Male twinning after the 2008 Obama election: A test of symbolic empowerment.

On November 4, 2008, Barack Obama was elected the first Black President of the United States. His campaign and electoral win served as a symbol of hope for a more just future, fostering an "Obama effect" that appears associated with improved well-being among non-Hispanic (NH) Black communities. Situating the Obama election within the symbolic empowerment framework, we consider the potentially protective role of the Obama election on NH Black fetal death, an important but understudied measure of perinatal health that has stark racial disparities.

The pandemic preterm paradox: a test of competing explanations.

Epidemiologists have long argued that side effects of the stress response include preterm birth. Research reports that fear of lethal infection stressed pregnant persons at the outset of the coronavirus disease (COVID-19) pandemic and that "shutdowns" and "social distancing" impeded access to social support and prenatal care. The decline in preterm births in high-income countries, including the United States, during the early months of the pandemic therefore poses a paradox for science.

Does the Implementation of Reference Pricing Result in Reduced Utilization? Evidence From Inpatient and Outpatient Procedures.

Reference pricing (RP) is an insurance design that can be used to incentivize patients to use low-price settings. While RP is not intended to affect overall utilization, it could unintentionally reduce utilization. We examined whether utilization was reduced when a large employer adopted RP for selected elective surgeries, including inpatient joint replacement surgery and outpatient cataract surgery, colonoscopy, and arthroscopic surgery.

Social and demographic drivers of trend and seasonality in elective abortions in Denmark.

Background: Elective abortions show a secular decline in high income countries. That general pattern, however, may mask meaningful differences-and a potentially rising trend-among age, income, and other racial/ethnic groups. We explore these differences in Denmark, a high-income, low-fertility country with excellent data on terminations and births.

Cohort Variation in Selection During Pregnancy and Risk of Selected Birth Defects Among Males.

Background: The literature theorizes, but does not test, that variation over time in selective loss in utero affects the observed count of live-born birth defects cases. We test the hypothesis that the risk of birth defects among live-born males varies inversely with the strength of selection against males in utero.

Methods: We identified a subset of six birth defect phenotypes among males from the California Birth Defects Monitoring Program, an active surveillance system for over 490,000 male singletons born in eight California counties from 1986 to 2004.

Twinning in Norway Following the Oslo Massacre: Evidence of a 'Bruce Effect' in Humans.

Emerging theory and empirical work suggest that the 'Bruce Effect', or the increase in spontaneous abortion observed in non-human species when environments become threatening to offspring survival, may also appear in humans. We argue that, if it does, the effect would appear in the odds of twins among male and female live births. We test the hypothesis, implied by our argument, that the odds of a twin among male infants in Norway fell below, while those among females rose above, expected levels among birth cohorts in gestation in July 2011 when a deranged man murdered 77 Norwegians, including many youths.

Spontaneous Pregnancy Loss in Denmark Following Economic Downturns.

An estimated 11%-20% of clinically recognized pregnancies result in spontaneous abortion. The literature finds elevated risk of spontaneous abortion among women who report adverse financial life events. This work suggests that, at the population level, national economic decline-an ambient and plausibly unexpected stressor-will precede an increase in spontaneous abortion.

Post-term birth as a response to environmental stress : The case of September 11, 2001.

Background And Objectives: Despite growing interest in the role of maternal psychosocial stress as a determinant of preterm birth, no existing work has examined the relation between maternal stress and post-term birth (≥42 weeks). We hypothesize that prolonging gestation past term may represent an adaptive strategy to a suboptimal environment.

Methodology: We examined the relationship between exposure to the September 2001 terrorist attacks and odds of post-term birth in California.

Ambient temperature during gestation and cold-related adult mortality in a Swedish cohort, 1915-2002.

For all climatic regions, mortality due to cold exceeds mortality due to heat. A separate line of research indicates that season of birth predicts lifespan after age 50. This and other literature implies the hypothesis that ambient temperature during gestation may influence cold-related adult mortality.

Income gains and very low-weight birth among low-income black mothers in California.

We test the hypothesis suggested in the literature that an acute income gain in the form of the earned income tax credit reduces the odds of a very low-weight birth among low-income non-Hispanic black mothers. We apply ecological time series and supplemental individual-level logistic regression methods to monthly birth data from California between 1989 and 1997. Contrary to our hypothesis, the odds of very low-weight birth increases above its expected value two months after mothers typically receive the credit.

The contribution of attenuated selection in utero to small-for-gestational-age (SGA) among term African American male infants.

Natural selection conserves mechanisms allowing women to spontaneously abort gestations least likely to yield fit offspring. Small gestational size has been proposed as an indicator of fitness observable by maternal biology. Previous research suggests that exposure to ambient stress in utero results in more "culling" of small fetuses and therefore lower rates of small-for-gestational-age (SGA).

Impact of capacity reductions in acute public-sector inpatient psychiatric services.

Objective: This study tested the hypothesis that reductions in acute public-sector psychiatric inpatient capacity in a major urban area would be associated with negative impacts on patients and the community.

Methods: The impact of two discrete service changes that reduced acute inpatient capacity by 50% in a single public-sector general hospital setting was examined. Indicators of impact were obtained from existing administrative databases for a 33-month period.

Transient cultural influences on infant mortality: Fire-Horse daughters in Japan.

Objectives: Parental investment theory suggests that the quality and quantity of parental care depends, in part, on assessments of whether offspring will survive and yield grandchildren. Consistent with this theory, we hypothesize that parental perception that a birth cohort will have low reproductive success coincides with higher than expected infant mortality in the cohort. We test this hypothesis in industrialized Japan in 1966 when cultural aversion to females born in the astrological year of the Fire-Horse may have jeopardized the life of female infants.

Infant mortality and diminished entelechy in three European countries.

Individual-level research reports that adverse environmental conditions during infancy increase the risk of mortality later in life. Extending this model to populations implies what we call the "diminished entelechy" hypothesis in which birth cohorts subjected to virulent environmental insults early in life experience increased mortality at older ages and do not realize their otherwise expected lifespan. Controversy remains as to whether the individual-level findings generalize to populations.

A sex-specific test of selection in utero.

We find support for the hypothesis that changes in the monthly odds of a twin among live-born males predict subsequent and opposite changes in the odds of a twin among live-born females. The hypothesis arises from the long standing argument that natural selection has conserved mechanisms by which pregnant women in stressed populations spontaneously abort fetuses least likely to yield grandchildren. Previous attempts to empirically test this argument focus almost entirely on males.

The effect of community-level unemployment on preventive oral health care utilization.

Objective: To test the hypothesis that high community-level unemployment is associated with reduced use of preventive dental care services by a dentally insured population.

Data: The study uses monthly data on population dental visits and unemployment in the Seattle and Spokane areas from 1995 to 2004. Utilization data come from Washington Dental Services.

Rates of unemployment and incidence of police-initiated examinations for involuntary hospitalization in Florida.

Objective: This study tested the hypothesis that contraction of regional economies affects the incidence of involuntary admissions to psychiatric emergency services by reducing community tolerance for persons perceived as threatening to others.

Methods: This hypothesis was tested with time-series analyses of the relationship between initial claims for unemployment in Florida between July 4, 1999, and June 28, 2003, and the weekly number of men and women presented by police to be examined for involuntary psychiatric hospitalization because of danger to others. The analyses controlled for admissions presented by mental health professionals because of danger to others and for admissions presented by police because of neglect or disability.

Economic antecedents of sudden infant death syndrome.

Purpose: To test the hypothesis that labor market contraction is associated with an elevated number of deaths due to sudden infant death syndrome (SIDS).

Methods: We apply time-series methods to monthly counts of SIDS deaths and total employment from the state of California beginning January 1989 and ending December 2001. The methods control for trends, seasonal cycles, and other forms of autocorrelation that could induce spurious associations.

Involuntary psychiatric examinations for danger to others in Florida after the attacks of September 11, 2001.

Objective: Theories of perceived risk state that when people feel threatened, they will react more strongly than they would otherwise. This study tested the hypothesis that evaluations for involuntary psychiatric hospitalizations that were initiated by law enforcement personnel in Florida increased in the weeks after the attacks of September 11, 2001.

Methods: The authors applied interrupted time-series designs to determine whether there was a relationship between the number of involuntary psychiatric examinations initiated by law enforcement officials and the attacks of September 11, 2001.

The impact of capitated financing on psychiatric emergency services.

Objective: Studies of capitated financing of mental health services have generally focused on the cost and utilization of services. Relatively little research has addressed whether capitation has an impact on the effectiveness of the mental health system as a whole. This study examined the impact of capitation on hospital emergency department visits, a widely cited indicator of the effectiveness of the other components of the system.

Economic antecedents of the Swedish sex ratio.

Literature describing environmental influences on human conception and gestation implies that the ratio of male to female live births should vary positively over time with the population's ability to produce and distribute goods and services. No direct test of this hypothesis appears in the literature despite its apparent importance in understanding the biological implications of collective choices. We offer a test based on Swedish data for the years 1862 through 1991.

Psychiatric emergencies after the terrorist attacks of September 11, 2001.

Objective: Population surveys suggest that the events of September 11, 2001, resulted in psychiatric emergencies in U.S. communities.

Sex ratios in the two Germanies: a test of the economic stress hypothesis.

Background: Literature describing temporal variation in the secondary sex ratio among humans reports an association between population stressors and declines in the odds of male birth. Explanations of this phenomenon draw on reports that stressed females spontaneously abort male more than female fetuses, and that stressed males exhibit reduced sperm motility. This work has led to the argument that population stress induced by a declining economy reduces the human sex ratio.