Shu Xu
Shu Xu
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Clinical Associate Professor of Biostatistics
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Professional overview
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Dr. Shu Xu’s work represents a balance of both statistical and applied aspects of quantitative methodology. Her primary quantitative interests include evaluating and developing statistical methods for longitudinal data analysis. Specifically, Dr. Xu’s research focuses on various aspects of latent growth models, missing data methods, and causal inference models.
Dr. Xu has collaborated with substance use, family, and health researchers to advance and share her knowledge of quantitative methodology and pursue a better understanding of the social sciences and public health. She has conducted research with the Family Translational Research Group at NYU and the Methodology Center at the Pennsylvania State University.
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Education
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BS, Psychology, East China Normal University, Shanghai, ChinaMS, Quantitative Psychology, University of California, DavisPhD, Quantitative Psychology, University of California, Davis
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Areas of research and study
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BiostatisticsFamily researchLongitudinal Data AnalysisMissing Data MethodsMixture ModelsQuantitative Research
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Publications
Publications
Native Hawaiian and Other Pacific Islanders: Disparities in the Prevalence of Multiple Chronic Conditions
AbstractCabrera, J. D., Cuevas, A. G., Xu, S., & Chang, V. W. (n.d.).Publication year
2025Journal title
American Journal of Health PromotionVolume
39Issue
7Page(s)
1037-1041AbstractPurpose: To examine multimorbidity prevalence by race/ethnicity and unique health disparities for Native Hawaiian and Other Pacific Islanders (NHPI). Design: Cross-sectional study. Setting: This study uses combined data from the 2014 National Health Interview Survey (NHIS) and the 2014 NHPI-NHIS. Sample: 38,965 adults, including a representative sample of 2,026 NHPIs. Measures: Self-reported diagnoses of ten chronic conditions and race/ethnicity, including Non-Hispanic (NH) Whites, NH Blacks, NH Asians, NH NHPIs, Hispanics and NH Mixed Race. Covariates include age, sex, marital status, education, family income, and employment status. Analysis: We used multinomial logistic regression models to evaluate the adjusted association between race/ethnicity and number of chronic conditions: none, 1, and ≥ 2 (multimorbidity). Results: Compared to Whites, Asians and Hispanics (aRRR = 0.39, P < .001 and aRRR = 0.59, P < .001) had significantly lower odds of having multimorbidity relative to no chronic condition. In contrast, Black Americans and NHPIs (aRRR = 1.27, P < .001 and aRRR = 1.22, P < .05) had significantly higher odds of multimorbidity compared to Whites. Of note, NHPIs showed significantly higher odds of multimorbidity compared to Asians (aRRR = 3.07, P < .001). Conclusion: Our findings highlight significantly higher risk of multimorbidity for NHPIs relative to Whites as well as Asians. This underscores the importance of disaggregating NHPI data from Asians as a whole. Future studies should incorporate additional social factors relevant to the NHPI community.Role of social-cognitive factors in the relationship between e-cigarette use and subsequent cigarette smoking among U.S. youth: A causal mediation analysis
AbstractXu, S., Coffman, D. L., Luta, G., Mai, A., Jiang, N., & Niaura, R. S. (n.d.).Publication year
2025Journal title
Addictive BehaviorsVolume
161AbstractObjective: E-cigarette use is associated with subsequent cigarette smoking among youth. The current study examined the mediating role of social-cognitive factors in this association. Methods: Data from four waves of the Population Assessment of Tobacco and Health study (2013/4 – 2017/8) were analyzed. Among youth who had heard about e-cigarettes at Wave 1 but never used cigarettes before Wave 2, we conducted both causal and traditional mediation analyses to examine the mediated effect of social-cognitive factors (including relative harm perception of e-cigarettes versus cigarettes, harm perception of e-cigarette use, perceptions of addictiveness of e-cigarette use, and e-cigarette use among best friends) in the association between e-cigarette use and subsequent cigarette ever or current smoking, adjusting for covariates. We included sampling weights in all analyses; hence, results are generalizable to the U.S. youth (12 – 14 years) from the 2013–2014 cohort. Results: Results from causal mediation analyses indicated that the total effect of e-cigarette use, compared to no use, increased the risk of cigarette ever smoking (20.9 %) and current smoking (4.6 %). A portion of this effect (4.2 % − 15.1 % for ever smoking; less than 10.6 % for current smoking) can be attributed to changes in social-cognitive factors induced by e-cigarette use. However, these mediated effects were small in magnitude relative to their standard errors and not statistically significant. Results from the traditional mediation analyses largely aligned with these findings, except for a few small sized pathways. Conclusions: For the U.S. youth population, social-cognitive factors may only minimally or not at all mediate the association between e-cigarette use and subsequent cigarette smoking. Further investigation into the mediation role of social-cognitive factors is warranted. Tobacco control interventions that focus on cigarette smoking initiation among youth should target other mediating factors.Longitudinal association between e-cigarette use and respiratory symptoms among US adults: Findings from the Population Assessment of Tobacco and Health Study Waves 4–5
AbstractKarey, E., Xu, S., He, P., Niaura, R. S., Cleland, C. M., Stevens, E. R., Sherman, S. E., El-Shahawy, O., Cantrell, J., & Jiang, N. (n.d.).Publication year
2024Journal title
PloS oneVolume
19Issue
2AbstractBackground We assessed longitudinal effects of e-cigarette use on respiratory symptoms in a nationally representative sample of US adults by combustible tobacco smoking status. Methods We analyzed Waves 4–5 public-use data from the Population Assessment of Tobacco and Health Study. Study sample included adult respondents who reported no diagnosis of respiratory diseases at Wave 4, and completed Waves 4–5 surveys with no missing data on analytic variables (N = 15,291). Outcome was a validated index of functionally important respiratory symptoms based on 7 wheezing/cough questions (range 0–9). An index score of 2 was defined as having important respiratory symptoms. Weighted lagged logistic regression models were performed to examine the association between e-cigarette use status at Wave 4 (former/current vs. never use) and important respiratory symptoms at Wave 5 by combustible tobacco smoking status (i.e., never/former/current smokers), adjusting for Wave 4 respiratory symptom index, sociodemographic characteristics, secondhand smoke exposure, body mass index, and chronic disease. Results Among current combustible tobacco smokers, e-cigarette use was associated with increased odds of reporting important respiratory symptoms (former e-cigarette use: adjusted odds ratio [AOR] = 1.39, 95% confidence interval [CI]: 1.07–1.81; current e-cigarette use: AOR = 1.55, 95% CI: 1.17–2.06). Among former combustible tobacco smokers, former e-cigarette use (AOR = 1.51, 95% CI: 1.06–2.15)—but not current e-cigarette use (AOR = 1.59, 95% CI: 0.91–2.78)—was associated with increased odds of important respiratory symptoms. Among never combustible tobacco smokers, no significant association was detected between e-cigarette use and important respiratory symptoms (former e-cigarette use: AOR = 1.62, 95% CI: 0.76–3.46; current e-cigarette use: AOR = 0.82, 95% CI: 0.27–2.56). Conclusions The association between e-cigarette use and respiratory symptoms varied by combustible tobacco smoking status. Current combustible tobacco smokers who use e-cigarettes have an elevated risk of respiratory impairments.Prevalence and risk factors of PTSD symptoms: a 3-month follow-up study
AbstractShang, Z., Pan, X., Cheng, S., Yang, Y., Yan, W., Sun, L. L., Huang, H., Bai, Y., Xie, W., & Xu, S. (n.d.).Publication year
2024Journal title
Therapeutic Advances in PsychopharmacologyVolume
14AbstractBackground: During the peak of the epidemic, hospitalized patients frequently encountered significant health risks and potentially life-threatening circumstances, including uncertainty regarding treatment and the potential for complications. Objective: The present study aimed to explore the prevalence of post-traumatic stress disorder (PTSD) symptoms among hospitalized patients 3 months after discharge during the first peak of the epidemic, and the association of PTSD with disease-related characteristics. Design: A single-center and full-sample follow-up study was conducted on COVID-19 patients from the Optical Valley Branch of Maternal and Child Hospital of Hubei Province, Wuhan, China. Data were collected during their hospitalization and 3 months after discharge. Methods: PTSD symptoms were evaluated by primary care post-traumatic stress disorder (PC-PTSD), a total score of 3 or above was considered as clinically significant PTSD symptoms. Demographic and disease-related characteristics were collected to identify related associations with PTSD symptoms. Results: A total of 903 patients completed the follow-up survey, yielding a response rate of 63.5%. A total of 212 (23.5%) of the patients were positive in PC-PTSD screening. Univariate regression analysis identified several factors correlated with PTSD symptoms, including female gender, younger age, a lower body mass index (BMI), preexisting sleep problems, bereavement due to COVID-19, a severe clinical diagnosis, the presence of three or more clinical symptoms at disease onset, and residual respiratory symptoms after discharge. Notably, in the multivariate regression analysis, experiencing three or more clinical symptoms at onset emerged as a robust predictor of PTSD symptoms (OR = 2.09, 95% CI: 1.48–2.95). An intriguing finding was that patients who underwent radiological assessment post-discharge reported a higher incidence of PTSD symptoms, whereas those who underwent re-testing for IgG or IgM antibodies exhibited a lower prevalence of PTSD symptoms. Conclusion: Three months post-recovery, PTSD symptoms prevalence among COVID-19 patients was 23.5%. Those with three or more clinical symptoms at onset or residual respiratory symptoms post-discharge showed higher risk. These findings highlighted the long-term effect of COVID-19 on mental health, urging enhanced attention and interventions for survivors.The impact of the 2014 military conflict in the east of Ukraine and the Autonomous Republic of the Crimea among patients receiving opioid agonist therapies
AbstractMeteliuk, A., Sazonova, Y., Goldmann, E., Xu, S., Liutyi, V., Liakh, T., Spirina, T., Lekholetova, M., Islam, Z., & Ompad, D. C. (n.d.).Publication year
2024Journal title
Journal of Substance Use and Addiction TreatmentVolume
160AbstractBackground: Opioid agonist therapies (OAT) for people with opioid use disorders (OUD) have been available in Ukraine since 2004. This study assessed the effect of 2014 Russian invasion of Ukraine on OAT re-enrollment and retention in conflict areas. Methods: We analyzed the Ukraine national registry of OAT patients containing 1868 people with OUD receiving OAT as of January 2014 in conflict areas (Donetsk, Luhansk, and the Autonomous Republic [AR] of the Crimea). We developed logistic regression models to assess the correlates of re-enrollment of OAT patients in government-controlled areas (GCA) from conflict areas and retention on OAT at 12 months after re-enrollment. Results: Overall, 377 (20.2 %) patients were re-enrolled at an OAT site in a GCA from confict areas, of whom 182 (48.3 %) were retained on OAT through 2021. Correlates of re-enrollment were residing in Donetsk (adjusted odds ratios (aOR) = 7.06; 95 % CI: 4.97–10.20) or Luhansk (aOR = 6.20; 95 % CI: 4.38–8.93) vs. AR Crimea; age 18–34 (aOR = 2.03; 95 % CI: 1.07–3.96) or 35–44 (aOR = 2.09; 95 % CI: 1.24–3.71) vs. ≥55 years, and being on optimal (aOR = 1.78; 95 % CI: 1.33–2.39) or high OAT dosing (aOR = 2.76; 95 % CI: 1.93–3.96) vs. low dosing. Correlates of retention were drug use experience 15–19 years (aOR = 3.69; 95 % CI: 1.47–9.49) vs. <14 years of drug use; take-home (aOR = 3.42; 95 % CI: 1.99–5.96) vs. daily on-site dosing, and optimal (aOR = 2.19; 95 % CI:1.05–4.72) vs. low OAT dosing. Conclusion: Our study showed that one-fifth of patients were re-enrolled at sites in GCA areas, less than half of re-enrolled patients were retained. Disruption of OAT has implications for drug-, HIV-, and HCV-related morbidity and mortality. Funding: AM was funded by NIH-funded grant D43TW010562; DCO was funded by the NIDA-funded Center for Drug Use and HIV|HCV Research (P30DA011041).Association of Racial Discrimination With Adiposity in Children and Adolescents
AbstractCuevas, A. G., Krobath, D. M., Rhodes-Bratton, B., Xu, S., Omolade, J. J., Perry, A. R., & Slopen, N. (n.d.).Publication year
2023Journal title
JAMA network openVolume
6Issue
7AbstractIMPORTANCE Childhood obesity is a major public health issue and is disproportionately prevalent among children from minority racial and ethnic groups. Personally mediated racism (commonly referred to as racial discrimination) is a known stressor that has been linked to higher body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) in adults, but little is known about the association of racial discrimination and childhood and adolescent adiposity. OBJECTIVE To assess the prospective association between self-reported experiences of racial discrimination and adiposity (BMI and waist circumference) in a large sample of children and adolescents in the Adolescent Brain Cognitive Development (ABCD) study. DESIGN, SETTING, AND PARTICIPANTS This cohort study used complete data from the ABCD study (2017 to 2019), involving a total of 6463 participants. The ABCD study recruited a diverse sample of youths from across the US, with rural, urban, and mountain regions. Data were analyzed from January 12 to May 17, 2023. EXPOSURE The child-reported Perceived Discrimination Scale was used to quantify racial discrimination, reflecting participants’ perceptions of being treated unfairly by others or unaccepted by society based on their race or ethnicity. MAIN OUTCOMES AND MEASURES Weight, height, and waist circumference were measured by trained research assistants. BMI z scores were computed by applying the US Centers for Disease Control and Prevention’s age and sex-specific reference standards for children and adolescents. Waist circumference (inches) was quantified as the mean of 3 consecutive measures. Measurements were taken from time 1 (ie, 2017 to 2019) and time 2 (ie, 2018 to 2020). RESULTS Of the 6463 respondents with complete data, 3090 (47.8%) were female, and the mean (SD) age was 9.95 (0.62) years. Greater racial discrimination exposure at time 1 was associated with higher BMI z score in both unadjusted (β, 0.05; 95% CI, 0.02-0.08) and adjusted regression models (β, 0.04; 95% CI, 0.01-0.08). Discrimination at time 1 was associated with higher waist circumference in unadjusted (β, 0.35; 95% CI, 0.15-0.54) and adjusted (β, 0.24; 95% CI, 0.04-0.44) models. CONCLUSIONS AND RELEVANCE In this cohort study of children and adolescents, racial discrimination was positively associated with adiposity, quantified by BMI z score and waist circumference. Interventions to reduce exposure to racial discrimination in early life may help reduce the risk of excess weight gain across throughout life.Examining the effects of cumulative environmental stressors on Gulf Coast child and adolescent health
AbstractMeltzer, G. Y., Merdjanoff, A. A., Xu, S., Gershon, R., Emrich, C. T., & Abramson, D. M. (n.d.).Publication year
2023Journal title
Population and EnvironmentVolume
45Issue
3AbstractThis study examines how community-level cumulative environmental stress affects child and adolescent emotional distress and chronic health conditions both directly and indirectly through stressors at the household, family, and individual levels. Data comes from the Women and their Children’s Health (WaTCH) Study, which sought to understand the health implications of exposure to the 2010 Deepwater Horizon oil spill (DHOS) among a cohort of 596 mothers with children ages 10 to 17 in southeastern Louisiana. Community-level environmental stress was measured using a newly developed geospatial index. Household-level stressors included previous hurricane impacts, impacts of DHOS, degree of financial difficulty, and degree of housing physical decay. Family stressors included maternal depression, self-rated physical health, and degree of parenting stress. Child stress was based on perceived stress; child mental health was based on serious emotional disturbance; and child physical health was based on diagnosis of chronic illness. Structural equation modeling used weighted least squares means and variance and theta parameterization. Results showed a significant negative direct path between community-level cumulative environmental stress and child/adolescent serious emotional disturbance and chronic illness. However, the indirect relationship through household, family, and individual-level stressors was significant and positive for both child/adolescent serious emotional disturbance and chronic illness. These findings point to the centrality of the household and family in determining child and adolescent physical and mental health outcomes in communities exposed to frequent disasters and ongoing environmental stressors.Predictors of Crosscutting Patterns of Psychological Health and Family Maltreatment
AbstractNichols, S. R., Rhoades, K. A., Lorber, M. F., Xu, S., Heyman, R. E., & Slep, A. M. (n.d.).Publication year
2023Journal title
Military MedicineVolume
188Issue
9Page(s)
3134-3142AbstractIntroduction: Psychological problems and family maltreatment are significant public health problems. Although research focuses almost exclusively on either individual psychological problems or family maltreatment, there is substantial co-occurrence of these problems. Similarly, intervention services are often “siloed”: individuals with mental health needs are referred for mental health services, individuals with family conflict are referred for family-based treatment, etc. These treatment “silos” may miss the larger picture of the co-occurrence of risk, promotion, and the problems themselves. In a previous paper, we used latent class analysis to identify subgroups of individuals with crosscutting patterns (i.e., classes) of psychological and family maltreatment problems. In this study, we explored the predictors of these latent classes. Materials and Methods: Participants consisted of two large population samples of U.S. Air Force active duty members (ns = 27,895 and 30,841) who were married or cohabiting and had one or more children living in their household. Participants completed an anonymous community assessment survey, which included questionnaire items tapping personal, family, and community problems and well-being. Assessments were conducted in 2008 and 2011. All study procedures were approved by the authors’ Institutional Review Board. We used exploratory factor analysis and latent class analysis to (1) identify higher-order factors of risk and promotive variables and (2) examine them as predictors of our previously identified latent classes. Results: Findings indicated that individuals who reported better physical well-being as well as personal and family coping, relationship satisfaction, and support were more likely to be in the lowest-risk subgroup. Notably, individuals in the subgroup most at risk for serious violence and suicide, evidencing disinhibitory psychopathology, endorsed lower risk and higher promotive factors than those individuals in other high-risk subgroups who fell along the internalizing/externalizing continuum. Conclusions: These findings reinforce the need for integrated prevention and treatment of psychological and family maltreatment problems. Not only do these problems often co-occur, but their risk and promotive factors also tend to be intertwined. The unique (i.e., not on the continuum of the other five classes) problem profile of participants evidencing disinhibitory psychopathology is matched by a unique risk/promotive factor profile, and they will thus likely require a unique intervention approach.Tutorial on Causal Mediation Analysis With Binary Variables: An Application to Health Psychology Research
AbstractXu, S., Coffman, D. L., Luta, G., & Niaura, R. S. (n.d.).Publication year
2023Journal title
Health PsychologyVolume
42Issue
11Page(s)
778-787AbstractMediation analysis has been widely applied to explain why and assess the extent to which an exposure or treatment has an impact on the outcome in health psychology studies. Identifying a mediator or assessing the impact of a mediator has been the focus of many scientific investigations. This tutorial aims to introduce causal mediation analysis with binary exposure, mediator, and outcome variables, with a focus on the resampling and weighting methods, under the potential outcomes framework for estimating natural direct and indirect effects. We emphasize the importance of the temporal order of the study variables and the elimination of confounding. We define the causal effects in a hypothesized causal mediation chain in the context of one exposure, one mediator, and one outcome variable, all of which are binary variables. Two commonly used and actively maintained R packages, mediation and medflex, were used to analyze a motivating example. R code examples for implementing these methods are provided.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
AbstractJiang, N., Xu, S., Li, L., Cleland, C. M., & Niaura, R. S. (n.d.).Publication year
2023Journal title
Addictive BehaviorsVolume
139AbstractIntroduction: Electronic nicotine delivery system (ENDS) devices evolve rapidly and impact nicotine dependence. This study described the type of ENDS devices used most frequently by U.S. youth and adults from 2013/14 to 2018/19. Methods: We analyzed Waves 1–5 data of the Population Assessment of Tobacco and Health Study. Among current ENDS users, descriptive statistics summarized the most frequently used ENDS devices (i.e., disposable cigalike, refillable cartridge, nonrefillable cartridge, tank, mod, prefilled pod, disposable pod) among youth (12–17 years), young adults (18–34 years), and older adults (≥35 years) for each wave. Results: The proportion of current ENDS users who reported they most frequently used disposable cigalikes and cartridge-based devices declined over time across all age groups. At Waves 1–4, tank was generally the most popular type for all ages and an increasing proportion of ENDS users reported they most frequently used tanks. The primary use of mods decreased among youth, and fluctuated among young and older adults. At Wave 5, prefilled pods became the dominant type (youth: 55.0%; young adults: 44.7%; older adults: 42.7%), and 4.2–10.0% of ENDS users reported using disposable pods most often. The popularity of tanks, mods, and prefilled pods was more evident in youth and young adults, and primary use of disposable pods was more common in older adults. Conclusions: The primary use of ENDS devices changed over the years and varied by age. More research is warranted to continuously monitor the characteristics of ENDS devices in youth and adults to inform product regulations and intervention efforts.Cigar Use Progression Among New Cigar Initiators: A Two-Part Growth Curve Analysis Among a Youth and Young Adult Cohort
AbstractCantrell, J., Xu, S., Kreslake, J., Liu, M., & Hair, E. (n.d.).Publication year
2022Journal title
Nicotine and Tobacco ResearchVolume
24Issue
1Page(s)
28-36AbstractIntroduction: Youth and young adults (YYAs) are at high risk of cigar use. This study's objective was to examine progression and sociodemographic differences in current cigar use and frequency among new cigar initiators. Aims and Methods: We conducted a two-part latent growth model among a nationally representative cohort of cigar initiators (aged 15-25) to examine 24-month trajectories of current cigar use and frequency (n = 1483). The cohort was recruited via address-based sampling with online data collection from 2014 to 2019 and surveyed approximately every 6 months. Results: The unconditional odds of current cigar use (ie, past 30-day use) within 6 months of initiation was 0.72 (95% confidence interval: 0.63, 0.82), corresponding to a probability of 42%. The odds of current use among recent cigar initiates declined 6 months after initiation and was followed by a stabilization in use over time. Among continued users, frequency (# days used in past 30 days) increased linearly over time but remained low (3.47 days/months at 24 months). Younger individuals, non-Hispanic African Americans, those with lower subjective financial status, and current users of cigarettes, other tobacco products and/or marijuana were at highest risk within 6 months of initiation. Males, younger users, and current cigarette smokers had the highest risk for cigar progression over time. Conclusions: This study is the first to examine longitudinal cigar use patterns among YYA cigar initiators. Findings emphasize the need for research across the cigar use spectrum and the importance of interventions targeted by age, stage of use, cigarette, other tobacco, and marijuana use and key sociodemographics to interrupt use pathways. Implications: This study is the first to examine progression of cigar use among YYAs who have newly initiated cigars. Results show a high probability of current cigar use within 6 months of initiation followed by a rapid decline and stabilization over time. Frequency increases among those who continue using cigars. Males, younger users, and current cigarette smokers had the highest risk for cigar progression over time. Findings emphasize the need for targeting interventions by age, stage of use, cigarette, other tobacco, and marijuana use and key sociodemographics to interrupt use pathways.Passive exposure to e-cigarette emissions is associated with worsened mental health
AbstractFarrell, K. R., Weitzman, M., Karey, E., Lai, T. K., Gordon, T., & Xu, S. (n.d.).Publication year
2022Journal title
BMC public healthVolume
22Issue
1AbstractBackground: Cigarette smoking, secondhand cigarette smoke (SHS) exposure, and e-cigarette use (“vaping”) are each associated with increased rates of depressive symptoms and other internalizing mental health disorders. The prevalence of vaping has increased greatly, yet the mental health correlates of secondhand exposure to e-cigarette emissions are as yet to be investigated. This study examined the potential adverse mental health outcomes associated with different tobacco exposures (direct and passive), with a particular focus on the mental health correlates of secondhand exposure to e-cigarette emissions. Methods: The Population Assessment of Tobacco and Health Study data collected from a sample of 16,173 Wave 4 adults were used to test the hypothesis that secondhand e-cigarette emissions exposure is associated with increased odds of internalizing mental health disorders. Individuals were categorized as exclusive cigarette smokers, exclusive e-cigarette users, cigarette and e-cigarette dual users, exclusive noncombustible tobacco users, secondhand smoke exposed non-users, secondhand e-cigarette emissions exposed non-users, and non-users with no current SHS/secondhand e-cigarette aerosol exposure. Adjusted weighted logistic regression analysis was used to investigate the association between exposure type and internalizing problems as assessed by scores on the Global Appraisal of Individual Needs-Short Screener (GAIN-SS), a widely used instrument for assessing mental health problems. Results: Cigarette smokers (AOR = 2.53, 95% CI: 2.19–2.92), e-cigarette users (AOR = 3.14, 2.41–4.09), dual users (AOR = 3.37, 2.85–4.00), noncombustible tobacco users (AOR = 1.48, 1.01–2.17), SHS exposed non-users (AOR = 1.63, 1.37–1.94), and secondhand e-cigarette emissions exposed non-users (AOR = 1.43, 1.03–1.99) were each associated with increased odds of moderate to severe internalizing mental health problems as compared to unexposed non-users. Odds of internalizing problems among SHS and secondhand e-cigarette emissions exposed non-users did not differ (p = 0.46). Conclusions: This is the first study, to our knowledge, to identify an association between recent secondhand exposure to e-cigarette emissions and mental health problems, and the risk is comparable to that of SHS. Corroboration of this relationship needs further research to explicate directionality and mechanisms underlying this association.Recurrent Injecting Drug Use as a Mediator between Psychiatric Disorder and Non-Fatal Overdose
AbstractBarnes, D. M., Xu, S., Cleland, C. M., McKnight, C., & Des Jarlais, D. (n.d.).Publication year
2022Journal title
Substance Use and MisuseVolume
57Issue
8Page(s)
1248-1256AbstractBackground: Unintentional drug overdose has increased markedly in the United States. Studies document an association between psychiatric disorder and unintentional overdose; we extend this research through a preliminary test of a causal model of recurrent injection drug use mediating this relationship. Methods: In a cross-sectional study of 241 adults in New York City with a possible current substance use disorder, we conducted conventional and Imai’s mediation analyses to examine if psychiatric disorder is associated with increased prevalence of ever overdosing and if recurrent injection drug use mediates this association. Our cross-sectional data permit the first step of assessing causal models: testing if statistical associations are consistent with the model. Results: Fifty-eight percent of the sample endorsed previous psychiatric disorder diagnosis and 35.7% reported ever overdosing. Imai’s mediation analysis showed that, adjusting for covariates, the total association between psychiatric diagnosis and ever overdosing (adjusted prevalence difference [aPD] = 0.16, 95% CI 0.04–0.28) was composed of a direct effect (aPD = 0.09, 95% CI −0.03 − 0.21, p = 0.136) and an indirect effect (aPD = 0.07, 95% CI 0.02–0.13). Recurrent injecting drug use contributed to 42% (ratio of indirect effect to total effect; 95% CI 12 − 100%, p = 0.02) of the association between psychiatric diagnosis and ever overdosing. Conventional mediation analysis produced similar results. Conclusions: Our results provide a warrant for taking the necessary next step for assessing a causal model using longitudinal data, potentially providing a strong rationale for intervening on psychiatric disorders to stem overdose.Relationships Between E-cigarette Use and Subsequent Cigarette Initiation Among Adolescents in the PATH Study: an Entropy Balancing Propensity Score Analysis
AbstractXu, S., Coffman, D. L., Liu, B., Xu, Y., He, J., & Niaura, R. S. (n.d.).Publication year
2022Journal title
Prevention ScienceVolume
23Issue
4Page(s)
608-617AbstractThis study aimed to examine the relationship between electronic cigarette use and subsequent combustible cigarette use, controlling for confounding by using a propensity score method approach. Data from the first three annual waves of the Population Assessment of Tobacco and Health study were analyzed (n = 6309). Participants were tobacco-naïve at Wave 1; used e-cigarettes exclusively (n = 414), used combustible cigarettes exclusively (n = 46), or not used any tobacco products (n = 5849) at Wave 2. We conducted entropy balancing propensity score analysis to examine the association between exclusive e-cigarette or cigarette initiation and subsequent cigarette use at Wave 3, adjusting for non-response bias, sampling bias, and confounding. Among tobacco-naïve youth, exclusive e-cigarette use was associated with greater risk for subsequent combustible cigarette smoking initiation (OR = 3.42, 95% CI = (1.99, 5.93)) and past 30-day combustible cigarette use (OR = 2.88, 95% CI = (1.22, 6.86)) in the following year. However, the latter risk was comparatively lower than the risk if youth started with a combustible cigarette (OR = 25.79, 95% CI = (9.68, 68.72)). Results of sensitivity analyses indicated that estimated effects were robust to unmeasured confounding. Use of e-cigarettes in tobacco-naïve youth is associated with increased risk of subsequent past 30-day combustible cigarette use but the risk is an order of magnitude higher if they start with a combustible cigarette.The Mediating Effect of E-Cigarette Harm Perception in the Relationship between E-Cigarette Advertising Exposure and E-Cigarette Use
AbstractJiang, N., Xu, S., Li, L., El-Shahawy, O., Freudenberg, N., Shearston, J. A., & Sherman, S. E. (n.d.).Publication year
2022Journal title
International journal of environmental research and public healthVolume
19Issue
10AbstractExposure to e-cigarette advertising is associated with e-cigarette use among young people. This study examined the mediating effect of e-cigarette harm perception on the above relationship. Cross-sectional survey data were collected from 2112 college students in New York City in 2017–2018. The analytic sample comprised 2078 participants (58.6% females) who provided completed data. Structural equal modeling was performed to examine if e-cigarette harm perception mediated the relationship between e-cigarette advertising exposure (via TV, radio, large signs, print media, and online) and ever e-cigarette use and susceptibility to e-cigarette use. About 17.1% of participants reported ever e-cigarette use. Of never users, 17.5% were susceptible to e-cigarette use. E-cigarette advertising exposure was mainly through online sources (31.5%). Most participants (59.4%) perceived e-cigarettes as equally or more harmful than cigarettes. Advertising exposure showed different effects on e-cigarette harm perception depending on the source of the advertising exposure, but perceiving e-cigarettes as less harmful than cigarettes was consistently associated with e-cigarette use and susceptibility. Low harm perception mediated the association between advertising exposure (via online, TV, and radio) and ever e-cigarette use and between online advertising exposure and e-cigarette use susceptibility. Regulatory actions are needed to address e-cigarette marketing, particularly on the Internet.Youth E-Cigarette Use and Functionally Important Respiratory Symptoms: The Population Assessment of Tobacco and Health (PATH) Study Waves 3 and 4
AbstractStevens, E. R., Xu, S., Niaura, R., Cleland, C. M., Sherman, S. E., Mai, A., Karey, E., & Jiang, N. (n.d.).Publication year
2022Journal title
International journal of environmental research and public healthVolume
19Issue
22AbstractRespiratory effects of e-cigarette use among youth are not fully understood. This study investigated the longitudinal association between e-cigarette use and a validated index of functionally important respiratory symptoms among US youth. Data from Waves 3–4 of the Population Assessment of Tobacco and Health Study were analyzed. The sample included youth (aged 12–17) without asthma at baseline (Wave 3), who completed a follow-up survey (Wave 4), and were not missing data for analytic variables (n = 3899). Exposure was e-cigarette use status (never, former, or current) at baseline. The outcome was a respiratory symptom index based on responses for seven wheezing items at Wave 4. An index of ≥2 was defined as having functionally important respiratory symptoms. Lagged logistic regression models examined the association between baseline e-cigarette use and functionally important respiratory symptoms at follow-up by combustible tobacco use status (never or ever), and controlling for baseline covariates. At baseline, 13.7% of participants reported former e-cigarette use, and 4.3% reported current use. Baseline e-cigarette use did not increase the odds of having functionally important respiratory symptoms at follow-up regardless of combustible tobacco use status. Future research on larger populations of e-cigarette users with longer follow-up periods will improve our understanding of the respiratory risks associated with e-cigarette use among youth.Cannabis Use and the Onset of Cigarette and E-cigarette Use: A Prospective, Longitudinal Study among Youth in the United States
AbstractWeinberger, A. H., Zhu, J., Lee, J., Xu, S., & Goodwin, R. D. (n.d.).Publication year
2021Journal title
Nicotine and Tobacco ResearchVolume
23Issue
3Page(s)
609-613AbstractIntroduction: Cigarette use is declining among youth in the United States, whereas cannabis use and e-cigarette use are increasing. Cannabis use has been linked with increased uptake and persistence of cigarette smoking among adults. The goal of this study was to examine whether cannabis use is associated with the prevalence and incidence of cigarette, e-cigarette, and dual product use among U.S. youth. Methods: Data included U.S. youth ages 12-17 from two waves of the Population Assessment of Tobacco and Health (PATH) Study (Wave 1 youth, n = 13 651; Wave 1 tobacco-naive youth, n = 10 081). Weighted logistic regression models were used to examine the association between Wave 1 cannabis use and (1) Wave 1 prevalence of cigarette/e-cigarette use among Wave 1 youth and (2) Wave 2 incidence of cigarette/e-cigarette use among Wave 1 tobacco-naive youth. Analyses were run unadjusted and adjusted for demographics and internalizing/externalizing problem symptoms. Results: Wave 1 cigarette and e-cigarette use were significantly more common among youth who used versus did not use cannabis. Among Wave 1 tobacco-naive youth, Wave 1 cannabis use was associated with significantly increased incidence of cigarette and e-cigarette use by Wave 2. Conclusions: Youth who use cannabis are more likely to report cigarette and e-cigarette use, and cannabis use is associated with increased risk of initiation of cigarette and e-cigarette use over 1 year. Continued success in tobacco control-specifically toward reducing smoking among adolescents-may require focusing on cannabis, e-cigarette, and cigarette use in public health education, outreach, and intervention efforts. Implications: These data extend our knowledge of cigarette and e-cigarette use among youth by showing that cannabis use is associated with increased prevalence and incidence of cigarette and e-cigarette use among youth, relative to youth who do not use cannabis. The increasing popularity of cannabis use among youth and diminished perceptions of risk, coupled with the strong link between cannabis use and tobacco use, may have unintended consequences for cigarette control efforts among youth.E-cigarette use, systemic inflammation, and depression
AbstractFarrell, K. R., Karey, E., Xu, S., Gibbon, G., Gordon, T., & Weitzman, M. (n.d.).Publication year
2021Journal title
International journal of environmental research and public healthVolume
18Issue
19AbstractBackground: E-cigarette use (vaping) is an emerging public health problem. Depression has been found to be associated with e-cigarette use, and vaping and depression are each associated with elevated systemic inflammation. To date, the role of inflammation in the relationship between vaping and depression has not been explored. Objective: To assess the independent associations between e-cigarette use, depression, and inflammation, and to investigate whether the likelihood of depression among current e-cigarette users is associated with systemic inflammation. Methods: Nationally representative NHANES data from 2015–2018 were used (n = 4961). Systemic inflammation was defined as serum C-reactive protein (CRP) ≥ 8.0 mg/L. Depressed individuals were characterized by a score ≥ 10 on the Patient Health Questionnaire-9 (PHQ-9). Current e-cigarette users were defined as individuals who vaped at least once in the past 30 days and these individuals were stratified by use: exclusive users (reported smoking less than 100 combustible cigarettes in their lifetime), dual users (reported current use of electronic and combustible cigarettes), and e-cigarette users who were previous smokers. Bivariate analyses were used to assess independent associations between vaping, depression, and inflammation; and weighted logistic regression analyses adjusting for BMI, sex, and economic status were used to determine the odds ratios (ORs) for depression by e-cigarette category stratified by differential CRP levels. Results: Depression occurred in 16.7% of all e-cigarette users vs. 5.0% of those who never used e-cigarettes (p < 0.001). In adjusted analyses, the following elevated ORs were found: all current e-cigarette users with CRP <8 = 3.37 (95% CI: 2.06, 5.51) vs. CRP ≥8 = 6.70 (2.48, 18.11); exclusive e-cigarette users with CRP <8 = 1.91 (0.78, 4.69) vs. those with CRP ≥8 = 5.09 (1.44, 18.02); and dual users with CRP <8 = 4.31 (2.35, 7.89) vs. those with CRP ≥8 = 7.37 (1.85, 29.41). These ORs indicate that depression is associated with each category of e-cigarette use; however, we found this association did not vary by systemic inflammation level (interaction p-values > 0.05). Conclusion: While a pattern of greater ORs for depression among e-cigarette users with elevated CRP provides provocative findings that might suggest a potential role of inflammation in the association between vaping and depression, we failed to find evidence that inflammation clearly moderates this association. While it is possible that depression among e-cigarette users may be influenced by systemic inflammation, a reproduction of the current study is necessary among a larger cohort to elucidate the effect of inflammation on depression among e-cigarette users.Self-report measures of coercive process in couple and parent–child dyads.
AbstractMitnick, D. M., Lorber, M. F., Smith Slep, A. M., Heyman, R. E., Xu, S., Bulling, L. J., Nichols, S. R., & Eddy, J. M. (n.d.).Publication year
2021Journal title
Journal of Family PsychologyVolume
35Issue
3Page(s)
388-398AbstractOne of the most influential behavioral models of family conflict is G. R. Patterson’s (1982) coercive family process theory. Self-reports for behaviors related to coercion (e.g., hostility toward a family member) abound; however, there are no self-report measures for coercive process itself, which is, by definition, a dyadic process. Operationalizations of coercive process are measured with behavioral observation, typically including sequential analyzed, microcoded behaviors. Despite its objectivity and rigor, coding of behavior observation is not always feasible in research and applied settings because of the high training, personnel, and time costs the observation requires. Because coercive process has been shown to predict a host of maladaptive outcomes (e.g., parent–child conflict, aggression, negative health outcomes) and given the complete absence of self-report measures of coercive process, we recently designed brief questionnaires to assess coercive process in couple (Couple Coercive Process Scale [CCPS]) and parent–child interactions (Parent–Child Coercive Process Scale [PCCPS]) and tested them via Qualtrics participant panels in samples recruited to mirror socioeconomic generalizability to U.S. Census data. The CCPS and PCCPS exhibited initial evidence of psychometric quality in measuring coercive process in couple and parent–child dyads: Both measures are unifactorial; have evidence of reliability, especially at higher levels of coercive process; and demonstrate concurrent validity with constructs in their nomological networks, with medium to large effect sizes.High Sensitivity and Specificity Screening for Clinically Significant Intimate Partner Violence
AbstractHeyman, R. E., Baucom, K. J., Xu, S., Smith Slep, A. M., Snarr, J. D., Foran, H. M., Lorber, M. F., Wojda, A. K., & Linkh, D. J. (n.d.).Publication year
2020Journal title
Journal of Family PsychologyAbstractThe U.S. Preventive Services Task Force has recommended that clinicians screen patients for intimate partner violence (IPV). This article aims to develop and test the first screeners for clinically significant physical and psychological IPV (i.e., acts meeting criteria in the International Classification of Diseases (11th ed.; ICD-11; World Health Organization, 2019) and the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5; American Psychiatric Association, 2013). The goal was to derive screeners that (1) are maximally brief, while still achieving high sensitivity and specificity; (2) assess perpetration and victimization when either men or women are reporting; and (3) use ICD-11/DSM-5 criteria as the reference standard. Random samples of active duty service members at 82 installations worldwide were obtained via e-mail invitation (2006: N = 54,543; 2008: N = 48,909); their response rates were excellent for long general population surveys with no payment (2006: 44.7%, 2008: 49.0%). The population of spouses at the participating installation was invited by mailed postcard (2006: N = 19,722; 2008: N = 12,127; response rates-2006: 12.3%, 2008: 10.8%). Clinically significant physical intimate partner violence can be effectively screened with as few as four items, with sensitivities >90% and specificities >95%; clinically significant psychological intimate partner violence can be screened with two items. Men and women can be screened with equivalent accuracy, as can those committing the violence and those victimized by it.Psychology of wearing face masks to prevent transition of COVID-19
Song, L. J., Xu, S., Xu, S. L., Sun, Z., & Liu, W. (n.d.).Publication year
2020Journal title
General PsychiatryVolume
33Issue
6The lump-versus-split dilemma in couple observational coding: A multisite analysis of rapid marital interaction coding system data.
AbstractHeyman, R. E., Otto, A. K., Reblin, M., Wojda, A. K., & Xu, S. (n.d.).Publication year
2020Journal title
Journal of Family PsychologyVolume
35Issue
4AbstractHistorically, observational couple communication researchers have oscillated between splitting behaviors into narrowly defined discrete codes and grouping behaviors into broader codes—sometimes within the same study. We label this the “lump-versus-split dilemma.” Coding across a decade and 11 investigators were used to recommend the most meaningful number of codes to use when observing couples’ conflict. We combined data from 14 studies that used the Rapid Marital Interaction Coding System (RMICS) to score communication behavior during different-sex couples’ conflict interactions. In each study, couples completed at least one 10-min, video-recorded conflict discussion. Communication during these interactions was coded by trained research staff using RMICS; all codes were compiled into a single data set for descriptive analysis and exploratory factor analyses (EFAs). The final sample comprised N = 2,011 couples. Several RMICS codes were extremely infrequent—specifically, distress-maintaining attributions, psychological abuse, withdrawal, dysphoric affect, and relationship-enhancing attributions. By far, the most frequent code was constructive problem discussion. EFAs yielded two factors for both women and men. Factor 1 (Negative) contained two items: distress-maintaining attributions and hostility. Factor 2 (Nonnegative) contained constructive problem discussion and humor (and, for women only, acceptance). Results side heavily with the “lump” camp in the lump-versus-split dilemma in couple observational coding. These RMICS factor analysis results converge with those from other systems and imply that the microanalytic “splitting” era in couples coding should draw to a close, with future studies instead focused on negative, neutral, and positive codes.Using Security Questions to Link Participants in Longitudinal Data Collection
AbstractXu, S., Chan, A., Lorber, M. F., & Chase, J. P. (n.d.).Publication year
2020Journal title
Prevention ScienceVolume
21Issue
2Page(s)
194-202AbstractAnonymous data collection systems are often necessary when assessing sensitive behaviors but can pose challenges to researchers seeking to link participants over time. To assist researchers in anonymously linking participants, we outlined and tested a novel security question linking (security question linking; SEEK) method. The SEEK method includes four steps: (1) data management and standardization, (2) many-to-many matching, (3) fuzzy matching, and (4) rematching and verification. The method is demonstrated in SAS with two samples from a longitudinal study of adolescent dating violence. After an initial assessment during a laboratory visit, participants were asked to complete an online assessment either (a) once, 3 months later (Sample 1, n = 60), or (b) three times at 1-month intervals (Sample 2, n = 140). Demographics, eye color, and responses to nine security questions were used as key variables to link responses from the laboratory and online follow-up assessments. The rates of matched cases were 100% in Sample 1 and from 94.3 to 98.3% in Sample 2. To quantify the confidence in the data quality of successfully matched pairs, we reported the means and standard deviations of the number of matched security questions. In addition, we reported the rank order and counts of the mismatched components in key variables. Results indicate that the SEEK method provides a feasible and reliable solution to link responses in longitudinal studies with sensitive questions.A Randomized, Controlled Trial of the Impact of the Couple CARE for Parents of Newborns Program on the Prevention of Intimate Partner Violence and Relationship Problems
AbstractHeyman, R. E., Slep, A. M., Lorber, M. F., Mitnick, D. M., Xu, S., Baucom, K. J., Halford, W. K., & Niolon, P. H. (n.d.).Publication year
2019Journal title
Prevention ScienceVolume
20Issue
5Page(s)
620-631AbstractEffective, accessible prevention programs are needed for adults at heightened risk for intimate partner violence (IPV). This parallel group randomized controlled trial examines whether such couples receiving the American version of Couple CARE for Parents of Newborns (CCP; Halford et al. 2009) following the birth of a child, compared with controls, report fewer first occurrences of clinically significant IPV, less frequent physical and psychological IPV, and improved relationship functioning. Further, we test whether intervention effects are moderated by level of risk for IPV. Couples at elevated risk for IPV (N = 368) recruited from maternity units were randomized to CCP (n = 188) or a 24-month waitlist (n = 180) and completed measures of IPV and relationship functioning at baseline, post-program (when child was 8 months old), and two follow-ups (at 15 and 24 months). Intervention effects were tested using intent to treat (ITT) as well as complier average causal effect (CACE; Jo and Muthén 2001) structural equation models. CCP did not significantly prevent clinically significant IPV nor were there significant main effects of CCP on clinically significant IPV, frequency of IPV, or most relationship outcomes in the CACE or ITT analyses. Risk moderated the effect of CCP on male-to-female physical IPV at post-program, with couples with a planned pregnancy declining, but those with unplanned pregnancies increasing. This study adds to previous findings that prevention programs for at-risk couples are not often effective and may even be iatrogenic for some couples.Patterns of psychological health problems and family maltreatment among United States Air Force members
AbstractLorber, M. F., Xu, S., Heyman, R. E., Slep, A. M., & Beauchaine, T. P. (n.d.).Publication year
2018Journal title
Journal of Clinical PsychologyVolume
74Issue
7Page(s)
1258-1271AbstractObjectives:: We sought to identify subgroups of individuals based on patterns of psychological health problems (PH; e.g., depressive symptoms, hazardous drinking) and family maltreatment (FM; e.g., child and partner abuse). Method:: We analyzed data from very large surveys of United States Air Force active duty members with romantic partners and children. Results:: Latent class analyses indicated six replicable patterns of PH problems and FM. Five of these classes, representing ∼98% of survey participants, were arrayed ordinally, with increasing risk of multiple PH problems and FM. A sixth group defied this ordinal pattern, with pronounced rates of FM and externalizing PH problems, but without correspondingly high rates/levels of internalizing PH problems. Conclusions:: Ramifications of these results for intervention are discussed.