Health advisory
Relation between 20-year income volatility and brain health in midlife: The CARDIA study
Leslie Grasset et al.
Neurology, forthcoming
Methods: We studied 3,287 participants aged 23–35 years in 1990 from the Coronary Artery Risk Development in Young Adults prospective cohort study. Income volatility data were created using income data collected from 1990 to 2010 and defined as SD of percent change in income and number of income drops ≥25% (categorized as 0, 1, or 2+). In 2010, cognitive tests (n = 3,287) and brain scans (n = 716) were obtained.
Results: After covariate adjustment, higher income volatility was associated with worse performance on processing speed (β = −1.09, 95% confidence interval [CI] −1.73 to −0.44) and executive functioning (β = 2.53, 95% CI 0.60–4.50) but not on verbal memory (β = −0.02, 95% CI −0.16 to 0.11). Similarly, additional income drops were associated with worse performance on processing speed and executive functioning. Higher income volatility and more income drops were also associated with worse microstructural integrity of total brain and total white matter. All findings were similar when restricted to those with high education, suggesting reverse causation may not explain these findings.
U.S. obesity as delayed effect of excess sugar
Alexander Bentley, Damian Ruck & Hillary Fouts
Economics & Human Biology, forthcoming
Abstract:
In the last century, U.S. diets were transformed, including the addition of sugars to industrially-processed foods. While excess sugar has often been implicated in the dramatic increase in U.S. adult obesity over the past 30 years, an unexplained question is why the increase in obesity took place many years after the increases in U.S. sugar consumption. To address this, here we explain adult obesity increase as the cumulative effect of increased sugar calories consumed over time. In our model, which uses annual data on U.S. sugar consumption as the input variable, each age cohort inherits the obesity rate in the previous year plus a simple function of the mean excess sugar consumed in the current year. This simple model replicates three aspects of the data: (a) the delayed timing and magnitude of the increase in average U.S. adult obesity (from about 15% in 1970 to almost 40% by 2015); (b) the increase of obesity rates by age group (reaching 47% obesity by age 50) for the year 2015 in a well-documented U.S. state; and (c) the pre-adult increase of obesity rates by several percent from 1988 to the mid-2000s, and subsequent modest decline in obesity rates among younger children since the mid-2000s. Under this model, the sharp rise in adult obesity after 1990 reflects the delayed effects of added sugar calories consumed among children of the 1970s and 1980s.
The Impact of Sugar-Sweetened Beverage Taxes on Purchases: Evidence from Four City-Level Taxes in the U.S.
John Cawley, David Frisvold & David Jones
NBER Working Paper, October 2019
Abstract:
Since 2017, many U.S. cities have implemented taxes on sugar-sweetened beverages (SSBs) to decrease consumption of sugary beverages and raise revenue. In this paper, we analyze household receipt data to examine the impact of SSB taxes on households’ purchases of taxed and untaxed beverages in the four largest U.S. cities with such taxes: Philadelphia, Pennsylvania; San Francisco, California; Seattle, Washington; and Oakland, California. We estimate the impact of these taxes by comparing changes in monthly household purchases in the treatment cities to changes in one of two comparison groups: 1) areas adjacent to the treatment cities; or 2) a matched set of households nationally. We find that an increase in the beverage tax rate of 1 cent per ounce decreases household purchases of taxed beverages by 53.0 ounces per month or 12.2 percent. This impact is small in magnitude and consistent with a reduction in individual consumption of 5 calories per day per household member and eventual reduction in weight of 0.5 pounds. When we examine results separately by city, we find that the decline was concentrated in Philadelphia, where the tax decreased purchases by 27.7 percent. We do not find impacts of the taxes in the other three cities combined.
Impact of Physical Education Litigation on Fifth Graders’ Cardio–Respiratory Fitness, California, 2007–2018
Hannah Thompson et al.
American Journal of Public Health, November 2019, Pages 1557-1563
Methods: We used annual school-level data for all California schools with measures of fifth graders’ cardio–respiratory fitness spanning 2007–2008 through 2017–2018. A difference-in-difference design assessed changes before and after lawsuits in the proportion of students meeting fitness standards in schools in districts that were parties to PE lawsuits (n = 2715) versus in schools in districts not involved (n = 3152). We ran separate models with the proportion of students meeting fitness standards by sex, race/ethnicity, and low-income status as outcomes.
Results: PE litigation led to a 1-percentage-point increase in the proportion of fifth-grade students meeting cardio–respiratory fitness standards (95% confidence interval [CI] = 0.03%, 2.0%). Effects were especially pronounced for female (1.3-percentage-point increase; 95% CI = 0.1%, 2.5%), African American (3.4-percentage-point increase; 95% CI = 0.5%, 6.2%), and low-income (2.8-percentage-point increase; 95% CI = 0.5%, 6.0%) students.
Can Diffuse Delivery System Reforms Improve Population Health? A Study of the State Innovation Models Initiative
Partha Deb, Anjelica Gangaram & Hoda Khajavi
NBER Working Paper, October 2019
Abstract:
We examine the effects of the State Innovation Models (SIM) on population-level health status. The SIM initiative provided $250 million to six states in 2013 for delivery system reforms. We use data from the Behavioral Risk Factor Surveillance System for the years 2010 -- 2016 to compare health of the populations in 6 SIM states to 15 states that were not involved in any aspects of SIM. We examine changes in health using an event study design. We develop a Latent Class Profile model that takes multiple measures of latent health into a common, latent health status to study the effect of the intervention. Such models can yield informative estimates where separate estimation of measures do not. We find that individuals in states that implemented SIM saw significant improvements in health across a number policy-relevant subpopulations.
Aedes albopictus Body Size Differs Across Neighborhoods With Varying Infrastructural Abandonment
Grace Katz, Paul Leisnham & Shannon LaDeau
Journal of Medical Entomology, forthcoming
Abstract:
Mosquitoes pose an increasing risk in urban landscapes, where spatial heterogeneity in juvenile habitat can influence fine-scale differences in mosquito density and biting activity. We examine how differences in juvenile mosquito habitat along a spectrum of urban infrastructure abandonment can influence the adult body size of the invasive tiger mosquito, Aedes albopictus (Skuse) (Diptera: Culicidae). Adult Ae. albopictus were collected across 3 yr (2015–2017) from residential blocks in Baltimore, MD, that varied in abandonment level, defined by the proportion of houses with boarded-up doors. We show that female Ae. albopictus collected from sites with higher abandonment were significantly larger than those collected from higher income, low abandonment blocks. Heterogeneity in mosquito body size, including wing length, has been shown to reflect differences in important traits, including longevity and vector competence. The present work demonstrates that heterogeneity in female size may reflect juvenile habitat variability across the spatial scales most relevant to adult Aedes dispersal and human exposure risk in urban landscapes. Previous work has shown that failure to manage abandonment and waste issues in impoverished neighborhoods supports greater mosquito production, and this study suggests that mosquitoes in these same neighborhoods could live longer, produce more eggs, and have different vector potential.