When push comes to shove: implementing VBAC practice guidelines

The dramatic increase in U.S. cesarean sections over the past two decades has been significantly driven by repeat C-sections. In response to this trend, clinical guidelines recommending vaginal birth after cesarean-section (VBAC) have been promulgated by national organizations. Adherence to these guidelines would reduce the number of repeat C-sections, lower the overall C-section rate, and improve both the quality and the cost of health care. While these guidelines have received professional endorsement, their implementation has been clouded by issues of patient acceptance and provider payment. To examine implementation of these guidelines by health care organizations, the authors surveyed 156 members of the American College of Physician Executives to determine their policies, practices, and attitudes toward VBAC guidelines. Those surveyed generally were medical directors in HMOs, hospitals, and other practice settings. The findings indicate that the health care organizations represented by these physician executives have not consistently implemented VBAC guideline and that they are reluctant to hold physicians, their patients, or hospitals accountable for the financial, utilization, and quality impact of the elective decision ot to pursue appropriate VBACs. We conclude that, even when widely accepted, clinical practice guidelines may be ineffective in reducing the costs or improving the quality of medical care.     

Recent fertility trends in industrialized countries: Toward a fluctuating or a stable pattern?

By the mid-1980s, fertility in most of the world's developed countries had declined to unprecedentedly low levels. Since then, it has declined still further in some, increased slightly in others, and fluctuated in still others. Irrespective of cause, these changes could not have occurred in the absence of substantial control over childbearing.While future increases and decreases are both possible, it is argued that, contrary to the usual demographic expectations for populations exercising substantial control over fertility, fertility in most of these countries will increase to approximate replacement levels and then undergo only minor fluctuations around these levels thereafter.     

A cultural economy perspective on service sector migration in the global city: the case of Hong Kong

This article argues that in order to fully understand the geography of labour migration to global cities, it is necessary to consider economic forces in conjunction with mediating socio-cultural influences. Support for this argument is based on an examination of the pattern of migration to Hong Kong, a city which plays a significant role in the world economy.
Reported here are the results of an analysis of recently released 1996 by-census data, and the authors' interviews with foreign domestic workers in Hong Kong. These findings have shown that highly skilled immigrant workers were drawn largely from developed countries, the main sources of inward investment in this city, while less skilled immigrants were drawn from less developed neighbouring labour markets.
While the geographical pattern of immigration followed broadly that predicted from Hong Kong's position in the world economy, the results have revealed that cultural influences such as language and social networks are also important in shaping the economic roles of migrant workers.     

Circuit optimization via sequential computer experiments: design of an output buffer

In electrical engineering, circuit designs are now often optimized via circuit simulation computer models. Typically, many response variables characterize the circuit's performance. Each response is a function of many input variables, including factors that can be set in the engineering design and noise factors representing manufacturing conditions. We describe a modelling approach which is appropriate for the simulator's deterministic input–output relationships. Non-linearities and interactions are identified without explicit assumptions about the functional form. These models lead to predictors to guide the reduction of the ranges of the designable factors in a sequence of experiments. Ultimately, the predictors are used to optimize the engineering design. We also show how a visualization of the fitted relationships facilitates an understanding of the engineering trade-offs between responses. The example used to demonstrate these methods, the design of a buffer circuit, has multiple targets for the responses, representing different trade-offs between the key performance measures.     

The paradox of multiple elections

Assume that voters must choose between voting yes (Y) and voting no (N) on three propositions on a referendum. If the winning combination is NYY on the first, second, and third propositions, respectively, the paradox of multiple elections is that NYY can receive the fewest votes of the 2³ = 8 combinations. Several variants of this paradox are illustrated, and necessary and sufficient conditions for its occurrence, related to the “incoherence” of support, are given. The paradox is shown, via an isomorphism, to be a generalization of the well-known paradox of voting. One real-life example of the paradox involving voting on propositions in California, in which not a single voter voted on the winning side of all the propositions, is given. Several empirical examples of variants of the paradox that manifested themselves in federal elections – one of which led to divided government – and legislative votes in the US House of Representatives, are also analyzed. Possible normative implications of the paradox, such as allowing voters to vote directly for combinations using approval voting or the Borda count, are discussed. Received: 31 July 1996 / Accepted: 1 October 1996     

Bequests as a heir "disciple device."

This paper develops a model ofinter vivos gifts and bequests in a setting of moral hazard and adverse selection. Altruistic parents do not perfectly know how much effort their children make to earn their living, nor do they know their true level of ability.Inter vivos gifts take place prior to the realization of the children's earnings whereas at the moment of bequests, parents do observe them. We show that an optimal transfer policy generally uses a mix ofinter vivos gifts — deemed as more efficient — and bequests — deemed as more redistributive.We are thankful to Allessandro Cigno, Jacques Cremer, Claude d Aspremont and anonymous referees for their comments.Responsible editor: Alessandro Cigno     

Batch sampling to improve power in a community trial. Experience from the Pawtucket Heart Health Program

Experiments involving large social units, such as schools, work sites, or whole cities, are commonly limited in statistical power because the number of randomized units is small, leaving few degrees of freedom for residual (between-unit) error. The authors describe a method for increasing residual degrees of freedom in a community experiment without substantially increasing cost or difficulty. In brief, they propose that the experimental units should be divided into random subsamples (batches). Batch sampling can improve statistical power if the community endpoint means are stable over time or if their temporal variation is comparable in period to the batch-sampling schedule. The authors demonstrate the theoretical advantages of the batch system and illustrate its use with data from the Pawtucket Heart Health Program, in which such a design was implemented.     

The health status of elderly people and the new direction of health services

The projected increase of people in Japan aged 75 years and older in the years to come implies the increase of the disabled elderly. Thus, the core of societal preparation for the aging of the population is generally considered to be the expansion of services for the disabled elderly. However, gerontological studies on the health status of the elderly conducted in Japan show that the prevalence of disability is quite low and even decreasing. Relative to the services for the disabled elderly, preventive services for the healthy elderly have long been overlooked. In 1994, the Metropolitan Tokyo Government organized a task force to develop a new health education program as the preventive health service for the healthy urban elderly. A preliminary plan outlining the health education program--consisting of propagation with a booklet, on-the-job training of practitioners, and development of new curricula and teaching materials--was proposed by the authors for discussion within the task force. Although the inquiry has just begun and the plan is still nascent, it seems adequate to fit the needs for preventive health services in the near future.