Identification of outlying height and weight data in the Iranian National Health Survey 1990-92

Data on the weights and heights of children 2-18 yeas old in Iran were obtained in a National Health Survey of 10 660 families in 1990-92. Data were 'cleaned' in 1 year age groups. After excluding gross outliers by inspection of bivariate scatter plots, Box-Cox power transformations were used to normalize the distributions of height and weight. If a multivariate Box-Cox power transformation to normality exists, then it is equivalent to normalizing the data variable by variable. After excluding gross outliers, exclusions based on the Mahalanobis distance were almost identical to those identified by Hadi's iterative procedure, because the percentages of outliers were small. In all, 1% of the observations were gross outliers and a further 0.4% were identified by multivariate analysis. Review of records showed that the outliers identified by multivariate analysis resulted from data-processing errors. After transformation and 'cleaning', the data quality was excellent and suitable for the construction of growth charts.     

Walking a Tightrope: Case Management Services and Outpatient Commitment

Effective case managers in community mental health are successful at forging a working alliance with recipients. This article explores one key aspect of case management practice, serving involuntary clients, specifically those on outpatient commitment orders. In 19 intensive interviews, a subset of a larger study, case managers shared their perceptions of the utility of outpatient commitment with a focus on how such orders impacted the professional relationship. We argue that the use of advance psychiatric directives and shared decision-making processes can reduce the need for coercive practice.     

Sensitivity of Physiologically Based Pharmacokinetic Models to Variation in Model Parameters: Methylene Chloride

The parameters in a physiologically based pharmacokinetic (PBPK) model of methylene chloride were varied systematically, and the resulting variation in a number of model outputs was determined as a function of time for mice and humans at several exposure concentrations. The importance of the various parameters in the model was highly dependent on the conditions (concentration, species) for which the simulation was performed and the model output (dose surrogate) being considered. Model structure also had a significant impact on the results. For sensitivity analysis, particular attention must be paid to conservation equations to ensure that the variational calculations do not alter mass balance, introducing extraneous effects into the model. All of the normalized sensitivity coefficients calculated in this study ranged between −1.12 and 1, and most were much less than 1 in absolute value, indicating that individual input errors are not greatly amplified in the outputs. In addition to ranking parameters in terms of their impact on model predictions, time-dependent sensitivity analysis can also be used as an aid in the design of experiments to estimate parameters by predicting the experimental conditions and sampling points which will maximize parameter identifiability.     

Planning vs strategy—which will win?

The author describes some of the changes that are taking place in strategic planning at General Electric—a company which is trying to be the most competitive enterprise in the world. He explains why these changes are necessary, the problems of implementation and how they are working out.     

Children's and carers' perspectives of a therapeutic intervention for children affected by sexual abuse

This paper presents the findings of a qualitative study with children affected by sexual abuse who had recently completed a therapeutic intervention (N = 12) and their carers (N = 17). Four themes emerged from the thematic analysis that influenced participants' satisfaction with the service: the attribution of the child's recovery to the therapeutic support received; the therapeutic relationship between the child and practitioner; children's recollection of important aspects of the intervention and the relationship between the carer and the child's practitioner. The findings indicate that the process elements of therapeutic support, including the development of strong relationships and allowing children choice and control, are as important as the content.     

Examining Associations between Occupation and Health by using Routinely Collected Data

When examining a large number of associations simultaneously, as happens when routinely collected data are used to assess associations between occupation and health, it is not obvious how best to identify associations requiring further investigation since some risks may be high, or low, by chance alone. We have developed an approach to deal with this problem which is relatively easy to apply and appropriate to applications where data are not too sparse. Observed to expected ratios are estimated using an empirical Bayes procedure. Anomalous associations can be seen as outliers in a normal probability plot of the log-ratios. The method is illustrated in the analysis of 252 000 cancers registered in men in England during 1981–87.     

Test inversion bootstrap confidence intervals

In this paper we explore the theoretical and practical implications of using bootstrap test inversion to construct confidence intervals. In the presence of nuisance parameters, we show that the coverage error of such intervals is O ( n ^−1/2) which may be reduced to O ( n ⁻¹) if a Studentized statistic is used. We present three simulation studies and compare the performance of test inversion methods with established methods on the problem of estimating a confidence interval for the dose–response parameter in models of the Japanese atomic bomb survivors data.     

Working in Multidisciplinary Community Mental Health Teams: The Impact on Social Workers and Health Professionals of Integrated Mental Health Care

Correspondence to Professor John Carpenter, Centre for Applied Social Studies, University of Durham, Elvet Riverside II, Durham DH1 3JT, UK. E-mail: J.S.W.Carpenter{at}dur.ac.uk Summary This study investigated the relationships between the organizationof community mental health services and professional and teamidentification, team functioning and the psychological well-beingand job satisfaction of staff working in multidisciplinary communitymental health teams (CMHTs). Staff in four districts in theNorth of England completed anonymous questionnaires on two occasions,twelve months apart. There were systematic differences in teamfunctioning, favouring teams in districts where mental healthand social care services were integrated. However, service organizationhad no evident impact on professional or team identificationor on outcomes for staff in terms of stress or job satisfaction.There were differences between social workers (n = 31) and healthservice professionals (n = 82) indicating that social workershad poorer perceptions of team functioning and experienced higherlevels of role conflict. Controlling for other factors includingthe study districts, role conflict was a significant predictorof stress and of job dissatisfaction, while role clarity promotedjob satisfaction. We conclude that support and supervision aimedat ensuring a social work contribution to multidisciplinaryworking should be provided in the course of establishing CMHTsand integrated health and social care services.     

A novel bootstrap procedure for assessing the relationship between class size and achievement

Summary. There is on-going concern about the relationship between class size and achievement for children in their first years of schooling. The Institute of Education's class size project was set up to address this issue and began recruiting in the autumn of 1996. However, because of the non-normality of achievement measures, especially in mathematics, the results have hitherto been presented by using transformed achievement measures. This makes the interpretation difficult for non-statisticians. Ideally, the data would be modelled on the original scale and a bootstrap procedure used to ensure that inferences are robust to non-normality. However, the data are multilevel. In the paper we therefore propose a nonparametric residual bootstrap procedure that is suitable for multilevel models, show that it is consistent and present a simulation study which demonstrates its potential to yield substantial reductions in the difference between nominal and actual confidence interval coverage, compared with a parametric bootstrap, when the underlying distribution of the data is non-normal. We then apply our approach to estimate the relationship between class size and achievement for children in their reception year, after adjusting for other possible determinants.     

The 150-hour rule as a barrier to entering public accountancy

In many states, CPA licensure now requires 150 credit hours of college coursework thereby adding an extra semester or year of schooling beyond typical undergraduate degree requirements. Thus, the “150-hour rule” should increase the cost of becoming a CPA and, consequently, reduce the supply of new CPAs. We test this hypothesis using panel data on the number of first-time candidates for the CPA exam in each state over the years 1985 to 2002. We find that the imposition of the 150-hour education requirement reduces the number of candidates sitting for the CPA exam by 60 percent and that the “grandfathering” provisions of the 150-hour rule produce a substantial transitory increase in the number of candidates sitting for the exam in the year prior to the rule’s effective date. Examination of candidates’ pass rates on the exam also finds behavior consistent with the hypothesis that the 150-hour rule is a barrier to entry. We thank Wilson Mixon and particular the 2002 Western Economics Association and 2002 Southern Economisc Association meetings for helpful comments. We also thank Ian Elkin, Steven Simms, and especially, Keri Anderson for extraordinarily diligent ressearch assistance.