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Background: Burnout is common among residents and negatively impacts patient care and professional development. Residents vary in terms of their experience of burnout. Our objective was to employ cluster analysis, a statistical method of separating participants into discrete groups based on response patterns, to uncover resident burnout profiles using the exhaustion and engagement sub-scales of the Oldenburg Burnout Inventory (OLBI) in a cross-sectional, multispecialty survey of United States medical residents. Methods: The 2017 ACGME resident survey provided residents with an optional, anonymous addendum containing 3 engagement and 3 exhaustion items from the OBLI, a 2-item depression screen (PHQ-2), general queries about health and satisfaction, and whether respondents would still choose medicine as a career. Gaussian finite mixture models were fit to exhaustion and disengagement scores, with the resultant clusters compared across PHQ-2 depression screen results. Other variables were used to demonstrate evidence for the validity and utility of this approach. Results: From 14 088 responses, 4 clusters were identified as statistically and theoretically distinct: Highly Engaged (25.8% of respondents), Engaged (55.2%), Disengaged (9.4%), and Highly Exhausted (9.5%). Only 2% of Highly Engaged respondents screened positive for depression, compared with 8% of Engaged respondents, 29% of Disengaged respondents, and 53% of Highly Exhausted respondents. Similar patterns emerged for the general query about health, satisfaction, and whether respondents would choose medicine as a career again. Conclusion: Clustering based on exhaustion and disengagement scores differentiated residents into 4 meaningful groups. Interventions that mitigate resident burnout should account for differences among clusters.
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BACKGROUND: Recent studies have challenged the reported causal association between acute kidney injury and iodinated contrast administration, ascribing some cases to changes in renal function that are independent of contrast administration. METHODS: We studied 1779 consecutive patients undergoing right heart catheterization (RHC) at a Veterans Administration Medical Center. We compared the incidence of acute kidney injury and of nephropathy at 3 months in veterans undergoing right and left heart catheterization and coronary angiography (R&LHC) to the incidence of acute kidney injury and of nephropathy at 3 months in patients undergoing RHC only. RESULTS: The incidence of acute kidney injury at 3 days was 47 (9.7%) in the R&LHC group and 58 (9.6%) in the RHC group (P = .99). The incidence of nephropathy at 3 months was 115 (17%) in the L&RHC group and 141 (19.2%) in the RHC group (P = 0.31). In a propensity score-paired analysis of 782 patients and after adjustment for baseline characteristics, the odds ratio for acute kidney injury at 3 days among patients undergoing R&LHC was 1.25 (95% confidence interval, 0.65-2.42; P = .50), and the odds ratio for nephropathy at 3 months was 0.69 (95% confidence interval, 0.46-1.04; P = .08). CONCLUSION: The incidence of changes in creatinine consistent with acute kidney injury at 3 days and of nephropathy at 3 months was not significantly different in patients undergoing R&LHC compared with patients undergoing RHC only. This supports the thesis that not all changes in creatinine after procedures involving administration of contrast are caused by the contrast.
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Lesión Renal Aguda , Cateterismo Cardíaco , Medios de Contraste , Angiografía Coronaria , Humanos , Lesión Renal Aguda/epidemiología , Lesión Renal Aguda/etiología , Cateterismo Cardíaco/efectos adversos , Masculino , Angiografía Coronaria/efectos adversos , Angiografía Coronaria/métodos , Femenino , Anciano , Persona de Mediana Edad , Medios de Contraste/efectos adversos , Incidencia , Estudios RetrospectivosRESUMEN
BACKGROUND: Assessment of the Core Entrustable Professional Activities for Entering Residency requires direct observation through workplace-based assessments (WBAs). Single-institution studies have demonstrated mixed findings regarding the reliability of WBAs developed to measure student progression towards entrustment. Factors such as faculty development, rater engagement and scale selection have been suggested to improve reliability. The purpose of this investigation was to conduct a multi-institutional generalisability study to determine the influence of specific factors on reliability of WBAs. METHODS: The authors analysed WBA data obtained for clerkship-level students across seven institutions from 2018 to 2020. Institutions implemented a variety of strategies including selection of designated assessors, altered scales and different EPAs. Data were aggregated by these factors. Generalisability theory was then used to examine the internal structure validity evidence of the data. An unbalanced cross-classified random-effects model was used to decompose variance components. A phi coefficient of >0.7 was used as threshold for acceptable reliability. RESULTS: Data from 53 565 WBAs were analysed, and a total of 77 generalisability studies were performed. Most data came from EPAs 1 (n = 17 118, 32%) 2 (n = 10 237, 19.1%), and 6 (n = 6000, 18.5%). Low variance attributed to the learner (<10%) was found for most (59/77, 76%) analyses, resulting in a relatively large number of observations required for reasonable reliability (range = 3 to >560, median = 60). Factors such as DA, scale or EPA were not consistently associated with improved reliability. CONCLUSION: The results from this study describe relatively low reliability in the WBAs obtained across seven sites. Generalisability for these instruments may be less dependent on factors such as faculty development, rater engagement or scale selection. When used for formative feedback, data from these instruments may be useful. However, such instruments do not consistently provide reasonable reliability to justify their use in high-stakes summative entrustment decisions.
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Competencia Clínica , Evaluación Educacional , Lugar de Trabajo , Humanos , Evaluación Educacional/métodos , Reproducibilidad de los Resultados , Competencia Clínica/normas , Estudiantes de Medicina/psicología , Educación Basada en Competencias , Internado y Residencia , Prácticas ClínicasRESUMEN
OBJECTIVE: Although headache (HA) is a common sequela of traumatic brain injury (TBI), early predictors of chronic HA after moderate to severe TBI are not well established, and the relationship chronic HA has with psychosocial functioning is understudied. Thus, we sought to (1) determine demographic and injury predictors of chronic HA 1 or more years after moderate to severe TBI and (2) examine associations between chronic HA and psychosocial outcomes. SETTING: Community. PARTICIPANTS: Participants in the TBI Model System (TBIMS) with moderate to severe TBI who consented for additional chronic pain questionnaires at the time of TBIMS follow-up. DESIGN: Multisite, observational cohort study using LASSO (least absolute shrinkage and selection operator) regression for prediction modeling and independent t tests for psychosocial associations. MAIN OUTCOME MEASURES: Chronic HA after TBI at year 1 or 2 postinjury and more remotely (5 or more years). RESULTS: The LASSO model for chronic HA at 1 to 2 years achieved acceptable predictability (cross-validated area under the curve [AUC] = 0.70). At 5 or more years, predictability was nearly acceptable (cross-validated AUC = 0.68), but much more complex, with more than twice as many variables contributing. Injury characteristics had stronger predictive value at postinjury years 1 to 2 versus 5 or more years, especially sustained intracranial pressure elevation (odds ratio [OR] = 3.8) and skull fragments on head computed tomography (CT) (OR = 2.5). Additional TBI(s) was a risk factor at both time frames, as were multiple socioeconomic characteristics, including lower education level, younger age, female gender, and Black race. Lower education level was a particularly strong predictor at 5 or more years (OR up to 3.5). Emotional and participation outcomes were broadly poorer among persons with chronic HA after moderate to severe TBI. CONCLUSIONS: Among people with moderate to severe TBI, chronic HA is associated with significant psychosocial burden. The identified risk factors will enable targeted clinical screening and monitoring strategies to enhance clinical care pathways that could lead to better outcomes. They may also be useful as stratification or covariates in future clinical trial research on treatments.
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Lesiones Traumáticas del Encéfalo , Lesiones Encefálicas , Trastornos de Cefalalgia , Humanos , Femenino , Lesiones Encefálicas/psicología , Lesiones Traumáticas del Encéfalo/complicaciones , Lesiones Traumáticas del Encéfalo/diagnóstico , Estudios de Cohortes , Cefalea , Trastornos de Cefalalgia/complicacionesRESUMEN
Researchers are often interested in examining between-individual differences in within-individual processes. If the process under investigation is tracked for a long time, its trajectory may show a certain degree of nonlinearity, so that the rate of change is not constant. A fundamental goal of modeling such nonlinear processes is to estimate model parameters that reflect meaningful aspects of change, including the parameters related to change and other parameters that shed light on substantive hypotheses. However, if the measurement occasion is unstructured, existing models cannot simultaneously estimate these two types of parameters. This article has three goals. First, we view the change over time as the area under the curve (AUC) of the rate of change versus time ( r - t ) graph. Second, using the instantaneous rate of change midway through a time interval to approximate the average rate of change during that interval, we propose a new specification to describe longitudinal processes. In addition to obtaining the individual change-related parameters and other parameters related to specific research questions, the new specification allows for unequally spaced study waves and individual measurement occasions around each wave. Third, we derive the model-based interval-specific change and change from baseline, two common measures to evaluate change over time. We evaluate the proposed specification through a simulation study and a real-world data analysis. We also provide OpenMx and Mplus 8 code for each model with the novel specification.
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Individualidad , Modelos Estadísticos , Humanos , Simulación por ComputadorRESUMEN
Research documents racial disparities in chronic low back pain (CLBP). Few studies have examined racial disparities in movement-related appraisals and no studies have examined anticipatory appraisals prior to or pain behaviors during functional activities among individuals with CLBP. This cross-sectional study examined racial differences in anticipatory appraisals of pain, concerns about harm, and anxiety, appraisals of pain and anxiety during movement, and observed pain behaviors during 3 activities of daily living (supine-to-standing bed task, sitting-to-standing chair task, floor-to-waist lifting task) in a sample (N = 126) of non-Hispanic Black (31.0%), Hispanic (30.2%), and non-Hispanic White (38.9%) individuals with CLBP. Hispanic participants reported more expected pain, concerns about harm, and pre-movement anxiety prior to the bed and chair tasks compared to non-Hispanic White participants. Hispanic participants reported more pain during the bed task and more anxiety during the bed and chair tasks compared to non-Hispanic White participants. Non-Hispanic Black participants reported more expected pain, concerns about harm, and pre-movement anxiety prior to the bed task and more pre-movement anxiety prior to the chair task compared to non-Hispanic White participants. Non-Hispanic Black participants reported more anxiety during the bed and chair tasks compared to non-Hispanic White participants. Non-Hispanic Black participants were observed to have significantly more verbalizations of pain during the bed task compared to non-Hispanic White participants. Current findings identify racial disparities in important cognitive-behavioral and fear-avoidance mechanisms of pain. Results indicate a need to revisit traditional theoretical and treatment models in CLBP, ensuring racial disparities in pain cognitions are considered. PERSPECTIVE: This study examined racial disparities in anticipatory and movement-related appraisals, and pain behaviors during activities of daily living among Non-Hispanic Black, Non-Hispanic White, and Hispanic individuals with CLBP. Racial disparities identified in the current study have potentially important theoretical implications surrounding cognitive-behavioral and fear-avoidance mechanisms of pain.
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Objective: Long-term changes to EEG spectra after mild traumatic brain injury (mTBI, i.e., concussion) have been reported; however, the role of injury characteristics in long-term EEG changes is unclear. It is also unclear how any chronic EEG changes may underlie either subjective or objective cognitive difficulties, which might help explain the variability in recovery after mTBI. Methods: This study included resting-state high-density electroencephalography (EEG) and mTBI injury data from 340 service members and veterans collected on average 11 years after injury as well as measures of objective and subjective cognitive functioning. The average absolute power within standard bands was computed across 11 spatial regions of the scalp. To determine how variation in brain function was accounted for by injury characteristics and aspects of cognition, we used regression analyses to investigate how EEG power was predicted by mTBI history characteristics [number, number with post-traumatic amnesia and witnessed loss of consciousness (PTA + LOC), context of injury (combat or non-combat), potentially concussive blast exposures], subjective complaints (TBIQOL General Cognitive and Executive Function Concerns), and cognitive performance (NIH Toolbox Fluid Intelligence and premorbid IQ). Results: Post-traumatic amnesia (PTA) and loss of consciousness (LOC), poorer cognitive performance, and combat experience were associated with reduced power in beta frequencies. Executive function complaints, lower premorbid IQ, poorer cognitive performance, and higher psychological distress symptoms were associated with greater power of delta frequencies. Multiple regression confirmed the relationship between PTA + LOC, poor cognitive performance, cognitive complaints, and reduced power in beta frequencies and revealed that repetitive mTBI was associated with a higher power in alpha and beta frequencies. By contrast, neither dichotomous classification of the presence and absence of mTBI history nor blast exposures showed a relationship with EEG power variables. Conclusion: Long-term alterations in resting EEG spectra measures of brain function do not appear to reflect any lasting effect of a history of mTBI or blast exposures. However, power in higher frequencies reflects both injury characteristics and subjective and objective cognitive difficulties, while power in lower frequencies is related to cognitive functions and psychological distress associated with poor long-term outcomes after mTBI.
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Growth mixture modeling (GMM) is an analytical tool for identifying multiple unobserved sub-populations in longitudinal processes. In particular, it describes change patterns within each latent sub-population and investigates between-individual differences in within-individual change for each sub-group. A key research interest in using GMMs is examining how covariates influence the heterogeneity in change patterns. Liu & Perera (2022b) extended mixture-of-experts (MoE) models, which primarily focus on time-invariant covariates, to allow covariates to account for both within-group and between-group differences and investigate the heterogeneity in nonlinear trajectories. The present study further extends Liu & Perera, 2022b by examining the effects of time-varying covariates (TVCs) on trajectory heterogeneity. Specifically, we propose methods to decompose a TVC into an initial trait (the baseline value of the TVC) and a set of temporal states (interval-specific slopes or changes of the TVC). The initial trait is allowed to account for within-group differences in growth factors of trajectories (i.e., baseline effect), while the temporal states are allowed to impact observed values of a longitudinal process (i.e., temporal effects). We evaluate the proposed models using a simulation study and real-world data analysis. The simulation study demonstrates that the proposed models are capable of separating trajectories into several clusters and generally producing unbiased and accurate estimates with target coverage probabilities. The proposed models reveal the heterogeneity in initial trait and temporal states of reading ability across latent classes of students' mathematics performance. Additionally, the baseline and temporal effects on mathematics development of reading ability are also heterogeneous across the clusters of students.
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PURPOSE/OBJECTIVE: Examine contributors to resilience among caregivers of individuals who have sustained a moderate-to-severe traumatic brain injury (TBI), with the goal of identifying important targets for an intervention to improve caregiver resilience as well as outcomes for people with TBI. RESEARCH METHOD/DESIGN: Participants were adult caregivers (n = 176) and individuals with TBI who required inpatient rehabilitation at six TBI Model System sites. Measures included the Connor-Davidson Resilience Scale-10, Family Needs Questionnaire, Zarit Burden Interview, Patient Health Questionnaire-9, and Generalized Anxiety Disorder-7. Data were collected between September 2018 and June 2021. RESULTS: Caregivers endorsed levels of personal resilience that were comparable to norms for community samples and slightly higher than groups under stress or with medical illness. Reports of the burden associated with the caregiving role were relatively low, as was reported psychological distress. In a multivariable model, higher proportions of met emotional support needs were associated with increased resilience. CONCLUSIONS/IMPLICATIONS: Resilience may be strengthened by emotional support networks, including friends or family who may not already be directly involved in the provision of care. Supporting engagement with community agencies, peer mentors, or other informal resources within the family system that provide emotional support may bolster resilience outcomes for caregivers. (PsycInfo Database Record (c) 2023 APA, all rights reserved).
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Lesiones Traumáticas del Encéfalo , Cuidadores , Adulto , Humanos , Cuidadores/psicología , Lesiones Traumáticas del Encéfalo/psicología , Trastornos de Ansiedad , Encuestas y Cuestionarios , Pacientes Internos , Adaptación PsicológicaRESUMEN
BACKGROUND: Genetic counseling and testing (GCT) informs risk reduction and management strategies in women at risk for carrying a pathogenic variation in the BRCA1 or BRCA2 (BRCA1/2) genes. African American (hereinafter referred to as Black) women are less likely to receive GCT services for hereditary breast and ovarian cancer (HBOC). The objective of this work was to examine existing literature regarding successful culturally tailored GCT interventions for Black women and to describe the rationale and protocol for a randomized feasibility trial to test the efficacy of a culturally tailored GCT intervention. METHODS/DESIGN: The For Our Health (FOH) study is a two-arm randomized control trial designed to test the efficacy of a video intervention to promote the uptake of GCT among Black women with a high risk of HBOC. The culturally tailored video intervention targets key beliefs, knowledge gaps, misconceptions, and key anticipated emotions relevant for GCT. After completing the baseline survey, 50 women at risk of HBOC will be randomized (1:1) to one of two trial arms: a YouTube video intervention or a publicly available fact sheet. Final assessments will immediately follow receipt of either video or fact sheet. CONCLUSION: Few studies have tested interventions to improve GCT uptake among Black women. The FOH trial will fill an important scientific gap in knowledge regarding strategies to reduce disparities in GCT among Black women at risk of HBOC.
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Neoplasias de la Mama , Neoplasias Ováricas , Femenino , Humanos , Negro o Afroamericano , Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias de la Mama/psicología , Asesoramiento Genético/psicología , Pruebas Genéticas , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
Background: The vaginal microbiome (VMB) plays an important role in the persistence of human papillomavirus (HPV) infection and differs by race and among women with cervical intraepithelial neoplasia (CIN). Materials and Methods: We explored these relationships using 16S rRNA VMB taxonomic profiles of 3050 predominantly Black women. VMB profiles were assigned to three subgroups based on taxonomic markers indicative of vaginal wellness: optimal (Lactobacillus crispatus, L. gasseri, and L. jensenii), moderate (L. iners), and suboptimal (Gardnerella vaginalis, Atopobium vaginae, Ca. Lachnocurva vaginae, and others). Multivariable Firth logistic regression models were adjusted for age, smoking, VMB, HPV, and pregnancy status. Results: VMB prevalence by subgroup was 18%, 30%, and 51% for the optimal, moderate, and suboptimal groups, respectively. In fully adjusted models, the risk of CIN grade 3 (CIN3) among non-Latina (nL) Blacks was twice that of nL Whites (odds ratio [OR] = 2.0, 95% confidence interval [CI]: 1.1, 3.9, p = 0.02). The VMB modified this association (p = 0.04) such that the risk of CIN3 was significantly higher for nL Blacks than for nL Whites only among women with optimal VMBs (OR = 7.8, 95% CI: 1.7, 74.5, p = 0.007). Within racial groups, the risk of CIN3 was only elevated among nL White women with suboptimal VMBs (OR = 6.0, 95% CI: 1.3, 56.9, p = 0.02) compared with their racial counterparts with optimal VMBs. Conclusions: Our findings suggest that race is a modifier of the VMB in HPV carcinogenesis. An optimal VMB does not appear to be protective for nL Black women compared with nL White women.
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Microbiota , Infecciones por Papillomavirus , Displasia del Cuello del Útero , Femenino , Embarazo , Humanos , ARN Ribosómico 16S/genética , Vagina , Displasia del Cuello del Útero/epidemiologíaRESUMEN
Almost always, developmental processes are multivariate in nature such that several outcomes and the development among these variables are correlated; therefore, empirical researchers often desire to examine two or more variables over time to understand how these outcomes and their change patterns are correlated. Multivariate growth models (MGMs) allow researchers to examine the correlations among developmental parameters. This study relaxes one population assumption of MGMs to investigate possible latent classes of joint development. The developed model enables the investigation of heterogeneity in the correlation between longitudinal outcomes and the effect of covariates on heterogeneity. More importantly, we propose using the piecewise linear functional form to estimate the stage-specific growth rates and stage-specific correlations. We demonstrate the proposed model through a simulation study and an analysis of real-world data. Our simulation study shows that the proposed model can separate joint development into multiple latent classes and provide unbiased and accurate point estimates with target coverage probabilities for the parameters of interest. Using longitudinal reading and mathematics scores from Grade K to 5, we demonstrate that the proposed model can capture heterogeneity in the correlation between joint development and estimate the stage-specific correlations. Additionally, we demonstrate how to identify the covariates that contribute the most to latent classes and transform candidate covariates from a large set to a manageable set while retaining the meaningful properties of the original covariate set for the mixture model with joint developmental processes. (PsycInfo Database Record (c) 2023 APA, all rights reserved).
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Researchers are usually interested in examining the impact of covariates when separating heterogeneous samples into latent classes that are more homogeneous. The majority of theoretical and empirical studies with such aims have focused on identifying covariates as predictors of class membership in the structural equation modeling framework. In other words, the covariates only indirectly affect the sample heterogeneity. However, the covariates' influence on between-individual differences can also be direct. This article presents a mixture model that investigates covariates to explain within-cluster and between-cluster heterogeneity simultaneously, known as a mixture-of-experts (MoE) model. This study aims to extend the MoE framework to investigate heterogeneity in nonlinear trajectories: to identify latent classes, covariates as predictors to clusters, and covariates that explain within-cluster differences in change patterns over time. Our simulation studies demonstrate that the proposed model generally estimates the parameters unbiasedly, precisely, and exhibits appropriate empirical coverage for a nominal 95% confidence interval. This study also proposes implementing structural equation model forests to shrink the covariate space of the proposed mixture model. We illustrate how to select covariates and construct the proposed model with longitudinal mathematics achievement data. Additionally, we demonstrate that the proposed mixture model can be further extended in the structural equation modeling framework by allowing the covariates that have direct effects to be time-varying. (PsycInfo Database Record (c) 2023 APA, all rights reserved).
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Modelos Teóricos , Humanos , Simulación por Computador , Análisis de Clases LatentesRESUMEN
Longitudinal processes often unfold concurrently where the growth patterns of two or more longitudinal outcomes are associated. Additionally, if the study under investigation is long, the growth curves may exhibit nonconstant change with respect to time. Multiple existing studies have developed multivariate growth models with nonlinear functional forms to explore joint development where two longitudinal records are correlated over time. However, the relationship between multiple longitudinal outcomes may also be unidirectional. Accordingly, it is of interest to estimate regression coefficients of such unidirectional paths. One statistical tool for such analyses is longitudinal mediation models. In this study, we develop two models to evaluate mediational processes where the linear-linear piecewise functional form is utilized to capture the change patterns. We define the mediational process as either the baseline covariate or the change in covariate influencing the change in the mediator, which, in turn, affects the change in the outcome. We present the proposed models through simulation studies and real-world data analyses. Our simulation studies demonstrate that the proposed mediational models can provide unbiased and accurate point estimates with target coverage probabilities with a 95% confidence interval. The empirical analyses demonstrate that the proposed models can estimate covariates' direct and indirect effects on the change in the outcome. We also provide the corresponding code for the proposed models.
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Modelos Estadísticos , Humanos , Modelos Lineales , Simulación por Computador , Probabilidad , Estudios LongitudinalesRESUMEN
OBJECTIVE: Racial discrimination is a stressor for young Black women that leads to poor health outcomes, including maladaptive eating. This study presents findings on racial discrimination and maladaptive eating behaviors (overeating, LOC eating) using ecological momentary assessment (EMA). METHODS: Black emerging adult women (N = 27) with overweight or obesity participated in a 14-day EMA study examining exposure to racial discrimination, eating behaviors, and racial identity. Frequencies and chi-square tests were used to characterize the type of racial discrimination experienced and frequency of overeating. Mixed effect ordinal logistic regression models were used to assess the relation between racial discrimination and maladaptive eating. Moderation analysis was conducted by creating interaction terms for discrimination and racial identity variables. RESULTS: 81.5% of participants reported experiencing racial discrimination. Young Black women reporting exposure to racial discrimination were more likely to endorse higher levels of both overeating and LOC eating compared to times when discrimination was not experienced (p < .0001). Racial identity moderated the link between racial discrimination and maladaptive eating (overeating, LOC) such that reporting greater levels of private regard buffered the deleterious effect of racial discrimination. Higher levels of public regard exacerbated the association between racial discrimination and both overeating, and LOC. Higher centrality worsened the relation between racial discrimination and LOC. CONCLUSION: Young Black women might use maladaptive eating to cope with exposure to racial discrimination, which underscores the importance of examining the link between racism and disordered eating, particularly among Black women submerged in a society that continuously exposes them to racial discrimination. PUBLIC SIGNIFICANCE: Emerging adult Black women are exposed to racial discrimination daily. In theory, exposure to racial discrimination could contribute to overeating and loss of control eating in this population. Using ecological momentary assessment, to capture experiences and eating behaviors in the moment they occur, this project quantified the magnitude of racial discrimination and how it was associated with maladaptive eating behaviors. Further, it examined ways in which racial identity was linked to this association.
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Racismo , Femenino , HumanosRESUMEN
PRIMARY OBJECTIVE: While repetitive transcranial magnetic stimulation (rTMS) has shown efficacy for cognitive difficulties accompanying depression, it is unknown if it can improve cognition in persons with traumatic brain injury. RESEARCH DESIGN: Using a sham-controlled crossover design, we tested the capacity of high frequency rTMS of the prefrontal cortex to improve neuropsychological performance in attention, learning and memory, and executive function. METHODS: Twenty-six participants with cognitive complaints and a history of mild-to-moderate traumatic brain injury were randomly assigned to receive first either active or sham 10 Hz stimulation for 20 minutes (1200 pulses) per session for five consecutive days. After a one-week washout, the other condition (active or sham) was applied. Pre- and post-treatment measures included neuropsychological tests, cognitive and emotional symptoms, and EEG. MAIN OUTCOMES AND RESULTS: Results indicated no effect of treatment on cognitive function. Subjective measures of depression, sleep dysfunction, post-concussive symptoms (PCS), and executive function showed significant improvement with stimulation, retaining improved levels at two-week follow-up. EEG delta power exhibited elevation one week after stimulation cessation. CONCLUSIONS: While there is no indication that rTMS is beneficial for neuropsychological performance, it may improve PCS and subjective cognitive dysfunction. Long-term alterations in cortical oscillations may underlie the therapeutic effects of rTMS.
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Lesiones Traumáticas del Encéfalo , Estimulación Magnética Transcraneal , Lesiones Traumáticas del Encéfalo/complicaciones , Lesiones Traumáticas del Encéfalo/terapia , Electroencefalografía , Humanos , Pruebas Neuropsicológicas , Corteza Prefrontal/fisiología , Estimulación Magnética Transcraneal/métodos , Resultado del TratamientoRESUMEN
BACKGROUND: Mitochondrial health is an important predictor of several health-related comorbidities including obesity, type 2 diabetes mellitus, and cardiovascular disease. In persons with spinal cord injury (SCI), mitochondrial health has been linked to several important body composition and metabolic parameters. However, the complex interplay of how mitochondrial health is affected has yet to be determined in this population. OBJECTIVE: In this study, we examined the contribution of visceral adiposity, inflammatory biomarkers, testosterone and circulating serum growth factors as predictors of mitochondrial health in persons with chronic SCI. PARTICIPANTS: Thirty-three individuals with chronic SCI (n = 27 Males, n = 6 Females, age: 40 ± 13.26 years, level of injury: C4-L1, BMI: 23 ± 5.57) participated in this cross-sectional study. METHODS: Visceral adipose tissue (VAT) was measured via magnetic resonance imaging (MRI). After an overnight fast, serum testosterone, inflammatory biomarkers [interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), c-reactive protein (CRP)], and anabolic growth factors [insulin-like growth factor 1 (IGF-1), insulin-like growth factor binding protein 3 (IGFBP-3)] were measured. Skeletal muscle biopsies were obtained from the vastus lateralis muscle to measure citrate synthase (CS) and Complex III activity. Regression analyses were used to examine predictors of mitochondrial mass and activity. RESULTS: CS activity was negatively associated with VAT (r 2 = 0.360, p < 0.001), CRP (r 2 = 0.168, p = 0.047), and positively associated with testosterone (r 2 = 0.145, p = 0.042). Complex III activity was negatively associated with VAT relative to total lean mass (VAT:TLM) (r 2 = 0.169, p = 0.033), trended for CRP (r 2 = 0.142, p = 0.069), and positively associated with testosterone (r 2 = 0.224, p = 0.010). Multiple regression showed CS activity was significantly associated with VAT + CRP (r 2 = 0.412, p = 0.008) and VAT + Testosterone (r 2 = 0.433, p = 0.001). Complex III activity was significantly associated with VAT relative to total trunk cross-sectional area (CSA) + CRP (VAT:total trunk CSA + CRP; r 2 = 0.286, p = 0.048) and VAT + Testosterone (r 2 = 0.277, p = 0.024). CONCLUSION: Increased visceral adiposity and associated inflammatory signaling (CRP) along with reduced testosterone levels predict mitochondrial dysfunction following SCI. Specifically, lower VATCSA and higher testosterone levels or lower VATCSA and lower CRP levels positively predict mitochondrial mass and enzyme activity in persons with chronic SCI. Future research should investigate the efficacy of diet, exercise, and potentially testosterone replacement therapy on enhancing mitochondrial health in chronic SCI. CLINICAL TRIAL REGISTRATION: [www.ClinicalTrials.gov], identifier: [NCT02660073].
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Latent growth curve models with spline functions are flexible and accessible statistical tools for investigating nonlinear change patterns that exhibit distinct phases of development in manifested variables. Among such models, the bilinear spline growth model (BLSGM) is the most straightforward and intuitive but useful. An existing study has demonstrated that the BLSGM allows the knot (or change-point), at which two linear segments join together, to be an additional growth factor other than the intercept and slopes so that researchers can estimate the knot and its variability in the framework of individual measurement occasions. However, developmental processes usually unfold in a joint development where two or more outcomes and their change patterns are correlated over time. As an extension of the existing BLSGM with an unknown knot, this study considers a parallel BLSGM (PBLSGM) for investigating multiple nonlinear growth processes and estimating the knot with its variability of each process as well as the knot-knot association in the framework of individual measurement occasions. We present the proposed model by simulation studies and a real-world data analysis. Our simulation studies demonstrate that the proposed PBLSGM generally estimate the parameters of interest unbiasedly, precisely and exhibit appropriate confidence interval coverage. An empirical example using longitudinal reading scores, mathematics scores, and science scores shows that the model can estimate the knot with its variance for each growth curve and the covariance between two knots. We also provide the corresponding code for the proposed model. (PsycInfo Database Record (c) 2022 APA, all rights reserved).
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Simulación por Computador , HumanosRESUMEN
Background: To exchange the type of subjective Bayesian prior selection for assumptions more directly related to statistical decision making in clinician studies and trials, the decreasingly informative prior (DIP) is considered. We expand standard Bayesian early termination methods in one-parameter statistical models for Phase II clinical trials to include decreasingly informative priors (DIP). These priors are designed to reduce the chance of erroneously adapting trials too early by parameterize skepticism in an amount always equal to the unobserved sample size. Method: We show how to parameterize these priors based on effective prior sample size and provide examples for common single-parameter models, include Bernoulli, Poisson, and Gaussian distributions. We use a simulation study to search through possible values of total sample sizes and termination thresholds to find the smallest total sample size (N) under admissible designs, which we define as having at least 80% power and no greater than 5% type I error rate. Results: For Bernoulli, Poisson, and Gaussian distributions, the DIP approach requires fewer patients when admissible designs are achieved. In situations where type I error or power are not admissible, the DIP approach yields similar power and better-controlled type I error with comparable or fewer patients than other Bayesian priors by Thall and Simon. Conclusions: The DIP helps control type I error rates with comparable or fewer patients, especially for those instances when increased type I error rates arise from erroneous termination early in a trial.
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Background: Young men are at high risk for developing obesity-related health complications, yet are markedly underrepresented in lifestyle interventions. This pilot study examined the feasibility and preliminary efficacy of a lifestyle intervention (self-guided + health risk messaging) targeting young men. Methods: 35 young men (Age = 29.3 ± 4.27; BMI = 30.8 ± 4.26; 34% racial/ethnic minority) were randomly assigned to the intervention or delayed treatment control. The intervention (ACTIVATE) included 1 virtual group session, digital tools (wireless scale, self-monitoring app), access to self-paced content via a secure website, and 12 weekly texts to reinforce health risk messaging. Fasted objective weight was assessed remotely at baseline and 12-weeks. Perceived risk was assessed via survey at baseline, 2-week, and 12-week. T-tests were used to compare weight outcomes between arms. Linear regressions examined the association between percent weight change and perceived risk change. Results: Recruitment was successful as evidenced by 109% of target enrollment achieved in a 2-month period. Retention was 86% at 12 weeks, with no differences by arm (p = 0.17). Participants in the intervention arm experienced modest weight loss at 12 weeks, whereas slight gains were observed in the control arm (-1.6% ± 2.5 vs. +0.31% ± 2.8, p = 0.04). Change in perceived risk was not associated with change in percent weight (p > 0.05). Conclusions: A self-guided lifestyle intervention showed initial promise for weight management among young men, but these findings are limited by small sample size. More research is needed to bolster weight loss outcomes while retaining the scalable self-guided approach. Clinical Trial Registration: NCT04267263 (https://www.clinicaltrials.gov/ct2/show/NCT04267263).