A model-driven approach to better identify older people at risk of depression

Depression in later life is one of the most common mental disorders. Several instruments have been developed to detect the presence or the absence of certain symptoms or emotional disorders, based on cut-off points. However, the use of a cut-off does not allow identification of depression sub-types or distinguish between mild and severe depression. As a result, depression may be under- or over-diagnosed in older people. This paper aims to apply a model-driven approach to classify individuals into distinct sub-groups, based on different combinations of depressive and emotional conditions. This approach is based on two distinct statistical solutions: first, a latent class analysis is applied to the items collected by the depression scale and, according to the final model, the probability of belonging to each class is calculated for every individual. Second, a factor analysis of these classes is performed to obtain a reduced number of clusters for easy interpretation. We use data collected through the EURO-D scale in a large sample of older individuals, participants of the sixth wave of the Survey of Health, Ageing and Retirement in Europe. We show that by using such a model-based approach it is possible to classify individuals in a more accurate way than the simple dichotomisation ‘depressed’ versus ‘non-depressed’

Statistical features of edge turbulence in RFX-mod from Gas Puffing Imaging

Plasma density fluctuations in the edge plasma of the RFX-mod device are measured through the Gas Puffing Imaging Diagnostics. Statistical features of the signal are quantified in terms of the Probability Distribution Function (PDF), and computed for several kinds of discharges. The PDFs from discharges without particular control methods are found to be adequately described by a Gamma function, consistently with the recent results by Graves et al [J.P. Graves, et al, Plasma Phys. Control. Fusion 47, L1 (2005)]. On the other hand, pulses with external methods for plasma control feature modified PDFs. A first empirical analysis suggests that they may be interpolated through a linear combination of simple functions. An inspection of the literature shows that this kind of PDFs is common to other devices as well, and has been suggested to be due to the simultaneous presence of different mechanisms driving respectively coherent bursts and gaussian background turbulence. An attempt is made to relate differences in the PDFs to plasma conditions such as the local shift of the plasma column. A simple phenomenological model to interpret the nature of the PDF and assign a meaning to its parameters is also developed.Comment: 27 pages. Published in PPC

Screening for data clustering in multicenter studies: the residual intraclass correlation

status: publishe

Effect of having private health insurance on the use of health care services: the case of Spain

Background: Several stakeholders have undertaken initiatives to propose solutions towards a more sustainable health system and Spain, as an example of a European country affected by austerity measures, is looking for ways to cut healthcare budgets. Methods: The aim of this paper is to study the effect of private health insurance on health care utilization using the latest micro-data from the European Community Household Panel (ECHP), the Spanish National Health Survey (SNHS) and the European Union Statistics on Income and Living Conditions (EU-SILC). We use matching techniques based on propensity score methods: single match, four matches, bias-adjustment and allowing for heteroskedasticity. Results: The results demonstrate that people with a private health insurance, use the public health system less than individuals without double health insurance coverage. Conclusions: Our conclusions are useful when policy makers design public-private partnership policie

Home enteral nutrition in children—2010 nationwide survey of the polish society for clinical nutrition of children

Published epidemiologic data on the administration rates of enteral/parenteral home nutrition is very limited. The aim of this first nationwide study was to assess the availability of pediatric home enteral nutrition (HEN) services in Poland. The questionnaire was sent to all regional centers providing pediatric HEN services in Poland (n = 14). The analysis included the number of pediatric patients who received HEN in 2010, their demographic characteristics and geographical distribution. Furthermore, the distributions of indications and methods of enteral nutrition administration were analyzed, along with the reasons of withdrawal from the HEN program. The number and fraction of children receiving HEN increased in 2010, from 433 (11.34 per 1 million inhabitants) on January 1st to 525 (13.75) on December 31st. Marked differences were observed in geographical distribution of this parameter, from zero to up to 30 pediatric patients per 1 million inhabitants. Median age of patients was 6 years (range: 9 months–18 years). In most cases, HEN was prescribed due to neurological disorders (n = 337, 64.2%), and administered by means of gastrostomy (n = 450, 85.71%). This study revealed the dynamic development of pediatric HEN services in Poland but also documented their potential regional shortages

The perception of healthcare quality of elderly in the city of Bari, South Italy

<p>Abstract</p> <p>Background</p> <p>In recent decades in Italy, as in all the industrialized nations, the proportion of elderly subjects in the total population is constantly on the increase. However the increased life expectancy is not always paralleled by a true improvement in the quality of life.</p> <p>In this context, it is essential to analyze elderly real health needs and the responses to these needs, especially in terms of healthcare, that the territorial services are perceived to offer.</p> <p>Methods</p> <p>In the period from June to September 2006 we selected randomly one General Practitioner (GP) for each district of the Bari Municipal Area and, form each GP, we randomly chose 25 patients over 65 years old (YO). We conducted phone interviews using a standard data collection questionnaire and, for each of the recruited subjects, the GP filled a data collection sheet.</p> <p>Results</p> <p>Although the mean age (73.6 years) of the population under study was quite high, the general state of health was judged good both by the G P- and by their elderly patients (>75%).</p> <p>Notably, the great majority of elderly patients considered the healthcare they receive to be satisfactory (>60%): in particular, the GP was the true point of reference for this slice of the population for strictly medical problems as well as for advice. On the contrary, the patients attributed little value to social services, which were poorly known and scarcely used (8.5%). Public hospital facilities played a central role in second level healthcare in more than 30% of cases; private facilities covered by public health insurance were also very important. As possible solutions to the problem of loneliness, 36.6% of the patients declared that they approved of nursing homes.</p> <p>Conclusion</p> <p>Decision makers need to create services supporting the key role played by General Practitioners, who are well aware that their assistance is not sufficient to satisfy the health needs of the elderly.</p

When One Size Does Not Fit All: A Simple Statistical Method to Deal with Across-Individual Variations of Effects

In science, it is a common experience to discover that although the investigated effect is very clear in some individuals, statistical tests are not significant because the effect is null or even opposite in other individuals. Indeed, t-tests, Anovas and linear regressions compare the average effect with respect to its inter-individual variability, so that they can fail to evidence a factor that has a high effect in many individuals (with respect to the intra-individual variability). In such paradoxical situations, statistical tools are at odds with the researcher’s aim to uncover any factor that affects individual behavior, and not only those with stereotypical effects. In order to go beyond the reductive and sometimes illusory description of the average behavior, we propose a simple statistical method: applying a Kolmogorov-Smirnov test to assess whether the distribution of p-values provided by individual tests is significantly biased towards zero. Using Monte-Carlo studies, we assess the power of this two-step procedure with respect to RM Anova and multilevel mixed-effect analyses, and probe its robustness when individual data violate the assumption of normality and homoscedasticity. We find that the method is powerful and robust even with small sample sizes for which multilevel methods reach their limits. In contrast to existing methods for combining p-values, the Kolmogorov-Smirnov test has unique resistance to outlier individuals: it cannot yield significance based on a high effect in one or two exceptional individuals, which allows drawing valid population inferences. The simplicity and ease of use of our method facilitates the identification of factors that would otherwise be overlooked because they affect individual behavior in significant but variable ways, and its power and reliability with small sample sizes (<30–50 individuals) suggest it as a tool of choice in exploratory studies