radiographic, and pathologic findings, occurs as a result of exposure to asbestos fibers. Several approaches have attempted to describe the presence, progression, or extent of asbestosis. However, these approaches have attempted to describe the presence, progression, or extent of asbestosis. However, these approaches have limitations or lack correlations with other diagnostic modalities. We propose a comprehensive clinical diagnostic model that uses the sensitivities and specificities of the various clinical, radiographic, and pathologic findings to generate a set of "likelihood numbers." These likelihood numbers, contribute to the calculation of a value that can indicate the probability of asbestosis. The clinical diagnostic model is heuristic in that a specific feature supportive of the diagnosis of asbestosis may be tested as to its sensitivity and specificity, and new features may be added to the model. The model also indicates how probabilistic a given set of findings is in the diagnosis of asbestosis and suggests what additional data may make the diagnosis more or less statistically probable. Regarding the radiologic considerations of asbestosis, the strength of the clinical diagnostic model is that it is capable of supporting a diagnosis of asbestosis in the presence of a normal chest radiograph and, conversely, may reject the diagnosis of asbestosis despite the radiographic finding of pulmonary fibrosis.

Lateral diffusion of lipids in membranes by pulse saturation recovery electron spin resonance.

Short-pulse saturation recovery electron spin resonance methods have been used to measure lateral diffusion of nitroxide-labeled lipids in multilamellar liposomal dispersions. Nitroxides with 14N and 15N isotopes introduced both separately and together were used. Differential equations have been written and solved for complex saturation recovery signals involving several superimposed exponentials. The time constants contain various combinations of the spin-lattice relaxation time (T1e) for both isotopes, Heisenberg exchange rates, and nuclear spin-lattice relaxation times (T1n). Signals of high quality were fitted by Monte Carlo variation of the amplitudes and time constants. The reliability of the approach was tested extensively by verifying that (i) the predicted number of exponentials agreed with the experimental number, (ii) relaxation parameters that were determined were independent of the observed hyperfine transition, (iii) the time constants were independent of saturating pulse length, (iv) T1e and T1n do not change when Heisenberg exchange is changed by varying the concentration, and (v) Heisenberg exchange is indeed proportional to the concentration. It has been established that bimolecular collision rates over a wide range of conditions can be reliably measured using the methodology described here. The methods depend on the favorable match of bimolecular collision rates at micromolar concentrations to nitroxide spin-lattice relaxation probabilities.

A prepaid medical plan. Cost, use, and effects in a retirement home.

A model experience of a prepaid medical plan for a group of people is analyzed. No-barrier cost and physician access lead to altered use characteristics. Among these are increased physician, nurse, and nursing home use, and decreased hospital use. The overall cost is increased. Any comprehensive health-care plan that would propose comprehensive first-dollar coverage would likely encounter similar use characteristics.

Environmental correlates of pediatric social illness: preventive implications of an advocacy approach.

A control prospective study of child abuse and neglect, failure to thrive, accidents and poisonings included 303 inpatients and 257 outpatients. Analysis of maternal interview clinical data demonstrated significant differences between cases and controls in summative indices of environmental stress, including housing, employment, and access to essential services. The associations with a postulated common causal underpinning of these illnesses argue for a broadened, ecologic conceptualization of etiology and a wider range of preventive approaches. A family advocacy program addressing the stress issues and utilizing community based individual was offered to families with pediatric social illness and to a comparison group. Indirect corroboration of the impact of environmental crisis is idicated by the prevalence of requests for this help in impatient cases of abuse (38 per cent) and ingestions (38 per cent) vs. controls (14 per cent). Discrimunant function regression analysis of data from the meternal interview demonstrates similarity between the attributes which most saliently describe the abuse group and those which decribe the users of advocacy.