Michael Silverstein

The Association of Maternal Obesity and Diabetes With Autism and Other Developmental Disabilities.

BACKGROUND: Obesity and diabetes are highly prevalent among pregnant women in the United States. No study has examined the independent and combined effects of maternal prepregnancy obesity and maternal diabetes on the risk of autism spectrum disorder (ASD) in parallel with other developmental disorders (DDs). METHODS: This study is based on 2734 children (including 102 ASD cases), a subset of the Boston Birth Cohort who completed at least 1 postnatal study visit at Boston Medical Center between 1998 and 2014. Child ASD and other DDs were based on physician diagnoses as documented in electronic medical records. Risks of ASD and other DDs were compared among 6 groups defined by maternal prepregnancy obesity and diabetes status by using Cox proportional hazard regression controlling for potential confounders. RESULTS: When examined individually, maternal prepregnancy obesity and pregestational diabetes (PGDM) were each associated with risk of ASD. When examined in combination, only mothers with obesity and PGDM (hazard ratio 3.91, 95% confidence interval 1.76–8.68) and those with obesity and gestational diabetes (hazard ratio 3.04, 95% confidence interval 1.21–7.63) had a significantly increased risk of offspring ASD. Intellectual disabilities (IDs), but not other DDs, showed a similar pattern of increased risk associated with combined obesity and PGDM. This pattern of risk was mostly accounted for by cases with co-occurring ASD and ID. CONCLUSIONS: Maternal prepregnancy obesity and maternal diabetes in combination were associated with increased risk for ASD and ID. ASD with ID may be etiologically distinct from ASD without ID.

Inconsolable Infant Crying and Maternal Postpartum Depressive Symptoms

OBJECTIVE: To quantify the extent to which maternal report of inconsolable infant crying, rather than colic (defined by Wessel’s criteria of daily duration of fussing and crying >3 hours), is associated with maternal postpartum depressive symptoms. METHODS: Participants were 587 mothers who were recruited shortly before or after delivery and followed longitudinally. At 5 to 6 weeks postpartum, mothers recorded the duration and mode (fussing, crying, or inconsolable crying) of their infant’s distress by using the Baby’s Day Diary. The Edinburgh Postnatal Depression Scale (EPDS) was administered at enrollment and at 8 weeks postpartum. Using regression models that included baseline EPDS scores and multiple confounders, we examined associations of colic and inconsolable crying with later maternal EPDS scores at 8 weeks postpartum. RESULTS: Sixty mothers (10%) met the EPDS threshold for “possible depression” (score ≥9) at 8 weeks postpartum. For mothers reporting >20 minutes of inconsolable crying per day, the adjusted odds ratio for an EPDS score ≥9 was 4.0 (95% confidence interval: 2.0–8.1), whereas the adjusted odds ratio for possible depression in mothers whose infants had colic was 2.0 (95% confidence interval: 1.1–3.7). These associations persisted after adjusting for baseline depression symptoms. CONCLUSIONS: Maternal report of inconsolable infant crying may have a stronger association with postpartum depressive symptoms than infant colic. Asking a mother about her ability to soothe her infant may be more relevant for potential intervention than questions about crying and fussing duration alone.

A comparison of PMRs and SMRs as estimators of occupational mortality.

Standardized mortality ratios (SMRs) for occupational diseases are confounded by health differences between industrial and general populations. In 109 industrial cohorts largely free of work-related mortality, these selection effects were sizable for both malignant and nonmalignant outcomes. All-cancer SMRs were considerably less than 1.0 for many cohorts, and lung cancer was subject to almost as much selection-derived confounding as nonmalignant disease. Standardized proportional mortality ratios (PMRs) (approximated by relative SMRs (RSMRs)) were less confounded than SMRs in estimating occupational risk. PMRs appeared to overestimate cancer mortality on average by 6%, while SMRs underestimated by 13%. PMRs underestimated nonmalignant respiratory disease by 16 percent but SMRs underestimated by 39 percent. The sources of confounding, in addition to selection on health status at hire, most likely include social class. SMRs, in the absence of internal population comparisons, would fail to detect both malignant and nonmalignant work-related mortality in many industrial cohorts

Cumulative trauma disorders of the hand and wrist in the auto industry.

Surveillance for cumulative trauma disorders (CTDs) of the hand and wrist was carried out in five US automotive plants from 1985 to 1986, using Occupational Safety and Health Administration (OSHA) Form 200 injury and illness logs and medical insurance claims. Results using both record sources indicated that hand and wrist disorders may be more common in foundries than in other types of automotive plants. Similarly, in assembly plants, employees in certain departments appeared to be at higher risk for CTDs. Although our results are based on small numbers of cases, they suggest plants and departments that might be targeted for more detailed investigation.

Infant Self-Regulation and Early Childhood Media Exposure

OBJECTIVES: Examine prospective associations between parent-reported early childhood self-regulation problems and media exposure (television and video viewing) at 2 years. We hypothesized that children with poor self-regulation would consume more media, possibly as a parent coping strategy. METHODS: We used data from 7450 children in the Early Childhood Longitudinal Study–Birth Cohort. When children were 9 months and 2 years old, parents completed the Infant Toddler Symptom Checklist (ITSC), a validated scale of self-regulation. With daily media use at 2 years as our outcome, we conducted weighted multivariable regression analyses, controlling for child, maternal, and household characteristics. RESULTS: Children watched an average of 2.3 hours per day (SD 1.9) of media at age 2 years. Infants with poor self-regulation (9-month ITSC score ≥3) viewed 0.23 hour per day (95% confidence interval [CI] 0.12–0.35) more media at 2 years compared with those with 9-month ITSC score of 0 to 2; this remained significant in adjusted models (0.15 hour per day [95% CI 0.02–0.28]). Children rated as having persistent self-regulation problems (ITSC ≥3 at both 9 months and 2 years) were even more likely to consume media at age 2 (adjusted β 0.21 hour per day [95% CI 0.03–0.39]; adjusted odds ratio for >2 hours per day 1.40 [95% CI 1.14–1.71]). These associations were slightly stronger in low socioeconomic status and English-speaking households. CONCLUSIONS: Early childhood self-regulation problems are associated with mildly increased media exposure, even after controlling for important confounding variables. Understanding this relationship may provide insight into helping parents reduce their children’s screen time.

Mortality among workers exposed to coal tar pitch volatiles and welding emissions: an exercise in epidemiologic triage.

The United Automobile Workers International Union has established a system of epidemiologic triage to evaluate patterns of mortality among groups of union members. In response to worker concerns, the Union examined mortality at a metal stamping plant, using a method which linked pension records with the State of Michigan computerized death registry. The observed proportion of malignant neoplasms was nearly twice that expected (95% Confidence Limits 1.36, 2.62). Two- to five-fold excess proportional mortality from cancer of the digestive organs, lung cancer, and leukemia accounted for most of the overall excess. Strong associations were found between lung and digestive organ cancer and employment as maintenance welders or millwrights in the plant (odds ratios greater than 10). High levels of six polycyclic aromatic hydrocarbons with mutagenic and carcinogenic properties were found during hot coal tar application to wood block floors, work conducted by the high-risk groups. These levels were substantially reduced following the purchase of new tar pots. The example demonstrates that epidemiologic tools can play a valuable role in occupational health decision making, but care must be taken to avoid mechanical reliance on quantitative testing and to acknowledge the important role of social and political value judgments in the establishment of responsible public policy.

The relationship between maternal depression, in-home violence and use of physical punishment: What is the role of child behaviour?

Background: The combined impact of maternal depression and in-home violence, and how their relationship with physical punishment varies with child behaviour are unknown. Objectives: To determine the combined impact of maternal depression and violence exposure on smacking and explore the role of child behaviours in this relationship. Methods: Multivariable regression analysis of a sample of kindergarten children. Maternal depressive symptoms, violence exposure and smacking were measured by parent interview. Child behaviours were reported by teachers. Results: 12 764 mother–child dyads were examined. The adjusted odds ratio (aOR) for smacking among depressed mothers was 1.59 (95% CI 1.40 to 1.80), mothers exposed to in-home violence 1.48 (95% CI 1.18 to 1.85) and dually exposed mothers 2.51 (95% CI 1.87 to 3.37). Adjusting for child self-control or externalising behaviour did not change these associations, and no effect modification by child behaviour was detected. Among mothers smacking children, depression was associated with increased smacking frequency (adjusted incident rate ratio (aIRR) 1.12; 95% CI 1.01 to 1.24), but became borderline significant after adjusting for child self-control or externalising behaviour (aIRRs 1.10; 95% CI 1.00 to 1.21). Depressed mothers exposed to violence demonstrated higher rates of smacking (aIRR 1.29; 95% CI 1.09 to 1.53); this remained stable when adjusting for child behaviours. Conclusion: Maternal depression and violence exposure are associated with smacking, particularly when depression and violence co-exist, when they are also associated with smacking frequency. Child self-control and externalising behaviour do not substantially impact the association between maternal depressive symptoms, violence exposure and smacking.

Getting Home Safe and Sound: Occupational Safety and Health Administration at 38

The Occupational Safety and Health Act of 1970 (OSHAct) declared that every worker is entitled to safe and healthful working conditions, and that employers are responsible for work being free from all recognized hazards. Thirty-eight years after these assurances, however, it is difficult to find anyone who believes the promise of the OSHAct has been met. The persistence of preventable, life-threatening hazards at work is a failure to keep a national promise. I review the history of the Occupational Safety and Health Administration and propose measures to better ensure that those who go to work every day return home safe and sound. These measures fall into 6 areas: leverage and accountability, safety and health systems, employee rights, equal protection, framing, and infrastructure.

Developments in asbestos cancer risk assessment.

BACKGROUND Efforts have been made for 25 years to develop asbestos risk assessments that provide valid information about workplace and community cancer risks. Mathematical models have been applied to a group of workplace epidemiology studies to describe the relationships between exposure and risk. EPAs most recent proposed method was presented at a public meeting in July 2008. METHODS Risk assessments prepared by USEPA, OSHA, and NIOSH since 1972 were reviewed, along with related literature. RESULTS AND CONCLUSIONS None of the efforts to use statistical models to characterize relative cancer potencies for asbestos fiber types and sizes have been able to overcome limitations of the exposure data. Resulting uncertainties have been so great that these estimates should not be used to drive occupational and environmental health policy. The EPA has now rejected and discontinued work on its proposed methods for estimating potency factors. Future efforts will require new methods and more precise and reliable exposure assessments. However, while there may be genuine need for such work, a more pressing priority with regard to the six regulated forms of asbestos and other asbestiform fibers is to ban their production and use.

Use of Mobile Technology to Calm Upset Children: Associations With Social-Emotional Development

Use of Mobile Technology to Calm Upset Children: Associations With Social-Emotional Development Although it is known that parents of infants and toddlers with difficult behavior disproportionately use television and videos as calming tools,1 there are no published data regarding to what degree mobile technologies (such as cell phones and tablets) are used for this purpose. Previous qualitative work with parents has suggested that parental perceived control, defined as feelings of control over children’s behavior and development, may determine how parents set limits around screen media use2 and respond to difficult child behavior.3 We therefore sought to further explore this observation by examining associations between the social-emotional development of toddlers and mobile media use in a sample of parenttoddler dyads, and to determine whether potential associations are modified by parental perceived control.