Global benefit-risk assessment in designing clinical trials and some statistical considerations of the method

When characterizing a therapy, the efficacy and the safety are two major aspects under consideration. In prescribing a therapy to a patient, a clinician puts the two aspects together and makes a decision based on a consolidated thought process. The global benefit-risk (GBR) measures proposed by Chuang-Stein et al. (Stat. Med. 1991; 10:1349-1359) are useful in facilitating the thinking, and creating the framework for making statistical comparisons based on benefit-risk point of view. This article describes how a GBR linear score was defined and used as the primary outcome measure in a clinical trial design. The robustness of the definitions of 'benefit' and 'risk' are evaluated using different criteria. The sensitivity of the pre-specified weights is also analyzed using alternative weights; one of those was determined by the relative to an identified distribution integral transformation approach (Biometrics 1958; 14:18-38). Statistical considerations are illustrated using pooled data from clinical trials studying antidepressant. The pros and cons for using GBR assessments in the setting of clinical trials are discussed.     

Natives and migrants in the London labour market, 1929–1931

Migrants are sometimes regarded as marginal workers in metropolitan labour markets. London has long been a major destination for migrants from elsewhere in Britain and abroad. In this paper we examine the earnings and unemployment experience in 1929–1931 of male workers who migrated to London, or within London. We use data from the New Survey of London Life and Labour, a large survey of working class households, the records from which have recently been computerised. Our findings indicate that migrants were not marginal, in fact they enjoyed slightly higher earnings and lower unemployment incidence than native Londoners. Much of the advantage can be explained by differences in average skill levels and personal characteristics. Received: 2 November 1999/Accepted: 3 August 2000     

Neuropsychiatric complications of traumatic brain injury

Traumatic brain injury (TBI) may be defined as any extracranial mechanical force to the brain that results in any period of loss of consciousness, any loss of memory for events immediately before or after the event, or any alteration in mental status at the time of the event. The major causes are automobile accidents, falls, sporting injuries, and assaults. Many soldiers returning from combat in Afghanistan and Iraq have also experienced TBI. This article provides an overview of the neuropsychiatric complications of TBI, including impairment of consciousness, posttraumatic amnesia, cognitive disorders and dementia, posttraumatic epilepsy, aphasia, depression, mania, psychosis, anxiety disorders, personality changes, aggression, behavioral dyscontrol, fatigue/apathy, and increased risk of suicide. Discussion will focus primarily on issues affecting mental health clinicians. Because mental health providers are more involved in care of chronic issues related to TBI, these issues will be discussed in more detail, although acute neuropsychiatric complications of TBI will be briefly explained.     

Gambling Problems Among Community Cocaine Users

Cocaine use is highly prevalent and a major public health problem. While some studies have reported frequent comorbidity problems among cocaine users, few studies have included evaluation of gambling problems. This study aimed to estimate the prevalence of gambling problems and compare those who were at-risk gamblers with non-problem gamblers in terms of mental health problems, substance use problems, and some risk factors (i.e. family antecedents, erroneous perceptions and coping strategies) among individuals who smoke or inject cocaine. A total of 424 smoked or injected cocaine users recruited through community-based programs in Montreal (Quebec) completed the questionnaire, including the Canadian Pathological Gambling Index, the Composite International Diagnostic Interview, the CAGE, and the Severity Dependence Scale. Of the sample, 18.4 % were considered at-risk gamblers, of whom 7.8 % had problems gambling and 10.6 % were moderate-risk gamblers. The at-risk group was more likely to have experienced a recent phobic disorder and alcohol problems than the non-problem group. A multivariate analysis showed that, compared to those who were non-problem gamblers, the at-risk ones were more likely to have lost a large sum of money when they first started gambling, believed that their luck would turn, and gambled in reaction to painful life events. These results indicate the need to include routines for screening to identify gambling problem among cocaine users.     

Ecosystem services in managing residential landscapes: priorities,value dimensions,and cross-regional patterns

Although ecosystem services have been intensively examined in certain domains (e.g., forests and wetlands), little research has assessed ecosystem services for the most dominant landscape type in urban ecosystems—namely, residential yards. In this paper, we report findings of a cross-site survey of homeowners in six U.S. cities to 1) examine how residents subjectively value various ecosystem services, 2) explore distinctive dimensions of those values, and 3) test the urban homogenization hypothesis. This hypothesis posits that urbanization leads to similarities in the social-ecological dynamics across cities in diverse biomes. By extension, the thesis suggests that residents’ ecosystem service priorities for residential landscapes will be similar regardless of whether residents live in the humid East or the arid West, or the warm South or the cold North. Results underscored that cultural services were of utmost importance, particularly anthropocentric values including aesthetics, low-maintenance, and personal enjoyment. Using factor analyses, distinctive dimensions of residents’ values were found to partially align with the Millennium Ecosystem Assessment’s categories (provisioning, regulating, supporting, and cultural). Finally, residents’ ecosystem service priorities exhibited significant homogenization across regions. In particular, the traditional lawn aesthetic (neat, green, weed-free yards) was similarly important across residents of diverse U.S. cities. Only a few exceptions were found across different environmental and social contexts; for example, cooling effects were more important in the warm South, where residents also valued aesthetics more than those in the North, where low-maintenance yards were a greater priority.     

Building Financial Knowledge Is Not Enough: Financial Self-Efficacy as a Mediator in the Financial Capability of Low-Income Families

ABSTRACT

Policymakers in many countries have taken an interest in population-level financial capability. Limited empirical work has examined how constructs that makeup financial capability relate and how they function for individuals with low incomes. Using a national sample of low-income Canadians, we investigate relationships between financial knowledge, financial self-efficacy, and savings outcomes. Overall, we find that financial self-efficacy fully mediated the relationship between objective financial knowledge and postsecondary-education saving. The association between objective financial knowledge and retirement saving and emergency saving passed through financial self-efficacy. Efforts to promote financial capability need to focus on more than objective financial knowledge.     

On a measure of information gain for regression models in survival analysis

Papers dealing with measures of predictive power in survival analysis have seen their independence of censoring, or their estimates being unbiased under censoring, as the most important property. We argue that this property has been wrongly understood. Discussing the so-called measure of information gain, we point out that we cannot have unbiased estimates if all values, greater than a given time τ, are censored. This is due to the fact that censoring before τ has a different effect than censoring after τ. Such τ is often introduced by design of a study. Independence can only be achieved under the assumption of the model being valid after τ, which is impossible to verify. But if one is willing to make such an assumption, we suggest using multiple imputation to obtain a consistent estimate. We further show that censoring has different effects on the estimation of the measure for the Cox model than for parametric models, and we discuss them separately. We also give some warnings about the usage of the measure, especially when it comes to comparing essentially different models.     

Beyond friendship: the nature and meaning of close personal relationships as perceived by people with learning disabilities

Many people with learning disabilities aspire to having friends and to forming close relationships. Often the latter are discouraged, but for those who enter into such a relationship little is known about the meaning and value it brings to their lives. The aim of this study was to gain an insight into the close relationships of eight couples with learning disabilities using a combination of dyadic and one-to-one interviews. Data collection and analysis was informed and guided by the core principles of grounded theory. Five significant types of benefits were identified from having close personal relationships, namely: comradeship, a sense of contentment, availability of mutual support, coping with the ups and downs of relationships, and a continuing commitment. Service providers could do more to facilitate the formation of close meaningful relationships, and strategies for doing this need to be identified and evaluated.     

Problems with the Doctrine of Interchangeable Indices

Survey researchers can choose (1) to maximize their accuracy in estimating the relations among a few abstract variables or (2) to maximize the number of variables covered. In the former case, many indicators per variable are required; in the latter case, few or one. Lazarsfeld's "doctrine of interchangeable indices" offers some support for the second approach, but this doctrine is shown to neglect or perpetuate three kinds of measurement problems: (1) attenuation of the relations between unmeasured abstract variables, (2) correlated measurement errors, and (3) low data quality and imprecision. An alternative form of the doctrine is presented which is more compatible with the implications of causal models.     

Assessing the Potential Impact of the HIV-1 Epidemic on Orphanhood and the Demographic Structure of Populations in sub-Saharan Africa

Much of the debate on the demographic consequences of the HIV epidemic in sub-Saharan Africa has so far centred around the plausibility of population declines in areas where unprecendently high rates of population growth have recently been in evidence. In this article, the authors use a mathematical model, which combines epidemiological and demographic processes, to illustrate how, under a broad range of impacts on population growth, major changes in demographic features, such as the extent of orphanhood within populations, are likely to occur. At the same time, HIV epidemics are liable to cause significant shifts in the age and sex composition of affected populations, which may have important implications for the ways in which they are best able to cope with the increases in orphanhood, as well as those in infant, early childhood and adult mortality.