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The strategy of tuberculosis (TB) contact investigation is essential for enhancing disease detection. We conducted a cross-sectional study to evaluate the yield of contact investigation for new TB cases, estimate the prevalence of TB, and identify characteristics of index cases associated with infection among contacts of new cases notified between 2010 and 2020 in São Paulo, Brazil. Out of 186466 index TB cases, 131055 (70.3%) underwent contact investigation. A total of 652286 contacts were screened, of which 451704 (69.2%) were examined. Of these, 12243 were diagnosed with active TB (yield of 1.9%), resulting in a number needed to screen of 53 and a number needed to test of 37 to identify one new TB case. The weighted prevalence for the total contacts screened was 2.8% (95% confidence interval [CI]: 2.7%–2.9%), suggesting underreporting of 6021 (95% CI: 5269–6673) cases. The likelihood of TB diagnosis was higher among contacts of cases identified through active case-finding, abnormal chest X-ray, pulmonary TB, or drug resistance, as well as among children, adults, women, individuals in socially vulnerable situations, and those with underlying clinical conditions. The study highlights significant TB underreporting among contacts, recommending strengthened contact investigation to promptly identify and treat new cases.
We propose a hierarchical Bayesian model for analyzing multi-site experimental fMRI studies. Our method takes the hierarchical structure of the data (subjects are nested within sites, and there are multiple observations per subject) into account and allows for modeling between-site variation. Using posterior predictive model checking and model selection based on the deviance information criterion (DIC), we show that our model provides a good fit to the observed data by sharing information across the sites. We also propose a simple approach for evaluating the efficacy of the multi-site experiment by comparing the results to those that would be expected in hypothetical single-site experiments with the same sample size.
Human performance in cognitive testing and experimental psychology is expressed in terms of response speed and accuracy. Data analysis is often limited to either speed or accuracy, and/or to crude summary measures like mean response time (RT) or the percentage correct responses. This paper proposes the use of mixed regression for the psychometric modeling of response speed and accuracy in testing and experiments. Mixed logistic regression of response accuracy extends logistic item response theory modeling to multidimensional models with covariates and interactions. Mixed linear regression of response time extends mixed ANOVA to unbalanced designs with covariates and heterogeneity of variance. Related to mixed regression is conditional regression, which requires no normality assumption, but is limited to unidimensional models. Mixed and conditional methods are both applied to an experimental study of mental rotation. Univariate and bivariate analyzes show how within-subject correlation between response and RT can be distinguished from between-subject correlation, and how latent traits can be detected, given careful item design or content analysis. It is concluded that both response and RT must be recorded in cognitive testing, and that mixed regression is a versatile method for analyzing test data.
Classical factor analysis assumes a random sample of vectors of observations. For clustered vectors of observations, such as data for students from colleges, or individuals within households, it may be necessary to consider different within-group and between-group factor structures. Such a two-level model for factor analysis is defined, and formulas for a scoring algorithm for estimation with this model are derived. A simple noniterative method based on a decomposition of the total sums of squares and crossproducts is discussed. This method provides a suitable starting solution for the iterative algorithm, but it is also a very good approximation to the maximum likelihood solution. Extensions for higher levels of nesting are indicated. With judicious application of quasi-Newton methods, the amount of computation involved in the scoring algorithm is moderate even for complex problems; in particular, no inversion of matrices with large dimensions is involved. The methods are illustrated on two examples.
Van Breukelen offers a promising method for modeling both response speed and response accuracy. However, the underlying conception of both dependent measures is somewhat flawed, leading the author to conclude that the approach possesses limitations that, under revised assumptions, may not hold. The central misconception, and a set of related misconceptions, is addressed, and it is suggested that this approach holds a good deal of promise for application in the perceptual and cognitive sciences.
We extend dynamic generalized structured component analysis (GSCA) to enhance its data-analytic capability in structural equation modeling of multi-subject time series data. Time series data of multiple subjects are typically hierarchically structured, where time points are nested within subjects who are in turn nested within a group. The proposed approach, named multilevel dynamic GSCA, accommodates the nested structure in time series data. Explicitly taking the nested structure into account, the proposed method allows investigating subject-wise variability of the loadings and path coefficients by looking at the variance estimates of the corresponding random effects, as well as fixed loadings between observed and latent variables and fixed path coefficients between latent variables. We demonstrate the effectiveness of the proposed approach by applying the method to the multi-subject functional neuroimaging data for brain connectivity analysis, where time series data-level measurements are nested within subjects.
The adoption of policies promoting healthier restaurant food environments is contingent on their acceptability. Limited evidence exists regarding individual characteristics associated with restaurant food environment policy acceptability, especially health-related characteristics. This study examined associations between health characteristics and restaurant food environment policy acceptability among urban Canadians.
Design:
Links between health characteristics and complete agreement levels with selected policies were examined using data in the cross-sectional Targeting Healthy Eating and Physical Activity survey study, that is, a large pan-Canadian study on policy acceptability. For each policy, several logistic multilevel regression analyses were conducted.
Setting:
Canada’s seventeen most populated census metropolitan areas.
Participants:
Urban Canadian adults responded to the survey (n 27 162).
Results:
Body mass index was not associated with acceptability after adjustments for other health and sociodemographic characteristics were made. Across all policies and analyses, those reporting excellent or very good health statuses were more likely to be in complete agreement with targeted policies than those with good health statuses. For selected policies and analyses, those reporting poor health statuses were also more likely to be in complete agreement than those describing their health status as good. For all policies and analyses, both those consuming restaurant-prepared foods daily and those never consuming these foods were more likely to be in complete agreement than those consuming these foods once per week.
Conclusions:
More research is needed to explain discrepancies in acceptability according to health characteristics. Bringing this study’s findings to the attention of policymakers may help build momentum for policy enactment.
This study employs social cognitive theory to examine the dynamics of ethical climate, environmental passion, and low-carbon behaviours among Malaysian public servants based on data from 407 employees across 37 departments. Although ethical climate did not have a direct impact on low-carbon behaviour, a significant association with environmental passion was observed. Additionally, environmental passion exhibited a noteworthy relationship with low-carbon behaviour, and emerged as a mediator between ethical climate and low-carbon behaviour, with green mindfulness moderating this relationship. These findings underscore the importance of nurturing environmental passion and green mindfulness to promote low-carbon behaviour among employees and aid organisations in addressing environmental challenges. By addressing these empirical gaps, this study contributes to the literature on low-carbon behaviour and offers both theoretical insights and practical implications for sustainability initiatives.
Trust in national and local institutions is an essential component of democracy. The literature has dealt mainly with the former, while less attention has been given to the latter. This paper advances a novel theoretical approach to inquire about trust in local institutions, which is also used to test national ones. We posit that trust is affected by the perceptions individuals have of the physical space where they live. Both a) the perceived quality of life in the neighbourhood where individuals live and b) the neighbourhood (perceived) peripherality are hypothesized to affect trust in local (and to a lesser extent) national institutions. We test our hypotheses in Italy, over a large representative sample of more than 40.000 respondents. We show that both variables are crucial predictors of local trust, but only the perceived quality of life predicts national trust. Equally important, social, cultural and economic individual capital does not modify the relation.
To examine how executive functioning (EF) relates to academic achievement longitudinally in children with neurofibromatosis type 1 (NF1) and plexiform neurofibromas (PNs) and whether age at baseline moderates this relationship.
Method:
Participants included 88 children with NF1 and PNs (ages 6–18 years old, M = 12.05, SD = 3.62, 50 males) enrolled in a natural history study. Neuropsychological assessments were administered three times over 6 years. EF (working memory, inhibitory control, cognitive flexibility, and attention) was assessed by performance-based (PB) and parent-reported (PR) measures. Multilevel growth modeling was used to examine how EF at baseline related to initial levels and changes in broad math, reading, and writing across time, controlling for demographic variables.
Results:
The relationship between EF and academic achievement varied across EF and academic domains. Cognitive flexibility (PB) uniquely explained more variances in initial math, reading, and writing scores; working memory (PB) uniquely explained more variances in initial levels of reading and writing. The associations between EF and academic achievement tended to remain consistent across age groups with one exception: Lower initial levels of inhibitory control (PR) were related to a greater decline in reading scores. This pattern was more evident among younger (versus older) children.
Conclusions:
Findings emphasize the heterogeneous nature of academic development in NF1 and that EF skills could help explain the within-group variability in this population. Routine cognitive/academic monitoring via comprehensive assessments and early targeted treatments consisting of medication and/or systematic cognitive interventions are important to evaluate for improving academic performance in children with NF1 and PNs.
Overweight and obesity have been related to a variety of adverse health outcomes. Understanding the overweight and obesity epidemic in Bangladesh, particularly among reproductive-aged women, is critical for monitoring and designing effective control measures. The purpose of this study was to determine the prevalence of overweight and obesity in reproductive-aged women and to identify the risk factors of overweight and obesity.
Design:
A total of 70 651 women were obtained from the five most recent and successive Bangladesh Demographic and Health Surveys (BDHS). The multilevel logistic regression model was used to explore the individual- and community-level factors of overweight and obesity.
Setting:
Five most recent nationally representative household surveys across all regions.
Approximately 35·2 % (95 % CI: 34·9–35·6 %) of women were either overweight or obese in Bangladesh. At the individual- and community-level, higher age (adjusted odds ratio (aOR) = 5·79, 95 % CI: 5·28–6·34), secondary or higher education (aOR = 1·69 [1·60–1·78]), relatively wealthiest households (aOR = 4·41 [4·10–4·74]), electronic media access (aOR = 1·32 [1·26–1·37]) and community high literacy (aOR = 1·10 [1·04–1·15]) of women were significantly positively associated with being overweight or obese. Whereas, rural residents (aOR = 0·79 [0·76–0·82]) from larger-sized households (aOR = 0·80 [0·73–0·87]) and have high community employment (aOR = 0·92 [0·88–0·97]) were negatively associated with the probability of being overweight or obese.
Conclusion:
Individual- and community-level factors influenced the overweight and obesity of Bangladeshi reproductive-aged women. Interventions and a comprehensive public health plan aimed at identifying and addressing the growing burden of overweight and obesity should be a top focus.
Although the older adult population faces a higher risk of poverty compared to others, there is no clear picture of their poverty in Iran. The aim of this study was to measure multidimensional poverty and its related factors among Iranian older adults. This cross-sectional study was conducted from July to November 2019 and collected data by interviewing 1,280 participants in Tehran, Iran. To compute multidimensional poverty, four dimensions were used: health (disabilities), education, housing and standard of living. Single and multidimensional poverty and the joint distribution of deprivation were calculated. Multilevel logistic regression models were used to determine the relationship between predictor variables and outcome (multidimensional poverty). Multidimensional poverty among Tehran's older people was 59.0 per cent. The prevalence of health, housing, education and standard of living deprivations were 15.4, 25.3, 29.5 and 29.9 per cent, respectively. Furthermore, multivariate analysis shows that living with a spouse, being employed, and having health and social insurance coverage were protective factors, while being female was a risk factor for multidimensional poverty. Approximately 21 per cent of multidimensional poverty variance was attributed to the district level and the remaining was assigned to individual-level factors. This study showed that the older adults living in different areas of Tehran experience different aspects of poverty. So paying attention to the dimensions of multidimensional poverty can play an important role in customising the policies of each district. Also, the findings of this study on risk and protective factors of multidimensional poverty can be effective in designing and implementing interventions to mitigate poverty among the older adults.
To assess the association of sociodemographic and environmental factors with the obesity occurrence in Argentina from a sex- and age-comparative perspective and a multilevel approach.
Design:
Cross-sectional study based on secondary data from the National Survey of Chronic Diseases Risk Factors (CDRF) 2018, Argentina. Two-level logistic regression models stratified by sex and age were used.
Setting:
The nationwide probabilistic sample of the CDRF survey and twenty-four geographical units.
Participants:
16 410 adult people, living in Argentine towns of at least 5000 people, nested into 24 geographical units. Sex and age groups were defined as young (aged 18–44 years), middle-aged (45–64 years) and older (65 years and older) men and women.
Results:
Single men (all age groups) and divorced/widowed men (aged 45 years or older) had a lower obesity risk compared to married ones. In the middle-aged group, men with higher education showed a lower risk than men with incomplete primary education. In young women, a marked social gradient by educational level was observed. A low-income level coupled with highly urbanised contexts represents an unfavourable scenario for young and middle-aged women. Having a multi-person household was a risk factor for obesity (OR = 1·26, P = 0·038) in middle-aged women. Contextual factors linked to the availability of socially constructed recreational resources and green spaces were associated with obesity among young adults.
Conclusions:
Socio-environmental determinants of obesity seem to operate differently according to sex and age in Argentina. This entails the need to address the obesity epidemic considering gender inequalities and the socio-environmental context at each stage of life.
The co-existence of under- and overweight at population level around the globe is well documented. However, this has yet to be explored using suitable statistical techniques in the context of Bangladesh. This study aimed to examine the prevalence and risk factors for being underweight and overweight or obese compared with normal weight in ever-married non-pregnant women aged 15–49 years in Bangladesh using data from the most recent Bangladesh Demographic and Health Survey conducted in 2014. Multilevel multinomial logistic regression (MLMLR) and quantile regression models were fitted to examine the associations of socioeconomic and individual-, household- and community-level factors on the nutritional status of women as measured by BMI. Overall, the prevalences of underweight, normal weight, overweight and obese women were 19%, 58%, 19% and 4%, respectively, in 2014. The MLMLR analysis revealed that women of young age, widowed/divorced/separated, having a larger family size and children aged ≤5 years in the household, currently amenorrhoeic and members of non-government organizations were at significantly increased risk of being underweight; those of older age, having higher parity, more educated, frequently watched TV and non-poor were more likely to be overweight or obese relative to normal BMI. Women from more affluent communities and urban areas were more likely to be overweight or obese relative to normal BMI than their counterparts from less-affluent and rural communities. Women’s nutritional status was found to be heterogeneous across the regions of the country. The findings indicate that, along with individual-level factors, community-level characteristics are also important in explaining women’s BMI in Bangladesh. The issue of under- and overweight or obesity among women in Bangladesh requires the immediate adoption of a public health policy for its mitigation. When developing intervention programmes, important determinants and uniform development of regions should be taken into consideration to combat the dual burden of under- and overweight among women in Bangladesh.
Works in detail through important empirical examples – including a canonical one from Max Weber – showing how supra-individual social causal processes often provide more sensible depictions of historical processes than do cumbersome ones imagining highly autonomous individual and organizational actors.
Economic progress in India over the past three decades has not been accompanied by a commensurate improvement in the nutritional status of children, and a disproportionate burden of undernutrition is still focused on socioeconomically disadvantaged populations in the poorest regions. This study examined the nutritional status of children under 3 years of age using data from the fourth round of Indian National Family Health Survey conducted in 2015–2016. Child undernutrition was assessed in a sample of 126,431 under-3 children using the anthropometric indices of stunting, underweight and wasting (‘anthropometric failure’) across 640 districts, 5489 primary sampling units and 35 states/UTs of India. Descriptive statistics were used to examine the regional pattern of childhood undernutrition. Multilevel logistic regression models were fitted to examine the adjusted effect of social group (tribal vs non-tribal) and economic, demographic and contextual factors on the risks of stunting, underweight and wasting accounting for the hierarchical nature of the data. Interaction effects were estimated to model the joint effects of socioeconomic position (household wealth, maternal education, urban/rural residence and geographical region) and social group (tribal vs non-tribal) with the likelihood of anthropometric failure among children. The burden of childhood undernutrition was found to vary starkly across social, economic, demographic and contextual factors. Interaction effects demonstrated that tribal children from economically poorer households, with less-educated mothers, residing in rural areas and living in the Central region of India had elevated odds of anthropometric deprivation than other tribal children. The one-size-fits-all approach to tackling undernutrition in tribal children may not be efficient and could be counterproductive.
Unit cohesion may protect service member mental health by mitigating effects of combat exposure; however, questions remain about the origins of potential stress-buffering effects. We examined buffering effects associated with two forms of unit cohesion (peer-oriented horizontal cohesion and subordinate-leader vertical cohesion) defined as either individual-level or aggregated unit-level variables.
Methods
Longitudinal survey data from US Army soldiers who deployed to Afghanistan in 2012 were analyzed using mixed-effects regression. Models evaluated individual- and unit-level interaction effects of combat exposure and cohesion during deployment on symptoms of post-traumatic stress disorder (PTSD), depression, and suicidal ideation reported at 3 months post-deployment (model n's = 6684 to 6826). Given the small effective sample size (k = 89), the significance of unit-level interactions was evaluated at a 90% confidence level.
Results
At the individual-level, buffering effects of horizontal cohesion were found for PTSD symptoms [B = −0.11, 95% CI (−0.18 to −0.04), p < 0.01] and depressive symptoms [B = −0.06, 95% CI (−0.10 to −0.01), p < 0.05]; while a buffering effect of vertical cohesion was observed for PTSD symptoms only [B = −0.03, 95% CI (−0.06 to −0.0001), p < 0.05]. At the unit-level, buffering effects of horizontal (but not vertical) cohesion were observed for PTSD symptoms [B = −0.91, 90% CI (−1.70 to −0.11), p = 0.06], depressive symptoms [B = −0.83, 90% CI (−1.24 to −0.41), p < 0.01], and suicidal ideation [B = −0.32, 90% CI (−0.62 to −0.01), p = 0.08].
Conclusions
Policies and interventions that enhance horizontal cohesion may protect combat-exposed units against post-deployment mental health problems. Efforts to support individual soldiers who report low levels of horizontal or vertical cohesion may also yield mental health benefits.
Quantitative comparative social scientists have long worried about the performance of multilevel models when the number of upper-level units is small. Adding to these concerns, an influential Monte Carlo study by Stegmueller (2013) suggests that standard maximum-likelihood (ML) methods yield biased point estimates and severely anti-conservative inference with few upper-level units. In this article, the authors seek to rectify this negative assessment. First, they show that ML estimators of coefficients are unbiased in linear multilevel models. The apparent bias in coefficient estimates found by Stegmueller can be attributed to Monte Carlo Error and a flaw in the design of his simulation study. Secondly, they demonstrate how inferential problems can be overcome by using restricted ML estimators for variance parameters and a t-distribution with appropriate degrees of freedom for statistical inference. Thus, accurate multilevel analysis is possible within the framework that most practitioners are familiar with, even if there are only a few upper-level units.
We studied the relation between individual and neighborhood socioeconomic characteristics and the probability of:
– new long-duration antidepressant treatment;
– early antidepressant discontinuation.
Methods
We followed two cohorts of inhabitants of Marseille (aged 18–64 years) covered by the National Health Insurance Fund (NHIF) for 2.5 years. In the first cohort (316,412 individuals in 2008), we studied new long-duration antidepressant treatments (≥ 4 antidepressants prescription claims within 6 months after the index claim, and none in the 6 months before). The second cohort was restricted to the 14,518 individuals with a new episode of antidepressant treatment prescribed by a private GP in 2008–2009 to study early treatment discontinuation: < 4 antidepressant prescription claims in the 6 months following the index claim. We developed a deprivation index at the neighborhood level (census block) and used multivariate multilevel logistic models adjusted for consultations with GPs and psychiatrists. In the second cohort, analyses were further adjusted on GPs characteristics.
results
First cohort: the probability of new long-duration antidepressant treatments was negatively associated with both individual low income and neighborhood deprivation. Second cohort: low income, and prescribers’ clientele composition (high proportion of disadvantaged patients) were independently associated with an increased risk of early discontinuation. A significant interaction was found between low income and gender.
Conclusions
Our results add further evidence supporting the existence of inequalities in antidepressant treatment at both the individual, GP and neighborhood levels, and that these inequalities occur principally during the processes of care. Inequalities in antidepressant continuation are more pronounced among women. Further research is warranted to improve our understanding of their mechanisms.