Multilevel Analysis in Household Survey: An Application to Health Condition Data

The aim of this thesis is to apply multilevel regression model in context of household surveys. Hierarchical structure in this type of data is characterized by many small groups. In last years comparative and multilevel analysis in the field of perceived health have grown in size. The purpose of this thesis is to develop a multilevel analysis with three level of hierarchy for Physical Component Summary outcome to: evaluate magnitude of within and between variance at each level (individual, household and municipality); explore which covariates affect on perceived physical health at each level; compare model-based and design-based approach in order to establish informativeness of sampling design; estimate a quantile regression for hierarchical data. The target population are the Italian residents aged 18 years and older. Our study shows a high degree of homogeneity within level 1 units belonging from the same group, with an intraclass correlation of 27% in a level-2 null model. Almost all variance is explained by level 1 covariates. In fact, in our model the explanatory variables having more impact on the outcome are disability, unable to work, age and chronic diseases (18 pathologies). An additional analysis are performed by using novel procedure of analysis :"Linear Quantile Mixed Model", named "Multilevel Linear Quantile Regression", estimate. This give us the possibility to describe more generally the conditional distribution of the response through the estimation of its quantiles, while accounting for the dependence among the observations. This has represented a great advantage of our models with respect to classic multilevel regression. The median regression with random effects reveals to be more efficient than the mean regression in representation of the outcome central tendency. A more detailed analysis of the conditional distribution of the response on other quantiles highlighted a differential effect of some covariate along the distribution.

“Studio antropologico dei resti umani appartenenti alla Famiglia principesca degli Aragona Tagliavia di Castelvetrano: l’importanza delle ossa nell’analisi storica in contesto archeologico – funerario”

Per comprendere le vicende di una famiglia illustre e nobile il cui ruolo politico e sociale in Sicilia si data alle soglie del XIV secolo, non possiamo astenerci dal ricordare i fatti e gli eventi che hanno dominato la storia siciliana e determinato l’ascesa di Castelvetrano come centro signorile per eccellenza. E’ necessario, quindi, collocare geograficamente e storicamente l’isola per inserirla all’interno di un preciso quadro socio-politico. All’origine della sua storia sono sicuramente da individuare sia il legame intercorso nei secoli tra l’Asia e l’Europa, in particolare tra l’Asia Minore bizantina e l’area mediterranea unificata proprio dall’impero di Bisanzio, sia le lotte per l’egemonia tra Chiesa e Impero, (che abbastanza presto sarà impero d’Occidente) lotte che vedono entrambe le parti impegnate a contendersi il ruolo di guida politica, morale e spirituale dell’intera cristianità medievale, ritenendo ogni altro potere subordinato al proprio.