Management of premature menopause

There has been some confusion among women and health professionals since the publication of the Women's Health Initiative and Million Women studies about the management of premature ovarian failure (POF). Both studies were undertaken in women aged 50 and over, and cannot be extrapolated to their younger counterparts, who would normally be producing their endogenous estrogen, since they have functioning ovaries. Estrogen-based replacement therapy is the main stay of treatment for women with POF and is recommended at least until the average age of natural menopause (52 years in the UK). This view is endorsed by regulatory bodies such as the Committee on Safety of Medicines (now the Commission on Human Medicines) in the UK. No evidence shows that estrogen replacement increases the risk of breast cancer to a level greater than that found in normally menstruating women, and women with POF do not need to start mammographic screening early unless other risk factors are present, such as family history.     

Region of Birth and Disability Among Recent U.S. Immigrants: Evidence from the 2000 Census

This study aimed to test the “healthy immigrant” hypothesis and assess health heterogeneity among newly arrived working-age immigrants (18–64 years) from various regions of origin. Using the 5% sample of the 2000 U.S. Census (PUMS), we found that, compared with their native-born counterparts, immigrants from all regions of the world were less likely to report mental disability and physical disability. Immigrants from selected regions of origin were, however, more likely to report work disability. Significant heterogeneity in disabilities exists among immigrants: Those from Eastern Europe and Southeast Asia reported the highest risk of mental and physical disability, and those from East Asia reported the lowest risk of physical disability. Furthermore, Mexican immigrants reported the lowest risk of mental disability, and Canadian immigrants reported the lowest risk of work disability. Socioeconomic status and English proficiency partially explained these differences. The health advantage of immigrants decreased with longer U.S. residence.     

Classification with discrete and continuous variables via general mixed-data models

We study the problem of classifying an individual into one of several populations based on mixed nominal, continuous, and ordinal data. Specifically, we obtain a classification procedure as an extension to the so-called location linear discriminant function, by specifying a general mixed-data model for the joint distribution of the mixed discrete and continuous variables. We outline methods for estimating misclassification error rates. Results of simulations of the performance of proposed classification rules in various settings vis-à-vis a robust mixed-data discrimination method are reported as well. We give an example utilizing data on croup in children.     

Dignity and development

This paper explores how expanding the notion of informal institutions in the broader institutional framework provides a more complete explanation for development. Specifically, I incorporate McCloskey's notion of ‘dignity and liberty’ as part of the institutional nexus. By doing so, a richer explanation and understanding of the importance of institutions in explaining different economic outcomes is offered. Focusing on bourgeois dignity offers a precise mechanism to explain how institutions matter to support economic growth. In addition, analyzing the changing attitudes toward the bourgeoisie provides a specific example of mechanisms that can lead to institutional change.     

Statistical review by research ethics committees

This paper discusses some of the issues surrounding statistical review by research ethics committees (RECs). A survey of local RECs in 1997 revealed that only 27/184 (15%) included a statistician member at that time, although 70/175 (40%) recognized the need for such. The role of the statistician member is considered and the paper includes a summary of a meeting of the Royal Statistical Society to discuss statistical issues that frequently arise in the review of REC applications. A list of minimum qualifications which RECs should expect from anyone claiming to be a statistician would be useful, together with a list of statisticians who are well qualified and willing to serve on RECs, and a list of training courses for REC members covering the appropriate statistical issues.     

Bias in meta-analysis due to outcome variable selection within studies

Although bias in meta-analysis arising from selective publication has been studied, within-study selection has received little attention. Chronic diseases often have several possible outcome variables. Methods based on the size of the effect allow results from studies with different outcomes to be combined. However, the possibility of selective reporting of outcomes must be considered. The effect of selective reporting on estimates of the size of the effect and significance levels is presented, and sensitivity analyses are suggested. Substantial publication bias could arise from multiple testing of outcomes in a study, followed by selective reporting. Two meta-analyses, on anthelminth therapy and a treatment for incontinence, are reassessed allowing for within-study selection, as it is clear that more outcomes had been measured than were reported. The sensitivity analyses show that the robustness of the anthelminth results is dependent on what assumption one makes about the reporting strategy for the largest trial. The possible influence of correlation between within-child measurements was such that the conclusions could easily be reversed. The effect of a mild assumption on within-trial selection alone could alter general recommendations about the treatment for incontinence.