American journal of epidemiology最新文献

Despite established links between prenatal nutritional deprivation and impaired offspring growth, the underlying dynamics and potential moderators remain largely unexplored. This study investigates the dynamics underlying Ramadan during pregnancy and its associations with children's linear growth, using data from the Indonesian Family Life Survey (1993 - 2015). We exploit Ramadan during pregnancy as a natural experiment, separating exposure from maternal background characteristics and season of birth effects. Employing OLS and logistic regressions, we explore two key mechanisms predicted by medical theory. First, the realization of health impairments in response to prenatal shocks is influenced by postnatal circumstances. Our results reveal significant growth impairments primarily in children raised under poor sanitary conditions, which is a risk factor for diminished linear growth by itself. Secondly, we assess whether prenatal Ramadan prompts epigenetic shifts towards earlier reproductive activity, potentially at the expense of height growth. Our data shows that prenatally exposed women tend to have their first childbirth at a younger age, though menarche onset remains unaffected. These results suggest that postnatal environments play a crucial role in mitigating sensitivity to prenatal shocks, highlighting the critical need for favorable living conditions for all children.

To develop and evaluate the validity of the Pregnancy Physical Activity Questionnaire-Short Form (PPAQ-SF). A prospective cohort of participants (N=50) completed the updated PPAQ (long-form) and wore an ActiGraph for 7 days on the nondominant wrist in early, mid, and late pregnancy. The top ten questions with the highest relative contribution to the between-person variance in PPAQ-assessed total MET-hours/day were selected. Internal validity was evaluated using the ActiGraph and the updated PPAQ (long-form) within the current dataset. Validity was also assessed in an external validation dataset of 222 pregnant participants using the updated and original PPAQ (long-forms). Spearman correlations between the PPAQ-SF and ActiGraph estimates of MVPA MET-hours/day were r = 0.34 (95% CI 0.18-0.48) for overall pregnancy and ranged from 0.21 (95% CI -0.07-0.47) in early pregnancy to 0.49 (95% CI 0.23-0.69) in mid-pregnancy. In the external validation dataset, correlations between the PPAQ-SF and the PPAQ (long forms) estimates of MVPA MET-hours/day were statistically significant across pregnancy (r=0.94-0.99). Reproducibility ranged from 0.35 in early pregnancy to 0.77 in mid pregnancy. In summary, the PPAQ-SF can provide a time-efficient measure of MVPA during pregnancy with acceptable validity; reproducibility was reasonable in mid-pregnancy.

Recreational cannabis outlets may influence rates of interpersonal violence, but research has yielded inconsistent findings. Modification by alcohol outlet density may help explain inconsistencies. We estimated the impacts of recreational cannabis outlets on neighborhood-level assault injury rates in California and evaluated whether alcohol outlet density moderated these associations. We applied Bayesian spatiotemporal analyses to ZIP code-level statewide data on alcohol outlets, recreational cannabis outlets, and injuries and deaths due to firearm and nonfirearm assault, 2017-2019, accounting for confounders and spatial autocorrelation. Using the model posteriors, we estimated parameters corresponding to hypothetical shifts in outlet densities, overall and by age, sex, and race/ethnicity. If recreational cannabis outlets were never introduced, we estimated that nonfirearm assault injuries would have been 1.63 per 100,000 lower (95%CI: -3.08, 0.01) but we observed no association with firearm assault injuries (RD per 100,000: -0.07; 95%CI: -0.34, 0.21). These associations did not depend on alcohol outlet density, but a hypothetical 20% reduction in alcohol outlet densities was associated with fewer firearm (RD per 100,000: -1.89; 95%CI: -0.46, 0.09) and nonfirearm (RD per 100,000: -5.67; 95%CI: -7.44, -3.95) assault injuries. The introduction of recreational cannabis outlets may have contributed to a small increase in nonfirearm assault injuries.

Natural-experiment designs that compare survivors of in-utero famine exposure to unaffected controls suggest that in-utero undernutrition predisposes to development of obesity. However, birth rates drop dramatically during famines. Selection bias could arise if factors that contribute to obesity also protect fertility and/or fetal survival under famine conditions. We investigated this hypothesis using genetic analysis of a famine-exposed birth cohort. We genotyped participants in the Dutch Hunger Winter Families Study (DHWFS, N=950; 45% male), of whom 51% were exposed to the 1944-1945 Dutch Famine during gestation and 49% were their unexposed same-sex siblings or "time controls" born before or after the famine in the same hospitals. We computed body-mass index (BMI) polygenic indices (PGIs) in DHWFS participants and compared BMI PGIs between famine-exposed and control groups. Participants with higher polygenic risk had higher BMIs (Pearson r=0.42, p<0.001). However, differences between BMI PGIs of famine-exposed participants and controls were small and not statistically different from zero across specifications (Cohen's d=0.10, p>0.092). Our findings did not indicate selection bias, supporting the validity of the natural-experiment design within DHWFS. In summary, our study outlines a novel approach to explore the presence of selection bias in famine and other natural experiment studies.

Over the past 35 years, the term "leaky vaccine" has gained widespread use in both mathematical modeling and epidemiologic methods for evaluating vaccines. Here we present a short history as we recall it of how the term was coined in the context of the history of sporozoite malaria vaccines that were thought to be possibly leaky in the 1980s. We draw a contrast with the all-or-none vaccine mechanism and review a few consequences for study design and population level effects. We invite readers to contribute information covering the time period preceding our memories in the 1980s as we may have overlooked something.

Cognitive ability and cognitive decline are related to mortality in older adults. Cognitive interventions have been found to improve cognitive performance and slow cognitive decline in later life. However, the longitudinal effects of cognitive interventions on mortality in older adults remain unclear. Using twenty-year follow-up data from the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) trial, we examined the association between cognitive trajectory (i.e., intercept, slope, and retest effect) and mortality, using shared growth-survival models. We evaluated the effect of ACTIVE cognitive training (memory, reasoning, and speed of processing) on mortality risk. Among the 2,802 participants, 2,021 died on or before the year 2019 (72.1%). Higher baseline, slower decline, and greater retest effects in general cognitive performance were associated with lower mortality risk after adjusting for covariates. Associations with mortality were similar contrasting general and domain-specific cognitive abilities. We did not observe any significant effects of ACTIVE cognitive training in memory, reasoning, or speed of processing on all-cause mortality. Our findings suggest cognitive training interventions do not have a significant effect on cognitive trajectory and mortality among older adults; rather, older adults with higher education tend to incur greater survival benefits from memory training.

Firearm-related deaths lead to the most person-years of life lost in the US. There were 48,830 deaths from homicides and suicides in 2021 alone. Firearm access remains at an all-time high in most states - indicated by record manufacturing, sales, employment in firearm industry, taxes collected from sales, and the number of federal background check applications in 2020 and 2021. Yet, firearm injury is a politically contentious topic to the point of stalling progress on an important public health topic. This politicization led to nearly three decades of federal disinvestment in firearm research; reduced surveillance of firearm-related crime, injury, and death; and degraded data quality. This left generations of researchers with limited epidemiologic tools to conduct firearm policy research, jeopardizing the amount and quality of research conducted. Despite these limitations, research has persisted and promising approaches to reduce firearm morbidity and mortality have been identified. Yet the field has struggled to keep pace with methodological advancements and conceptualizations of racial and ethnic disparities as products of systemic racism. In this commentary, we highlight some existing evidence-informed policies, explicate some limitations in the field, and identify opportunities to address the limitations of prior work to strengthen future capacity for evidence-informed prevention.

Negative controls are increasingly used to evaluate the presence of potential unmeasured confounding in observational studies. Beyond the use of negative controls to detect the presence of residual confounding, proximal causal inference (PCI) was recently proposed to de-bias confounded causal effect estimates, by leveraging a pair of treatment and outcome negative control or confounding proxy variables. While formal methods for statistical inference have been developed for PCI, these methods can be challenging to implement as they involve solving complex integral equations that are typically ill-posed. We develop a regression-based PCI approach, employing two-stage generalized linear regression models (GLMs) to implement PCI, which obviates the need to solve difficult integral equations. The proposed approach has merit in that (i) it is applicable to continuous, count, and binary outcomes cases, making it relevant to a wide range of real-world applications, and (ii) it is easy to implement using off-the-shelf software for GLMs. We establish the statistical properties of regression-based PCI and illustrate their performance in both synthetic and real-world empirical applications.