Geometric Method and Generalized Linear Models. Two Opposite Multiparametric Approaches Illustrated on a Sample of Pituitary Adenomas

We used two statistical methods to identify prognostic factors: a log-linear model (logistic and COX regression, based on the notions of linearity and multiplicative relative risk), and the CORICO method (ICOnography of CORrelations) based on the geometric significance of the correlation coefficient. We applied the methods to two different situations (a "case-control study' and a "historical cohort'). We show that the geometric exploratory tool is particularly suited to the analysis of small samples with a large number of variables. It could save time when setting up new study protocols. In this instance, the geometric approach highlighted, without preconceived ideas, the potential role of multihormonality in the course of pituitary adenoma and the unexpected influence of the date of tumour excision on the risk attached to haemorrhage.     

Spatial Inequality in Mortality in France over the Past Two Centuries

This article analyzes the evolution of spatial inequalities in mortality across 90 French territorial units since 1806. Using a new database, we identify a period from 1881 to 1980 when inequalities rapidly shrank while life expectancy rose. This century of convergence across territories was mainly due to the fall in infant mortality. Since 1980, spatial inequalities have levelled out or occasionally widened, due mainly to differences in life expectancy among the elderly. The geography of mortality also changed radically during the century of convergence. Whereas in the 19th century high mortality occurred mainly in larger cities and along a line from North-west to South-east France, it is now concentrated in the North, and Paris and Lyon currently enjoy an urban advantage.     

Does Part-Time Mothering Help Get a Job? The Role of Shared Custody in Women’s Employment

Though child shared physical custody arrangements after divorce are much more frequent and parents who use it more diverse in many European countries, little is known about their economic consequences for parents. By relaxing family time constraints, does shared custody help divorced mothers return to or stay on work more easily? Since lone mothers are one of the least-employed groups, and they face high unemployment rates, the type of child custody arrangement adopted after divorce is of particular interest for their employability. This article analyses to what extent the type of child custody arrangement affects mothers’ labour market patterns after divorce.Using a large sample of divorcees from an exhaustive French administrative income tax database, and taking advantage of the huge territorial discrepancies observed in the proportion of shared custody, we correct for the possible endogeneity of shared custody. Results show that not repartnered mothers with shared custody arrangements are 24 percentage points more likely to work one year after divorce compared to those having sole custody, while no significant effect is found for repartnered mothers. Among lone mothers, we also highlight huge heterogeneous effects: larger positive effects are observed for previously inactive women, for those belonging to the lowest income quintiles before divorce, for those with a young child, and for those who have three or more children. Thus, shared physical custody arrangements may reduce work–family conflict by diminishing childcare expenses and enlarge the possibilities to find a suitable job because of more relaxed time constraints for lone mothers.     

Applications of Bayesian analysis to proof‐of‐concept trial planning and decision making

Decision making is a critical component of a new drug development process. Based on results from an early clinical trial such as a proof of concept trial, the sponsor can decide whether to continue, stop, or defer the development of the drug. To simplify and harmonize the decision‐making process, decision criteria have been proposed in the literature. One of them is to exam the location of a confidence bar relative to the target value and lower reference value of the treatment effect. In this research, we modify an existing approach by moving some of the “stop” decision to “consider” decision so that the chance of directly terminating the development of a potentially valuable drug can be reduced. As Bayesian analysis has certain flexibilities and can borrow historical information through an inferential prior, we apply the Bayesian analysis to the trial planning and decision making. Via a design prior, we can also calculate the probabilities of various decision outcomes in relationship with the sample size and the other parameters to help the study design. An example and a series of computations are used to illustrate the applications, assess the operating characteristics, and compare the performances of different approaches.     

Les effets pervers du partage de la sécurité. Polices publiques et privées dans une gare et un centre commercial

This article focuses on controlling delinquency in a train station and a shopping center in a big French city. The increasing implication of private organizations in implementing security policies in public areas has spawned a literature about the “dangers of privatization”. As this fieldwork shows, private security officers and NGOs assume duties (related, for example to public relations or social policy) left vacant by police officers. Owing to this sharing of security, the police concentrate on its purely bureaucratic assignments and this has a negative impact on its legitimacy. A historical approach helps us understand how relations between the police and other parties have soured.     

Job strain and psychotropic drug use among white-collar workers

The main objective of this study was to measure the association between simultaneous exposure to high psychological demand and low decision latitude at work and the use of psychotropic drugs among white-collar workers. A second objective was to determine whether social support at work modified this association. A cross-sectional study was performed that included 2786 workers from the public sector in the Greater Quebec City area. A self-administered questionnaire was used in order to evaluate psychological demand, decision latitude and social support at work. Psychotropic drug use was measured over a period of 2 days. The prevalence of psychotropic drug use among the participants was found to be 3.9%, even though 20.5% were exposed to job strain. The association between job strain and psychotropic drug use, after adjustment for social support at work, age, gender, education, family income, employment status, occupation, stressful life events, cigarette smoking, alcohol consumption and physical activity, was statistically significant (odds ratio: 4.5, 95% CI 1.7?12.2). Social support did not appear to modify this association. The results of this study suggest that job strain might be a determinant of psychotropic drug use among white collar workers. Social support at work does not appear, however, to modify this association.     

Reliability and validity of the French version of the 18-item Karasek job content questionnaire

Previous studies have shown that job strain, a combination of high psychological demands and low decision latitude, may be involved in the development of cardiovascular diseases and other health outcomes. In 1985, Karasek recommended a standard questionnaire to measure psychological demands (nine items) and job decision latitude (nine items). The internal consistency, factorial validity, discriminant validity, and 1-year stability of the French version of this instrument were evaluated in a population of 8263 white collar workers. Participants filled out the questionnaire during working hours in the context of a larger cardiovascular study. A subgroup of the study population completed the questionnaire again 1 year later (n = 953). Internal consistency was adequate: .74 for men and .73 for women for psychological demands and .83 for men and .81 for women for decision latitude. The results of the factor analysis were consistent with the two dimensions expected from the theory, although some items had high loading on two factors. Variations in the means of psychological demand and decision latitude scores and variations in the prevalence of high job strain by gender, job category, and age support the discriminant validity. These results were generally comparable to those observed with the English version. The percentages of workers remaining, after 1 year, in the same category of psychological demands, decision latitude, and job strain were 86.6, 86.1 and 75.2% respectively. These data provide evidence of the reliability and validity of the French version of these psychological demand and decision latitude scales