Health-related Quality of Life of Thai children with HIV infection: a comparison of the Thai Quality of Life in Children (ThQLC) with the Pediatric Quality of Life Inventory™ version 4.0 (PedsQL™ 4.0) Generic Core Scales

The purpose of this study was to evaluate the reliability and validity of the Thai Quality of Life in Children (ThQLC) and compare it with the Pediatric Quality of Life Inventory (PedsQL™ 4.0) in a sample of children receiving long-term HIV care in Thailand. The ThQLC and the PedsQL™ 4.0 were administered to 292 children with HIV infection aged 8–16 years. Clinical parameters such as the current viral load, CD4 percent, and clinical staging were obtained by medical record review. Three out of five ThQLC scales and three out of four PedsQL™ 4.0 scales had acceptable internal consistency reliability (i.e., Cronbach’s alpha >0.70). Cronbach’s alpha values of each scale ranged from 0.52 to 0.75 and 0.57 to 0.75 for the ThQLC and the PedsQL™ 4.0, respectively. Corresponding scales (physical functioning, emotional well-being, social functioning, and school functioning) of the ThQLC and the PedsQL™ 4.0 correlated substantially with one another (r = 0.47, 0.67, 0.59 and 0.56, respectively). Both ThQLC and PedsQL™ 4.0 overall scores significantly correlated with the child’s self-rated severity of the illness (r = −0.23 for the ThQLC and −0.28 for the PedsQL™ 4.0) and the caregiver’s rated overall quality of life (r = 0.07 for the ThQLC and 0.13 for the PedsQL™ 4.0). The overall score of the ThQLC correlated with clinical and immunologic categories of the United State-Centers for Disease Control and Prevention (US-CDC) classification system (r = −0.12), while the overall score of the PedsQL™ 4.0 significantly correlated with the number of disability days (r = −0.12) and CD4 percent (r = −0.15). However, the overall score from both instruments were not significantly different by clinical stages of HIV disease. A multitrait-multimethod analysis results demonstrated that the average convergent validity and off-diagonal correlations were 0.58 and 0.45, respectively. Discriminant validity was partially supported with 62% of validity diagonal correlations exceeding correlations between different domains (discriminant validity successes). The Hays-Hayashi MTMM quality index was 0.61. Multivariate regression analysis revealed that the ThQLC physical functioning scale provided unique information in predicting child self-rated severity of the illness and overall quality of life beyond that explained by the PedsQL™ 4.0 in Thai children with HIV infection. We found evidence in support of the reliability and validity of the ThQLC and the PedsQL™ 4.0 for measuring the health-related quality of life of Thai children with HIV infection

Measuring Empathizing and Systemizing with a Large US Sample

A large number of people completed one of two versions of the empathizing quotient (EQ) and systemizing quotient (SQ). One version had the negatively phrased items all re-worded. These re-worded items were answered more rapidly than the original items, and for the SQ produced a more reliable scale. Subjects gave self-assessments of empathizing and systemizing, and these were moderately correlated, r≈.6, with their respective quotients. Females had on average higher empathizing scores and males had on average higher systemizing scores. If a female-male pair was chosen at random, the female would have the higher empathizing score about two-thirds of the time, and the males would have the higher systemizing score about two-thirds of the time

Influence of sense of coherence on adolescents' self-perceived dental aesthetics:a cross-sectional study

Background Sense of coherence (SOC) is a psychosocial factor capable of influencing perception of health, improving one’s ability to manage life. It is the central construct of salutogenesis. SOC allows for identification and mobilization of resources to effectively manage or solve problems, promoting health and quality of life. Using Wilson-Cleary’s conceptual model we hypothesized that SOC might contribute to self-perception of dental aesthetics. The aim of this study was to investigate whether SOC levels were related to self-perception of dental aesthetics against assessed normative orthodontic treatment need among adolescents. Methods A cross-sectional study was conducted with 615 male and female adolescents aged 12 to 15 years. Data collection comprised socio-demographic and socio-economic characteristics, SOC (SOC 13), self-perceived dental aesthetics (Oral Aesthetic Subjective Impact Scale), and assessment of orthodontic treatment need (Dental Aesthetic Index). Statistical analysis involved Pearson’s chi-square test, Kruskal-Wallis test, Mann-Whitney test and multiple linear regression. Spearman’s correlation coefficient was calculated for the determination of the strength of correlations among the numerical variables. The level of significance was set at 5% (p < 0.05). Results 50.1% of the participants were classified as having a high SOC (≥ median). Overall, SOC was associated with self-perceived dental aesthetics (p = 0.048). In the adolescents with no orthodontic treatment need, those with a low SOC perceived their dental aesthetics more negatively than those with high levels of SOC. The multiple regression analysis demonstrated an inverse relationship between SOC and: 1) age (p = 0.007), SOC being higher in the younger age group; 2) self-perceived dental aesthetics (p = 0.001), a higher SOC being associated with those who had a positive dental self-perception. Conclusions SOC was associated with self-perceived dental aesthetics and adolescents with a high SOC were more likely to perceive their dental aesthetics more positively. SOC did not seem to influence self-perception of dental aesthetics in adolescents who were clinically assessed as having an orthodontic treatment need, however, in those where there was no orthodontic treatment need, a low SOC was associated with a negative self-perception of dental appearance

How Much Does Effortful Thinking Underlie Observers’ Reactions to Victimization?

From blaming to helping innocent victims, just-world research has revealed that observers react to victimization in a variety of ways. Recent research suggests that such responses to victimization require effortful thought, whereas other research has shown that people can react to these situations intuitively. Along with manipulating just-world threat, across seven experiments, we manipulated or measured participants’ level of mental processing before assessing judgments of victim derogation, blame, willingness to help, and ultimate justice reasoning. The effect of just-world threat on these responses held constant over a range of manipulations/measures, suggesting that the processes involved in maintaining a belief in a just world are not restricted to the rational, deliberative level of mental processing but also occur intuitively

Statistical power as a function of Cronbach alpha of instrument questionnaire items

Abstract Background In countless number of clinical trials, measurements of outcomes rely on instrument questionnaire items which however often suffer measurement error problems which in turn affect statistical power of study designs. The Cronbach alpha or coefficient alpha, here denoted by C α , can be used as a measure of internal consistency of parallel instrument items that are developed to measure a target unidimensional outcome construct. Scale score for the target construct is often represented by the sum of the item scores. However, power functions based on C α have been lacking for various study designs. Methods We formulate a statistical model for parallel items to derive power functions as a function of C α under several study designs. To this end, we assume fixed true score variance assumption as opposed to usual fixed total variance assumption. That assumption is critical and practically relevant to show that smaller measurement errors are inversely associated with higher inter-item correlations, and thus that greater C α is associated with greater statistical power. We compare the derived theoretical statistical power with empirical power obtained through Monte Carlo simulations for the following comparisons: one-sample comparison of pre- and post-treatment mean differences, two-sample comparison of pre-post mean differences between groups, and two-sample comparison of mean differences between groups. Results It is shown that C α is the same as a test-retest correlation of the scale scores of parallel items, which enables testing significance of C α . Closed-form power functions and samples size determination formulas are derived in terms of C α , for all of the aforementioned comparisons. Power functions are shown to be an increasing function of C α , regardless of comparison of interest. The derived power functions are well validated by simulation studies that show that the magnitudes of theoretical power are virtually identical to those of the empirical power. Conclusion Regardless of research designs or settings, in order to increase statistical power, development and use of instruments with greater C α , or equivalently with greater inter-item correlations, is crucial for trials that intend to use questionnaire items for measuring research outcomes. Discussion Further development of the power functions for binary or ordinal item scores and under more general item correlation strutures reflecting more real world situations would be a valuable future study