Health Advice
The Effect of Information From Black Health Care Professionals on COVID Vaccination Take-Up
Martin Abel, Tanya Byker & Jeffrey Carpenter
Health Economics, forthcoming
Abstract:
This study experimentally tests the impact of providing information about vaccine safety and efficacy delivered by Black health care professionals. We find that providing general information increases vaccination rates after 5 months by 8 percentage points (17%), driven by a 9.8 pp (24%) increase among white participants. Political affiliation emerges as a key moderator to explain this discordant effect. Across race, general information is more effective for politically moderate and conservative respondents, most of whom are white. Among this most vaccine-hesitant group, the information effectively addresses concerns about both side effects and unknown long-run effects due to the fast approval of the vaccine, increasing vaccination rates by 14 pp.
Links between COVID-19 lockdowns and drug overdose deaths, evidence from panel data
Yimin Wang
Economics & Human Biology, September 2025
Abstract:
This paper studies the impacts of divergent state government responses to the COVID-19 pandemic on drug overdose deaths. Using Difference-in-Differences method, I exploit the cross-state variation in the timing of lockdown policies to examine how COVID-19 lockdowns affected drug overdose deaths. To the author’s knowledge, this is the first study that comprehensively examines the causal links between COVID-19 lockdowns and drug overdose deaths in the US. By emphasizing the impacts of lockdown “mandates” vs. “recommendations,” I find credible evidence supporting that the implementation of lockdown mandates led to more drug overdose deaths. My baseline estimates indicate a 15% to 20% increase in drug overdose deaths. To make my results generalizable, I examine three potential mechanisms, including labor market outcomes, mental health, and isolation. I find that isolation induced by the COVID-19 lockdown mandates likely contributes to the increase in drug overdose deaths, while there is only weak evidence that labor market outcomes and mental health serve as plausible channels.
Do laws protecting tenants’ health work?: Implied warranties of habitability and respiratory health
Gabriel Schwartz & Lela Chu
American Journal of Epidemiology, forthcoming
Abstract:
Housing quality is a powerful determinant of health. When US renters’ housing conditions deteriorate, state policies known as “implied warranties of habitability” are meant to force landlords to ameliorate pathogenic habitability violations, allowing renters to sue or withhold rent until repairs are completed. No research, however, has tested whether these policies work -- whether they succeed at protecting population health. At issue is whether warranties are effective when bringing legal action is so onerous for renters in practice. We thus use generalized difference-in-differences models to estimate warranties’ effects on renters’ general and respiratory health, including event study and triple-difference models that employ homeowners as negative controls. Health outcome data from the National Health Interview Survey (1993-2018) was limited to the 10 states that did not have a warranty at baseline and had sufficient pre-implementation data. We found null associations near 0 for nearly all outcomes. It is unclear whether this is because (A) our sample mostly included states with weak policies, (B) US renters are not guaranteed lawyers in civil court, or (C) a completely different, more pro-active rental inspection approach is needed. Regardless, results suggest policies must change if we are to realize the public health promise of healthier housing.
School opening associated with lower test-adjusted COVID-19 case rates in children
Ambarish Chandra & Tracy Høeg
International Journal of Epidemiology, August 2025
Methods: Regression-based observational study to estimate the relationship between school openings and COVID-19 case rates among children, while accounting for potential confounders including community case rates, mitigations in schools, and rates of testing among schoolchildren. The setting is US school districts in the Fall of 2021, from 3 weeks prior through 12 weeks after school opening, using restricted data obtained from the Centers for Disease Control and Prevention. Data were available for school districts in 2592 counties, containing 86% of the US population.
Results: School openings were associated with a brief rise in cases among children relative to adults, with a peak of 39.3 [37.7, 40.9] additional cases per 100 000 per week. However, children were tested at higher rates when schools were in session. After adjusting for testing rates, case rates among children were significantly lower after schools reopened by 4.7 cases per 100 000 compared with over summer break.
Walkability and Mental Health Resiliency During the COVID-19 Pandemic
Karen Smith Conway & Andrea Menclova
Health Economics, forthcoming
Abstract:
This study investigates if local walkability helped mitigate the well-documented mental health impacts of the COVID-19 pandemic. Walkability may improve mental health by facilitating walking (which our data suggest occurred during the pandemic), as well as through other avenues such as time spent outdoors and improved social ties. However, estimating the causal effects of walkability is challenged by its lack of exogenous time variation. Our empirical approach uses the pandemic as a geographically-variable and arguably-random shock to mental health which, when combined with Census tract measures of walkability and mental health, sheds light on the possible impact of local walkability on mental health resiliency. Focusing on within-county, over-time variation in mental health and controlling for a wide set of local factors, results suggest that those living in a more walkable community experienced smaller declines in mental health. The magnitudes are reasonable; increasing walkability by one standard deviation is associated with a 4 percent reduction in the average pandemic-related deterioration in mental health. These findings are robust to many sensitivity checks and falsification tests. Although the pandemic is the random shock studied here, this research has implications for the potential role of walkability in diminishing the mental health effects of other stressors.
Countrywide natural experiment links built environment to physical activity
Tim Althoff et al.
Nature, forthcoming
Abstract:
While physical activity is critical to human health, most people do not meet recommended guidelines. Built environments that are more walkable have the potential to increase activity across the population. However, previous studies on the built environment and physical activity have led to mixed findings, possibly due to methodological limitations such as small cohorts, over-reliance on self-reported measures and cross-sectional designs. Here we address these limitations by leveraging a large US cohort of smartphone users (N = 2,112,288) to evaluate within-person longitudinal behaviour changes that occurred over 248,266 days of objectively measured physical activity across 7,447 relocations among 1,609 US cities. By analysing the results of this natural experiment, which exposed individuals to differing built environments, we find that increases (decreases) in walkability are associated with significant increases (decreases) in physical activity after relocation. For example, moving from a less walkable (25th percentile) city to a more walkable city (75th percentile) increased walking by 1,100 daily steps, on average. These changes hold across different genders, ages and body mass index values, and are sustained over 3 months. The added activity is predominantly composed of moderate-to-vigorous physical activity, which is linked to an array of associated health benefits. Evidence against residential self-selection confounding is reported. Our findings provide robust evidence supporting the importance of the built environment in directly improving health-enhancing physical activity and offer potential guidance for public policy activities in this area.
An oat fiber intervention for reducing PFAS body burden: A pilot study in male C57Bl/6 J mice
Jennifer Schlezinger et al.
Toxicology and Applied Pharmacology, February 2025
Abstract:
Perfluoroalkyl substances (PFAS) are a major public health concern, in part because several PFAS have elimination half-lives on the order of years and are associated with adverse health outcomes. While PFAS can be transported into bile, their efficient reuptake by intestinal transporter proteins results in minimal fecal elimination. Here, we tested the hypothesis that consumption of oat β-glucan, a dietary supplement known to disrupt the enterohepatic recirculation of bile acids, will reduce PFAS body burdens. Male C57Bl/6 J mice were fed diets based on the “What we eat in America” analysis that were supplemented with inulin or oat β-glucan and exposed via drinking water to a seven PFAS mixture (PFHpA, PFOA, PFNA, Nafion Byproduct-2, PFHxS and PFOS) for 6 weeks. One cohort of mice was euthanized at the end of the exposure, and one cohort continued on the experimental diets for 4 more weeks without additional PFAS exposure. The β-glucan fed mice drank significantly more water than the inulin fed mice, resulting in a significantly higher dose of PFAS. Relative to overall exposure, we observed lower serum concentration trends (p < 0.1) in β-glucan fed mice for PFHpA, PFOA and PFOS. Additionally, β-glucan fed mice had lower adipose:body weight ratios and liver and jejunum triglyceride concentrations. Hepatic mRNA expression of Cyp4a10, Cyp2b10 and Cyp3a11 were elevated in PFAS exposed mice, with only the expression of Cyp3a11 decreasing following depuration. This pilot study generates support for the hypothesis that oat β-glucan supplementation can reduce PFAS body burdens and stimulate healthful effects on lipid homeostasis.
A novel fusion architecture for detecting Parkinson’s Disease using semi-supervised speech embeddings
Tariq Adnan et al.
npj Parkinson's Disease, June 2025
Abstract:
We introduce a framework for screening Parkinson’s disease (PD) using English pangram utterances. Our dataset includes 1306 participants (392 with PD) from both home and clinical settings, covering diverse demographics (53.2% female). We used deep learning embeddings from Wav2Vec 2.0, WavLM, and ImageBind to capture speech dynamics indicative of PD. Our novel fusion model for PD classification aligns different speech embeddings into a cohesive feature space, outperforming baseline alternatives. In a stratified randomized split, the model achieved an AUROC of 88.9% and an accuracy of 85.7%. Statistical bias analysis showed equitable performance across sex, ethnicity, and age subgroups, with robustness across various disease durations and PD stages. Detailed error analysis revealed higher misclassification rates in specific age ranges for males and females, aligning with clinical insights. External testing yielded AUROCs of 82.1% and 78.4% on two clinical datasets, and an AUROC of 77.4% on an unseen general spontaneous English speech dataset, demonstrating versatility in natural speech analysis and potential for global accessibility and health equity.
Characterizing rapid changes in the prevalence and concentration of key compounds in Philadelphia’s street opioid retail supply, March 2024-March 2025
Karli Hochstatter et al.
Drug and Alcohol Dependence, September 2025
Methods: From March 2024-March 2025, samples of street drugs sold as opioids were collected at a harm reduction program in Philadelphia’s Kensington neighborhood and shipped to the National Institute of Standards and Technology, where they underwent qualitative testing using direct analysis in real-time mass spectrometry and quantitative testing using liquid chromatography tandem mass spectrometry. Bootstrapped quantile regression models assessed changes in concentration over time.
Results: Among 260 samples, fentanyl (98%) and xylazine (65%) were the most prevalent psychoactive compounds. While fentanyl was consistently present, the median fentanyl concentration decreased significantly, from 9.6% by mass in May 2024 to 5.3% by mass in March 2025 (P = 0.020). Xylazine prevalence declined from 100% in March 2024 to 58% in March 2025. Conversely, lidocaine and tetracaine prevalence increased from 3% each in March 2024 to 63% each in March 2025. Two novel compounds, medetomidine and bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate (BTMPS), were first detected in April and June 2024, reaching prevalence rates of 83% and 25% by March 2025, respectively.