Stability analysis using mixed models: A critique of tolerance interval methods and a probabilistic solution

Recently, tolerance interval approaches to the calculation of a shelf life of a drug product have been proposed in the literature. These address the belief that shelf life should be related to control of a certain proportion of batches being out of specification. We question the appropriateness of the tolerance interval approach. Our concerns relate to the computational challenges and practical interpretations of the method. We provide an alternative Bayesian approach, which directly controls the desired proportion of batches falling out of specification assuming a controlled manufacturing process. The approach has an intuitive interpretation and posterior distributions are straightforward to compute. If prior information on the fixed and random parameters is available, a Bayesian approach can provide additional benefits both to the company and the consumer. It also avoids many of the computational challenges with the tolerance interval methodology.     

Beyond Social Constructionism: Critical Realism and Social Work

Summary Theories within the social and psychological sciences continueto shape social work practice. However, recent debates withinthese sciences on the shortcomings of ‘social constructionism’,and the attempt to overcome them through a critical realistposition, have so far failed to capture social work's attention.This paper provides a critical overview of these theoreticaldebates, highlighting the shortcomings of social constructionismfor social work. The critical realist challenge to social constructionism,as articulated by the British philosopher Roy Bhaskar, is consideredand its relevance to social work formulated in terms of a returnto ‘depth’ in practice.     

Developing creative solutions to the problems of children and their families: communicative reason and the use of forum theatre

The paper represents a further development of work previously reported in this journal by Spratt & Houston (1999) and Spratt et al. (2000) . The authors have sought to develop ways of understanding current social work with children and families in line with the critical theory of Jurgen Habermas. This analysis has been complemented by an adoption of the methodology of the radical dramatist, Augusto Boal. In synthesizing Habermas's analysis of communicative discourses with the consciousness raising methodology of Boal, the authors have already demonstrated the effectiveness of this hybrid in problem‐solving exercises with social workers. The present paper reports on an application of this developing theory to practice, utilizing the centrepiece of Boal's method, forum theatre. A forum theatre project, concerned with the issue of bullying, is described and evaluated. It is argued that the project provides an exemplar of an innovative, democratizing and effective methodology that might profitably be utilized in social work with children and families. Finally, suggestions are made as to how these ideas could be developed in practice.     

Fitting Hierarchical Holographic Modeling into the Theory of Scenario Structuring and a Resulting Refinement to the Quantitative Definition of Risk

A point of view is suggested from which the Hierarchical Holographic Modeling (HHM) method can be seen as one more method within the Theory of Scenario Structuring (TSS), which is that part of Quantitative Risk Assessment having to do with the task of identifying the set of risk scenarios. Seen in this way, HHM brings strongly to our attention the fact that different methods within TSS can result in different sets of risk scenarios for the same underlying problem. Although this is not a problem practically, it is a bit awkward conceptually from the standpoint of the "set of triplets" definition of risk, in which the scenario set is part of the definition. Accordingly, the present article suggests a refinement to the set of triplets definition, which removes the specific set of scenarios, found by any of the TSS methods, from the definition of risk and casts it, instead, as an approximation to the "true" set of scenarios that is native to the problem at hand and not affected by the TSS method used.     

Business Interest Group Power and Temporary Assistance to Needy Families*

Objectives. Our aim is to test the influence of business interest groups on Temporary Assistance to Needy Families (TANF) policy at the state level. Methods. We use the state TANF guarantee, the length of time recipients have before they lose their benefits, and the existence of a “family cap” as dependent variables in three models. Each of the models tests business interest group power and several other measures that represent possible influences on the dependent variable. Results. We find that business interest group power is significantly related to both the generosity of the TANF guarantee and to TANF time limits. However, it is not related to the presence of the family cap in state TANF policy. Conclusions. The evidence we found is consistent with the idea that those state TANF policies that are most intimately related to business interests are just those policies that are most affected by business group influence. States' TANF policies regarding maximum benefit and time limits both have a direct impact on wealth redistribution and labor‐market behavior. On the other hand, business interest groups do not seem to have much influence on the presence of TANF family caps, policies that are arguably less the concern of business interest groups, and more connected to public attitudes toward families and children.     

Neo-natal mortality in South Asia: The special role of tetanus

First-year mortality in rural Uttar Pradesh is characterized by a predominance (60 per cent) of deaths during the first month of life, of which 66 per cent are reported to be due to tetanus. This pattern is not typical of the historical experience of many developed countries and the current experience of some less developed countries where post-neo-natal mortality predominates. To examine this phenomenon, two causal models of neo-natal mortality (one for tetanus and one for all other diseases) are developed and tested using retrospective survey data from 2000 couples living in rural Uttar Pradesh.

Neo-natal tetanus mortality is found to be primarily a function of opportunities for exposure to the disease (e.g. lack of antiseptic birth practices, ownership of large animals) rather than of socio-economic status or demographic variables. The importance of examining neo-natal mortality by cause, and the shortcomings inherent in making inferences from the historical experiences of Western nations are emphasized.     

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.