About

Shu (Violet) Xu is a Clinical Associate Professor of Biostatistics at NYU School of Global Public Health. Her work balances both statistical and applied aspects of quantitative methodology, with primary interests in evaluating and developing statistical methods for longitudinal data analysis. Her research focuses on latent growth models, missing data methods, and causal inference models. Dr. Xu has collaborated with substance use, family, and health researchers to advance quantitative methodology and to better understand social sciences and public health issues. She has conducted research with the Family Translational Research Group at NYU and the Methodology Center at Pennsylvania State University. Her educational background includes a BS in Psychology from East China Normal University in Shanghai, China, and both an MS and PhD in Quantitative Psychology from the University of California, Davis.

Research topics

• Environmental health
• Medicine
• Internal medicine
• Demography
• Sociology
• Psychology
• Gerontology
• Psychiatry

Selected publications

• Effectiveness of nicotine vape products (E-cigarettes) as a smoking cessation aid for US adults: a narrative review of findings from the population assessment of tobacco and health study

  Nicotine & Tobacco Research · 2026-03-28

  article1st authorCorresponding

  INTRODUCTION: Controversy remains regarding whether nicotine vaping products (NVPs) are associated with cigarette cessation in observational research. Reviews have largely overlooked studies using the same data source. To address this gap, we conducted a narrative review to examine the heterogeneity in the reported association that used data from the same source, which may help to explain inconsistent findings. METHODS: We identified empirical studies through PubMed and Google searches that exclusively used the Population Assessment of Tobacco and Health (PATH) Study data to examine associations between NVP use and smoking cessation among adults. Adapting Arksey and O'Malley's approach, we extracted and summarized key study characteristics, including inclusion criteria, participant characteristics, study durations, definitions of NPV exposure and smoking outcomes, covariate adjustment, and analytic methods. We also conducted regression and regression tree analyses to examine how these characteristics were related to study findings. RESULTS: We identified 28 articles comprising 38 analyses of NVP use and cigarette cessation. Of these, 24 studies (63.2%) reported a positive association, concluding that NVP use predicted cessation. Substantial heterogeneity existed across study characteristics. Evidence suggests that daily NVP use may promote cessation, whereas studies restricted to participants with an intention to quit were less likely to observe cessation than those including participants regardless of quit intention. CONCLUSIONS: Researchers are advised against making broad claims based on any single PATH Study analysis of NVP use and smoking cessation. Rather, multiple studies using the same data source must be carefully examined in order to synthesize evidence and assess consistency of the findings. IMPLICATIONS: Whether NVPs help adult smokers quit remains controversial in observational research, partly due to heterogeneity in study characteristics across studies using the same data source. Our review of observational studies based exclusively on a single data source-an approach often overlooked-suggests that (1) daily NVP use may support smoking cessation, and (2) studies that restricted participants to those with an intention to quit were less likely to observe cessation than studies that included participants regardless of quit intention. These findings underscore the value of multiple analyses using the same data source to synthesize evidence and assess consistency.

  PublisherDOI

• Research on Factors of Influencing Consumer Behavior Patterns in the Food Service Industry

  Advances in Economics Management and Political Sciences · 2025-02-08 · 1 citations

  articleOpen access1st authorCorresponding

  This article provides a comprehensive review of the literature on consumer behavior in the food and beverage industry, with the aim of summarizing and analyzing the factors that influence consumer behavior patterns and providing certain improvement measures for food and beverage industry enterprises. The food and beverage industry is an important part of the economy, so its consumer behavior patterns have a wide-ranging impact on social and economic development. This review mainly includes the factors that influence consumer behavior and their operating modes. Firstly, this paper explores the psychological motives of consumers to a certain extent, mainly divided into brand identification and demand, emphasizing the important roles of brand identification and consumer demand. Secondly, this paper analyzes the factors that influence consumer behavior, mainly including price-performance ratio, consumption experience, marketing strategies, brand image, and product variety, and explains the operating modes and underlying reasons of each factor. Finally, by summarizing consumer behavior patterns and providing some suggestions for the development of the food and beverage industry, this paper offers a forecast for the industry's development. These suggestions mainly include the creation of a brand image and the emphasis on consumption experience.

  PublisherOA PDFDOI

• Study on the Dynamic Characteristics of DM-DFBL Self-Delayed Feedback with an Optoelectronic Oscillation Loop

  Photonics · 2025-05-13

  articleOpen access

  Nonlinear dynamical states generated by self-delayed feedback based on fiber structures have broad applications. However, fiber-based optoelectronic feedback or pure optical feedback systems exhibit long delays, and the coupling mechanisms between these two loops differ significantly from those in short-delay systems. A systematic investigation of feedback coupling mechanisms under long-delay conditions is of great significance for optimizing such systems. In this paper, the nonlinear dynamic state generated by directly modulated distributed feedback semiconductor laser (DM-DFBL) self-delayed feedback with an optoelectronic oscillation loop is studied. Both numerical and experimental results show that the DM-DFBL’s dynamical states vary with changes in optical and electrical feedback intensities. In the self-delayed feedback, the DM-DFBL exhibits an evolutionary path from a chaos (CO) state to a period-one (P1) state and finally becomes a steady state with the decrease of optical feedback intensity. In the optoelectronic oscillation loop, the DM-DFBL generates a microwave frequency comb (MFC), a full-frequency oscillation, and a P1 state. Additionally, the dynamic state of the DM-DFBL can be disturbed, and the stability of the P1 state and the QP state can be enhanced when the optoelectronic oscillation loop is introduced. These conclusions contribute to the precise control of dynamic evolution.

  PublisherOA PDFDOI

• Skin Ulcer Development and Deterioration of Social Engagement among Nursing Home Residents

  Journal of the American Medical Directors Association · 2025-02-11

  articleOpen access
  PublisherOA PDFDOI

• A Large-Scale Survey of Barriers and Attractors to Mental Healthcare Utilization for Active-Duty Service Members in the U.S. Department of the Air Force

  Psychology International · 2025-04-01

  articleOpen access

  Despite expanded mental health services and outreach within the military, most active-duty members who endorse mental health problems do not seek services. Little is known about why this is the case, but cognitions may play a key role. In this study, cognitions relevant to service seeking were compared among three subgroups of active-duty members: those who endorse one or more mental health problems and sought services, those who endorse problems and do not seek services, and those who do not endorse problems. To examine differences and similarities among these groups, a stratified random sample of 162,340 was drawn from all active-duty members of the U.S. Department of the Air Force serving at 91 installations around the world. Each selected member was invited to anonymously complete the Air Force Community Assessment, and 63,227 members (39% of those invited) participated. Of these, one in five reported at least one mental health problem, and one in three reported receiving services within the past two years. Participants reporting problems and who had not sought services perceived more peer and institutional stigma, reported more knowledge and logistic barriers, reported more negative attitudes towards mental health services, and reported fewer attractors to mental health services compared with those who did not report problems. Those who reported problems and sought services reported more problems and more negative attitudes than those reporting problems who had not sought services. Nine of ten who reported problems but had not received services indicated they had no intention to seek them.

  PublisherOA PDFDOI

• ShengqingJiangzhuo Decoction Restores the Immunotherapy Response by Reprogramming the IFN-γ/JAK-STAT1/PD-L1 Pathway in Hepatocellular Carcinoma

  SSRN Electronic Journal · 2025-01-01

  preprintOpen accessSenior author
  PublisherDOI

• Revising the ambient air quality standards for SO2 in China: A comprehensive analysis of air quality trends, health impacts, and global alignment

  Ecotoxicology and Environmental Safety · 2025-08-01 · 2 citations

  articleOpen access

  China has achieved remarkable progress in reducing sulfur dioxide (SO₂) emissions, largely attributable to rigorous control measures on coal consumption. However, the nation’s ambient air quality standards (AAQS) for SO₂ have not been updated for over 40 years, rendering them outdated and inadequate to address the evolving SO 2 concentration characteristics and meet the growing public demand for enhanced air quality. This study undertook a comprehensive evaluation and revision of China’s AAQS for SO₂ by analyzing historical atmospheric SO 2 concentration data collected from national monitoring stations across the country between 2019 and 2023, assessing the potential health benefits of revised standards and comparing them with international standards. Results indicate that atmospheric SO 2 concentrations at over 98 % of monitoring sites are consistently below the primary standard for the 24-h average (50 µg/m³), with SO₂ concentrations remaining under 25 µg/m³ in the past two years. Despite this progress, seasonal fluctuations and regional variations persist, with higher concentrations observed in winter months and in northern cities. Compared to international standards, China’s secondary limits remain less stringent. To better align with global benchmarks and enhance public health outcomes, this study recommends revising the 24-h and annual average SO₂ concentrations limits to 40 µg/m³ and 15 µg/m³ for primary standard and 50 µg/m³ and 20 µg/m³ for secondary standard, respectively. These revisions could deliver substantial health benefits, particularly in regions with high pollution levels. The findings of this study provide robust scientific evidence supporting the urgent need for updated AAQS for SO₂ in China, ensuring the reduced limits align with global best practices while promoting significant health and environmental benefits. • China's SO₂ limits fall behind global standards, requiring urgent stricter revisions. • SO₂ levels have dropped since 2022, with 24-hr < 25 µg/m³ and annual < 15 µg/m³. • Coal use and industry drive SO₂ peaks, showing need for stricter controls. • Lower SO₂ limits to 40 µg/m³ (24-h) and 15 µg/m³ (annual) for health. • Stricter SO₂ limits cut deaths, acid rain, and protect health and ecosystems.

  PublisherDOI

• Development of a Brief Screener for Crosscutting Patterns of Family Maltreatment and Psychological Health Problems

  Psychology International · 2025-10-03

  articleOpen access1st author

  Prior work established the presence of six crosscutting patterns of clinically significant family maltreatment (FM) and psychological health (PH) problems among active-duty service members. Here, we develop a brief screener for these patterns via Classification and Regression Trees (CART) analyses using a sample of active-duty members of the United States Air Force. CART is a predictive algorithm used in machine learning. It balances prediction accuracy and model parsimony to identify an optimal set of predictors and identifies the thresholds on those predictors in relation to a discrete condition of interest (e.g., diagnosis of pathology). A 22-item screener predicted membership in five of the six classes (sensitivities and specificities &gt; 0.96; positive and negative predictive values &gt; 0.90). However, for service members at extremely high risk of clinically significant externalizing behavior, sensitivity and positive predictive values were much lower. The resulting 22-item brief screener can facilitate feasible, cost-effective detection of five of the six identified FM and PH problem patterns with a small number of items. The sixth pattern can be predicted far better than chance. Researchers and policymakers can use this tool to guide prevention efforts for FM and PH problems in service members.

  PublisherOA PDFDOI

• Corrigendum to “Use of electronic nicotine delivery system (ENDS) devices among U.S. Youth and adults: Findings from the Population Assessment of Tobacco and Health Study Waves 1–5” [Addict. Behav. 139 (2023) 107588]

  Addictive Behaviors · 2025-03-27

  erratumOpen access
  PublisherDOI

• Measurement invariance of the perceived discrimination scale across race/ethnicity and sex: Findings from the Adolescent Brain and Cognitive Development (ABCD) study

  SSM - Mental Health · 2025-08-22 · 3 citations

  articleOpen access1st authorCorresponding

  Perceived racial discrimination during childhood and adolescence is a critical social determinant of health disparities. However, few scales measure perceived racial discrimination in these age groups, and even fewer are validated with robust psychometric properties or demonstrate measurement invariance across racial and ethnic or sex groups. This study examines the psychometric properties of the Perceived Discrimination (PD) scale, a seven-item questionnaire designed to assess societal rejection based on racial or ethnic background among youth. Using data from the Adolescent Brain Cognitive Development Study, we conducted exploratory and confirmatory factor analyses to examine youth-reported perceived discrimination across racial/ethnic groups (Non-Hispanic White, Non-Hispanic Black, Hispanic, and NH Asian, Native Hawaiian or Pacific Islander ) and sex groups (male and female). These analyses drew on two data sets: one based on youth’s racial/ethnicity reported by parents (Data Set 1, n = 9967) and the other based on self-reported race/ethnicity (Data Set 2, n = 7645). Analyses identified a well-fitting bi-factor model, comprising a general perceived discrimination factor and a specific perceived social exclusion factor, demonstrating high reliability. The general perceived discrimination factor exhibited strong predictive validity, effectively forecasting changes in mental health outcomes over a one-year interval. Results from multi-group confirmatory factor analysis support the configural, weak, and strong measurement invariance of the PD scale across racial/ethnic and sex groups. Sensitivity analyses affirmed the robustness of these findings, showing consistency across reporting types (parent- vs. self-reporting for youth race/ethnicity) and coding strategies (three- vs. five-point rating scales). Overall, this study provides compelling evidence for the high reliability and predictive validity of the PD scale, underscoring its utility in assessing perceived racial discrimination among diverse youth populations in the US. • This is one of the first analyses to examine the factorial structure and measurement invariance across racial groups of the Perceived Discrimination (PD) scale in a sample of US children and adolescents. • This study established strong measurement invariance of the PD scale among a national sample of White, Black, and Hispanic children from the Adolescent Brain and Cognitive Development Study. • Studies with larger Asian or other racial samples are needed to test the robustness of our findings. • Our results pave the way for more rigorous and equitable research on health disparities in children and adolescents by demonstrating that racism influences health differently depending on how the individual is racialized in society.

  PublisherDOI

Frequent coauthors

• Yin Zhu

  First Affiliated Hospital of Jiangxi Medical College

  13 shared

• Youxiang Chen

  First Affiliated Hospital of Jiangxi Medical College

  13 shared

• Yong Zhu

  École Polytechnique Fédérale de Lausanne

  12 shared

• Pi Liu

  Nanchang University

  10 shared

• Ling Ding

  First Affiliated Hospital of Jiangxi Medical College

  10 shared

• Michael F. Lorber

  9 shared

• Chae Man Lee

  UConn Health

  9 shared

• Xiaozhi Li

  The First Affiliated Hospital, Sun Yat-sen University

  8 shared