STATISTICAL CHALLENGES OF AIDS: (The 1990 Knibbs Lecture, Canberra, 27 November 1990)

Issues that are central to the understanding and management of the HIV epidemic have generated numerous statistical challenges. This paper considers questions concerning the incubation period, the effects of treatments, pre diction of AIDS cases, the choice of surrogate end points for the assessment of treatments and design of strategies for screening blood samples. These issues give rise to a broad range of intriguing problems for statisticians. We describe some of these problems, how they have been tackled so far and what remains to be done. The discussion touches on topical statistical methods such as smoothing, bootstrapping, interval censoring and the ill-posed inverse problem, as well as asking fundamental questions for frequentist statistics.     

Young Adult Carers: The Impact of Caring on Health and Education

Research has shown that young people who care for parents and relatives (young carers and young adult carers) are at greater risk of mental and emotional difficulties and are more likely to do badly at school or college. To explore the difficulties faced by young adult carers (aged 14–25) in the UK, an online survey was conducted. Almost half (45%) of the 295 respondents reported having a mental health problem. The relationship between the extent of caring and perceived mental health problems and the impact of caring responsibilities on work and education were investigated.     

Counting Young Carers in Switzerland – A Study of Prevalence

An online survey of children in school grades 4–9 (mostly aged 10–15) was conducted in order to determine the prevalence of young carers in Switzerland using a 2‐stage stratified sampling approach. 4082 respondents were drawn from 230 schools. A total of 3991 respondents were included in the analysis and of these 307 (7.7%) were identified as young carers. The population estimate of prevalence was 7.9 per cent. This suggests that there are around 38 400 young carers in school grades 4–9 in Switzerland. Extrapolating to the 9–16 age group gives a figure of almost 51 500.     

Model-based potential analysis of the distribution logistics: a case study

Abstract

The design of its distribution logistics has a decisive influence on a company’s logistical costs and performance. They therefore make an essential contribution to corporate success. This article describes a method for analysing the potential of distribution logistics in terms of logistical costs and performance. In contrast to previous procedures of business process re-engineering, this method maps distribution logistics holistically under variable distribution structures. The article is focused on the approach and results of a case study in a multinational manufacturer of propulsion and automation technologies for machine construction and systems engineering. The developed method is distinguished by a high degree of practicality and applicability. It will contribute to a more efficient design of distribution logistics.     

Field work with the computer: Criteria for assessing systems

Computers, both large and small, can be of great assistance to a field worker. This assistance falls mainly in the area of relieving the field worker from tedious mechanical phases such as typing, sorting, and retrieving information. An examination of field work methods identifies issues and problems which must be addressed by any system for undertaking field work. A rationale for a loose and inclusive (as opposed to an exhaustive and mutually exclusive) coding system is presented. Efficiency, confidentiality, data reduction, and flexibility of testing propositions are discussed as criteria for assessing any system which facilitates field work. The paper concludes by contrasting the methods previously used to collect data, reduce its bulk, code, and retrieve information with what is possible with today's computer hardware and software, and with what will be possible in the near future.We wish to thank Peter Conrad, Susan LeBailly, and the anonymous reviewer of this article for their comments and suggestions.     

Sampling Weights for Analyses of Couple Data: Example of the Demographic and Health Surveys

In some surveys, women and men are interviewed separately in selected households, allowing matching of partner information and analyses of couples. Although individual sampling weights exist for men and women, sampling weights specific for couples are rarely derived. We present a method of estimating appropriate weights for couples that extends methods currently used in the Demographic and Health Surveys (DHS) for individual weights. To see how results vary, we analyze 1912 estimates (means; proportions; linear regression; and simple and multinomial logistic regression coefficients, and their standard errors) with couple data in each of 11 DHS surveys in which the couple weight could be derived. We used two measures of bias: absolute percentage difference from the value estimated with the couple weight and ratio of the absolute difference to the standard error using the couple weight. The latter shows greater bias for means and proportions, whereas the former and a combination of both measures show greater bias for regression coefficients. Comparing results using couple weights with published results using women’s weights for a logistic regression of couple contraceptive use in Turkey, we found that 6 of 27 coefficients had a bias above 5 %. On the other hand, a simulation of varying response rates (27 simulations) showed that median percentage bias in a logistic regression was less than 3 % for 17 of 18 coefficients. Two proxy couple weights that can be calculated in all DHS surveys perform considerably better than either male or female weights. We recommend that a couple weight be calculated and made available with couple data from such surveys.     

Sind türkischstämmige Kinder beim Schulstart im Nachteil?

This article analyses the effect of a Turkish migration background on the risk of delayed school entry. Besides the social background, we control general and host country specific individual skill levels of the child. We assume that children’s individual skills can affect the school entry decision both directly and indirectly. We use data of the longitudinal project “Preschool education and educational careers among migrant children” (German acronym ESKOM VG). About 500 German parents and 500 Turkish-origin parents were interviewed in this study. Standardized developmental tests were conducted with the children in various domains. We find that the Turkish migration background does not have an independent effect on the probability of delayed school entry when the social background and individual skills are controlled. We furthermore disentangle the indirect effect of the Turkish migration background using the khb method. The results indicate that mathematic skills and cultural knowledge have the largest contribution on this indirect effect.     

/r/ and the construction of place identity on New York City's Lower East Side1

This paper argues that a group of white residents on the Lower East Side of Manhattan use a New York City English (NYCE) feature – non‐rhoticity in the syllable coda – in the construction of a place identity, one aspect of identity tied to localness and authenticity. A quantitative analysis confirms that the change in progress towards rhoticity in NYCE ( Labov 1966 ) continues to advance slowly, so that non‐rhoticity remains a resource for New Yorkers, imbued with local social meaning. Ethnographic observation of the Lower East Side reveals conflict among residents, which motivates one group to highlight their place identity by using non‐rhoticity. These Lower East Siders utilize micro‐variation of /r/ in stretches of interview talk, increasing non‐rhoticity when discussing neighborhood topics. Results support a social practice approach to stylistic and sociolinguistic variation, where Lower East Siders use /r/ in constructing a place identity in order to present themselves as authentic neighborhood residents.     

A cross-national and comparative classification of in-country awareness and policy responses to ‘young carers’

The reality for many families where there is chronic illness, mental health problems, disability, alcohol or substance misuse is that children under the age of 18 are involved in caring. Many of these children – known as ‘young carers’ – will be providing regular and significant care, either episodically or over many years, often ‘hidden’ to health, social care and other welfare professionals and services. These children have most often been invisible in social policy and professional practice. What are the reasons why some countries recognize young carers as a priority for social policy while others (most) do not? What are the key factors that influence a country’s awareness and responses to these children? This article provides an original classification and analysis of country-level responses to young carers, drawing on published research, grey literature, policy documents and the authors’ extensive engagement in policy and practice networks for young carers and their families in a wide range of countries. The analysis identifies two of the key factors that influence the extent and nature of these policy responses, focusing on the importance of a reliable in-country research base and the contribution of influential national NGOs and their networks.