Jeanne Wendel

The effect of herbaceous plant communities and soil textures on particle erosion of alluvial streambanks

Soil texture and plants are understood to be important determinants of erosion. However, there is a paucity of research on the quantitative effect of various soils, plants, or the interaction of the two, on streambank erosion. This study measures the influence of herbaceous plant communities and sandy loam, loam and clay loam soils on particle erosion rates. It demonstrates that the interaction of plants and soil are important. Seventy-one samples from the banks of 5 streams were tested using a flume. Multivariate regression analysis was used to analyze a dependent variable of erosion rate with independent variables of root density, soil texture, and plant communities. Autocorrelation was treated with the maximum chi-square method. Nebraska sedge (Carex nebrascensis) and Baltic rush (Juncus balticus) communities had the lowest erosion rates, followed by mixed sedge (Carex lanuginosa, C. rostrata and others) then mixed grass (Poa pratensis with Deschampsia caespitosa) communities. Silt had a negative effect on erosion for the Nebraska sedge, Baltic rush and mixed grass plant communities, but had no effect with the mixed sedge community due to a silt-by-sedge interaction. An increase in percent clay correlated with an increase in erosion. As percentages of clay or silt increased, root-volume density declined. Root-volume density was correlated negatively with erosion. Clay to silt ratio correlated negatively with erosion. Thus knowledge of both vegetation and soil texture are necessary to predict or manage strembank erodibility.

Uncompensated Hospital Care: Charitable Mission or Profitable Business Decision?

Provision of hospital uncompensated care is generally assumed to be adversely affected as increased healthcare competition decreases demand for compensated hospital services. Economic theory, however, suggests the question is more complex. Non-profit hospitals are assumed in this paper to maximize utility as a function of uncompensated care, subject to the constraint that revenues cover costs. For-profit hospitals, in contrast, are assumed to maximize profit while recognizing that failure to meet community expectations regarding provision of uncompensated care could negatively impact profits. Therefore, for-profit hospital supply of uncompensated care focuses on balancing the hospitals marginal costs and marginal benefits. These models predict that non-profit hospitals will respond to increased competition by reducing the supply of uncompensated care. In contrast, for-profit hospitals will increase the supply of uncompensated care when market demand decreases since the concurrent decrease in compensated care reduces the marginal cost of producing uncompensated care. The models also predict that for-profit hospitals will respond to changes in community expectations regarding the provision of uncompensated care.

Estimating VAR models under non-stationarity and cointegration: alternative approaches for forecasting cattle prices

Multivariate VAR models estimated with non-stationary data raise difficult econometric questions because differencing to achieve stationary can introduced distortions into multivariate models. Three approaches have been suggested for estimating such models:(1) Vector error correction (VEC) models difference the data to achieve stationary and use an error correction term to replace the long-run information lost through differencing; (2) VAR models can be estimated with raw data in levels if the non-stationary data is also cointegrated because recent theoretical work proves that estimation with such data will yield consistent parameter estimates; (3) Bayesian parameter estimates are not affected by non-stationarity, although some analysts argue that Bayesian analysis is not appropriate for data that is also cointegrated. A multivariate cattle price model provides a good framework for comparing these approaches because the major variables are both non-stationary and cointegrated, and because the models opti...

Interactions between hospital admissions, cost per day and average length of stay

Hospital cost per day (COST), annual admissions per capita (ADMIT), and average length of stay (ALOS) are important health policy variables because each variable provides important information about hospital industry performance. This study uses country-level data to explore the empirical relationships between COST, ADMIT, and ALOSin three steps: OLS estimation, application of the Wu-Hausman endogeneity test, and re-estimation with two-stage least squares. The major results are (i) ADMITand ALOSexert exogenous influences on COSTand (ii) ADMITand ALOSare endogenously related with possible one-way casuality from ADMITto ALOS.

Evaluating an employee wellness program

What criteria should be used to evaluate the impact of a new employee wellness program when the initial vendor contract expires? Published academic literature focuses on return-on-investment as the gold standard for wellness program evaluation, and a recent meta-analysis concludes that wellness programs can generate net savings after one or two years. In contrast, surveys indicate that fewer than half of these programs report net savings, and actuarial analysts argue that return-on-investment is an unrealistic metric for evaluating new programs. These analysts argue that evaluation of new programs should focus on contract management issues, such as the vendor’s ability to: (i) recruit employees to participate and (ii) induce behavior change. We compute difference-in-difference propensity score matching estimates of the impact of a wellness program implemented by a mid-sized employer. The analysis includes one year of pre-implementation data and three years of post-implementation data. We find that the program successfully recruited a broad spectrum of employees to participate, and it successfully induced short-term behavior change, as manifested by increased preventive screening. However, the effects on health care expenditures are positive (but insignificant). If it is unrealistic to expect new programs to significantly reduce healthcare costs in a few years, then focusing on return-on-investment as the gold standard metric may lead to early termination of potentially useful wellness programs. Focusing short-term analysis of new programs on short-term measures may provide a more realistic evaluation strategy.

Is post-smoking-cessation weight-gain a significant trigger for relapse?

While the Surgeon Generals Consumer Guide lists weight-gain as an important relapse trigger, the 2001 Surgeon Generals Report on Women and Smoking concludes, paradoxically, that actual weight-gain during cessation does not appear to predict relapse. This dichotomous view reflects longstanding scientific uncertainty about the role of weight-gain in triggering relapse. This scientific uncertainty, which stems from mixed clinical trial results, is problematic for insurance coverage decisions such as state Medicaid programme decisions to cover or exclude smoking-cessation and weight-control pharmaceuticals. Analysts hypothesize that selection bias may explain the inconsistency between the negative clinical results and the persistent view that weight-gain triggers relapse, if weight-concern is both a key determinant of the transition from ‘smoker’ to ‘ex-smoker,’ and a key moderating variable in the relationship between weight-gain and relapse. We therefore use the nationally representative 1997 National Longitudinal Survey of Youth (NLSY97) to test the relapse-trigger hypothesis, and conclude that post-smoking-cessation weight-gain triggers relapse among weight-concerned white women, but it is associated with quitting success among Hispanic women. In addition, our results do not support the hypothesis that the mixed clinical trial results reflect selection bias based on weight-concern.

Quality Improvement: Boon or Boondoggle?

Is quality improvement (QI) reducing healthcare costs while improving patient care? Researchers find that QI has improved employee satisfaction and morale, but it was designed to do more. One solution is to use problem-solving techniques to help teams identify the level at which they want to address a problem, whether that be the subinstitutional, institutional, or system level. If QI is to fulfill its promise, skilled managers must create effective teams capable of defining and solving complex problems.

Are prenatal care resources distributed efficiently across high-risk and low-risk mothers?

The Institute for Clinical Systems Improvement recommends reducing the number of prenatal care visits recommended for low-risk women, citing evidence from a randomized clinical trial indicating that the reduction would not adversely impact infant health. We investigate the implicit hypothesis that prenatal care resources are not distributed efficiently across high-risk and low-risk women. Using clinic-reported prenatal care and an inclusive measure of infant health, we report evidence indicating inefficient resource utilization: prenatal care only boosts infant health when mothers have specific pre-existing diagnoses, but women with high potential to benefit from care do not obtain more care than other women.

Finding Value While Planning a Statewide Health Information Exchange

Implementing a statewide health information exchange (HIE) provides the opportunity to explore the application of IS planning methods to complex inter-organizational systems (IOS). This study describes the HIE planning process followed by one state. The traditional planning steps recommended by the U.S. federal government did not compel project stakeholders to develop a sustainable business value proposition for the system. Unlike traditional project planning methods, planning a complex, relatively undefined IOS such as a health information exchange may require that IT professionals go beyond traditional planning activities and more actively facilitate definition of possible system value. In addition, the results show that technology should be considered earlier in the planning process, underscoring the need to anticipate the impact of IT architecture on the resulting system capabilities and value.

Integrated Care: Potential Disaster or Golden Opportunity?

This chapter explores the advantages and drawbacks of managed care and integrated primary and behavioral health care. It examines the implications of the trend toward increased integration of behavioral health care and primary care services. If integrated care can consistently generate sufficient medical cost offsets to fund the cost of providing the behavioral care, these programs can help managed care organizations solve the fundamental problem of delivering cost effective plans to employers without sacrificing health outcomes. In addition, behavioral health care providers may offer the expertise needed by managed care companies to understand consumer perceptions of health care and consumer values. The chapter highlights that some innovative providers have produced good patient outcomes by integrating behavioral health care into a primary care setting. To the extent that behavioral health care providers can successfully reduce patient medical expenditures via improved mental health, improved compliance with medical care instructions, and improved management of chronic diseases, behavioral health care providers may offer the solution to the fundamental dilemma posed by managed care.