Statistics for weighing benefits and harms in a proposed genetic substudy of a randomized cancer prevention trial

Summary.  When evaluating potential interventions for cancer prevention, it is necessary to compare benefits and harms. With new study designs, new statistical approaches may be needed to facilitate this comparison. A case in point arose in a proposed genetic substudy of a randomized trial of tamoxifen versus placebo in asymptomatic women who were at high risk for breast cancer. Although the randomized trial showed that tamoxifen substantially reduced the risk of breast cancer, the harms from tamoxifen were serious and some were life threaten-ing. In hopes of finding a subset of women with inherited risk genes who derive greater bene-fits from tamoxifen, we proposed a nested case–control study to test some trial subjects for various genes and new statistical methods to extrapolate benefits and harms to the general population. An important design question is whether or not the study should target common low penetrance genes. Our calculations show that useful results are only likely with rare high penetrance genes.     

Adolescents Conceived through Donor Insemination in Mother‐Headed Families: A Qualitative Study of Motivations and Experiences of Contacting and Meeting Same‐donor Offspring

This study interviewed adolescents conceived using sperm donation to examine their experiences of contacting and meeting ‘same‐donor offspring’ (i.e. donor‐conceived offspring raised in different families who share the same donor), their motivations for this contact, and how they make meaning of these relationships. This in‐depth qualitative study involved semi‐structured interviews with 23 young people aged 12–19 years (mean = 14 years). Interviewees were motivated by curiosity about their biological relations and by wanting to extend their family. Contact with same‐donor offspring was described as being either normal/neutral or as a unique experience that was integrated into their identity. This study highlights the importance of contact between same donor offspring, particularly during adolescence, a developmental stage associated with identity formation. The findings have important policy implications as they suggest that donor‐conceived individuals may benefit from contact with others conceived using the same donor prior to the age of 18 years.     

Multidimensional Resilience: Predictive and Construct Validity of the Individual,Family, and Community Resilience Profile

Few measures parallel the robust depth offered in the existing multidimensional and ecologically informed theories of resilience. This study sought to evaluate the test–retest reliability, construct, and predictive validity of the individual, family, and community resilience resource profile (IFCR-R). The IFCR-R measures a family’s access to resilience resources and protective factors across multiple ecological levels. Confirmatory factor analysis was used with a sample of n?=?810 low-income families. And 159 families completed multiple time point measures for test–retest reliability and predictive validity evaluation. Results of this study support the proposed multidimensional ecological structure of the IFCR-R and found that the IFCR-R offers an acceptable test–retest reliability and predictive validity for outcomes of mental and physical health.     

The Value of Information in Decision‐Analytic Modeling for Malaria Vector Control in East Africa

Decision analysis tools and mathematical modeling are increasingly emphasized in malaria control programs worldwide to improve resource allocation and address ongoing challenges with sustainability. However, such tools require substantial scientific evidence, which is costly to acquire. The value of information (VOI) has been proposed as a metric for gauging the value of reduced model uncertainty. We apply this concept to an evidenced‐based Malaria Decision Analysis Support Tool (MDAST) designed for application in East Africa. In developing MDAST, substantial gaps in the scientific evidence base were identified regarding insecticide resistance in malaria vector control and the effectiveness of alternative mosquito control approaches, including larviciding. We identify four entomological parameters in the model (two for insecticide resistance and two for larviciding) that involve high levels of uncertainty and to which outputs in MDAST are sensitive. We estimate and compare a VOI for combinations of these parameters in evaluating three policy alternatives relative to a status quo policy. We find having perfect information on the uncertain parameters could improve program net benefits by up to 5–21%, with the highest VOI associated with jointly eliminating uncertainty about reproductive speed of malaria‐transmitting mosquitoes and initial efficacy of larviciding at reducing the emergence of new adult mosquitoes. Future research on parameter uncertainty in decision analysis of malaria control policy should investigate the VOI with respect to other aspects of malaria transmission (such as antimalarial resistance), the costs of reducing uncertainty in these parameters, and the extent to which imperfect information about these parameters can improve payoffs.     

Using relative utility curves to evaluate risk prediction

Summary.  Because many medical decisions are based on risk prediction models that are constructed from medical history and results of tests, the evaluation of these prediction models is important. This paper makes five contributions to this evaluation: the relative utility curve which gauges the potential for better prediction in terms of utilities, without the need for a reference level for one utility, while providing a sensitivity analysis for misspecification of utilities, the relevant region, which is the set of values of prediction performance that are consistent with the recommended treatment status in the absence of prediction, the test threshold, which is the minimum number of tests that would be traded for a true positive prediction in order for the expected utility to be non-negative, the evaluation of two-stage predictions that reduce test costs and connections between various measures of performance of prediction. An application involving the risk of cardiovascular disease is discussed.     

Change and continuity in British voluntary organisations, 1976 to 1988

A cohort of twenty British national voluntary agencies serving handicapped people was studied in 1976 and again in 1989 after a decade of major shifts in public policy. Changes and continuities were identified in income, structure, governance, management, programme, interorganisation relations and advocacy. A consistent pattern of growth, bureaucratisation and professionalisation was found, with relatively little change in the dominant mode of financing, statutory or philanthropic. A three-stage model is proposed to describe the development of British voluntary agencies since the 1970s, and some of the organisational implications of current policies for the 1990s are noted.This research is part of a Fulbright, Western European Regional Research Grant for 1989 and also received support from the University of California, Institute for International Studies and the Committee for Research at Berkeley. I wish to thank Marilyn Taylor and Stuart Etherington in London, and my colleagues Neil Gilbert, Bart Grossman and Paul Terrell for their helpful comments on an earlier draft. The assistance of David Billis, Director, and the staff of the Centre for Voluntary Organisation, London School of Economics, is also gratefully acknowledged.     

Patterns of Childlessness among Catholic and Non-Catholic Women in the U.S.: A Log-Linear Analysis*

The principal objective of this paper is to conduct a log-linear analysis of patterns of childlessness among Catholic and non-Catholic women in the United States. We address this issue by examining white women between the ages of thirty-five and forty-four, ascertaining whether they are voluntarily, involuntarily, or temporarily childless or childed. Given the long-standing emphasis of the Catholic Church regarding the importance of children in marriage and the family, an emphasis which was not reversed during the Second Vatican Council, we suggest that even after controlling for religious activity and educational attainment, Catholic women should be less disposed than non-Catholic women to choose voluntarily to have no children. We review various aspects of Church doctrine leading to such an hypothesis. Our results do not suggest an “end” to Catholic-non-Catholic differentials in childlessness. Catholic women between the ages of thirty-five and forty-four in 1976 were very far apart from non-Catholic women with respect to the voluntary decision to have no children. And they are also very different from non-Catholic women regarding patterns of involuntary childlessness. These differential patterns of voluntary and involuntary childlessness are discussed and analyzed.