Regression calibration for logistic regression with multiple surrogates for one exposure

Methods have been developed by several authors to address the problem of bias in regression coefficients due to errors in exposure measurement. These approaches typically assume that there is one surrogate for each exposure. Occupational exposures are quite complex and are often described by characteristics of the workplace and the amount of time that one has worked in a particular area. In this setting, there are several surrogates which are used to define an individual's exposure. To analyze this type of data, regression calibration methodology is extended to adjust the estimates of exposure-response associations for the bias and additional uncertainty due to exposure measurement error from multiple surrogates. The health outcome is assumed to be binary and related to the quantitative measure of exposure by a logistic link function. The model for the conditional mean of the quantitative exposure measurement in relation to job characteristics is assumed to be linear. This approach is applied to a cross-sectional epidemiologic study of lung function in relation to metal working fluid exposure and the corresponding exposure assessment study with quantitative measurements from personal monitors. A simulation study investigates the performance of the proposed estimator for various values of the baseline prevalence of disease, exposure effect and measurement error variance. The efficiency of the proposed estimator relative to the one proposed by Carroll et al. [1995. Measurement Error in Nonlinear Models. Chapman & Hall, New York] is evaluated numerically for the motivating example. User-friendly and fully documented Splus and SAS routines implementing these methods are available (http://www.hsph.harvard.edu/faculty/spiegelman/multsurr.html).     

Challenging the generational transmission of tobacco smoking: a novel harm reduction approach in vulnerable families

Anti‐smoking measures have been effective in reducing smoking in the general population but have been less effective with people in lower economic quintiles. The effects of parental smoking on children are adverse, long reaching and increase the likelihood of smoking in adulthood. Thus, persistent tobacco smoking is often a feature in generational patterns of poverty and marginalization. In this project, the researcher, a social worker, developed a hypothesis about how links between poverty, smoking and its impact on children at risk could be challenged. A literature review was conducted to explore the hypothesis and the findings were used to develop a strategy to work with impoverished, marginalized parents of children considered at risk by the Child Protection system. The strategy was applied as an exploratory study using qualitative methods to garner insights into factors that changed smoking behaviour at home. Quantitative methods were used to measure change. The study indicated that the strategy is promising, with all parents either ceasing or significantly reducing daily smoking. The number of children exposed to tobacco smoke at home was reduced from 36 to 5. The promising results of this study may enhance the range of solution behaviours for parents and social workers seeking to improve the health and well‐being of vulnerable children.     

Impact of Adult Sons’ Incarceration on African American Mothers’ Psychological Distress

This longitudinal study examines the effect of sons’ incarceration on their mothers’ psychological distress. Interviews were conducted over the life course with a community cohort of African American mothers who had children in first grade in 1966 – 1967 when the study began (N =615). Thirty years later, their sons had significant rates of incarceration (22.4%). Structural equation modeling showed that the more recent the incarceration, the greater the mothers’ psychological distress, even controlling for earlier socioeconomic status and psychological well‐being. Financial difficulties and greater burden of grandparenting are associated with having a son incarcerated and they mediate the relationship between the incarceration and a mother’s psychological distress. Results suggest that incarceration has important effects on family members’ well‐being.     

Reports of childhood sexual abuse by adolescents and young adults: Stability over time

The consistency of childhood sexual abuse (CSA) reporting was explored in this study. Two‐hundred seventeen adolescents and young adults (ages 14–24) enrolled in urban health care clinics completed self‐report questionnaires assessing CSA and other problem behaviors at enrollment and at 7 months. Results indicated that the stability of CSA self‐report at two time points was poor (58% consistent nonreporters of CSA, 20% consistent reporters, 22% inconsistent reporters). Consistent and inconsistent reporters were differentiated on risk measures. Adolescents who endorsed more items from the CSA scale were five times more likely to be consistent reporters. In sum, adolescent CSA reporting was quite inconsistent over time. Using multi‐item scales and assessing CSA at two time points enhances accuracy of reporting.     

The impact of state-level restrictions on abortion

This research examines 23 different laws passed by state governments in an effort to restrict the number of abortions. It assesses both laws passed and laws actually enforced after the Supreme Court permitted states to restrict access to abortion in 1989. None of the policy actions by state governments has had a significant impact on the incidence of abortion from 1982 to 1992. Abortion rates continue to reflect past abortion rates, the number of abortion providers, whether the state funds abortions for Medicaid-eligible women, urbanism, and racial composition of the population. Recent restrictive policies have not affected these trends.     

The age-varying effects of adolescent stress on impulsivity and sensation seeking

Adolescence is defined in part by heightened exposure and sensitivity to stressors. In a longitudinal cohort of youth at risk for substance use problems, we examined the age-varying relationship between stress exposure and traits that are central to the dual systems model. The positive associations between stress exposure, impulsivity, sensation seeking varied as function of age. Specifically, the influence of stress exposure on impulsivity strengthened during early adolescence and remained stable into early adulthood, while the influence of stress exposure on sensation seeking strengthened from early- to mid-adolescence and weakened thereafter. These findings suggest that the maturational imbalance between the capacity to regulate impulsive tendencies and sensation seeking may be exaggerated for youth who are exposed to a high number of stressors.     

High Production Volume Chemical Amine Oxides [C8–C20] Category Environmental Risk Assessment

An environmental assessment of amine oxides has been conducted under the OECD SIDS High Production Volume (HPV) Program via the Global International Council of Chemical Associations (ICCA) Amine Oxides Consortium. Amine oxides are primarily used in conjunction with surfactants in cleaning and personal care products. Given the lack of persistence or bioaccumulation, and the low likelihood of these chemicals partitioning to soil, the focus of the environmental assessment is on the aquatic environment. In the United States, the E-FAST model is used to estimate effluent concentrations in the United States from manufacturing facilities and from municipal facilities resulting from consumer product uses. Reasonable worst-case ratios of predicted environmental concentration (PEC) to predicted no effect concentration (PNEC) range from 0.04 to 0.003, demonstrating that these chemicals are a low risk to the environment.