Alcohol and drug abuse among young adults who grew up in substitute care — Findings from a Swedish national cohort study

To what extent substitute long term care modifies intergenerational transmission of substance abuse has rarely been investigated. Using register data, we followed a national cohort born 1973–1985 consisting of 1012 national adoptees, 2408 former children from long term foster care, 348/846 environmental siblings of adoptees/foster children, and 952,935 majority population peers, from their 15th birthday to age 27–35. Using Cox regression, we calculated hazard ratios (HR) for hospital care and criminality associated with illicit drug/alcohol abuse, with adjustments for socio-demographic indicators of caring families, and substance abuse in caring and birth parents.     

Trainee programme reactions and work performance: the moderating role of intrinsic motivation

This study investigated the moderating role of intrinsic motivation on the relationship between trainee programme reactions and work performance among trainees enrolled in formal trainee programmes. The results from a cross-sectional survey among 114 trainees representing three Norwegian service organizations showed that the relationships between perception of the trainee programme and facets of self-reported work performance were positive only for trainees low in intrinsic motivation. Implications for practice and directions for future research are discussed.     

The Effort-Reward Imbalance model of psychosocial stress at the workplace—a comparison of ERI exposure assessment using two estimation methods

It is not unusual for old data to be used in epidemiological studies. Recently developed instruments for measuring work-related stress did not exist when the data collection was carried out. Therefore, approximate questions are sometimes used. An apparent problem is the lack of validation of proxy questions. The aim of this study was to compare the original questions for measuring Effort-Reward Imbalance (ERI) with approximate questions. The study population corresponded with a subgroup in the WOLF-n (WOrk, Lipids, Fibrinogen–north) cohort study of cardiovascular risk in a working population in the north of Sweden: 655 men and 178 women. The agreement in exposure between the original and the approximate ERI single questions was relatively low throughout, whereas the correlation between the ERI subscales and the ERI ratios was reasonable. The latter agreement between the original and the approximate ERI ratio indicates that the approximate measures might have been useful in the past. Yet, whenever possible the implementation of the original questionnaire in study protocols is recommended since a complete measurement of ERI might help to further improve the internal consistency and the predictive validity of this exposure to effort-reward imbalance.     

Covariance structure approximation via gLasso in high-dimensional supervised classification

Recent work has shown that the Lasso-based regularization is very useful for estimating the high-dimensional inverse covariance matrix. A particularly useful scheme is based on penalizing the ?₁ norm of the off-diagonal elements to encourage sparsity. We embed this type of regularization into high-dimensional classification. A two-stage estimation procedure is proposed which first recovers structural zeros of the inverse covariance matrix and then enforces block sparsity by moving non-zeros closer to the main diagonal. We show that the block-diagonal approximation of the inverse covariance matrix leads to an additive classifier, and demonstrate that accounting for the structure can yield better performance accuracy. Effect of the block size on classification is explored, and a class of asymptotically equivalent structure approximations in a high-dimensional setting is specified. We suggest a variable selection at the block level and investigate properties of this procedure in growing dimension asymptotics. We present a consistency result on the feature selection procedure, establish asymptotic lower an upper bounds for the fraction of separative blocks and specify constraints under which the reliable classification with block-wise feature selection can be performed. The relevance and benefits of the proposed approach are illustrated on both simulated and real data.     

Inequality of opportunity in the United Kingdom, 1991–2008

We investigate the extent to which the tax-and-transfer system of the United Kingdom equalizes opportunities for income attainment among citizens. Within the framework of Roemer’s theory of Equality of Opportunity, and using individual data from the British Household Panel Survey from 1991 to 2008, we calculate the tax rates necessary to equalize opportunities for different circumstances. We provide a ranking of these circumstances by the degree to which they influence income attainment. Although pre-fisc equality of opportunity increases over time, the tax rate necessary to equalize opportunities remains higher than the observed tax rate. Only under a relatively high labour supply elasticity the observed UK tax rate fares well in equalizing opportunities for income attainment.     

Explaining Changing Suicide Rates in Norway 1948–2004: The Role of Social Integration

Using Norway 1948–2004 as a case, I test whether changes in variables related to social integration can explain changes in suicide rates. The method is the Box-Jenkins approach to time-series analysis. Different aspects of family integration contribute significantly to the explanation of Norwegian suicide rates in this period. The estimated effect of separations is stronger than the effect of divorces, both for men and women, probably because separations are closer in time to the “real” marital breakup. This difference has not been demonstrated in earlier time-series research. Marriages decrease the suicide rates for males. The unemployment estimate for men has a negative sign, contributing to fewer suicides. Both increasing alcohol (beer) consumption and fewer marriages seem to be implicated in the soaring suicide rate for young men since 1970.

Measurement errors in survey questions: Explaining response variability

In this paper, the response variability in questions from the Swedish Survey of Living Conditions, is studied. A multivariate study of the variation over questions has been done. This study uses questions as statistical units. The questions have been classified in a number of respects, dealing with question character and structure, what the questions ask about and what they require from the interviewee. The study shows that a substantial part of the response variability, i.e., the variation in reliability, can be explained by a few characteristics of the questions.     

High-risk families: the unequal distribution of infant mortality in nineteenth-century Sweden

An analysis of infant mortality (based on 133,448 births) in two regions, Sundsvall and Skellefte?, in north-eastern Sweden during the nineteenth century shows that infant mortality was highly clustered with a relatively small number of families accounting for a large proportion of all infant deaths. Using logistic regression, two important factors were found to be associated with high-risk families: (i) a biological component evidenced by an over-representation of women who had experienced stillbirths, and (ii) a social component indicated by an increased risk among women who had remarried. The results strengthen the argument for using the family rather than the single child as the unit of analysis. The clustering of infant deaths points to the need to re-evaluate our interpretations of the causes of infant mortality in the past.