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.     

Efficient and effective learning for safety from incidents

Learning from incidents is important for improving safety. Many companies spend a great deal of time and money on such learning procedures. The objectives of this paper are to present some early results from a project aimed at revealing weaknesses in the procedures for learning from incidents and to discuss improvements in these procedures, especially in chemical process industries. The empirical base comes from a project assessing organizational learning and the effectiveness of the different steps of the learning cycle for safety and studying relations between safety-specific transformational leadership, safety climate, trust, safety-related behavior and learning from incidents. The results point at common weaknesses in the organizational learning, both in the horizontal learning (geographical spread) and in vertical learning (double-loop learning). Furthermore, the effectiveness in the different steps of the learning cycle is low due to insufficient information in incident reports, very shallow analyses of reports, decisions that focus at solving the problem only at the place where the incident took place, late implementations and weak solutions. Strong correlations with learning from incidents were found for all safety climate variables as well as for safety-related behaviors and trust. The relationships were very strong for trust, safety knowledge, safety participation and safety compliance.     

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.     

Demographic implications of the New United States certificates

To assist in developing uniform reporting of vital events among the fifty states, Puerto Rico, and the Virgin Islands, the United States government prepares standard certificates of birth, fetal death, death, marriage, and divorce. These model forms are revised, with the assistance of the states, approximately every ten years. Revisions are now being prepared by the National Center for Health Statistics which will become effective beginning January 1, 1968. Important new source material for demography will be introduced.Most changes will appear in the Standard Certificate of Live Birth and in the Standard Certificate of Fetal Death. An item on education of father and mother will provide detailed national data on education and fertility. The date of the last live birth to the mother and the date of the last fetal death will provide information on previous pregnancy outcome and on child-spacing. The recording of state file numbers for mates born alive and dead in the same delivery will make it easier to match live birth and fetal death certificates for the preparation of detailed tabulations on multiple births. Several new items related to maternal and child health have also been added. No significent changes were planned for the Standard Certificate of Death.The Standard Certificate of Marriage will include as new items the education of the bride and groom, the date on which the last marriage, if any, ended, and specification of the officiant as a religious or civil official. The Standard Certificate of Divorce or Annulment will obtain information on the education of husband and wife, the approximate date on which the couple separated, the mode of dissolution of the previous marriage, and the total number of living children. It is anticipated that most of the new items will be included in the certificates of all the states. The National Center for Health Statistics will provide detailed tabulations related to these items, beginning with data year 1968.Demographers are making an increased use of vital records and at the same time are extending their contacts with state health departments; in some states collaborative projects have been undertaken. Because of the importance of the source documents, which in some cases have not been exploited fully, demographers should increase their contact with the state vital statistics offices which develop, collect, and process the records. By indicating an interest in vital registration and by making their research needs known, demographers can encourage the acceptance of new concepts and collaborate in the improvement of vital records for demographic research purposes.