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Background: Previous research has identified differences in e-cigarette use and socioeconomic factors between different racial groups However, there is little research examining specific risk factors contributing to the racial differences. Objective: This study sought to identify racial disparities in e-cigarette use and to determine risk factors that help explain these differences. Methods: We used Wave 5 (2018–2019) of the Adult Population Assessment of Tobacco and Health (PATH) Study. First, we conducted descriptive statistics of e-smoking across our risk factor variables. Next, we used multiple logistic regression to check the risk effects by adjusting all covariates. Finally, we conducted a mediation analysis to determine whether identified factors showed evidence of influencing the association between race and e-cigarette use. All analyses were performed in R or SAS. The R package mma was used for the mediation analysis. Results: Between Hispanic and non-Hispanic White populations, our potential risk factors collectively explain 17.5% of the racial difference, former cigarette smoking explains 7.6%, receiving e-cigarette advertising 2.6%, and perception of e-cigarette harm explains 27.8% of the racial difference. Between non-Hispanic Black and non-Hispanic White populations, former cigarette smoking, receiving e-cigarette advertising, and perception of e-cigarette harm explain 5.2%, 1.8%, and 6.8% of the racial difference, respectively. E-cigarette use is most prevalent in the non-Hispanic White population compared to non-Hispanic Black and Hispanic populations, which may be explained by former cigarette smoking, exposure to e-cigarette advertising, and e-cigarette harm perception. Conclusions: These findings suggest that racial differences in e-cigarette use may be reduced by increasing knowledge of the dangers associated with e-cigarette use and reducing exposure to e-cigarette advertisements. This comprehensive analysis of risk factors can be used to significantly guide smoking cessation efforts and address potential health burden disparities arising from differences in e-cigarette usage.

Background: Studies in the United States are scarce that assess the survival differences between breast-conserving surgery plus radiation (Breast-Conserving Therapy; BCT) and mastectomy groups using population-based data while accounting for sociodemographic and clinical factors that affect the survival of women with early-stage breast cancer (ESBC). Objective: To assess whether BCT provides superior long-term overall survival (OS) and breast cancer-specific survival (BCSS) compared with mastectomy in women with ESBC, while considering key factors that impact survival. Design: Cohort study. Methods: We analyzed data on women aged 20 years and older diagnosed with stage I-II breast cancer (BC) in 2004 who received either BCT or mastectomy. The data were collected by 5 state cancer registries through the Centers for Disease Control and Prevention-funded Patterns of Care study. Multivariable Cox proportional hazard models, accounting for sociodemographic and clinical factors, were used to calculate hazard ratios (HRs) with 95% confidence intervals (CI). Sensitivity analysis involved optimal caliper propensity score (PS) matching to address residual confounding. Results: Of the 3495 women, 41.5% underwent mastectomy. The 10-year OS and BCSS were 82.7% and 91.1% for BCT and 72.3% and 85.7% for mastectomy, respectively. Adjusted models showed that mastectomy recipients had a 22% higher risk of all-cause deaths (ACD) (HR = 1.22, 95% CI = [1.06, 1.41]) and a 26% higher risk of breast cancer-specific deaths (BCD) (HR = 1.26, 95% CI = [1.02, 1.55]) than BCT recipients. Sensitivity analysis demonstrated that mastectomy was associated with a higher risk of ACD ( P

A mediation effect refers to the effect transmitted by a mediator intervening in the relationship between an exposure variable and a response variable. Mediation analysis is widely used to identify significant mediators and to make inferences on their effects. The Bayesian method allows researchers to incorporate prior information from previous knowledge into the analysis, deal with the hierarchical structure of variables, and estimate the quantities of interest from the posterior distributions. This paper proposes three Bayesian mediation analysis methods to make inferences on mediation effects. Our proposed methods are the following: (1) the function of coefficients method; (2) the product of partial difference method; and (3) the re-sampling method. We apply these three methods to explore racial disparities in the diagnostic age of breast cancer patients in Louisiana. We found that African American (AA) patients are diagnosed at an average of 4.37 years younger compared with Caucasian (CA) patients (57.40 versus 61.77, p< 0.0001). We also found that the racial disparity can be explained by patients’ insurance (12.90%), marital status (17.17%), cancer stage (3.27%), and residential environmental factors, including the percent of the population under age 18 (3.07%) and the environmental factor of intersection density (9.02%).

Abstract Background Breast‐conserving surgery plus radiation (BCT) yields equivalent or better survival than mastectomy for early‐stage breast cancer (ESBC) women. However, nationwide mastectomy trends increased in recent decades, attracting studies on underlying causes. Prior research identified that long distance to the radiation treatment facility (RTF) was associated with mastectomy. Still, it is unclear whether such association applies to young and old ESBC women comparably. We sought to delineate such impacts by age. Methods Women diagnosed with stages 0–II breast cancer in 2013–2017 receiving either BCT or mastectomy were identified from the Louisiana Tumor Registry. We assessed the association of surgery (mastectomy vs. BCT) with the distance to the nearest or nearest accessible RTFs using multivariable logistic regression adjusting the socio‐demographic and tumor characteristics. The nearest accessible RTF was determined based on patients' health insurance. For Medicaid, uninsured, and unknown insurance patients, the nearest accessible RTF is the nearest RTF owned by the government. The interaction effect of age and distance was evaluated as well. Results Of 11,604 patients, 46.7% received mastectomy. Compared with distance ≤5 miles to the nearest RTF, those with distance ≥40 miles or 15–40 miles had higher odds of mastectomy (adjusted (adj) OR = 1.39, 95% CI = 1.07–1.82; adj OR = 1.17, 95% CI = 1.02–1.34). To the nearest accessible RTF, the adj ORs were 1.25 (95% CI = 1.03–1.51) and 1.19 (95% CI = 1.04–1.35), respectively. Age‐stratified analysis showed the significant association (p

Objective:The aim of this study was to compare the tie wing fracture resistance of 4 different manufacturers’ ceramic brackets currently on the market.Methods:The tie wings of ceramic brackets from 4 manufacturers were tested with 10 samples in each group. The brackets were Ormco Symetri, 3M Clarity, American Radiance Plus, and Dentsply Ovation S. The brackets were mounted and fixed in a universal testing machine. A stainless steel ligature wire was looped around a tie wing and the mean tensile strength was both tested and recorded.Results:There was a significant overall difference in tensile strength among the 4 groups (P < .0001) with the 3M Clarity brackets having the highest MPa. When the groups were compared to each other, they also showed a significant difference in mean tensile strength with the exception being the American Radiance Plus and Ormco Symetri brackets.Conclusion:Test results concluded that the 3M Clarity brackets had the highest resistance to tie wing fracture, while the Dentsply Ovation S brackets had the lowest resistance.

OBJECTIVES/GOALS: Tobacco use remains a significant public health problem in rural America. Community health centers (CHCs) can help reduce the burden of tobacco use in rural areas, but we know little about their knowledge and implementation of best practices for tobacco control. This study assessed the knowledge and existence of tobacco control practices in rural CHCs. METHODS/STUDY POPULATION: Using a cross-sectional study design, we electronically surveyed health administrators and providers (n=64) in six rural CHCs in Louisiana between March 2021 and June 2023. The assessment measured 1) knowledge of the U.S. Public Health Service Clinical Practice Guideline for Treating Tobacco Use, 2) the priority given to smoking cessation programming, 3) the presence of best practices for tobacco control programming, such as having a tobacco control champion and team, 4) establishment of treatment and smoke-free campus policies, and 5) existence of referral procedure to external cessation services. We used descriptive statistics to characterize survey participants and responses. RESULTS/ANTICIPATED RESULTS: Most of the respondents were female (80%), White (61.8%), between 35 and 49 years of age (48.1%), and non-smokers (72.7%). Only half (51.6%) reported knowledge of the guideline for treating tobacco use among all respondents. Only a third (32.8%) said their health center gave smoking cessation high priority relative to other health priorities. Only a third (35.9%) reported having a tobacco champion; less than a fifth (18.8%) said they had a tobacco control team at their health center. Although all health centers had a smoke-free campus policy, about a quarter (23.4%) were unaware of the policy. Less than a quarter (23.4%) reported having a written policy for smoking cessation treatment at their health center, and less than half (46.7%) knew about cessation services to which they could refer patients. DISCUSSION/SIGNIFICANCE: Rural CHCs had limited knowledge of the guideline for tobacco use treatment. Smoking cessation lacked priority, and the prevalence of tobacco control best practices implementation was low. Rural CHCs must improve their implementation of guideline-recommend policies and clinical strategies to promote treatment and reduce the burden of tobacco use.

Background. The use of sports and energy drinks has drastically increased in the adolescent population. This population often is in orthodontic treatment, and the use of such drinks with poor oral hygiene promotes the development of white spot lesions (WSLs). Quantifying the degree of the lesion has been limited in the past. The hypothesis was that the Canary Caries Detection System could be used to quantify the degree of WSLs caused by different commercial beverages. Methods. A total of 105 extracted human premolars were divided into seven groups (n=15). Each group was tested in one of six beverages or a phosphate-buffered solution (control). The teeth were exposed to its beverage three times a day for 15 minutes for 28 days. Canary numbers and ambient light and fluorescent photographs were collected at baseline (T0 ) and on days 14 (T1 ) and 28 (T2 ). Results. The paired t test and one-way ANOVA found that T0 to T1 measurements were statistically significant (P

Introduction: At the completion of treatment, the orthodontic practitioner’s goal is to effectively remove all traces of adhesive and return enamel to its initial state. With the advent of new polishing systems being released each year, there may be one product that is superior to others. Aim: The purpose of this study is to determine the efficacy of new polishing systems (in the last 5–10 years) used in general dentistry on enamel surface roughness following debond utilizing profilometery and scanning electron microscopy and compare them to established orthodontic polishing systems results. Methods: Fifty-two mandibular incisors were randomly assigned to one of five test groups (N = 10) and two incisors (untreated enamel) were used for profilometer and scanning electron microscopy analysis at the end of testing. After bracket removal, the teeth were polished using traditional polishing products (Komet H48L bur, Reliance ‘Renew’ point) and newer polishing products (Coltene Spiral Composite Plus Polisher, Ultradent Jiffy Composite Polishing Spiral or 3M Sof-Lex™ Diamond Polishing System). The results were evaluated using a profilometer and scanning electron microscopy images. Results: The results of a one-way analysis of variance (ANOVA) determined that the mean change in enamel surface roughness was not statistically different both in the traditional and novel groups. Tukey’s Honestly Significant Difference (HSD) test found that there was no statistically significant difference in the change in enamel surface roughness between instrument groups. Conclusions: There was no statistically significant difference in enamel surface roughness after polishing between traditional orthodontic polishing systems and the selected novel polishing systems. SEM analysis revealed similar findings. This supports previous research suggesting that a wide variety of polishing systems or none at all, may be used to restore enamel smoothness after removal of orthodontic appliances.

Background: China is the largest tobacco producer and has the highest number of tobacco consumers in the world. Extensive research has demonstrated the utility of social media for smoking cessation. WeChat is the most commonly used social media platform in China, but has not yet been utilized for smoking cessation interventions. The objectives of this study are (1) to evaluate the efficacy of a WeChat-based smoking cessation intervention; and (2) to examine a possible additive effect of integrating oral health and smoking-related information into a tailored, Transtheoretical Model (TTM) guided smoking cessation intervention. Methods: Eligible adults were recruited through WeChat from July 1 to August 6, 2019, to participate in a 3-arm, single-blinded, randomized controlled trial. We enrolled and randomized 403 participants into three groups: the Standard Group, Enhanced Group, or a Waitlist-Control Group. Participants in the Standard Group received 20 smoking cessation-related messages for 2 weeks; participants in the Enhanced Group received this same protocol plus 6 oral health-related messages over an additional week. Participants in the Control Group received smoking cessation-related messages, after the post-intervention assessment. The primary outcome was TTM Stage of Change, and the secondary outcomes were 7-day Point Prevalence Abstinence (PPA), 24-h PPA, daily cigarette use, and nicotine dependence at 4 weeks follow-up post intervention, comparing intervention groups with the control group. The overall program attrition rate was 46%. Paired t-tests, McNemar tests, and linear and logistic regression were used to examine differences in smoking cessation outcomes within and between groups. Results: Participants in the Enhanced Group (β = −1.28, 95%CI: −2.13, −0.44) and the Standard Group (β = −1.13, 95%CI: −1.95, −0.30) reported larger changes in nicotine dependence scores, compared to participants in the Waitlist Group. No statistically significant differences were found between the Enhanced Group and the Standard Group. Discussion: This WeChat-based intervention was effective for smoking cessation overall. The addition of oral health information did not significantly improve the intervention.

OBJECTIVES/GOALS: Tobacco use remains a significant problem in rural America. Federally Qualified Health Centers (FQHCs) can help reduce the burden of tobacco use in rural areas. Still, we know little about center awareness and implementation of best practices for tobacco control. We assessed the knowledge and existence of tobacco control strategies in rural FQHCs. METHODS/STUDY POPULATION: We electronically surveyed health administrators and providers (n=33) in three rural Louisiana FQHCs between March and April 2021. The assessment measured awareness of the U.S. Public Health Service Clinical Practice Guideline for Treating Tobacco Use, center priority given to smoking cessation programming, the presence of best practices for tobacco control programming such as having a tobacco control champion and team, treatment and smoke-free campus policies, and referral to external cessation services. Descriptive statistics characterize survey respondents and responses. RESULTS/ANTICIPATED RESULTS: The majority of the respondents were female (88.5%), White (53.8%), between 35 and 54 years of age (69.2%), and non-smokers (65.4%). Among all respondents, 69.7% reported awareness of the U.S. Public Health Service Clinical Practice Guideline for Treating Tobacco Use. Less than half (48%) said their health center gave smoking cessation high priority relative to other health priorities. Only a third (36%) reported having a tobacco champion, and a quarter (25%) had a tobacco control team at their facility. Although all centers had a smoke-free campus policy, a quarter (27%) were unaware of the policy. Only a quarter (27%) reported having a written policy for smoking cessation treatment at their center, and a little more than half (56.7%) knew about cessation services to which they could refer tobacco users. DISCUSSION/SIGNIFICANCE: Centers had limited knowledge of the U.S. guideline for tobacco use treatment. Smoking cessation lacked priority, and tobacco control best practices implementation was low. FQHCs serving rural populations can implement guideline-recommend policies and clinical treatments, and future studies should test strategies to increase implementation.

Background:. Studies on symptomatic osteoarthritis suggest that Black patients report worse pain and symptoms compared with White patients with osteoarthritis. In this study, we aimed to quantify the relationship among variables such as overall health and socioeconomic status that may contribute to disparities in patient-reported outcomes. Methods:. A total of 223 patients were enrolled. A mediation analysis was used to evaluate cross-sectional associations between race and the Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaire, which was administered to patients prior to undergoing primary total knee arthroplasty. Results:. Black patients had worse KOOS pain, symptoms, and activities of daily living subscale scores than White patients. In our cohort, Black patients were younger, more likely to be female, and more likely to report lower educational status. We identified age, sex, Charlson Comorbidity Index, and education as partial mediators of racial disparities in KOOS subscale scores. Insurance status, deformity, radiographic (Kellgren-Lawrence) grade, C-reactive protein level, marital status, body mass index, and income did not show mediating effects. We found that, if age and sex were equal in both cohorts, the racial disparity in KOOS symptom scores would be reduced by 20.7% and 9.1%, respectively (95% confidence intervals [CIs], −5.1% to 47% and −5.5% to 26.3%). For KOOS pain scores, age and education level explained 18.9% and 5.1% of the racial disparity (95% CIs, −0.6% to 37% and −10.8% to 22.9%). Finally, for KOOS activities of daily living scores, education level explained 3.2% of the disparity (95% CI, −19.4% to 26.6%). Conclusions:. No single factor in our study completely explained the racial disparity in KOOS scores, but our findings did suggest that several factors can combine to mediate this disparity in outcome scores. Quantification of variables that mediate racial disparity can help to build models for risk adjustment, pinpoint vulnerable populations, and identify primary points of intervention. Level of Evidence:. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Research has shown cigarette smoking is a major risk factors for many type of cancer or cancer prognosis. Tobacco related health disparities were addressed continually in cancer screening, diagnosis, treatment, prevention and control. The present study evaluated the health disparities in attendance of smoking cessation counseling classes for 4,826 patients scheduled to attend between 2005 and 2007. Of 3,781 (78.4%) patients with records to calculate the distance from their home domicile to counseling sites using Geographic Information System technology, 1,435 (38%) of smokers who attended counseling had shorter travel distances to counseling sites (11.6 miles, SD = 11.29) compared to non-attendees (13.4 miles, SD = 16.72). When the travel distance was >20 miles, the estimated odds of attending decreased with greater travel distance. Smokers who actually attended were more likely to be older, female, White, living in urban areas, and receiving free healthcare. After controlling for other socio-demographic factors, shorter distances were associated with greater class attendance, and individuals more likely to attend included those that lived closer to the counseling site and in urban settings, were female, White, commercially insured, and older than their counterparts. These findings have the potential to provide important insights for reducing health disparities for cancer prevention and control, and to improve shared decision making between providers and smokers.

Abstract Background The aim of this study was to identify any associations between predictor variables, mainly clinician training and dental implant outcome, among the residents in different departments and to compare statistical analysis with the use of MATLAB R2017a™ to SAS version 9.4. Methods Dental records were reviewed from January 1, 2011, to December 31, 2015. Two thousand forty-eight dental implants were placed on 471 patients seen by residents from the departments of Periodontics, Prosthodontics, and Oral and Maxillofacial Surgery (OMFS) at Louisiana State University Health Sciences Center School of Dentistry. The following parameters were investigated by means of multilevel logistic regression analysis: demographics, implant parameters, department, and residents’ year of training. Results A total of 1449 implants were included in the study. Overall, within a 1–5-year time period, 1343 (92.6%) implants had survived and 106 (7.4%) implants failed. Discipline (p = 0.0004), residents’ year of training (p

Abstract Background Vulvovaginal candidiasis (VVC) is a common infection affecting women worldwide. Reports of patterns/risk factors/trends for episodic/recurrent VVC (RVVC) are largely outdated. The purpose of this study was to obtain current patient perspectives of several aspects of VVC/RVVC. Methods Business cards containing on-line survey information were distributed to healthy volunteers and patients seeking standard, elective, or referral gynecologic care in university-affiliated Obstetrics/Gynecology clinics. The internet-based questionnaire was completed by 284 non-pregnant women (78% Caucasian, 14% African American, 8% Asian). Results The majority of the participants (78%) indicated a history of VVC with 34% defined as having RVVC. The most common signs/symptoms experienced were itching, burning and redness with similar ranking of symptoms among VVC and RVVC patients. Among risk factors, antibiotic use ranked highest followed by intercourse, humid weather and use of feminine hygiene products. A high number of respondents noted ‘no known cause’ (idiopathic episodes) that was surprisingly similar among women with a history of either VVC or RVVC. VVC/RVVC episodes reported were primarily physician-diagnosed (73%) with the remainder mostly reporting self-diagnosis and treating with over-the-counter (OTC) medications. Most physician-diagnosed attacks utilized a combination of pelvic examination and laboratory tests followed by prescribed antifungals. Physician-treated cases achieved a higher level of symptom relief (84%) compared to those who self-medicated (57%). The majority of women with RVVC (71%) required continual or long-term antifungal medication as maintenance therapy to control symptoms. Conclusions Current patient perspectives closely reflect historically documented estimates of VVC/RVVC prevalence and trends regarding symptomatology, disease management and post-treatment outcomes.

Mediation analysis refers to the process of making inferences on effects of third variables that intervene in the relationship between an exposure and response variable. The relationships among variables can be modelled by generalized linear models (GLM). However, GLM are not sufficient to describe relationships among variables when there are nonlinear relationships and potential interaction effects. A general mediation analysis method was developed using not only GLMs, but also multiple additive regression trees and smoothing splines by Yu and Li (2017). The method is implemented in the R package, mma. In this paper, we developed SAS macros so that functions in the mma package can be called and the mediation analysis performed in the SAS environment. Funding statement: Research reported in this publication was supported by the National Institute On Minority Health And Health Disparities of the National Institutes of Health under Award Number R15MD012387. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Third-variable effect refers to the effect transmitted by third-variables that intervene in the relationship between an exposure and a response variable. Third-variable effect analysis has been broadly studied in many fields. However, it remains a challenge for researchers to differentiate indirect effect of individual factor from multiple third-variables, especially when the involving variables are of hierarchical structure. Yu et al. (2014) defined third-variable effects that were consistent for all different types of response (categorical or continuous), exposure, or third-variables. With these definitions, multiple third-variables can be considered simultaneously, and the indirect effects carried by individual third-variables can be separated from the total effect. In this paper, we extend the definitions of third-variable effects to multilevel data structures, where multilevel additive models are adapted to model the variable relationships. And then third-variable effects can be estimated at different levels. Moreover, transformations on variables are allowed to present nonlinear relationships among variables. We compile an R package mlma, to carry out the proposed multilevel third-variable analysis. Simulations show that the proposed method can effectively differentiate and estimate third-variable effects from different levels. Further, we implement the method to explore the racial disparity in body mass index accounting for both environmental and individual level risk factors.

Triple Negative Breast Cancer (TNBC) is an aggressive, heterogeneous subtype of breast cancer, which is more frequently diagnosed in African American (AA) women than in European American (EA) women. The purpose of this study is to investigate the role of social determinants in racial disparities in TNBC. Data on Louisiana TNBC patients diagnosed in 2010–2012 were collected and geocoded to census tract of residence at diagnosis by the Louisiana Tumor Registry. Using multilevel statistical models, we analyzed the role of neighborhood concentrated disadvantage index (CDI), a robust measure of physical and social environment, in racial disparities in TNBC incidence, stage at diagnosis, and stage-specific survival for the study population. Controlling for age, we found that AA women had a 2.21 times the incidence of TNBC incidence compared to EA women. Interestingly, the incidence of TNBC was independent of neighborhood CDI and adjusting for neighborhood environment did not impact the observed racial disparity. AA women were more likely to be diagnosed at later stages and CDI was associated with more advanced stages of TNBC at diagnosis. CDI was also significantly associated with poorer stage-specific survival. Overall, our results suggest that neighborhood disadvantage contributes to racial disparities in stage at diagnosis and survival among TNBC patients, but not to disparities in incidence of the disease. Further research is needed to determine the mechanisms through which social determinants affect the promotion and progression of this disease and guide efforts to improve overall survival.

Purpose: Over the past three decades, Hepatocellular Carcinoma (HCC) is one of few cancers for which incidence has increased in the United States (US). It is likely social determinants at the population level are driving this increase. We designed a population-based study to explore whether social determinants at the neighborhood level are geographically associated with HCC incidence in Louisiana by examining the association of HCC incidence with neighborhood concentrated disadvantage.Methods: Primary HCC cases diagnosed from 2008 to 2012 identified from the Louisiana Tumor Registry were geocoded to census tract of residence at the time of diagnosis. Neighborhood concentrated disadvantage index (CDI) for each census tract was calculated according to the PhenX Toolkit data protocol based on population and socioeconomic measures from the US Census. The incidence of HCC was modeled using multilevel binomial regression with individuals nested within neighborhoods.Results: The study included 1,418 HCC cases. Incidence of HCC was greater among males than females and among black than white. In multilevel models controlling for age, race, and sex, neighborhood CDI was positively associated with the incidence of HCC. A one standard deviation increase in CDI was associated with a 22% increase in HCC risk [Risk Ratio (RR) = 1.22; 95% CI (1.15, 1.31)]. Adjusting for contextual effects of an individual's neighborhood reduced the disparity in HCC incidence.Conclusion: Neighborhood concentrated disadvantage, a robust measure of an adverse social environment, was found to be a geographically associated with HCC incidence. Differential exposure to neighborhoods characterized by concentrated disadvantage partially explained the racial disparity in HCC for Louisiana. Our results suggest that increasing rates of HCC, and existing racial disparities for the disease, are partially explained by measures of an adverse social environment.

Mediation refers to the effect transmitted by mediators that intervene in the relationship between an exposure and a response variable. Mediation analysis has been broadly studied in many fields. However, it remains a challenge for researchers to consider complicated associations among variables and to differentiate individual effects from multiple mediators. [1] proposed general definitions of mediation effects that were adaptable to all different types of response (categorical or continuous), exposure, or mediation variables. With these definitions, multiple mediators of different types can be considered simultaneously, and the indirect effects carried by individual mediators can be separated from the total effect. Moreover, the derived mediation analysis can be performed with general predictive models. That is, the relationships among variables can be modeled using not only generalized linear models but also nonparametric models such as the Multiple Additive Regression Trees. Therefore, more complicated variable transformations and interactions can be considered in analyzing the mediation effects. The proposed method is realized by the R package 'mma'. We illustrate in this paper the proposed method and how to use 'mma' to estimate mediation effects and make inferences.

Background and objectives: Smoking is associated with a lower health-related quality of life (HRQOL). However, there is little information about the association between HRQOL in relation to race, income, and smoking status. The present study aimed to assess the association between HRQOL and smoking status for those of different races and income levels. Materials and Methods: This study applied a cross-sectional design using data from the 2017 patient survey of the Louisiana Tobacco Control Initiative. We obtained 1108 responses from patients at eight Louisiana public hospitals. The EuroQol (EQ-5D) US index score assessed HRQOL. Smoking status was classified into four groups: never smoked, former smoker, current smoker with a quit attempt, and current smoker without a quit attempt. Multivariate linear regression analyses were used to estimate the HRQOL for black or African Americans and whites. Results: The patients were predominantly black or African American (58.9%) with lower-income (71.2%). Bivariate analyses showed that there were differences in income levels between black or African Americans and whites (p = 0.006). Moreover, black or African Americans (median = 0.80) had a higher mean of HRQOL than whites (median = 0.76). Among lower-income black or African Americans, current smokers with a quit attempt had a lower HRQOL than current smokers (coefficient = −0.12; p < 0.01). Conclusions: Racial and income disparities were evident with regards to HRQOL, with lower-income black or African Americans who were current smokers with a quit attempt having a lower HRQOL. Intervention programs for smoking cessation should target lower-income black or African American smokers who have a prior quit attempt and provide effective cessation services to help them quit smoking and improve their HRQOL.

Many previous studies have suggested a link between alcohol outlets and assaultive violence. In this paper, we evaluate the impact of the “1992 Civil Unrest” in Los Angeles (which followed the “Rodney King incident”), in which many alcohol outlets were damaged leading to a decrease in alcohol outlet density, on crime. We leverage the natural experiment created by the closure of alcohol outlets in certain areas and not others to explore the effects of alcohol availability on assault crimes at the census tract level. We develop a hierarchical model that controls for important covariates (such as race and socio-economic status) and accounts for unexplained spatial and temporal variability. While our model is somewhat complex, its hierarchical Bayesian analysis is accessible via the WinBUGS software. Our results show that, keeping other effects fixed, the reduction in alcohol availability within a census tract was associated with a drop in the assaultive violence rate at the census tract level. Comparing several dual candidate changepoint models using the Deviance Information Criterion, the drop in assaultive violence rate is best seen as having occurred one year after the reduction in alcohol availability, with the effect lasting roughly five years. We also create maps of the fitted assault rates in Los Angeles, as well as spatial residual maps that suggest various spatially-varying covariates are still missing from our model.

ABSTRACT Objective: The objective of this study was to formulate experimental orthodontic bracket adhesives and test their mechanical properties, fluoride release and antibacterial activity. Methods: Four experimental antibacterial orthodontic bracket adhesives were prepared with different compositions of synthesized antibacterial monomers replacing total 5% of dental monomers in the control Transbond XT (3M): 5%C11, 3.5%C11+1.5%C2, 5%C16, and 3.5%C16+1.5%C2. Transbond XT alone was used as control. These groups were used to bond premolar brackets to extracted premolars. Shear bond strength (SBS) was tested using an Instron machine. For antibacterial test, disk specimens (10mm diameter, 1mm thick, n=4) were fabricated and incubated with cultures of cariogenic Streptococcus mutans for 48h, and following gentle sonication, S. mutans biofilms in colony-forming-units (CFU) on the disks were enumerated by plating on agar medium. The data were analyzed using ANOVA and Tukey test (α=0.05). Results: All experimental groups had similar shear bond strength (no significant difference) to the control. All experimental groups showed significant inhibitory effect against S. mutans biofilm formation, when compared to the control, but there was no significant difference between experimental groups. Conclusion: Antibacterial orthodontic adhesive can be fabricated to have similar mechanical properties but better caries-inhibitory effect than current adhesive.

The purpose of this pilot randomized controlled trial was to analyze and compare the effects of advanced platelet-rich fibrin (A-PRF) and plasma rich in growth factors (PRGF), combined with deproteinized bovine bone mineral (DBBM), in bone regeneration outcomes in maxillary sinus augmentation (MSA) procedures. The maxillary sinuses of 15 patients were grafted with DBBM alone (control group), DBBM mixed with A-PRF (PRF group), or DBBM mixed with PRGF (PRGF group). After a 6-month healing period, bone core biopsy samples were collected prior to implant placement for histologic and histomorphometric analyses, evaluating the mean percentages of mineralized tissue (MT), remaining bone graft material (RBGM), and nonmineralized tissue (NMT). Mean MT was 20.33% ± 11.50% for the control group, 32.20% ± 7.29% for the PRF group, and 34.80% ± 6.83% for the PRGF group. Mean RBGM was 24.00% ± 7.94% for the control group, 26.00% ± 7.78% for the PRF group, and 15.80% ± 8.23% for the PRGF group. Mean NMT was 55.66% ± 7.77% for the control group, 41.40% ± 8.32% for the PRF group, and 49.60% ± 5.68% for the PRGF group. No statistically significant differences (P > .05) were seen across the three groups for MT, RBGM, and NT. These findings suggest that adding A-PRF and PRGF to DBBM does not enhance new bone formation outcomes in maxillary sinus augmentation procedures. None of the two platelet concentrates were superior to the other in any of the variables assessed. [ABSTRACT FROM AUTHOR]