Analysis of the influence of the COVID-19 outbreak on household solid waste management: An empirical study using PLS-SEM.

The global increase in solid waste pollution due to economic growth and population growth has led to severe ecological deterioration. This situation is exacerbated by the ongoing coronavirus disease (COVID-19) pandemic, which has significantly impacted consumer behavior and consumption habits. Proper management of solid waste has thus become critical in mitigating environmental degradation. In this study, we aim to examine the relationship between the outbreak of COVID-19, environmental attitudes (EATT), social norms (SN), environmental knowledge (EK), technological innovation (TI), and solid waste management (SWM) in Ecuadorian households during the pandemic. We collected data from 426 households in Ecuador using an online questionnaire and analyzed it using the Partial Least Squares Structural Equation Model method to test the hypotheses. Likewise, we validated the measurement and structural model. The results are novel about SWM, considering a developing country severely affected during the pandemic. Our findings suggest that COVID-19 has a negative impact on SWM, while EATT, SN, and TI have a positive influence on SWM. However, we found that EK does not significantly affect SWM.

Peer assessment as a method for measuring harmful internet use.

Harmful Internet use (HIU) describes unintended use of the Internet. It could be both self-harm and harming others. Our research goal is to develop a more accurate method for measuring HIU by this novel peer assessment. As such, it may become, with our call for more research, a paradigm shift supplementing every rating scale or other type of Internet use assessment. In addition to classic statistical analysis, structural equations have been employed. Results indicate that the true positive rate (TPR) is substantially higher than assessed in other studies.•Peer assessment improvement.•AUC for ROC was computed to establish cut-off points for the used scale.•Results obtained by the Structural Equation model indicate that parental care has a moderate influence on subjects' attempts to fight HIU.

The Importance of Different Forms of Social Capital for Happiness in Europe: A Multilevel Structural Equation Model (GSEM).

This paper investigates the effects of different dimensions of social capital ​on happiness of Europeans. Unlike other studies, a categorical principal component analysis (CATPCA) is applied to obtain the dimensions of social capital. The data used come from the ninth wave of the European Social Survey (ESS), year 2018. Happiness is modelled using a multilevel structural equations model (GSEM) by country to study the role of social capital in Europeans' happiness, when controlling for the effect of factors such as gender, unemployment, age, low income, higher education, and living with a partner. Social capital is measured as a multidimensional concept composed of institutional trust, social trust, social ties and voluntary association, civility and sense of belonging, and religiosity. Among the results, we found that the five dimensions that build social capital have a positive impact on happiness. In addition to the positive effects of social capital, the control variables have the expected impact. In a context marked by growing individualism and social isolation, the results of this work can guide policy makers in using the dimensions of social capital to increase the subjective well-being of the population.

Relationships between parent-infant bonding, dyadic adjustment and quality of life, in an intra-partner sample.

The transition to parenthood represents a moment of change and adaptation in which the dyadic marital relationship becomes a triadic relationship. Facilitating a positive transition requires a thorough understanding of the explanatory model of the relationship between parental-infant bonding, dyadic adjustment and quality of life (QoL) from an integrative perspective of the family unit. The aim of this work was to analyse the relationships between parent-infant bonding, dyadic adjustment and QoL from an intra-partner perspective, 6-12 months after the birth of a child. A cross-sectional observational study was performed in a convenience sample of 222 couples 6-12 months postpartum, enrolled from October 2013 to March 2016. The mean age of the mothers was 34.07 years (SD = 3.67), and for the fathers, it was 35.75 years (SD = 4.02). Mothers perceived better QoL and greater mother-infant bonding compared to fathers. The perception of an adequate dyadic adjustment, together with positive parent-infant bonding, had positively influenced the individual QoL of both members of the couple 6-12 months after birth. From an intra-partner perspective, the positive transition was influenced by the relationship between parent-infant bonding, dyadic adjustment and QoL. Positive parent-infant bonding in mothers and fathers, as well as promotion of the quality of the relationships between couples, can help promote a better QoL. Positive health results can be achieved in terms of individual and family well-being by designing healthcare interventions that encourage the presence and participation of the family unit.

Exploratory multigroup structural equation modeling approach to analyzing H. pylori infection, serological pepsinogen levels, and life style factors in an elderly population in Costa Rica / Enfoque exploratorio del modelo de ecuaciones estructurales multigrupo para el análisis de la infección con H. pylori, niveles de pepsinógenos séricos y factores asociados a estilo de vida en una población de adultos mayores en Costa Rica

Abstract The aim of this work is to describe and analyze the association of PGI/PGII ratio (indicator of gastric atrophy) with H. pylori-CagA and life style factors such as caloric intake, obesity, and harmful habits amongst H. pylori-positive elderly people infected in Costa Rica using an exploratory multigroup structural equations model (SEM). Using a sample of 1748 H. pylori-positive elderly people from CRELES first wave study, a SEM was employed analyze if the relationships between PGI/PGII ratio with levels of H. pylori-CagA, caloric intake, obesity, and harmful habits, differs by sex, age and risk areas subgroups. The proposed SEMs exhibited a good fit in males (RMSEA = 0.039), females (RMSEA = 0.000), low-risk area (RMSEA = 0.038), middle-risk area (RMSEA = 0.042), individuals under 80 years (RMSEA = 0.038) and individuals aged 80 and over (RMSEA = 0.042), while an acceptable fit was observed for the high-risk area (RMSEA = 0.061). Fitted SEMs showed that CagA predicted PG-ratio as expected, with effects increasing with the risk area, but similar between sex and age groups. All indicators measuring obesity (BMI, arms, and waist) showed significant standardized coefficients, with similar effects between sex, age and risk area groups. No other significant effects or differences between groups were identified. We propose a good-fitted SEM model for the possible relationships between CagA and PG ratio and the geographical risk area level for elderly people. No differences were observed on measured parameters between male and female population, or between under 80 years and older individuals.

Resumen El objetivo de este trabajo es describir y analizar la asociación entre PGI/PGII (indicador de atrofia gástrica con H. pylori-CagA y factores asociados a estilo de vida como ingesta calórica, obesidad y hábitos nocivos entre adultos mayores positivos por H. pylori en Costa Rica utilizando modelos de ecuaciones estructurales multigrupo (SEM). Con una muestra de 1748 adultos mayores del estudio CRELES, se utilizó un SEM para analizar las relaciones entre PGI/PGII, CagA, ingesta calórica, obesidad y hábitos nocivos difieren por sexo, edad y áreas de riesgo. Los SEMs propuestos exhibieron un buen ajuste en hombres (RMSEA = 0.039), mujeres (RMSEA = 0.000), área de bajo riesgo (RMSEA = 0.038), áreas de riesgo medio (RMSEA = 0.042), individuos menores de 80 años (RMSEA = 0.038) e individuos de 80 años o más (RMSEA = 0.042), mientras que hubo un ajuste aceptable en áreas de alto riesgo (RMSEA = 0.061). Los SEMs ajustados mostraron que CagA predice la relación PGI/II en la dirección esperada con efectos proporcionales al área de riesgo, pero no por sexo y edad. Todos los indicadores medibles de obesidad (IMC, brazos y cintura) mostraron coeficientes estandarizados significativos con efectos similares entre los grupos por sexo, edad y área de riesgo. No se encontraron otros efectos o diferencias significativas. Proponemos un modelo SEM bien ajustado para las posibles relaciones entre CagA y PGI/II y el nivel de riesgo del área geográfica en adultos mayores. No se encontraron diferencias en las variables analizadas entre hombres y mujeres ni entre los grupos de edad.

Motives for gambling, cognitive distortions, and irresponsible gambling: Proposal for an explanatory model of gambling addiction in university students.

There are many factors that appear to be directly related to the development of gambling addiction problems, and it is important to understand these relationships from a clinical perspective in order to develop prevention and intervention programs. This research seeks to analyze the relationships these problems have with gambling motives, cognitive distortions and irresponsible gambling behavior, and proposes an explanatory model of gambling addiction. The sample was made up of 258 adults residing in the province of Valencia (59.5% women), with a mean age of 20.95 years (SD = 2.19). A series of questionnaires were applied to measure the variables involved, and bivariate correlations, simple and multiple linear regressions and a structural equation model were analyzed. The results indicated that gambling motives were positively related to cognitive distortions, acting as predictors of these. Additionally, the proposed theoretical model showed goodness of fit on various indices and explained 69% of variance in cognitive distortions, 37% of that in irresponsible gambling and 43% of that in gambling addiction. The main limitation of this research is that the sample belongs to a very specific population, who did not necessarily have gambling problems. The main contributions are uncovering some of the relationships between gambling motives and cognitive distortions and the proposal of a mediating role of irresponsible gambling in the relationship between cognitive distortions and the development of gambling problems. If the proposed model replicates, it can be of help to research and health professionals.

Beliefs and attitudes towards child epilepsy: A structural equation model.

PURPOSE: To analyze the possibly influencing factors of the beliefs and attitudes towards childhood epilepsy among users of the Family Health Strategy. METHODS: The participants were 300 users from three units of the Family Health Strategy in one city of northeastern Brazil. This primary health care service has a multidisciplinary team and operates close to the community, seeks to provide comprehensive care with actions to promote health, prevention, recovery, rehabilitation of diseases and frequent injuries in the community. Data were collected through a socioeconomic questionnaire and the Brazilian version of The Epilepsy Beliefs and Attitudes Scale - Adult Version, analyzed using descriptive statistics and structural equation analysis. RESULTS: Various associations were significant (p < 0.05), religion positively influences beliefs and attitudes (ß: 1.040; p: 0.044); an increase in educational level negatively influences beliefs and attitudes (ß: -0.723; p: 0.040); being the parent of a child negatively influences beliefs and attitudes (ß: 1.120; p: 0.043), but also positively influences beliefs (ß: -0.244; p: 0.028). CONCLUSION: This research contributed to identifying that having a religion, an increased educational level and being the parent of a child were factors that influence the beliefs and attitudes towards childhood epilepsy, aiming to contribute to a better implementation of actions directed to education in epilepsy.

Análisis Psicométrico de la Escala Orientación hacia la Dominancia Social (SDO) Mediante un Modelo de Ecuaciones Estructurales Exploratorias (ESEM) / Psychometric Analysis of the Social Dominance Orientation (SDO) Scale Through a Model of Exploratory Structural Equations (ESEM)

Resumen El objetivo de la presente investigación es analizar las propiedades psicométricas de la Escala Orientación hacia la Dominancia Social (SDO), en una muestra no universitaria de la ciudad de Arica, Chile, implementando técnicas psicométricas de acuerdo con el estado del arte disciplinar. El muestreo fue no probabilístico, por conveniencia y disponibilidad de 812 participantes, entre edades de 18 a 89 años. Se realizaron estimaciones de fiabilidad, análisis factoriales confirmatorios y modelos de ecuaciones estructurales exploratorios, contrastando diferentes modelos. Los resultados proporcionaron evidencia de validez basada en la estructura interna de la prueba, presentando buen ajuste de la estructura de la SDO (RMSEA=.076; CFI=.963; TLI=.956), y adecuados niveles estimados de fiabilidad (Oposición a la Igualdad: α=.85, ω=.84; Dominancia Grupal: α =.67, ω =.66). Finalmente, se concluye que las puntuaciones de la escala SDO poseen evidencia suficiente para sustentar su uso e interpretación, en población no universitaria equivalente a la del presente estudio.

Abstract The objective of this research is to analyze the psychometric properties of the Social Dominance Orientation (SDO) Scale in a non-university sample of the city of Arica, Chile, implementing psychometric techniques according to the state of disciplinary art. The sampling was non-probabilistic due to the convenience and availability of 812 participants in a range of ages from 18 to 89 years. To contrast different models were performed reliability estimates, confirmatory factorial analyses, and exploratory structural equation models. The results provided evidence of validity based on the internal structure of the test, presenting good adjustment of the SDO structure (RMSEA=.076; CFI=.963; TLI=.956), and estimated adequate levels of reliability (Opposition to the Equality: α=.85, ω=.84, Group dominance: α =.67, ω =.66). Finally, the research concluded that the scores of the SDO scale have sufficient evidence to support its use and interpretation, in a non-university population equivalent to that of the present study.

Motivation, Discipline, and Academic Performance in Physical Education: A Holistic Approach From Achievement Goal and Self-Determination Theories.

The analysis of disciplined behaviors and academic performance in a school context has become one of the main concerns within the educational community. Physical Education is highlighted as a key subject to analyze students' behavior. Researchers and Physical Education teachers are interested on the motivational processes that predict positive student outcomes in order to support them. Thus, the main purpose was to determine a predictive model of disciplined behaviors and academic performance in Physical Education students. The Achievement Goal Theory and Self-Determination Theory acted as the theoretical framework. A total of 919 Spanish secondary school students participated in the study. The studied variables were task-oriented motivational climate, basic psychological needs, autonomous motivation, disciplined behavior, and academic performance. Data collection included Spanish validated questionnaires. The Mplus statistical program was used to perform a structural equation model of prediction. It included antecedents (task-oriented climate), motivational processes (basic psychological needs and autonomous motivation), and consequences (disciplined behavior, Physical Education and overall students' performance). The results revealed that positive outcomes (discipline and academic performance in Physical Education) were positively predicted by autonomous motivation; autonomous motivation was positively predicted by basic psychological needs and these, in addition, by the task-oriented climate. The results highlighted the importance of the task-oriented motivational climate and the mediating role of the basic psychological needs and autonomous motivation in order to generate these positive student outcomes in Physical Education. This study could be a useful resource for teachers, since it offers the motivational variables that lead students to achieve disciplined behaviors and academic performance in Physical Education. Intervention programs based on the results of the present study could be applied in Physical Education classes in order to obtain better behavioral as well as cognitive positive student outcomes.

The Nature of Job Crafting: Positive and Negative Relations with Job Satisfaction and Work-Family Conflict.

This study investigated job crafting as mediator and its relation with job satisfaction and work-family conflict, considering job autonomy as antecedent. The research involved 389 participants working in a public organization. A structural equations model was estimated revealing that job autonomy is positively associated with job crafting and job satisfaction, and negatively associated with work-family conflict. Job crafting is positively related with job satisfaction and work-family conflict, as adverse effect of job crafting. As regards mediated effects, results show positive associations between job autonomy and both job satisfaction and work-family conflict through job crafting. This study contributes to literature, considering positive and negative outcomes, covering the lacking literature on job crafting and work-family conflict, and suggesting implications for employees' well-being.

Executive Functions, Episodic Autobiographical Memory, Problem-Solving Capacity, and Depression Proposal for a Structural Equations Model.

The executive functions play an important role in storing and recovering autobiographical memories, especially episodic memories. These types of memories provide information about solutions and experiences from the past that can be utilized as examples in the present when seeking solutions to any problem. In addition, a close relationship between depression and the executive functions has been widely recognized. This study aims to elaborate a structural equations model that empirically supports the relationships among the executive functions, episodic autobiographical memory, and the adaptive capacity to solve problems, taking into account the depressed mood state. In all, 32 healthy elderly people, 32 patients with Parkinson disease, 32 with amnestic mild cognitive impairment, and 32 with Alzheimer disease were evaluated. Structural equation models were estimated to test the effects among the constructs. The final model shows adequate fit indexes, thus revealing that an individual's problem-solving capacity will depend on the capacity to access the episodic autobiographical memory, which in turn will depend on the maintenance of executive functioning. In a parallel way, the mood state, and specifically depression, will play a modulator role because when there is depressive symptomatology, some capacities that depend on executive control can be diminished.

Psychometric analysis of a scale to measure fear of crime in Ecuadorian youths / Análise psicométrica de uma escala para medir o medo do delito em jovens equatorianos / Análisis psicométrico de una escala para medir el miedo al delito en jóvenes ecuatorianos

Abstract In Ecuador, as in the rest of Latin America, the problem of insecurity is undeniable. Although there are surveys in the country that measure the perception of insecurity or victimization, there is no instrument that measures fear of crime. This research was aimed at the structural validation of a scale to measure the fear of crime from the psychosocial perspective. To validate this theoretical model, an exploratory factor analysis (EFA) and confirmatory factor analyses (CFA) were conducted. A total of 298 students from the city of Ambato, Ecuador, participated in the study. The average age was 21.28 years (SD = 1.62). Results showed satisfactory psychometric and structural properties of the scale. Furthermore, two theoretical models of fear of crime were developed: a first order factor and a second order factor. Results confirm the relevance of the second order model for explaining the psychosocial construction of the fear of crime.

Resumo No Equador, assim como em toda a América Latina, a problemática da insegurança é inegável e, apesar de existirem, no país, pesquisas que meçam a percepção de insegurança ou vitimização, não há nenhum instrumento que meça o medo do delito. A presente pesquisa tem como propósito realizar um estudo psicométrico de uma escala do medo do delito que parte de uma perspectiva psicossocial. Para validar esse modelo teórico, realizou-se uma análise fatorial exploratória (AFE) e uma análise fatorial confirmatoria (AFC) com uma amostra conformada por 298 estudantes universitários da cidade de Ambato, Equador, com uma média de idade de 21.28 anos (DT=1.62); os resultados mostraram que a escala apresenta índices de bondade de ajuste satisfatórios. Especificamente, utilizaram-se dois modelos explicativos do medo do delito, um de primeira ordem e outro de segunda ordem; este último explicou melhor a estrutura psicossocial do medo do delito.

Resumen En Ecuador, al igual que en el resto de Latinoamérica, la problemática de la inseguridad es innegable, y a pesar de que en el país existen encuestas que miden la percepción de inseguridad o la victimización, no existe ningún instrumento que mida el miedo al delito. La presente investigación tiene como propósito realizar un estudio psicométrico de una escala del miedo al delito que parte de una perspectiva psicosocial. Para validar este modelo teórico se realizó un análisis factorial exploratorio (AFE) y un análisis factorial confirmatorio (AFC) con una muestra conformada por 298 estudiantes universitarios de la ciudad de Ambato, Ecuador, con un promedio de edad de 21.28 años (DT = 1.62). Los resultados muestran que la escala presenta índices de bondad de ajuste satisfactorios. Específicamente, se utilizaron dos modelos explicativos del miedo al delito, uno de primer orden y otro de segundo orden, siendo este último el que explicó mejor la estructura psicosocial del miedo al delito.

Factores que determinan el rendimiento académico en Matemáticas en el contexto de una universidad tecnológica: aplicación de un modelo de ecuaciones estructurales / Determinants of academic performance in Mathematics in the context of a technological university: application of Structural Equations Model

El estudio examinó, por medio de un modelo de ecuaciones estructurales, posibles factores causales del rendimiento académico en cursos de Matemáticas de la Universidad Nacional de Ingeniería de Nicaragua, en una muestra estratificada por conglomerados de 713 estudiantes de segundo año distribuidos en 33 grupos de clases, con sus respectivos profesores. Además de la nota final en el curso, se incluyeron en el modelo causal, y de acuerdo con la literatura, variables de dimensiones sociodemográficas, psicosociales, institucionales y pedagógicas. Los resultados destacan tres variables del estudiante como determinantes del desempeño en el curso de Matemática: la inteligencia fluida, los hábitos de estudio y las actitudes negativas hacia las Matemáticas, resultando relevantes también los efectos indirectos en las dos primeras, y en las direcciones esperadas. Las variables del docente que mostraron efectos directos de importancia fueron edad, nivel académico y la asistencia a cursos pedagógicos promovidos por la institución.

The study examined, using structural equations model (SEM) possible causal factors for Math achievement in students from the National University of Engineering in Nicaragua, using a stratified sample of complete conglomerates of 713 students in second year, spread over 33 groups and their respective teachers. Besides the final grade in the course, and according to the literature review, variables of the socio-demographic, psychosocial, institutional and pedagogical dimensions were included in the model. The results emphasized three student variables as determinants of the achievement in Math: fluid intelligence, study habits and negative attitudes towards Mathematics, with the indirect effects of the last two also relevant, and in the expected direction. Teacher variables that showed relevant direct effects were age, academic level and attendance to pedagogical courses promoted by the institution.

Path analysis of relationship among personality, perceived stress, coping, social support, and psychological outcomes.

AIM: To provide a structural model of the relationship between personality traits, perceived stress, coping strategies, social support, and psychological outcomes in the general population. METHODS: This is a cross sectional study in which the study group was selected using multistage cluster and convenience sampling among a population of 4 million. For data collection, a total of 4763 individuals were asked to complete a questionnaire on demographics, personality traits, life events, coping with stress, social support, and psychological outcomes such as anxiety and depression. To evaluate the comprehensive relationship between the variables, a path model was fitted. RESULTS: The standard electronic modules showed that personality traits and perceived stress are important determinants of psychological outcomes. Social support and coping strategies were demonstrated to reduce the increasing cumulative positive effects of neuroticism and perceived stress on the psychological outcomes and enhance the protective effect of extraversion through decreasing the positive effect of perceived stress on the psychological outcomes. CONCLUSION: Personal resources play an important role in reduction and prevention of anxiety and depression. In order to improve the psychological health, it is necessary to train and reinforce the adaptive coping strategies and social support, and thus, to moderate negative personality traits.

Causal mediation analysis with a latent mediator.

Health researchers are often interested in assessing the direct effect of a treatment or exposure on an outcome variable, as well as its indirect (or mediation) effect through an intermediate variable (or mediator). For an outcome following a nonlinear model, the mediation formula may be used to estimate causally interpretable mediation effects. This method, like others, assumes that the mediator is observed. However, as is common in structural equations modeling, we may wish to consider a latent (unobserved) mediator. We follow a potential outcomes framework and assume a generalized structural equations model (GSEM). We provide maximum-likelihood estimation of GSEM parameters using an approximate Monte Carlo EM algorithm, coupled with a mediation formula approach to estimate natural direct and indirect effects. The method relies on an untestable sequential ignorability assumption; we assess robustness to this assumption by adapting a recently proposed method for sensitivity analysis. Simulation studies show good properties of the proposed estimators in plausible scenarios. Our method is applied to a study of the effect of mother education on occurrence of adolescent dental caries, in which we examine possible mediation through latent oral health behavior.

A multilevel cross-lagged structural equation analysis for reciprocal relationship between social capital and health.

We investigated the reciprocal relationship between individual social capital and perceived mental and physical health in the UK. Using data from the British Household Panel Survey from 1991 to 2008, we fitted cross-lagged structural equation models that include three indicators of social capital vis. social participation, social network, and loneliness. Given that multiple measurement points (level 1) are nested within individuals (level 2), we also applied a multilevel model to allow for residual variation in the outcomes at the occasion and individual levels. Controlling for gender, age, employment status, educational attainment, marital status, household wealth, and region, our analyses suggest that social participation predicts subsequent change in perceived mental health, and vice versa. However, whilst loneliness is found to be significantly related to perceived mental and physical health, reciprocal causality is not found for perceived mental health. Furthermore, we find evidence for reverse effects with both perceived mental and physical health appearing to be the dominant causal factor with respect to the prospective level of social network. Our findings thus shed further light on the importance of social participation and social inclusion in health promotion and aid the development of more effective public health policies in the UK.

Sensitivity analyses for parametric causal mediation effect estimation.

Causal mediation analysis uses a potential outcomes framework to estimate the direct effect of an exposure on an outcome and its indirect effect through an intermediate variable (or mediator). Causal interpretations of these effects typically rely on sequential ignorability. Because this assumption is not empirically testable, it is important to conduct sensitivity analyses. Sensitivity analyses so far offered for this situation have either focused on the case where the outcome follows a linear model or involve nonparametric or semiparametric models. We propose alternative approaches that are suitable for responses following generalized linear models. The first approach uses a Gaussian copula model involving latent versions of the mediator and the final outcome. The second approach uses a so-called hybrid causal-observational model that extends the association model for the final outcome, providing a novel sensitivity parameter. These models, while still assuming a randomized exposure, allow for unobserved (as well as observed) mediator-outcome confounders that are not affected by exposure. The methods are applied to data from a study of the effect of mother education on dental caries in adolescence.

Functional and psychological variables both affect daily physical activity in COPD: a structural equations model.

BACKGROUND: Daily physical activity (DPA) level is reduced in patients with COPD. The aim of this study was to investigate the association of DPA with functional and psychological variables in these patients. METHODS: 155 COPD patients (102 males, median (IQR) age 62 years (54-69 years), predicted FEV1 60% (40-75%) were included. We assessed DPA (DigiWalker SW-200), functional capacity and psychological factors. RESULTS: DPA level was significantly associated with all functional capacity variables and two psychological variables (Perceived Physical Ability Subscale, depression subscale of the Hospital Anxiety and Depression Scale). The six-minute walking distance and St. George Respiratory Questionnaire activity score explained 37% of the variance of DPA in a regression analysis. A structural equations model revealed that psychological variables indirectly explained DPA through functional capacity variables. DPA was stronger associated with functional capacity variables and weaker with psychological variables in patients with lower functional status than in patients with higher functional status. CONCLUSIONS: Higher levels of DPA are associated with better functional capacity, but interestingly, DPA is also affected by psychological factors, though only indirectly, via functional capacity. The effect of specific treatment addressing psychological factors on DPA level and exercise tolerance needs further investigation. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT00614796.