Design priorities and disciplinary perspectives: the case of the US National Children's Study

Summary.  The National Children's Study (NCS), which was undertaken in 2000 by collaboration between several US federal government agencies, is one of the largest and boldest longitudinal studies of children's health ever undertaken. One of the key design issues has been the nature of the NCS sample. The paper describes the nature of the choices and the reasons for the decision that the NCS be based on a national probability sample. Designed as a study of the environmental influences on children's health and development, the NCS is expected to identify, enrol and follow about 100000 children from their birth to the age of 21 years. A broad definition of relevant environments of interest, and a full partnership between government, university and medical scientists, introduces considerable challenges in the design of the study.     

The Mean is within One Standard Deviation of Any Median

Statistics education is often restricted to teaching the mathematical equations and theories that form the foundation of statistical analysis. It can be argued, however, that the interpretation of the analysis and the communication of the results are equally important. The interdisciplinary role of statisticians requires us to examine real-life problems critically and communicate analytical results to nonstatisticians in a clear and concise manner. This article discusses the importance of including writing assignments as a routine part of statistics courses and presents benefits of the increased use of writing.     

Screening children with a history of maltreatment for post-traumatic stress disorder in frontline social care organizations: A process evaluation

The use of standardized screening tools to identify trauma exposure and associated symptoms is commonly recommended as a key component in the development of trauma informed services and is seen as integral to facilitating access to evidence-based therapies. However, there is limited evidence in the UK about the factors influencing the adoption of such tools into routine practice in children's social care. This paper presents the findings from a process evaluation of how practitioners implemented a screening tool for post-traumatic stress disorder, anxiety and depression into their day-to-say practice and what worked or did not work during the process. The findings from this study highlight the potential benefits for both young people and practitioners, alongside some of the challenges involved. In particular, practitioners need to see the direct benefit for young people of being assessed. Additionally, practitioners value regular mentoring as they become more proficient in using standardized screening tools.     

The relative impact of interviewer effects and sample design effects on survey precision

One of the principal sources of error in data collected from structured face-to-face interviews is the interviewer. The other major component of imprecision in survey estimates is sampling variance. It is rare, however, to find studies in which the complex sampling variance and the complex interviewer variance are both computed. This paper compares the relative impact of interviewer effects and sample design effects on survey precision by making use of an interpenetrated primary sampling unit–interviewer experiment which was designed by the authors for implementation in the second wave of the British Household Panel Study as part of its scientific programme. It also illustrates the use of a multilevel (hierarchical) approach in which the interviewer and sample design effects are estimated simultaneously while being incorporated in a substantive model of interest.     

Practitioners’ experiences of using blended models within family support: A proof of concept study involving Cognitive-Behavioural Therapy (CBT), Multisystemic Therapy (MST) and Incredible Years (IY) interventions

ABSTRACT

Evidence-based models have demonstrated significant potential for improving outcome. However, it has been proposed that single-issue interventions cannot adequately address the multiple needs that some families experiences. This paper outlines a novel approach in which three evidence-based practices (Multisystemic Therapy, Incredible Years, and Cognitive-Behavioural Therapy) were concurrently implemented within the same programme. The objectives are to explore the experience and perceptions of practitioners who implemented the blended model, to explore the novelty of blended approaches, to examine the extent to which families were engaged in and were retained in this programme, and compare the outcomes for families who received blended and nonblended approaches. Method: Data was collected for 158 families between March 2014 and March 2016. Thirty-one families engaged in the blended approach. to explore the feasibility, semistructured interviews were undertaken with 14 staff. Results: Not all families are in need of a blended approach, but families who experience multiple complexities may benefit more from this type of approach. From the perspective of practitioners, blended models provide an opportunity to address multiple needs within the family. However, there are implementation challenges that could be explored further.     

A multilevel exploration of the role of interviewers in survey non-response

This paper illustrates the use of multilevel statistical modelling of cross-classified data to explore interviewers' influence on survey non-response. The results suggest that the variability in whole household refusal and non-contact rates is due more to the influence of interviewers than to the influence of areas. The results from separate logistic regression models are compared with the results from multinomial models using a polytomous dependent variable (refusals, non-contacts and responses). Using the cross-classified multilevel approach allows us to estimate correlations between refusals and non-contacts, suggesting that interviewers who are good at reducing whole household refusals are also good at reducing whole household non-contacts.     

On optimality of a two-stage sawpling method for binomial populations

We consider a family of two-stage sampling methods for a binomial parameter that guarantee a certain precision. It is shown that, among all such methods, one due to Birnbaum and Healy minimizes the average expected second stage sample size with respect to a certain density on the parameter space. It does not, however, minimize the average expected second stage sample size with respect to the uniform density.     

Symmetric pattern models: a latent variable approach to item non-response in attitude scales

This paper proposes a new approach to the treatment of item non-response in attitude scales. It combines the ideas of latent variable identification with the issues of non-response adjustment in sample surveys. The latent variable approach allows missing values to be included in the analysis and, equally importantly, allows information about attitude to be inferred from non-response. We present a symmetric pattern methodology for handling item non-response in attitude scales. The methodology is symmetric in that all the variables are given equivalent status in the analysis (none is designated a 'dependent' variable) and is pattern based in that the pattern of responses and non-responses across individuals is a key element in the analysis. Our approach to the problem is through a latent variable model with two latent dimensions: one to summarize response propensity and the other to summarize attitude, ability or belief. The methodology presented here can handle binary, metric and mixed (binary and metric) manifest items with missing values. Examples using both artificial data sets and two real data sets are used to illustrate the mechanism and the advantages of the methodology proposed.