Search results for "Statistics as topic"
showing 10 items of 188 documents
Causal cross-spectral analysis of heart rate and blood pressure variability for describing the impairment of the cardiovascular control in neurally m…
2006
A causal approach to the calculation of coherence and transfer function between systolic pressure (SP) and RR interval variability was applied in eight patients and eight control subjects during prolonged tilt test for investigating the impairment of cardiovascular control related to neurally mediated syncope. The causal analysis showed a depressed baroreflex regulation in resting patients, with reduced gain and increased latency from SP to RR, and a drop of the baroreflex coupling immediately before syncope. These findings, which were not elicited by traditional cross-spectral analysis, strongly suggest the use of the causal approach for the study of syncope mechanisms. © 2006 IEEE.
Gender differences in human immunodeficiency virus–related oral lesions: An Italian study
2001
Abstract Objective: The purpose of this study was to investigate the relationship between oral lesions and gender, age, CD4+ cell count, human immunodeficiency virus-1 (HIV-1) viral load, antiretroviral therapy, and route of transmission in a group of HIV-infected (HIV+) persons from the Mediterranean region. Study Design: The participants in this study were HIV+ adults who sought dental care between January 1999 and June 1999 in the Department of Oral Medicine (University of Palermo, Italy). Results: One hundred thirty-six HIV+ adults came in for an initial oral examination. Their mean age was 35.2 years (SD ± 7.97), and 33% were women. Their mean CD4+ cell count was 325.3 × 106 /L (SD ± 2…
Cingulo-Insular Structural Alterations Associated with Psychogenic Symptoms, Childhood Abuse and PTSD in Functional Neurological Disorders
2017
Objective Adverse early-life events are predisposing factors for functional neurological disorder (FND) and post-traumatic stress disorder (PTSD). Cingulo-insular regions are implicated in the biology of both conditions and are sites of stress-mediated neuroplasticity. We hypothesised that functional neurological symptoms and the magnitude of childhood abuse would be associated with overlapping anterior cingulate cortex (ACC) and insular volumetric reductions, and that FND and PTSD symptoms would map onto distinct cingulo-insular areas. Methods This within-group voxel-based morphometry study probes volumetric associations with self-report measures of functional neurological symptoms, advers…
Pulsatile and steady 24-h blood pressure components as determinants of left ventricular mass in young and middle-aged essential hypertensives
2003
In order to explore the relations between left ventricular mass (LVM) and the pulsatile (pulse pressure) and steady (mean pressure) components of the blood pressure (BP) curve, 304 young and middle-aged essential hypertensive patients were studied by means of 24-h ambulatory BP monitoring and echocardiography. In the overall study population, both the BP components showed significant correlations with LVM. These correlations were unevenly distributed in the subgroups of subjects younger and in those older than 50 years. While in this latter subgroup, in multivariate analysis, both 24-h mean BP (24-MBP) (beta = 0.27; P = 0.008) and 24-h pulse pressure (24-h PP) (beta = 0.23; P = 0.02) were a…
Long-term course of interferon-treated chronic hepatitis C
1998
Abstract Background/Aims: To evaluate whether sustained response to α-interferon improves clinical outcome in patients with chronic hepatitis C. Methods: A cohort of 410 consecutive patients (65% with chronic hepatitis, 35% with cirrhosis) were treated with α-interferon in two trials (mean follow-up 62.1 months, range 7–109 months). All were serum HCV RNA positive before therapy and received first 10 then 5 million units of α-2b or α-n1 interferon three times weekly for 6 to 12 months. Sustained response was defined as normal aminotransferases 12 months after stopping interferon. Results: Sixty-two patients (15.1%: 54 with chronic hepatitis, eight with cirrhosis) were sustained responders. …
The clinical use of statistical permutation test methodology: a tool for identifying predictive variables of outcome.
2015
<b><i>Objectives:</i></b> To identify the predictive variables affecting the outcome after radical surgery for bladder cancer by a newer statistical methodology, i.e. nonparametric combination (NPC). <b><i>Methods:</i></b> A multicenter study enrolled 1,312 patients who had undergone radical cystectomy for bladder cancer in 11 Italian oncological centers from January 1982 to December 2002. A statistical analysis<b> </b>of their medical history and diagnostic, pathological and postoperative variables was performed using a NPC test. The<b> </b>patients were included in a comprehensive database with medical history and cli…
Coping strategies and postpartum depressive symptoms: A structural equation modelling approach
2015
BACKGROUND: Variables such as the mother's personality, social support, coping strategies and stressful events have been described as risk factors for postpartum depression. Structural Equation Modelling (SEM) analysis was used to examine whether neuroticism, perceived social support, perceived life events, and coping strategies are associated with postpartum depressive symptoms at the 8th and 32nd weeks. METHODS: A total of 1626 pregnant women participated in a longitudinal study. Different evaluations were performed 8 and 32weeks after delivery. Several measures were used: the Edinburgh Postnatal Depression Scale (EPDS), the Diagnostic Interview for Genetic Studies (DIGS), the Eysenck Per…
Differential nociceptive deficits in patients with borderline personality disorder and self-injurious behavior: laser-evoked potentials, spatial disc…
2003
Approximately 70-80% of women meeting criteria for borderline personality disorder (BPD) report attenuated pain perception or analgesia during non-suicidal, intentional self-mutilation. The aim of this study was to use laser-evoked potentials (LEPs) and psychophysical methods to differentiate the factors that may underlie this analgesic state. Ten unmedicated female patients with BPD (according to DSM-IV) and 14 healthy female control subjects were investigated using brief radiant heat pulses generated by a thulium laser and five-channel LEP recording. Heat pulses were applied as part of a spatial discrimination task (two levels of difficulty) and during a mental arithmetic task. BPD patien…
Mixed predictability and cross-validation to assess non-linear Granger causality in short cardiovascular variability series
2006
A method to evaluate the direction and strength of causal interactions in bivariate cardiovascular and cardiorespiratory series is presented. The method is based on quantifying self and mixed predictability of the two series using nearest-neighbour local linear approximation. It returns two causal coupling indexes measuring the relative improvement in predictability along direct and reverse directions, and a directionality index indicating the preferential direction of interaction. The method was implemented through a cross-validation approach that allowed quantification of directionality without constraining the embedding of the series, and fully exploited the available data to maximise th…
Biliary sludge and gallstones in pregnancy: Incidence, risk factors, and natural history
1993
To evaluate the incidence and symptoms of and risk factors for biliary sludge and gallstones during pregnancy and to assess the natural history of these conditions in the first year after delivery.Cohort study.A total of 272 pregnant women recruited in the first trimester.Biliary sludge and gallstones were diagnosed using ultrasonography, both during pregnancy and after delivery. Predictors of the presence or disappearance of sludge and stones were examined.Overall, from the first trimester of pregnancy until the immediate postpartum period, 67 women were newly diagnosed with biliary sludge, and 6 women were newly diagnosed with gallstones. The respective incidence rates were 31% (95% Cl, 2…