Moderating effects of dysregulation and fear of positive emotions on the relationship between posttraumatic stress disorder symptoms and positive memory count.

OBJECTIVES: We examined moderating effects of positive emotion dysregulation and fear of positive emotions in the relation between posttraumatic stress disorder (PTSD) severity and positive memory count. METHOD: Participants were 205 trauma-exposed community individuals (Mage = 35.44; 61.50% female). RESULTS: Moderation analyses indicated interaction effects of PTSD severity with nonacceptance of positive emotions (b = -0.01, p = .002) and difficulties with goal-directed behaviors when experiencing positive emotions (b = -0.01, p = .006) on positive memory count. CONCLUSIONS: Greater PTSD severity was associated with more specific positive memories when individuals reported less nonacceptance of positive emotions and fewer difficulties engaging in goal-directed behaviors in the context of positive emotions. Greater PTSD severity was associated with fewer specific positive memories when individuals reported greater nonacceptance of positive emotions and greater difficulties engaging in goal-directed behaviors in the context of positive emotions. Results support addressing positive emotion dysregulation in memory-focused interventions for PTSD.

Mean centering, multicollinearity, and moderators in multiple regression: The reconciliation redux.

In this article, we attempt to clarify our statements regarding the effects of mean centering. In a multiple regression with predictors A, B, and A × B (where A × B serves as an interaction term), mean centering A and B prior to computing the product term can clarify the regression coefficients (which is good) and the overall model fit R2 will remain undisturbed (which is also good).

The often overlooked issue of statistical power: this and other issues regarding assessing importance weighting in quality of life measures.

In the area of quality of life research, researchers may ask respondents to rate importance as well as satisfaction of various life domains (such as job and health) and use importance ratings as weights to calculate overall, or global, life satisfaction. The practice of giving more important domains more weight, known as importance weighting, has not been without controversy. Several previous studies assessed importance weighting using the analytical approach of moderated regression. This study discusses major issues related to how importance weighting has been assessed. Specifically, this study highlights that studies on importance weighting without considering statistical power are prone to type II error, i.e., failing to reject the null hypothesis of no significant weighting effect when the null hypothesis is actually false. The sample size required for adequate statistical power to detect importance weighting functions appeared larger than most previous studies could offer.

Configuring political relationships to navigate host-country institutional complexity: Insights from Anglophone sub-Saharan Africa.

We examine how ties with multiple host-country political institutions contribute to MNE subsidiary performance in countries with weak formal institutions. We suggest that forging relationships between subsidiaries and host-country government actors, local chieftains, and religious leaders generates regulative, normative, and cultural-cognitive political resources. We integrate institutional and configuration theories to argue that similarity to an ideal configuration of the three political resources contributes to MNE subsidiary performance, and that the more dysfunctional host-country institutions, the greater the impact on performance. We test our hypotheses using primary and archival data from 604 MNE subsidiaries in 23 Anglophone sub-Saharan African countries and find support for our hypotheses. In our conclusion, we discuss the wider theoretical, managerial, and public-policy implications of our findings.

Nous examinons comment les liens avec de multiples institutions politiques du pays d'accueil contribuent à la performance des filiales des entreprises multinationales (Multinational Enterprise ­ MNE) dans les pays où les institutions formelles sont faibles. Nous suggérons que l'établissement de relations entre les filiales et les acteurs gouvernementaux, les chefs locaux et les chefs religieux du pays d'accueil génère des ressources politiques régulatrices, normatives et culturelles-cognitives. Nous intégrons les théories institutionnelles et de la configuration pour arguer que la similitude avec une configuration idéale des trois ressources politiques contribue à la performance des filiales des MNEs, et que plus les institutions du pays d'accueil sont dysfonctionnelles, plus l'impact sur la performance est important. Nous testons nos hypothèses à l'aide des données primaires et d'archives provenant de 604 filiales des MNEs dans 23 pays anglophones d'Afrique subsaharienne. Les résultats de nos tests confirment nos hypothèses. Dans notre conclusion, nous discutons des implications théoriques, managériales et de politique publique plus larges de nos résultats.

Examinamos con los lazos como múltiples instituciones en el país anfitrión contribuye al desempeño de la filial en países con instituciones formales débiles. Proponemos que forjar relaciones entre las filiales y los actores gubernamentales de los países anfitriones, los caciques locales, y los lideres religiosos genera recursos políticos regulatorios, normativos y culturales-cognitivos. Integramos las teorías institucionales y de configuración para argumentar que la similitud a una configuración ideal entre los tres recursos políticos contribuye al desempeño de las filiales, y entre más disfuncional sean las instituciones en el país anfitrión, mayor será el impacto en el desempeño. Probamos nuestras hipótesis usando datos primarios y material de archivos de 604 filiales en 23 países anglófonos de África Sub-Sahariana, y encontramos apoyo para nuestras hipótesis. En nuestra conclusión discutimos las implicaciones más generales teóricas, gerenciales y de política pública de nuestros hallazgos.

Examinamos como laços com várias instituições políticas do país anfitrião contribuem para o desempenho de subsidiárias de MNE em países com instituições formais fracas. Sugerimos que forjar relacionamentos entre subsidiárias e atores do governo do país anfitrião, chefes locais e líderes religiosos gera recursos políticos regulatórios, normativos e cultural-cognitivos. Integramos as teorias institucionais e de configuração para argumentar que a semelhança com uma configuração ideal dos três recursos políticos contribui para o desempenho da subsidiária da MNE e que quanto mais disfuncionais forem as instituições do país anfitrião, maior será o impacto no desempenho. Testamos nossas hipóteses usando dados primários e secundários de 604 subsidiárias de MNEs em 23 países de língua inglesa da África subsaariana e encontramos suporte para nossas hipóteses. Em nossa conclusão, discutimos mais amplas implicações teóricas, gerenciais e de políticas públicas de nossas descobertas.

Factors Influencing the Total Functional Capacity Score as a Critical Endpoint in Huntington's Disease Research.

Background: The Total Functional Capacity (TFC) score is commonly used in Huntington's disease (HD) research. The classification separates each disease stage (1-5), e.g., as an inclusion criterion or endpoint in clinical trials accepted by the Food and Drug Administration (FDA). In addition to the quantification of age- and CAG-repeat-dependent effects as well as interacting effects of both on the TFC, we aimed to investigate factors influencing the TFC, such as neuropsychiatric, educational, and cognitive disease burden using data from the largest HD observational study to date. In addition, we analyzed data from pre-manifest stages to investigate the influence of the above-mentioned factors on the TFC in that stage. Methods: A moderated regression analysis was conducted to analyze the interaction effects of age and CAG-repeat length on the TFC in HD patients. A simple slope analysis was calculated to illustrate the effects. Depending on TFC results, motor-manifest patients were grouped into five stages. Data from pre-manifest participants were analyzed with regard to years to onset and CAP scores. Results: We identified N = 10,314 participants as manifest HD. A significant part of variance on the TFC was explained by age (R2 = 0.029, F (1;10,281) = 308.02, p < 0.001), CAG-repeat length (∆R2 = 0.132, ∆F (1;10,280) = 1611.22, p < 0.001), and their interaction (∆R2 = 0.049, ∆F (1;10,279) = 634.12, p < 0.001). The model explained altogether 20.9% of the TFC score's variance (F = 907.60, p < 0.001). Variance of psychiatric and cognitive symptoms significantly differed between stages. Exploratory analysis of median data in pre-manifest participants revealed the highest scores for neuropsychiatric changes between 5 to <20 years from the disease onset. Conclusions: TFC is mainly explained by the neurobiological factors, CAG-repeat length, and age, with subjects having more CAG-repeats showing a faster decline in function. Our study confirms TFC as a robust measure of progression in manifest HD.

Centering in Multiple Regression Does Not Always Reduce Multicollinearity: How to Tell When Your Estimates Will Not Benefit From Centering.

Within the context of moderated multiple regression, mean centering is recommended both to simplify the interpretation of the coefficients and to reduce the problem of multicollinearity. For almost 30 years, theoreticians and applied researchers have advocated for centering as an effective way to reduce the correlation between variables and thus produce more stable estimates of regression coefficients. By reviewing the theory on which this recommendation is based, this article presents three new findings. First, that the original assumption of expectation-independence among predictors on which this recommendation is based can be expanded to encompass many other joint distributions. Second, that for many jointly distributed random variables, even some that enjoy considerable symmetry, the correlation between the centered main effects and their respective interaction can increase when compared with the correlation of the uncentered effects. Third, that the higher order moments of the joint distribution play as much of a role as lower order moments such that the symmetry of lower dimensional marginals is a necessary but not sufficient condition for a decrease in correlation between centered main effects and their interaction. Theoretical and simulation results are presented to help conceptualize the issues.

Substance use and Psychosocial Functioning of Adolescents in Benue State, Nigeria: Assessing the role of age.

AIM: To assess whether Substance Use (SU) is associated with Psychosocial Function (PF) among adolescent. METHODS: Using a self-administered validated instrument, we obtained information on demographic, SU (defined as self-reported affirmative use of one or more of any form of alcoholic drinks, cigarettes, hemps etc) and PF [using the adolescent psychosocial functioning inventory comprising of three subscales; optimism and coping strategies (OCS), behaviour and relationship problems (BRP) and general psychosocial dysfunction designed (GPD)] among 2272 apparently healthy adolescents. PF was categorized as 'elevated' if the psychosocial functioning index (PFI) score were >75th percentile, otherwise, 'not elevated' and multivariable-adjusted logistic regression was used to compute odds ratio (OR) and 95% confidence interval (CI) of SU for elevated PF risk. In addition, we applied Johnson Neyman (JN) technique to identifying the JN significance regions at which age moderated the SU-PF relationship at a statistical significance of two-sided P<0.05. RESULTS: Prevalence of SU and elevated PF was 50.7% and 79.8% respectively. Prevalence of elevated PF differed insignificantly by sex, but the proportion of adolescent with elevated PFI on SU (82.6%) was significantly higher (P<0.001) compared to those with elevated PFI but not on SU (76.9%). Multivariable-adjusted odds of decreased OCS risk given SU exposure was; OR (95%CI): 1.3791 (1.1458-1.6698), P=0.0007. Similarly, multivariable-adjusted odds of elevated PF risk in the light of SU exposure was; OR (95%CI): 1.4286 (1.1617-1.7567), P=0.0007. Furthermore, the JN significance regions for moderated regression analyses of odds of decreased OCS risk was between 10.4years [OR (95%CI): 0.5820 (0.1411-1.0228), P=0.0097] and 16.7years [OR (95%CI): 0.3025 (0.0001-0.6050), P=0.0500]. CONCLUSION: Adolescents on SU are about one and half times at risk of psychosocial dysfunction and age significantly attenuated the SU-decreased OCS risk link particularly in early adolescence.

The contribution of mental health and gender attitudes to intimate partner violence in the context of war and displacement: Evidence from a multi-informant couple survey in Iraq.

RATIONALE: Intimate partner violence is a prevalent issue in refugee and internally displaced populations in post-war and migration settings including camps in the Middle East. In this context, partner violence has been associated with war-related trauma, camp factors, individual characteristics, and gender attitudes. OBJECTIVE: With a dual-informant survey among a sample of Iraqi couples residing in a camp for displaced people in the Kurdistan Region of Iraq (N = 92) this study investigated the relationship between war-related psychopathology, attitudes towards women, and male-perpetrated partner violence. METHOD: Moderated regression analysis was applied using information from both partners to predict partner violence reported by wives. RESULTS: Over 58% of the women in this sample reported past-year exposure to partner violence. Further analyses revealed significant main effects of men's self-reported psychopathology (posttraumatic stress disorder and depression) and their own gender attitudes on partner violence. In a multivariate regression, moderating effects were found, as higher psychopathology levels and inequitable gender attitudes in men interacted in the prediction of male-perpetrated partner violence. CONCLUSIONS: This study highlights the high prevalence of partner violence among Iraqi displaced women. In addition, the results show an interplay of several violence-impelling factors in war-affected men. This emphasizes the importance of addressing both mental health issues and gender attitudes in the efforts to reduce or end violence against women in post-war settings.

Using an innovative multiple regression procedure in a cancer population (Part 1): detecting and probing relationships of common interacting symptoms (pain, fatigue/weakness, sleep problems) as a strategy to discover influential symptom pairs and clusters.

BACKGROUND: The majority of patients with advanced cancer experience symptom pairs or clusters among pain, fatigue, and insomnia. Improved methods are needed to detect and interpret interactions among symptoms or diesease markers to reveal influential pairs or clusters. In prior work, I developed and validated sequential residual centering (SRC), a method that improves the sensitivity of multiple regression to detect interactions among predictors, by conditioning for multicollinearity (shared variation) among interactions and component predictors. MATERIALS AND METHODS: Using a hypothetical three-way interaction among pain, fatigue, and sleep to predict depressive affect, I derive and explain SRC multiple regression. Subsequently, I estimate raw and SRC multiple regressions using real data for these symptoms from 268 palliative radiation outpatients. RESULTS: Unlike raw regression, SRC reveals that the three-way interaction (pain × fatigue/weakness × sleep problems) is statistically significant. In follow-up analyses, the relationship between pain and depressive affect is aggravated (magnified) within two partial ranges: 1) complete-to-some control over fatigue/weakness when there is complete control over sleep problems (ie, a subset of the pain-fatigue/weakness symptom pair), and 2) no control over fatigue/weakness when there is some-to-no control over sleep problems (ie, a subset of the pain-fatigue/weakness-sleep problems symptom cluster). Otherwise, the relationship weakens (buffering) as control over fatigue/weakness or sleep problems diminishes. CONCLUSION: By reducing the standard error, SRC unmasks a three-way interaction comprising a symptom pair and cluster. Low-to-moderate levels of the moderator variable for fatigue/weakness magnify the relationship between pain and depressive affect. However, when the comoderator variable for sleep problems accompanies fatigue/weakness, only frequent or unrelenting levels of both symptoms magnify the relationship. These findings suggest that a countervailing mechanism involving depressive affect could account for the effectiveness of a cognitive behavioral intervention to reduce the severity of a pain, fatigue, and sleep disturbance cluster in a previous randomized trial.

Using an innovative multiple regression procedure in a cancer population (Part II): fever, depressive affect, and mobility problems clarify an influential symptom pair (pain-fatigue/weakness) and cluster (pain-fatigue/weakness-sleep problems).

BACKGROUND: Most patients with advanced cancer experience symptom pairs or clusters among pain, fatigue, and insomnia. However, only combinations where symptoms are mutually influential hold potential for identifying patient subgroups at greater risk, and in some contexts, interventions with "cross-over" (multisymptom) effects. Improved methods to detect and interpret interactions among symptoms, signs, or biomarkers are needed to reveal these influential pairs and clusters. I recently created sequential residual centering (SRC) to reduce multicollinearity in moderated regression, which enhances sensitivity to detect these interactions. METHODS: I applied SRC to moderated regressions of single-item symptoms that interact to predict outcomes from 268 palliative radiation outpatients. I investigated: 1) the hypothesis that the interaction, pain × fatigue/weakness × sleep problems, predicts depressive affect only when fever presents, and 2) an exploratory analysis, when fever is absent, that the interaction, pain × fatigue/weakness × sleep problems × depressive affect, predicts mobility problems. In the fever context, three-way interactions (and derivative terms) of the four symptoms (pain, fatigue/weakness, fever, sleep problems) are tested individually and simultaneously; in the non-fever context, a single four-way interaction (and derivative terms) is tested. RESULTS: Fever interacts separately with fatigue/weakness and sleep problems; these comoderators each magnify the pain-depressive affect relationship along the upper or full range of pain values. In non-fever contexts, fatigue/weakness, sleep problems, and depressive affect comagnify the relationship between pain and mobility problems. CONCLUSION: Different mechanisms contribute to the pain × fatigue/weakness × sleep problems interaction, but all depend on the presence of fever, a sign/biomarker/symptom of proinflammatory sickness behavior. In non-fever contexts, depressive affect is no longer an outcome representing malaise from the physical symptoms of sickness, but becomes a fourth symptom of the interaction. In outpatient subgroups at heightened risk, single interventions could potentially relieve multiple symptoms when fever accompanies sickness malaise and in non-fever contexts with mobility problems. SRC strengthens insights into symptom pairs/clusters.