Transforming national health policy: The significance of the stratification system

Policy formulation and decision-making occur within a continually changing sociopolitical environment. Presently, our national health policy lacks coherence and direction. It also is in a state of transition as evidenced by the recent restricted proposal to expand Medicare coverage to catastrophic illness. A comprehensive strategy for balancing escalating medical, hospital, and insurance costs as well as those associated with long-term care while extending access has not been devised. One of the most salient reasons for this is the failure of policy makers to grasp the complexities of the multifaceted stratification system. Its diverse, interrelated strata based on age, sex, economic status, and race are not incorporated in the process of shaping vitally needed and rational health policy. Doris Y. Wilkinson, a professor of sociology at the University of Kentucky, is a co-principal investigator on an intervention project funded by the National Cancer Institute. She recently received the Master of Public Health in Health Policy and Management from Johns Hopkins University.     

Conditional and unconditional tests with historical controls

Score statistics utilizing historical control data have been proposed to test for increasing trend in tumour occurrence rates in laboratory carcinogenicity studies. Novel invariance arguments are used to confirm, under slightly weaker conditions, previously established asymptotic distributions (mixtures of normal distributions) of tests unconditional on the tumor response rate in the concurrent control group. Conditioning on the control response rate, an ancillary statistic, leads to a new conditional limit theorem in which the test statistic converges to an unknown random variable. Because of this, a subasymptotic approximation to the conditional limiting distribution is also considered. The adequacy of these large-sample approximations in finite samples is evaluated using computer simulation. Bootstrap methods for use in finite samples are also proposed. The application of the conditional and unconditional tests is illustrated using bioassay data taken from the literature. The results presented in this paper are used to formulate recommendations for the use of tests for trend with historical controls in practice.     

Spot observation: Advantages and disadvantages for household time use research

The spot observation method of estimating time use is described in this article. Procedures for using this method in developing countries, where household activities are relatively easily observed, are contrasted with procedures used in countries characterized by very private living units and highly separated employment, educational, and household settings. Characteristics of various methods for collecting time use data are compared so that researchers can evaluate the trade-offs they can expect from selecting a particular method. A case example of using the spot observation method in a study of women's household and agricultural activities in the Njoro Region of Kenya is presented.Her research interests are household time allocation and women's economic status in developing countries.Her research interests include the time allocation of rural women and women in international development. She received her Ph.D. from the University of Illinois in 1995.The study of women's and children's time use reported in this paper was supported in part by the Center for African Studies, University of Illinois at Urbana-Champaign and by the Office of the Deputy Vice Chancellor for Academic Affairs, Egerton University, Njoro, Kenya.     

Nonparametric Bayes methods for directional data

A model for directional data in q dimensions is studied. The data are assumed to arise from a distribution with a density on a sphere of q — 1 dimensions. The density is unimodal and rotationally symmetric, but otherwise of unknown form. The posterior distribution of the unknown mode (mean direction) is derived, and small-sample posterior inference is discussed. The posterior mean of the density is also given. A numerical method for evaluating posterior quantities based on sampling a Markov chain is introduced. This method is generally applicable to problems involving unknown monotone functions.     

ETHNIC DIFFERENCES IN ACADEMIC ACHIEVEMENT BETWEEN VIETNAMESE AND CAMBODIAN CHILDREN: Cultural and Structural Explanations

Many Vietnamese and Cambodians fied war and communist takeover and entered the United States as part of the largest refugee resettlement program in the country's history. Both of the refugee groups traveled a great cultural distance and face similar barriers in adjusting to the United States. Despite these similarities in settlement, the two groups are adapting differently; this is made evident in their children's academic achievement. While the children of Vietnamese refugees seem to be successfully catching up to the children of other more established Asian immigrants, Cambodian children are trailing. Using the 1992 and 1996 data from the Children of Immigrants Longitudinal Study, I combine cultural and structural explanations of educational achievement and immigrant adaptation to explain differences in academic achievement between Vietnamese and Cambodian children.