Conditioning on the Pre-Test versus Gain Score Modelling: Revisiting the Controversy in a Multilevel Setting.

We consider estimating the effect of a treatment on a given outcome measured on subjects tested both before and after treatment assignment in observational studies. A vast literature compares the competing approaches of modelling the post-test score conditionally on the pre-test score versus modelling the difference, namely, the gain score. Our contribution lies in analyzing the merits and drawbacks of two approaches in a multilevel setting. This is relevant in many fields, such as education, where students are nested within schools. The multilevel structure raises peculiar issues related to contextual effects and the distinction between individual-level and cluster-level treatments. We compare the two approaches through a simulation study. For individual-level treatments, our findings align with existing literature. However, for cluster-level treatments, the scenario is more complex, as the cluster mean of the pre-test score plays a key role. Its reliability crucially depends on the cluster size, leading to potentially unsatisfactory estimators with small clusters.

Statistical methods to estimate the impact of remote teaching on university students' performance.

The COVID-19 pandemic manifested around the World since February 2020, leading to disruptive effects on many aspects of people social life. The suspension of face-to-face teaching activities in schools and universities was the first containment measure adopted by the Governments to deal with the spread of the virus. Remote teaching has been the emergency solution implemented by schools and universities to limit the damages of schools and universities closure to students' learning. In this contribution we intend to suggest to policy makers and researchers how to assess the impact of emergency policies on remote learning in academia by analysing students' careers. In particular, we exploit the quasi-experimental setting arising from the sudden implementation of remote teaching in the second semester of academic year 2019/2020: we compare the performance of the cohort 2019/2020, which represents the treatment group, with the performance of the cohort 2018/2019, which represents the control group. We distinguish the impact of remote teaching at two levels: degree program and single courses within a degree program. We suggest to use Difference-In-Differences approach in the former case and multilevel modeling in the latter one. The proposal is illustrated analysing administrative data referred to freshmen of cohorts 2018/2019 and 2019/2020 for a sample of degree programs of the University of Florence (Italy).

Multilevel IRT models for the analysis of satisfaction for distance learning during the Covid-19 pandemic.

The Covid-19 pandemic played a relevant role in the diffusion of distance learning alternatives to "traditional" learning based on classroom activities, to allow university students to continue attending lessons during the most severe phases of the pandemic. In such a context, investigating the students' perspective on distance learning provides useful information to stakeholders to improve effective educational strategies, which could be useful also after the end of the emergency to favor the digital transformation in the higher educational setting. Here we focus on the satisfaction in distance learning for Italian university students. We rely on data comprising students enrolled in various Italian universities, which were inquired about several aspects related to learning distance. We explicitly take into account the hierarchical nature of data (i.e., students nested in universities) and the latent nature of the variable of interest (i.e., students' learning satisfaction) through a multilevel Item Response Theory model with students' and universities' covariates. As the main results of our study, we find out that distance learning satisfaction of students: (i) depends on the University where they study; (ii) is affected by some students' socio-demographic characteristics, among which psychological factors related to Covid-19; (iii) is affected by some observable university characteristics.

Perceived Economic Uncertainty and Fertility Intentions in Couples: A Dyadic Extension of the Theory of Planned Behaviour.

By adopting a dyadic extension of the Theory of Planned Behavior (Ajzen, 1991), this study examined whether perceived economic uncertainty affects fertility intentions. Three-hundred thirty one heterosexual couples living in Italy participated in a randomized between-group experimental study, in which we manipulated perceived economic uncertainty (low vs. high vs. control). The participants subsequently completed a questionnaire measuring their attitudes, subjective norms, perceived behavioral control, and fertility intentions. We employed Structural Equation Modelling in estimating the Actor-Partner Interdependence Model. The model showed a good fit to the data. Women's attitudes, subjective norms, and perceived behavioral control were influenced by the high economic uncertain scenario, whereas among men these variables were affected only by the positive economic scenario. Attitudes and perceived behavioral control were significant predictors of fertility intentions for both sexes. Significant partner effects were observed as well. These findings suggest that fertility plans should be examined by adopting a dyadic perspective, as individuals' intentions are affected not only by their own beliefs, but also by those of their partners.

Male recognition bias in sex assignment based on visual stimuli.

According to previous ethnomethodological and cognitive studies on sex assignment, if a figure has male sexual characteristics people are more likely to think it is a man than they think it is a woman when the figure has female sexual characteristics. This bias in favor of male attribution is strongly reinforced when a penis is apparent in human nude pictures. In our contribution, we reported findings of three experiments aimed at replicating previous studies by administering the Sex/Gender Attribution Test for Adult (SGAT-A) created by digitally morphing the bodies of one human male and one human female model into realistic pictures. We observed the sex attribution and response time of 1706 young adult participants. A cross-cultural comparison was also carried out with a sample of young adult Chinese students. Findings substantially reconfirmed those obtained in previous studies. The male external genitalia overshadow any other features that might rather suggest a female identity. Indeed, when male external genitalia were exposed, the odds of male sex attribution were 5.688 compared to 1.823 female attribution when female external genitalia were shown. Moreover, the shortest response times were observed with masculine stimuli. Evolutionary and cultural determinants of the male sex bias are also discussed.

Students' Complex Problem Solving Profiles.

Complex problem solving (CPS) is an up-and-coming twenty-first century skill that requires test-takers to solve dynamically changing problems, often assessed using computer-based tests. The log data that users produce when interacting with a computer-based test provide valuable information about each individual behavioral action they undertake, but such data are rather difficult to handle from a statistical point of view. This paper addresses this issue by building upon recent research focused on decoding log data and aims to identify homogeneous student profiles with regard to their ability to solve CPS tasks. Therefore, we estimated a discrete two-tier item response theory model, which allowed us to profile units (i.e., students) while taking into account the multidimensionality of the data and the explanatory effect of individual characteristics. The results indicate that: (1) CPS can be thought of as a three-dimensional latent variable; (2) there are ten latent classes of students with homogenous profiles regarding the CPS dimensions; (3) students in the higher latent classes generally demonstrate higher cognitive and non-cognitive performances; (4) some of the latent classes seem to profit from learning-by-doing within tasks, whereas others seem to exhibit the reverse behavior; (5) cognitive and non-cognitive skills, as well as gender and to some extent age, contribute to distinguishing among the latent classes.

A joint model for longitudinal and survival data based on an AR(1) latent process.

A critical problem in repeated measurement studies is the occurrence of nonignorable missing observations. A common approach to deal with this problem is joint modeling the longitudinal and survival processes for each individual on the basis of a random effect that is usually assumed to be time constant. We relax this hypothesis by introducing time-varying subject-specific random effects that follow a first-order autoregressive process, AR(1). We also adopt a generalized linear model formulation to accommodate for different types of longitudinal response (i.e. continuous, binary, count) and we consider some extended cases, such as counts with excess of zeros and multivariate outcomes at each time occasion. Estimation of the parameters of the resulting joint model is based on the maximization of the likelihood computed by a recursion developed in the hidden Markov literature. This maximization is performed on the basis of a quasi-Newton algorithm that also provides the information matrix and then standard errors for the parameter estimates. The proposed approach is illustrated through a Monte Carlo simulation study and the analysis of certain medical datasets.

Evaluation of Student Performance through a Multidimensional Finite Mixture IRT Model.

In the Italian academic system, a student can enroll for an exam immediately after the end of the teaching period or can postpone it; in this second case the exam result is missing. We propose an approach for the evaluation of a student performance throughout the course of study, accounting also for nonattempted exams. The approach is based on an item response theory model that includes two discrete latent variables representing student performance and priority in selecting the exams to take. We explicitly account for nonignorable missing observations as the indicators of attempted exams also contribute to measure the performance (within-item multidimensionality). The model also allows for individual covariates in its structural part.

[Employment status and perceived health in Italy: data from the European Union Statistics on Income and Living Conditions (EU-SILC) longitudinal study]. / Condizione occupazionale e salute percepita in Italia: evidenze da dati longitudinali EU-SILC.

The aim of this study was to investigate the relationship between employment status (permanent employment, fixed-term employment, unemployment, other) and perceived health status in a sample of the Italian population. Data was obtained from the European Union Statistics on Income and Living Condition (EU-SILC) study during the period 2009 - 2012. The sample consists of 4,848 individuals, each with a complete record of observations during four years for a total of 19,392 observations. The causal relationship between perceived/self-reported health status and employment status was tested using a global logit model (STATA). Our results confirm a significant association between employment status and perceived health, as well as between perceived health status and economic status. Unemployment that was dependent on an actual lack of work opportunities and not from individual disability was found to be the most significant determinant of perceived health status; a higher educational level produces a better perceived health status.

Employment Condition, Economic Deprivation and Self-Evaluated Health in Europe: Evidence from EU-SILC 2009-2012.

Background: The mixed empirical evidence about employment conditions (i.e., permanent vs. temporary job, full-time vs. part-time job) as well as unemployment has motivated the development of conceptual models with the aim of assessing the pathways leading to effects of employment status on health. Alongside physically and psychologically riskier working conditions, one channel stems in the possibly severe economic deprivation faced by temporary workers. We investigate whether economic deprivation is able to partly capture the effect of employment status on Self-evaluated Health Status (SHS). Methods: Our analysis is based on the European Union Statistics on Income and Living Conditions (EU-SILC) survey, for a balanced sample from 26 countries from 2009 to 2012. We estimate a correlated random-effects logit model for the SHS that accounts for the ordered nature of the dependent variable and the longitudinal structure of the data. Results and Discussion: Material deprivation and economic strain are able to partly account for the negative effects on SHS from precarious and part-time employment as well as from unemployment that, however, exhibits a significant independent negative association with SHS. Conclusions: Some of the indicators used to proxy economic deprivation are significant predictors of SHS and their correlation with the employment condition is such that it should not be neglected in empirical analysis, when available and further to the monetary income.

A Western Dietary Pattern Increases Prostate Cancer Risk: A Systematic Review and Meta-Analysis.

Dietary patterns were recently applied to examine the relationship between eating habits and prostate cancer (PC) risk. While the associations between PC risk with the glycemic index and Mediterranean score have been reviewed, no meta-analysis is currently available on dietary patterns defined by "a posteriori" methods. A literature search was carried out (PubMed, Web of Science) to identify studies reporting the relationship between dietary patterns and PC risk. Relevant dietary patterns were selected and the risks estimated were calculated by a random-effect model. Multivariable-adjusted odds ratios (ORs), for a first-percentile increase in dietary pattern score, were combined by a dose-response meta-analysis. Twelve observational studies were included in the meta-analysis which identified a "Healthy pattern" and a "Western pattern". The Healthy pattern was not related to PC risk (OR = 0.96; 95% confidence interval (CI): 0.88-1.04) while the Western pattern significantly increased it (OR = 1.34; 95% CI: 1.08-1.65). In addition, the "Carbohydrate pattern", which was analyzed in four articles, was positively associated with a higher PC risk (OR = 1.64; 95% CI: 1.35-2.00). A significant linear trend between the Western (p = 0.011) pattern, the Carbohydrate (p = 0.005) pattern, and the increment of PC risk was observed. The small number of studies included in the meta-analysis suggests that further investigation is necessary to support these findings.

Preterm Birth: Analysis of Longitudinal Data on Siblings Based on Random-Effects Logit Models.

INTRODUCTION: The literature about the determinants of a preterm birth is still controversial. We approach the analysis of these determinants distinguishing between woman's observable characteristics, which may change over time, and unobservable woman's characteristics, which are time invariant and explain the dependence between the typology (normal or preterm) of consecutive births. METHODS: We rely on a longitudinal dataset about 28,603 women who delivered for the first time in the period 2005-2013 in the Umbria Region (Italy). We consider singleton physiological pregnancies originating from natural conceptions with birthweight of at least 500 g and gestational age between 24 and 42 weeks; the overall number of deliveries is 34,224. The dataset is based on the Standard Certificates of Life Birth collected in the region in the same period. We estimate two types of logit model for the event that the birth is preterm. The first model is pooled and accounts for the information about possible previous preterm deliveries, including the lagged response among the covariates. The second model takes explicitly into account the longitudinal structure of data through the introduction of a random effect that summarizes all the (time invariant) unobservable characteristics of a woman affecting the probability of a preterm birth. RESULTS: The estimated models provide evidence that the probability of a preterm birth depends on certain woman's demographic and socioeconomic characteristics, other than on the previous history in terms of miscarriages and the baby's gender. Besides, as the random-effects model fits significantly better than the pooled model with lagged response, we conclude for a spurious state dependence between repeated preterm deliveries. CONCLUSION: The proposed analysis represents a useful tool to detect profiles of women with a high risk of preterm delivery. Such profiles are detected taking into account observable woman's demographic and socioeconomic characteristics as well as unobservable and time-constant characteristics, possibly related to the woman's genetic makeup. TRIAL REGISTRATION: Not applicable.

The role and working conditions of Movement Science students employed in sport and recreational facilities: An Italian multicenter study.

BACKGROUND: In Italy, students from Movement Science (MS) Degree Courses often work in sport and recreational facilities before graduation. OBJECTIVE: The employment conditions of Movement Science students working in sport/recreational facilities were investigated, and the management and structural features of the facilities were evaluated, including safety policies. Regional differences were also considered. METHODS: Questionnaires were administered to undergraduate and graduate students (N = 4,217) in 17 Universities. Students' perceptions of the quality of the facilities where they had been employed was evaluated using multivariate analysis. A latent class model with covariates was used to evaluate how variables relating to participants, employment facilities or regions influence their opinions. RESULTS: A high proportion of MS students were employed in sporting facilities (undergraduate level: 33% ; graduate level: 55%), in most cases without any formal employment contracts. Both the structural and hygienic features, as well as the professional knowledge of the staff, were considered good to excellent by the majority of participants (about 70%). Communication of the basic behavioral rules was considered adequate by 61-63% of undergraduate students and 71-75% of graduate students, while nearly half of the participants were dissatisfied with the staff safety training. Correlations between the perceived good structural/hygienic conditions, the presence of regulations and training programs for the staff were investigated. Differences regarding occupational level and safety training among different regions of Italy were also observed. CONCLUSIONS: Italian students in Movement Science were easily employed in sport/recreational facilities, but frequently without a formal contract. This is a consequence of the lack of specific regulations in the field of recreational/leisure employment and could have negative implications, especially in terms of safety.

Differences in birthweight outcomes: a longitudinal study based on siblings.

OBJECTIVES: We investigate the differences in birthweight between first- and second-borns, evaluating the impact of changes in pregnancy (e.g., gestational age), demographic (e.g., age), and social (e.g., education level, marital status) maternal characteristics. DATA AND METHODS: All analyses are performed on data collected in Umbria (Italy) taking into account a set of 792 women who delivered twice from 2005 to 2008. Firstly, we use a univariate paired t-test for the comparison between weights of first- and second-borns; Secondly, we use linear and nonlinear regression approaches in order to: (i) evaluate the effect of demographic and social maternal characteristics and (ii) predict the odds-ratio of low and high birthweight infants, respectively. RESULTS: We find that the birthweight of second-borns is significantly higher than that of first-borns. Statistically significant effects are related with a longer gestational age, an increased number of visits during the pregnancy, and the gender of infants. On the other hand, we do not observe any significant effect related with mother's age and with other characteristics of interest.

Fecal concentrations of cortisol, testosterone, and progesterone in cotton-top tamarins housed in different zoological parks: relationships among physiological data, environmental conditions, and behavioral patterns.

The aim of this investigation was to study the welfare of 3 captive groups of cotton-top tamarins housed in different zoological parks. Ethological observations were conducted during 1 year. In addition, fecal samples were collected and the concentrations of glucocorticoids, androgens, and progestogens were measured. Within each group, no significant differences in fecal cortisol concentrations were found between subjects. The fecal concentrations of testosterone and progesterone significantly differed depending on the sexes and ages of the tamarins. A significant association was found among hormone concentrations, exhibit dimensions, and group composition. A highly significant correlation was found between all hormones considered and the space available for each subject. Significant differences in behavioral patterns were observed among groups, including social-individual, affiliative-aggressive, and anogenital-suprapubic scent marking. Correlations between hormone measurements and behaviors were detected. In conclusion, this study confirmed the associations between some behaviors exhibited by these nonhuman primates and both cortisol and testosterone; these data also highlight the role played by progesterone in these behaviors.

Temperament and character traits associated with health-related quality of life in cancer patients.

BACKGROUND: There is an increase in the attention to factors influencing the quality of life of cancer patients. The aim of the present study was to evaluate temperament and character traits related to health-related quality of life (HRQoL) in patients with cancer. METHODS: Two hundred and three inpatients from three Italian oncology departments filled in the Temperament Character Inventory (TCI-140) based on Cloninger's personality model, the SF-36 questionnaire assessing HRQoL, and the Hospital Anxiety and Depression Scale (HADS). Eighty percent of patients were undergoing chemotherapy. RESULTS: Lower levels of harm avoidance and higher levels of self-directedness were significantly correlated with a better HRQoL. Regression analysis controlling for psychopathology (anxiety and depression symptoms) showed that the influence of temperament and character traits on quality of life seemed to add little to the influence of psychopathology. CONCLUSIONS: The present study demonstrates the existence of some relations between HRQoL and temperament and character traits assessed using the TCI-140 questionnaire. However, among the psychological factors, psychopathology seems to retain more influence on HRQoL of cancer patients.