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An empirical approach based on quantile regression for estimating citation ageing
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An aspect of citation behavior, which has received longstanding attention in research, is how articles’ received citations evolve as time passes since their publication (i.e., citation ageing). Citation ageing has been studied mainly by the formulation and fit of mathematical models of diverse complexity. Commonly, these models restrict the shape of citation ageing functions and explicitly take into account factors known to influence citation ageing. An alternative—and less studied—approach is to estimate citation ageing functions using data-driven strategies. However, research following the latter approach has not been consistent in taking into account those factors known to influence citation ageing. In this article, we propose a model-free approach for estimating citation ageing functions which combines quantile regression with a non-parametric specification able to capture citation inflation. The proposed strategy allows taking into account field of research effects, impact level effects, citation inflation effects and skewness in the distribution of cites effects. To test our methodology, we collected a large dataset consisting of more than five million citations to 59,707 research articles spanning 12 dissimilar fields of research and, with this data in hand, tested the proposed strategy.
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MPRC People
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Sebastian Galiani, Ph.D.
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Sebastian Galiani Publications
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Genetic Clustering Analysis for HIV Infection among Men Who Have Sex with Men in Nigeria
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Background: The HIV epidemic continues to grow among MSM in countries across sub-Saharan Africa including Nigeria . To inform prevention efforts, we used a phylogenetic cluster method to characterize HIV genetic clusters and factors associated with cluster formation among MSM living with HIV in Nigeria . Methods: We analyzed HIV -1 pol sequences from 417 MSM living with HIV enrolled in the TRUST/RV368 cohort between 2013 and 2017 in Abuja and Lagos, Nigeria . A genetically linked cluster was defined among participants whose sequences had pairwise genetic distance of 1.5% or less. Binary and multinomial logistic regressions were used to estimate adjusted odds ratios (AORs) and 95% confidence intervals (CIs) for factors associated with HIV genetic cluster membership and size. Results: Among 417 MSM living with HIV , 153 (36.7%) were genetically linked. Participants with higher viral load (AOR = 1.72 95% CI: 1.04–2.86), no female partners (AOR = 3.66; 95% CI: 1.97–6.08), and self-identified as male sex (compared with self-identified as bigender) (AOR = 3.42; 95% CI: 1.08–10.78) had higher odds of being in a genetic cluster. Compared with unlinked participants, MSM who had high school education (AOR = 23.84; 95% CI: 2.66–213.49), were employed (AOR = 3.41; 95% CI: 1.89–10.70), had bacterial sexually transmitted infections (AOR = 3.98; 95% CI: 0.89–17.22) and were not taking antiretroviral therapy (AOR = 6.61; 95% CI: 2.25–19.37) had higher odds of being in a large cluster (size > 4). Conclusion: Comprehensive HIV prevention packages should include behavioral and biological components, including early diagnosis and treatment of both HIV and bacterial sexually transmitted infections to optimally reduce the risk of HIV transmission and acquisition.
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MPRC People
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Hongjie Liu, Ph.D.
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Hongjie Liu Publications
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Seizing opportunities for intervention: Changing HIV-related knowledge among men who have sex with men and transgender women attending trusted community centers in Nigeria
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Background Knowledge of HIV risk factors and reduction strategies is essential for prevention in key populations such as men who have sex with men (MSM) and transgender women (TGW). We evaluated factors associated with HIV-related knowledge among MSM and TGW and the impact of engagement in care at trusted community health centers in Nigeria. Methods The TRUST/RV368 cohort recruited MSM and TGW in Lagos and Abuja, Nigeria via respondent driven sampling. During study visits every three months, participants underwent structured interviews to collect behavioral data, received HIV education, and were provided free condoms and condom compatible lubricants. Five HIV-related knowledge questions were asked at enrollment and repeated after 9 and 15 months. The mean number of correct responses was calculated for each visit with 95% confidence intervals (CIs). Multivariable Poisson regression was used to calculate adjusted risk ratios and CIs for factors associated with answering more knowledge questions correctly. Results From March 2013 to April 2018, 2122 persons assigned male sex at birth were enrolled, including 234 TGW (11.2%). The mean number of correct responses at enrollment was 2.36 (95% CI: 2.31–2.41) and increased to 2.95 (95% CI: 2.86–3.04) and 3.06 (95% CI: 2.97–3.16) after 9 and 15 months in the study, respectively. Among 534 participants who completed all three HIV-related knowledge assessments, mean number of correct responses rose from 2.70 (95% CI: 2.60–2.80) to 3.02 (95% CI: 2.93–3.13) and then 3.06 (95% CI: 2.96–3.16). Factors associated with increased overall HIV-related knowledge included longer duration of study participation, HIV seropositivity, higher education level, and more frequent internet use. Conclusions There was suboptimal HIV-related knowledge among Nigerian MSM and TGW at that improved modestly with engagement in care. These data demonstrate unmet HIV education needs among Nigerian MSM and TGW and provide insights into modalities that could be used to address these needs.
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MPRC People
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Hongjie Liu, Ph.D.
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Hongjie Liu Publications
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Social Influences on Drinking Trajectories From Adolescence to Young Adulthood in an Urban Minority Sample
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OBJECTIVE: Research on the heterogeneity in drinking patterns of urban minorities within a socioecological framework is rare. The purpose of this study was to explore multiple, distinct patterns of drinking from adolescence to young adulthood in a sample of urban minority youth and to examine the influence of neighborhood, family, and peers on these trajectories. METHOD: Data are from a longitudinal study of 584 (56% male) primarily Black (87%) youth who were first sampled in childhood based on their residence in low-income neighborhoods in Baltimore City and followed up annually through age 26. Data were analyzed using group-based trajectory modeling and multinomial logistic regression. RESULTS: Modeling revealed six trajectories from ages 14 to 26: abstainer, experimenter, adult increasing, young adult increasing, adolescent limited, and adolescent increasing. Neighborhood disadvantage was a risk factor for drinking regardless of the timing of onset. Perceptions of availability, peer drinking, and parental approval for drinking were risk factors for underage drinking trajectories, whereas parental supervision was a significant protective factor. Positive social activities in neighborhoods was protective against increased drinking, whereas a decline in perceptions of peer drinking was associated with adolescent-limited drinking. CONCLUSIONS: Our findings uniquely highlight the importance of developing interventions involving parents for urban minority youth for whom family is particularly relevant in deterring underage drinking. Perhaps most importantly, our data suggest that interventions that support positive social activities in disadvantaged neighborhoods are protective against adolescent drinking and altering perceptions of peer drinking may reduce adolescent drinking among low-income, urban minority youth.
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MPRC People
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Kerry Green, Ph.D.
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Kerry Green Publications
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Local Health Department Activities to Reduce Emergency Department Visits for Substance Use Disorders
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ABSTRACT: The Affordable Care Act (ACA) provides financial incentives to prevent substance use disorders (SUDs). Local health departments (LHDs) can receive funds to establish care teams that partner with primary care providers and health systems. This study estimates the potential effect of LHDs on emergency visits for SUDs, using linked data sets from the Healthcare Cost and Utilization Project Emergency Department (ED) sample for the State of Maryland-2012, the National Association of County and City Health Officials Profiles Survey 2013, and Area Health Resource File 2013 to estimate potential effect of LHDs' provision of SUD preventive care and SUD-related policy implementation. Local health department involvement in SUD-related policy during the past 2 years and provision of preventive care for behavioral health in the past year significantly reduced the probability of having a SUD-related ED visit by 11% and 6%, respectively, after controlling for individual characteristics (odds ratio [OR] = 0.89, p < .001; OR = 0.93, p < .001). After adjusting for the individual and contextual factors, LHD involvement in policy was still associated with 14% reduction in SUD-related ED visits (OR = 0.86, p < .001). Results offer insights on the extent to which the LHD activities can possibly affect SUD-related ED visits and provide a foundation for future work to identify effective LHD interventions.
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MPRC People
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Kerry Green, Ph.D.
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Kerry Green Publications
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Examining prevalence and correlates of cigarette and marijuana co-use among young adults using ten years of NHANES data
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Background Prior research has documented a strong association between cigarette and marijuana use among young adults; it is critical to study patterns and risk factors for co-use. Methods Appended, cross-sectional National Health and Nutrition Examination Survey (NHANES) data were used to assess prevalence and correlates of cigarette and marijuana co-use among young adults (ages 21–30) over a 10-year period (2005–2014). Respondents (unweighted sample = 4,948) were classified into four categories regarding past-month behavior: neither use, cigarette-only use, marijuana-only use, and co-use of both. Regression models were computed to predict these categories using three waves of NHANES (unweighted sample = 3,073). Results Prevalence of past-month cigarette use decreased from 30.9% in 2005–2006 to 23.7% in 2013–2014 (p = 0.024) while past-month marijuana use (average 18.0%) and past-month co-use (average 9.8%) remained stable during this time. Co-use differed significantly by gender (p < 0.001; average 12.9% men, 6.8% women). Co-users were less likely to be married, more likely to endorse non-Hispanic black racial identity, more likely to have engaged in non-marijuana drug use in their lifetime and more likely to drink alcohol monthly than cigarette-only users. Co-users were more likely to have depressive symptoms, ever use non-marijuana drugs, live with a smoker, and initiate marijuana at a younger age than marijuana-only users. Conclusions Co-use of cigarettes and marijuana remained stable but high over a ten-year period; understanding the unique characteristics, living situations, experiences, and substance use behaviors of co-users can contribute to more effective, tailored prevention and education strategies to reduce the burden of comorbid cigarette and marijuana use.
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MPRC People
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Kerry Green, Ph.D.
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Kerry Green Publications
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Current tobacco use, nicotine dependence, and transitions across stages of alcohol involvement: A latent transition analysis approach
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This study aims to examine the (a) probability of transition between stages of alcohol involvement and (b) influence of tobacco use and nicotine dependence on transitions. Data came from Waves 1 and 2 of the National Epidemiologic Survey on Alcohol and Related Conditions. Latent transition analysis estimated the probability of transitioning between stages of alcohol involvement across waves and the impact of tobacco use and nicotine dependence at Wave 1 on transitions. Males reporting current tobacco use but no dependence at Wave 1 were more likely to progress from No Problems to Moderate Problems (adjusted odds ratio [aOR] = 1.79; 95% confidence interval [CI] [1.44, 2.22]) and from No Problems to Severe Problems (aOR = 2.44; 95% CI [1.25, 4.77]) than nontobacco users. Females reporting current tobacco use but no dependence were more likely to progress from No Problems to Moderate Problems (aOR = 2.00; 95% CI [1.37, 2.94]) and from No Problems to Severe Problems (aOR = 2.87; 95% CI [1.34, 6.13]). Females reporting current tobacco use and dependence were more likely than females not using tobacco to transition from Moderate to No Problems (aOR = 2.10; 95% CI [1.04, 4.22]). Results suggest that tobacco use is a preceding correlate of progression in alcohol involvement among males and females. Among females, tobacco use and nicotine dependence are also related to alcohol involvement recovery.
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MPRC People
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Kerry Green, Ph.D.
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Kerry Green Publications
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Teen Mothers’ Family Support and Adult Identity in the Emerging Adulthood: Implications for Socioeconomic Attainment Later in Life
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We examined the prospective role of parental support and adult identity profiles in the transition to adulthood on teen mothers’ socioeconomic outcomes in adulthood. Analyses were based on the National Longitudinal Study of Adolescent to Adult Health, a nationally representative sample of youth followed over a decade. We used data from Waves 1, 3, and 4 (mean age = 28.6, Wave 4). Analytical sample consisted of 981 females who gave birth before age 20. Analysis included design-based regression models. Findings from adjusted regression models showed no statistically significant associations between teen mothers’ parental support and socioeconomic outcomes. While teen mothers have already achieved an important marker of adulthood, variability in adult identity profiles was observed. Teen mothers with older subjective age, regardless of their levels of psychosocial maturation, had higher socioeconomic attainment on some indicators. Findings suggest that teen mothers’ adult identity profiles differentiate their socioeconomic trajectories later in life.
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MPRC People
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Kerry Green, Ph.D.
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Kerry Green Publications
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Substance Use, Academic Performance, and Academic Engagement Among High School Seniors
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BACKGROUND: Substance use is prevalent and is associated with academic performance among adolescents. Few studies have examined the association between abstinence from all substances and academic achievement. METHODS: Data from a nationally representative sample of 9578 12th graders from the 2015 Monitoring the Future survey were analyzed to examine relationships between abstinence from substance use and 4 academic variables: skipping school, grades, academic self-efficacy, and emotional academic engagement. Participants were categorized as lifetime non-users, former users, and past-year users based on the use of 14 substances. RESULTS: Approximately one-fourth of participants had never used cigarettes, alcohol, or other drugs during their lifetime, and 8% wt used at least one substance during their lifetime but not during the past year. Adjusting for demographic variables, past-year substance users had 2.71 greater odds of skipping school during the past month than lifetime non-users and 1.74 greater odds of having low grades. Lifetime non-users reported greater academic self-efficacy and emotional academic engagement than past-year users. CONCLUSIONS: Many 12th graders have abstained from all substance use during their lifetime, and these adolescents experience better academic outcomes than their substance-using peers. Substance use prevention programs should be evaluated as a way to promote academic achievement.
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Craig Fryer, Dr.P.H.
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Craig Fryer Publications
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Correlates of Health Promotion in a Community Sample of African American Churches
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Though many African American churches offer health promotion activities to their members, less is known about organizational factors that predict the availability of this programming. This study examines organizational capacity as a predictor of the amount and type of health programming offered by a convenience sample of 119 African American churches. Leaders completed a survey of health promotion activities provided in the previous 12 months and a measure of organizational capacity. Churches offered an average of 6.08 (SD = 2.15) different health programs targeting 4.66 (SD = 3.63) topics. Allocation of space and having a health ministry were positively associated with both the number of health programs and health topics addressed. When seeking to initiate health programming in an African American church setting, it is recommended that stakeholders partner with churches that have existing structures to support health promotion such as a health ministry, or help them build this capacity.
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MPRC People
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Craig Fryer, Dr.P.H.
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Craig Fryer Publications