Flexible modelling of simultaneously interval censored and truncated time‐to‐event data

This paper deals with the analysis of data from a HET‐CAM^VT experiment. From a statistical perspective, such data yield many challenges. First of all, the data are typically time‐to‐event like data, which are at the same time interval censored and right truncated. In addition, one has to cope with overdispersion as well as clustering. Traditional analysis approaches ignore overdispersion and clustering and summarize the data into a continuous score that can be analysed using simple linear models. In this paper, a novel combined frailty model is developed that simultaneously captures all of the aforementioned statistical challenges posed by the data. Copyright © 2015 John Wiley & Sons, Ltd.     

Performing armchair roundoff analyses of statistical algorithms

Numerical stability is but one of many desirable properties which should be considered when designing statistical software. However, rigorous roundoff analysis is rarely done because it seems not worth the price; the influence of rounding error is usually of secondary importance, and the analysis is thought to be beyond the reach of all but a few specialists. This note discusses the role of roundoff analysis in the design of a statistical program and shows that new techniques sometimes make assessment of the effect of rounding errors no more difficult than the verification of other program properties.     

Engendering Response: Professional Gesture and the Assessment of Eyesight in Optometry Consultations

Many of the procedures undertaken within healthcare require specialized forms of participation that may be unfamiliar, even disturbing, to patients or clients. The practitioner has to encourage and enable participation in the investigation in an appropriate fashion while preserving the structure and integrity of the procedure. In this article, we consider optometry and the deployment of a vision test, known as subject refraction, that provides data to help determine the characteristics of any corrective lens that may be required by clients. The procedure's ability to establish robust and reliable data relies upon the optometrist's ability to encourage the client to respond to a series of stimuli without consideration or reflection. That is, the client is required to produce an unwitting response—conduct that might be considered nonsymbolic rather than symbolic. In this article, we also consider the optometrist's talk and bodily comportment during subjective refraction and how it serves to shape and determine the quality of the client's response and participation, and in turn to produce reliable test results.     

Consequences and Costs of Closing a Publicly Funded Methadone Maintenance Clinic

Objective. We examine volunteering to support the relief effort after the bombing of the Murrah Federal Building. We address two issues: (1) how widespread was volunteering and what forms did it take, and (2) does Wilson and Musick’s (1997a) “integrated theory of volunteer work” help to explain variation in volunteering in this disaster situation? Methods. We use data from the 1996 Oklahoma City Survey (OKC Survey). The 1996 OKC Survey is based on a random sample of the adult population of Oklahoma City and was administered 10 months after the bombing. Results. Nearly 75 percent of the sample respondents volunteered to support the relief effort in at least one way; giving money and donating nonprofessional goods or services were the two most prevalent volunteer activities. Socioeconomic status, knowing someone killed or injured in the bombing, belonging to voluntary organizations before the bombing, and being affiliated with a religious denomination were predictors of volunteering, depending on the type of volunteer activity considered. Conclusions. The magnitude of volunteering after the Murrah Building bombing was in line with volunteer efforts after other disasters. The integrated theory of volunteer work is a useful framework for studying volunteering after disasters.     

Decision Making for Animal Health and Welfare: Integrating Risk‐Benefit Analysis with Prospect Theory

This study integrated risk‐benefit analysis with prospect theory with the overall objective of identifying the type of management behavior represented by farmers’ choices of mastitis control options (MCOs). Two exploratory factor analyses, based on 163 and 175 Swedish farmers, respectively, highlighted attitudes to MCOs related to: (1) grouping cows and applying milking order to prevent spread of existing infection and (2) working in a precautionary way to prevent mastitis occurring. This was interpreted as being based on (1) reactive management behavior on detection of udder‐health problems in individual cows and (2) proactive management behavior to prevent mastitis developing. Farmers’ assessments of these MCOs were found to be based on asymmetrical evaluations of risks and benefits, suggesting that farmers’ management behavior depends on their individual reference point. In particular, attitudes to MCOs related to grouping cows and applying milking order to prevent the spread of mastitis once infected cows were detected were stronger in the risk domain than in the benefit domain, in accordance with loss aversion. In contrast, attitudes to MCOs related to working in a precautionary way to prevent cows from becoming infected in the first place were stronger in the benefit domain than in the risk domain, in accordance with reverse loss aversion. These findings are of practical importance for farmers and agribusiness and in public health protection work to reduce the current extensive use of antibiotics in dairy herds.     

Organisation structure,management style and company performance

This paper examines the relationship between organisation structure and management style and their influence on organisational effectiveness measured in both ‘human’ and financial terms. Account has also been taken of related contextual factors such as differences in task, size and environment of a company. Using information collected from a sample of fifty small and medium size printing and building firms the authors have elaborated a conceptual model involving the independent attributes; integration, control, task orientation and people orientation. The validity of this model has been operationally tested and examined against the background of evidence reported by other research workers on the contextual determinants of organisational structure and management style. Substantially different patterns of association between ‘organisation’ and ‘style’ and company performance are found for the two industries and an important outcome of the research has been to produce further evidence in favour of the contingency theory of organisation. The paper concludes with some implications for management practice and organisational design.