Biostatistics Instruction at Meharry Medical College

In a variety of settings, it is desirable to display a collection of likelihoods over a common interval. One approach is simply to superimpose the likelihood curves. However, where there are more than a handful of curves, such displays are extremely difficult to decipher. An alternative is simply to display a point estimate with a confidence interval, corresponding to each likelihood. However, these may be inadequate when the likelihood is not approximately normal, as can occur with small sample sizes or nonlinear models. A second dimension is needed to gauge the relative plausibility of different parameter values. We introduce the raindrop plot, a shaded figure over the range of parameter values having log-likelihood greater than some cutoff, with height varying proportional to the difference between the log-likelihood and the cutoff. In the case of a normal likelihood, this produces a reflected parabola so that deviations from normality can be easily detected. An analogue of the raindrop plot can also be used to display estimated random effect distributions, posterior distributions, and predictive distributions.     

Reducing Boarding in a Post‐Anesthesia Care Unit

When operating room schedules in hospitals are produced, the constraints and preferences of surgeons and hospital workers are a primary consideration. The downstream impact on post‐operative bed availability is often ignored. This can lead to the boarding of patients overnight in the post‐anesthesia care unit (PACU) because intensive care unit beds are unavailable. In this paper, we apply integer programming and simulation to develop improved surgical scheduling assignments. We want to balance new surgeries with hospital discharges in order to reduce the variability of occupied beds from one day to the next and, as a result, to reduce boarding in the PACU.     

Staff experience of a new approach to family safeguarding in Oxfordshire Children's Social Care Services

This paper presents the findings from a qualitative study that sought to understand the experiences of frontline staff working in Oxfordshire County Council (OCC) Children's Social Care Services and their views on a new family safeguarding model (Family Solutions Plus). Focus group interviews were conducted with 20 frontline staff and managers in different teams across OCC Children's Social Care Services using video conferencing software. Thematic analysis identified three overarching themes: Preparation for the implementation of Family Solutions Plus, staff views on the implemented model, and challenges to its implementation. Staff voiced strong support for the new model, which places a much greater emphasis than previous practice on supporting the whole family, developing parenting skills and keeping children safe with their families. The challenges associated with the transition to a new model were considerable in the short term, partly due to the COVID-19 pandemic, but there was optimism that the new model could be sustained and stabilized over time.     

AN INTEGRATED WORK SHIFT SCHEDULING SYSTEM

An integrated work shift scheduling system is developed and applied in the scheduling of 2600 telephone operators in 43 locations of the General Telephone Company of California. The system involves the forecasting of calls on a half-hourly basis, the conversion to operator requirements, the scheduling of tours by a heuristic algorithm, the assignment of operators to tours, and the operation of the system.     

MANAGERIAL USE OF DYNAMIC STRUCTURAL MODELS*

Dynamic structural models were introduced as early as 1958 as “Industrial Dynamics, but there has been little managerial use and little response in the academic world. Yet, the basic modeling methods provide an important mode for examining the broad interacting effects of large systems. More recent work appears to make structural and dynamic models understandable and accessible to individuals not trained in the decision sciences. The nature of the modeling methods is such that managers and policy makers in public systems can be involved directly in the model building process. The authors hope that this survey paper may help rekindle interest.     

A Transaction‐Efficiency Analysis of an Internet Retailing Supply Chain in the Music CD Industry*

The emergence of the Internet may have fundamentally altered the mechanisms underlying information exchanges between sellers and end consumers. However, little attention has been given to the impact these mechanisms have on the efficiency of supply chain operations. This paper begins to address this deficiency in the literature by evaluating supply chain transaction efficiency effects from Internet purchases by consumers. It develops and empirically tests a theoretical framework examining the role Internet purchases have in establishing transaction‐efficiency levels in product exchanges involving sellers, placed at different supply chain echelons, and consumers. The theoretical framework integrates the transaction‐cost and internet economics, inter‐organizational information systems, and supply chain management literatures. Empirical testing, via structural equation modeling, is based on archival data in the Internet music CD market. The results show that Internet‐mediated purchases by consumers allow for greater transaction efficiencies when inventory ownership is postponed farther upstream in the supply chain and supply chain echelons are disintermediated. The results also indicate that channel structure configuration, defined by the supply chains' Internet retailing echelon, moderates these transaction efficiency effects.