Transgender Attitudes and Beliefs Scale-Greek (TABS-Gr) version: translation and initial evaluation of psychometric properties among medical students.

BACKGROUND: Transgender people face significantly greater discrimination and health disparities in health care settings than cisgender people. The role of education in eliminating this phenomenon has been increasingly recognized by many medical schools. However, transgender health content is sparse or lacking in the medical curricula of many countries. METHOD: This study was designed to validate the Greek version of the Transgender Attitudes and Beliefs Scale (TABS-Gr). The study adopted a cross-sectional, comparative-descriptive research design. Participants (N = 203) were contacted through online recruitment and invited to complete an anonymous web-based survey. The data were collected between December 2022 and February 2023. RESULTS: The overall reliability of the TABS-Gr questionnaire was high (Cronbach's α = 0.961, p. from Hotelling's T-squared test < 0.000). High Cronbach's alpha values were estimated for the three subscales, with α = 0.958 for Interpersonal Comfort, α = 0.906 for Gender Beliefs, and α = 0.952 for Human Values. Hotelling's T-squared test confirmed that all items on the scale had the same mean (p < 0.001 for all subgroups). Explanatory factor analysis (EFA) demonstrated adequate fit. Convergent and discriminant validity were validated based on the estimated correlations. The three-factor structure of the Greek TABS version was confirmed. The mean total score was 155.95 (SD = 30.63), indicating that medical students had a moderately positive attitude towards transgender people. Participants showed significantly less biased (more tolerant, positive) attitudes towards transgender people on the Interpersonal Comfort (IC) and Human Value (HV) subscales than on the Sex/Gender Beliefs (SGB) subscale. A demographic comparison was conducted and demonstrated a correlation between scores and sociodemographics, except for place of origin. A statistically significant increase in the total mean score was estimated for women compared to men. CONCLUSION: The overall psychometric findings provide some evidence to support the validity of the Greek version of the TABS. However, we call for further validation research in Greek medical schools. Since our claims for validity are based in part on an exploratory factor analysis, a future confirmatory factor analysis (CFA) is part of our call for further validation research. While the results of this study are mostly in line with the results of previous research, some nuances were identified. These results may inform educators, medical school curricula and education policy-makers.

Connectivity Analysis for Multivariate Time Series: Correlation vs. Causality.

The study of the interdependence relationships of the variables of an examined system is of great importance and remains a challenging task. There are two distinct cases of interdependence. In the first case, the variables evolve in synchrony, connections are undirected and the connectivity is examined based on symmetric measures, such as correlation. In the second case, a variable drives another one and they are connected with a causal relationship. Therefore, directed connections entail the determination of the interrelationships based on causality measures. The main open question that arises is the following: can symmetric correlation measures or directional causality measures be applied to infer the connectivity network of an examined system? Using simulations, we demonstrate the performance of different connectivity measures in case of contemporaneous or/and temporal dependencies. Results suggest the sensitivity of correlation measures when temporal dependencies exist in the data. On the other hand, causality measures do not spuriously indicate causal effects when data present only contemporaneous dependencies. Finally, the necessity of introducing effective instantaneous causality measures is highlighted since they are able to handle both contemporaneous and causal effects at the same time. Results based on instantaneous causality measures are promising; however, further investigation is required in order to achieve an overall satisfactory performance.

Non-Uniform Embedding Scheme and Low-Dimensional Approximation Methods for Causality Detection.

Information causality measures have proven to be very effective in uncovering the connectivity patterns of multivariate systems. The non-uniform embedding (NUE) scheme has been developed to address the "curse of dimensionality", since the estimation relies on high-dimensional conditional mutual information (CMI) terms. Although the NUE scheme is a dimension reduction technique, the estimation of high-dimensional CMIs is still required. A possible solution is the utilization of low-dimensional approximation (LA) methods for the computation of CMIs. In this study, we aim to provide useful insights regarding the effectiveness of causality measures that rely on NUE and/or on LA methods. In a comparative study, three causality detection methods are evaluated, namely partial transfer entropy (PTE) defined using uniform embedding, PTE using the NUE scheme (PTENUE), and PTE utilizing both NUE and an LA method (LATE). Results from simulations on well known coupled systems suggest the superiority of PTENUE over the other two measures in identifying the true causal effects, having also the least computational cost. The effectiveness of PTENUE is also demonstrated in a real application, where insights are presented regarding the leading forces in financial data.

Exploitation of Information as a Trading Characteristic: A Causality-Based Analysis of Simulated and Financial Data.

In financial markets, information constitutes a crucial factor contributing to the evolution of the system, while the presence of heterogeneous investors ensures its flow among financial products. When nonlinear trading strategies prevail, the diffusion mechanism reacts accordingly. Under these conditions, information englobes behavioral traces of traders' decisions and represents their actions. The resulting effect of information endogenization leads to the revision of traders' positions and affects connectivity among assets. In an effort to investigate the computational dimensions of this effect, we first simulate multivariate systems including several scenarios of noise terms, and then we apply direct causality tests to analyze the information flow among their variables. Finally, empirical evidence is provided in real financial data.

An estimate of the prevalence of COPD in Africa: a systematic analysis.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is among the leading causes of death globally, accounting for about 3 million deaths worldwide in 2011. We aimed to estimate the prevalence of COPD in Africa in the year 2010 to provide the information that could assist health policy in the region. METHODS: We conducted a systematic review of Medline, EMBASE and Global Health for studies on COPD published between 1990 and 2012. We included original population based studies providing estimates of the prevalence of COPD. We considered the reported estimates in terms of the mean age of the sample, sex ratio, the year of study and the country of the study as possible covariates. RESULTS from two different types of studies, i.e., based on spirometric and non-spirometric diagnosis of COPD, were further compared. The United Nation Population Division's population figures were used to estimate the number of COPD cases in the year 2010. RESULTS: Our search returned 243 studies, from which only 13 met our selection criteria and only five were based on spirometry. The difference in the median prevalence of COPD in persons aged 40 years or older based on spirometry data (13.4%; IQR: 9.4%-22.1%) and non-spirometry data (4.0%; IQR: 2.1%-8.9%) was statistically significant (p = 0.001). There was no significant effect of the gender or the year of the study on the reported prevalence of COPD in either set of studies. The prevalence of COPD increased with age in spirometry-based studies (p = 0.017), which is a plausible finding suggesting internal consistency of spirometry-based estimates, while this trend was not observed in studies using other case definitions. When applied to the appropriate age group (40 years or more), which accounted for 196.4 million people in Africa in 2010, the estimated prevalence translates into 26.3 million (18.5-43.4 million) cases of COPD. Comparable figures for the year 2000 based on the same prevalence rates would amount to 20.0 million (14.1-33.1), suggesting an increase of 31.5% over a decade that is attributable to ageing of the African population alone. CONCLUSION: Our findings suggest that COPD is likely to already represent a very large public health problem in Africa. Moreover, rapidly ageing African population should expect a steady increase in the number of COPD cases in the next decade and beyond. The quantity and quality of available evidence does not match the size of the problem. There is a need for more research on COPD prevalence, but also incidence, mortality and risk factors in Africa. We hope this study will raise awareness of COPD in Africa and encourage further research.

Estimating the incidence of colorectal cancer in South East Asia.

AIM: To estimate the burden of colorectal cancer (CRC) in South East Asia. METHODS: We reviewed the evidence from the published literature found through a systematic review in Medline, Embase, and Global Health and from unpublished data on cancer registries, which were sourced from the International Agency for Research on Cancer. Incidence rates were summarized by calculating descriptive statistics and meta-analysis estimates. RESULTS: The crude mean incidence of CRC in South East Asia for both sexes was 6.95/100000 population and the incidence increased with age. The crude meta-analysis estimate was 6.12/100000 population (95% confidence interval 5.64-6.60/100000) and the number of new CRC cases for 2000 was 32058 (29544-34573). CONCLUSION: The rates of CRC in South East Asia were much lower than those reported for high-income countries, but higher than those reported for Sub Saharan Africa.

Ageism among dentists who are Facebook users in Greece.

The phenomenon of ageism in healthcare is a significant threat to elderly people's well-being. There is a literature gap regarding the topic of ageism among dental professionals in Greece. This study aims to contribute to filling this gap. A cross-sectional study was conducted using recently validated in Greece 15-item ageism 6-point Likert-scale. The scale has been previously validated in the environment of senior dental students. Purposive sampling was used to select participants. A total of 365 dentists responded to the questionnaire. As to the internal consistency of the scale, Cronbach's alpha found to be very low (α = 0.590) to support the reliability of a total of 15 Likert-type questions (items) of the scale. However, the factor analysis resulted in three factors that achieved high reliability towards validity. The demographic comparison with these factors and single items revealed statistically significant gender differences in ageism (with males being more ageist than females), and differences related to other socio-demographic factors, which however, were related to factors or items individually. The study revealed that the Greek version of the ageism scale for dental students had not further validity and reliability among dentists. However, some items were distributed into three factors that presented significant validity and reliability. This is of great importance for the ongoing research on the topic ″ageism in dental healthcare″.

Reliability of Greek version of the Toronto empathy questionnaire in medical students and associations with sociodemographic and lifestyle factors.

BACKGROUND: Empathy is an important key driver of any therapeutic relationship. It is beneficial for both physicians and patients. Enhancing physician's empathy should be an important goal of medical education. As there was a literature gap regarding the topic of empathy among medical students in Greece, this study aimed to contribute to filling this gap. METHODS: A cross-sectional study was conducted. A socio-demographic questionnaire and the 52-item Greek version of the Toronto composite empathy scale (TCES) for measuring the cognitive and emotional aspects of empathy in both personal and professional life was administered to all the medical students in the Aristotle University of Thessaloniki, in Greece. Descriptive statistics were displayed for demographics. The associations of the variables were quantified by Chi-2 independence tests and Pearson's Correlation Coefficient. The reliability and validity of the questionnaire was determined by Cronbach's α, Hotelling's T-Squared Test, and Pearson correlation. Paired and Independent Sample T-Tests and One-way ANOVAs indicated statistically significant mean differences among the variables or subgroups of the variables. RESULTS: The 52-item TCES, 26 for the personal (Per) setting and another 26 for professional (Pro) life, equally divided into cognitive (Cog) and emotional (Emo) empathy in each case. The overall reliability of the TCES questionnaire was found to be high (Cronbach's α = 0.895, significant positive correlations between the subscales). The mean total score of empathy showed that students had a moderately high empathy. Further, there was a statistically significant difference in means between the Per-Cog and Per-Emo settings (p < 0.001), the Pro-Cog and Pro-Emo (p < 0.001), the Per-Cog and Pro-Cog (p = 0.004), and the Per-Emo and Pro-Emo (p < 0.001). Females had significantly higher empathy scores (mean score 208.04) than males (192.5) on the Per-Cog, Per-Emo and Pro-Emo subscales. Furthermore, a positive correlation was found between empathy and factors such as love for animals, interest in medical ethics, belief in God, having an ill person in the family, class year or carrier intention. CONCLUSIONS: The TCES is applicable to medical students. For the most part our findings were consistent with previous literature. However, we identified some nuances that might draw researchers' attention. The results of this study may contribute to plan interventions in the curriculum to enhance empathy in the medical students.

Assessment of resampling methods for causality testing: A note on the US inflation behavior.

Different resampling methods for the null hypothesis of no Granger causality are assessed in the setting of multivariate time series, taking into account that the driving-response coupling is conditioned on the other observed variables. As appropriate test statistic for this setting, the partial transfer entropy (PTE), an information and model-free measure, is used. Two resampling techniques, time-shifted surrogates and the stationary bootstrap, are combined with three independence settings (giving a total of six resampling methods), all approximating the null hypothesis of no Granger causality. In these three settings, the level of dependence is changed, while the conditioning variables remain intact. The empirical null distribution of the PTE, as the surrogate and bootstrapped time series become more independent, is examined along with the size and power of the respective tests. Additionally, we consider a seventh resampling method by contemporaneously resampling the driving and the response time series using the stationary bootstrap. Although this case does not comply with the no causality hypothesis, one can obtain an accurate sampling distribution for the mean of the test statistic since its value is zero under H0. Results indicate that as the resampling setting gets more independent, the test becomes more conservative. Finally, we conclude with a real application. More specifically, we investigate the causal links among the growth rates for the US CPI, money supply and crude oil. Based on the PTE and the seven resampling methods, we consistently find that changes in crude oil cause inflation conditioning on money supply in the post-1986 period. However this relationship cannot be explained on the basis of traditional cost-push mechanisms.

Global and regional estimates of COPD prevalence: Systematic review and meta-analysis.

BACKGROUND: The burden of chronic obstructive pulmonary disease (COPD) across many world regions is high. We aim to estimate COPD prevalence and number of disease cases for the years 1990 and 2010 across world regions based on the best available evidence in publicly accessible scientific databases. METHODS: We conducted a systematic search of Medline, EMBASE and Global Health for original, population-based studies providing spirometry-based prevalence rates of COPD across the world from January 1990 to December 2014. Random effects meta-analysis was conducted on extracted crude prevalence rates of COPD, with overall summaries of the meta-estimates (and confidence intervals) reported separately for World Health Organization (WHO) regions, the World Bank's income categories and settings (urban and rural). We developed a meta-regression epidemiological model that we used to estimate the prevalence of COPD in people aged 30 years or more. FINDINGS: Our search returned 37 472 publications. A total of 123 studies based on a spirometry-defined prevalence were retained for the review. From the meta-regression epidemiological model, we estimated about 227.3 million COPD cases in the year 1990 among people aged 30 years or more, corresponding to a global prevalence of 10.7% (95% confidence interval (CI) 7.3%-14.0%) in this age group. The number of COPD cases increased to 384 million in 2010, with a global prevalence of 11.7% (8.4%-15.0%). This increase of 68.9% was mainly driven by global demographic changes. Across WHO regions, the highest prevalence was estimated in the Americas (13.3% in 1990 and 15.2% in 2010), and the lowest in South East Asia (7.9% in 1990 and 9.7% in 2010). The percentage increase in COPD cases between 1990 and 2010 was the highest in the Eastern Mediterranean region (118.7%), followed by the African region (102.1%), while the European region recorded the lowest increase (22.5%). In 1990, we estimated about 120.9 million COPD cases among urban dwellers (prevalence of 13.2%) and 106.3 million cases among rural dwellers (prevalence of 8.8%). In 2010, there were more than 230 million COPD cases among urban dwellers (prevalence of 13.6%) and 153.7 million among rural dwellers (prevalence of 9.7%). The overall prevalence in men aged 30 years or more was 14.3% (95% CI 13.3%-15.3%) compared to 7.6% (95% CI 7.0%-8.2%) in women. CONCLUSIONS: Our findings suggest a high and growing prevalence of COPD, both globally and regionally. There is a paucity of studies in Africa, South East Asia and the Eastern Mediterranean region. There is a need for governments, policy makers and international organizations to consider strengthening collaborations to address COPD globally.

Prevalence of rheumatoid arthritis in low- and middle-income countries: A systematic review and analysis.

BACKGROUND: Rheumatoid arthritis (RA) is an autoimmune disorder that affects the small joints of the body. It is one of the leading causes of chronic morbidity in high-income countries, but little is known about the burden of this disease in low- and middle-income countries (LMIC). METHODS: The aim of this study was to estimate the prevalence of RA in six of the World Health Organization's (WHO) regions that harbour LMIC by identifying all relevant studies in those regions. To accomplish this aim various bibliographic databases were searched: PubMed, EMBASE, Global Health, LILACS and the Chinese databases CNKI and WanFang. Studies were selected based on pre-defined inclusion criteria, including a definition of RA based on the 1987 revision of the American College of Rheumatology (ACR) definition. RESULTS: Meta-estimates of regional RA prevalence rates for countries of low or middle income were 0.40% (95% CI: 0.23-0.57%) for Southeast Asian, 0.37% (95% CI: 0.23-0.51%) for Eastern Mediterranean, 0.62% (95% CI: 0.47-0.77%) for European, 1.25% (95% CI: 0.64-1.86%) for American and 0.42% (95% CI: 0.30-0.53%) for Western Pacific regions. A formal meta-analysis could not be performed for the sub-Saharan African region due to limited data. Male prevalence of RA in LMIC was 0.16% (95% CI: 0.11-0.20%) while the prevalence in women reached 0.75% (95% CI: 0.60-0.90%). This difference between males and females was statistically significant (P < 0.0001). The prevalence of RA did not differ significantly between urban and rural settings (P = 0.353). These prevalence estimates represent 2.60 (95% CI: 1.85-3.34%) million male sufferers and 12.21 (95% CI: 9.78-14.67%) million female sufferers in LMIC in the year 2000, and 3.16 (95% CI: 2.25-4.05%) million affected males and 14.87 (95% CI: 11.91-17.86%) million affected females in LMIC in the year 2010. CONCLUSION: Given that majority of the world's population resides in LMIC, the number of affected people is substantial, with a projection to increase in the coming years. Therefore, policy makers and health-care providers need to plan to address a significant disease burden both socially and economically.