Estimation of Dietary Exposure to Chemicals: A Case Study Illustrating Methods of Distributional Analyses for Food Consumption Data

There are a number of sources of variability in food consumption patterns and residue levels of a particular chemical (e.g., pesticide, food additive) in commodities that lead to an expected high level of variability in dietary exposures across a population. This paper focuses on examples of consumption pattern survey data for specific commodities, namely that for wine and grape juice, and demonstrates how such data might be analyzed in preparation for performing stochastic analyses of dietary exposure. Data from the NIAAA/NHIS wine consumption survey were subset for gender and age group and, with matched body weight data from the survey database, were used to define empirically-based percentile estimates for wine intake (μl wine/kg body weight) for the strata of interest. The data for these two subpopulations were analyzed to estimate 14-day consumption distributional statistics and distributions for only those days on which wine was consumed. Data subsets for all wine-consuming adults and wine-consuming females ages 18 through 45, were determined to fit a lognormal distribution ( R ²= 0.99 for both datasets). Market share data were incorporated into estimation of chronic exposures to hypothetical chemical residues in imported table wine. As a separate example, treatment of grape juice consumption data for females, ages 18–40, as a simple lognormal distribution resulted in a significant underestimation of intake, and thus exposure, because the actual distribution is a mixture (i.e., multiple subpopulations of grape juice consumers exist in the parent distribution). Thus, deriving dietary intake statistics from food consumption survey data requires careful analysis of the underlying empirical distributions.     

MARRIAGE, DEPRESSION, AND COGNITION: UNRAVELING THE GORDIAN KNOT-REPLY TO ETTINGER ET AL.

Heim and Snyder (1991) explicitly applied a multidimensional assessment and data-analytic strategy to predict husbands' and wives' depressive symptoms from measures of marital disaffection, overt marital conflict, appraisals of relationship prognosis, characterizations of the spouse, and causal attributions. For both genders, the best single predictor of depression was a measure of marital disaffection—accounting by itself for approximately one third of the variance in subjects' depressive symptoms. Additional attributional predictors of depression for married women indicated the need for therapists to support wives' assertive expression of relationship concerns and confrontation of husbands' behaviors contributing to their distress. We reiterate the complex and recursive relationships among marital difficulties, depression, congnitive processes, and their antecedents and consequences and encourage focused research on components of this intricate puzzle.     

NEAREST NEIGHBOUR ANALYSIS OF UNEQUALLY REPLICATED TRIALS

There has been much work on the use of neighbouring plots to control environmental variation in the analysis of agricultural field experiments. In particular, the Residual Maximum Likelihood Neighbour (REMLN) analysis of Gleeson&Cullis (1987) appears very promising. The application of the REMLN analysis to an unequally replicated field trial augmented with an additional variety planted every six plots in a grid system is here compared with a covariance (COV) analysis using the neighbouring grid or check plot values as the covariate. The results indicate that the REMLN analysis gives more accurate estimates of treatment contrasts than the COV analyses, but that the estimate of treatment means can be biased. The bias depends on the mean of the check plot. This bias can be removed by adjusting the estimates of the treatment means such that their average equals the average of the raw means rather than that of the raw data.     

Suicide among elderly white men: development of a profile.

1. Older white men have the highest suicide rate in the nation; a linear increase of suicide occurs with each passing year of chronological age. 2. Elderly who attempt suicide are more likely to communicate their intentions less frequently and to use violent and lethal means. 3. Chronic sleep problems, pain, degenerative illness, or clinical depression may be experienced by older white men at suicidal risk; somatic complaints including imaginary symptoms can mask depression. 4. Educational programs, outreach mental health programs, and enhanced consultation/coordination improve case findings and early intervention. Holistic nursing care, including pain alleviation, depression assessment, and simple comfort measures, are imperative in suicide prevention in the elderly.     

Families and donor insemination: the views of semen donors

One of the consequences of donor insemination for the semen donor is that he becomes a member of two families: his own family in which he has a genetic and social connection with his offspring; and the family of the recipient couple, in which he has a genetic connection to the offspring, but usually no social connection with either the offspring or the recipient couple. This article challenges the dominant view that donor insemination as a practice of mainly medical or legal importance by looking at the attitudes of donors to both their own family and the family to which they have contributed their genetic material. Results are presented concerning who donors have told about their donation, who they think should be told, whether they think recipient couples should tell their donor insemination offspring about their conception, and concerning their opinions about factors that are considered in matching donors with recipient fathers.     

Criteria for judging the credibility of children's statements about their sexual abuse

One hundred and three cases of child sexual maltreatment, where offenders confessed to some level of their abuse, were examined to determine the extent to which the children's statements about their victimization contained three widely accepted clinical criteria of a true sexual abuse allegation. The results support clinical assumptions that the criteria in question were valid ones for determining the truth of a sexual abuse allegation in cases involving confessions of abusers.     

Panel data regression for counts

A new panel data model for count data is introduced. We suggest alternative estimators, such as pseudo maximum likelihood and generalized method of moments, of structural and nuisance parameters. In addition, different test statistics of independence and overdispersion are obtained. The small sample performance of the estimators and tests are evaluated in Monte Carlo experiments. The model is applied to the number of days absent in Sweden 1981–1991 for a panel of Swedish male workers.     

Interrelationships between fertility and marital dissolution: Results of a simultaneous logit model

Previous studies have failed to examine (a) the simultaneity of decisions to bear children and to dissolve a marriage and (b) the effects of the childbearing in the period just before dissolution on the likelihood of disruption. We attempted to resolve both problems by developing a simultaneous logit model of the interrelationship between the probability of separation and of having a birth during this period (when dissolution presumably is being considered). The model was estimated at successive durations of first marriage, using data for white women in the 1970 National Fertility Survey. The results indicate that childbearing patterns— number of children and age of youngest child at the beginning of the marital interval being studied and fertility during the interval—did not influence the likelihood of separation in simple or consistent ways over the marital life course, nor did marital strife (as indicated by separation) seem to affect childbearing throughout marriage.     

Family violence: A microeconomic approach

A model of violence between adult family members is developed by integrating material from the sociological theories of family violence and social exchange, and the economic theories of crime and the family. Based on this model a decrease in the dictator's internal sanctions against violence would be expected to increase the amount of time allocated to violence by the dictator. Further, if the level of fines and other monetary costs imposed by external agencies (e.g., the courts) as a result of the family violence do not vary with the level of violence, then the model indicates that an increase in such monetary sanctions will cause a reduction in the amount of time the dictator allocates to violence. If both the dictator and victim are risk neutral, an increase in the probability of external intervention will decrease the time allocated to violence. In addition, it is found that increases in the opportunities available to the victim outside the marriage will tend to improve the well-being of the victim in the marriage even if it has no effect on the time allocated to violence by the dictator. The model also provides insights for empirical work in family violence such as (1) suggestions of relevant independent variables, (2) the specification of a functional form for estimation, and (3) the specification of an error structure for the empirical model.