Search results for " Statistical"
showing 10 items of 1649 documents
Accuracy of the water-siphon test associated to barium study in a high prevalence gastro-oesophageal reflux disease population: a novel statistical a…
2010
Abstract RATIONALE, AIMS AND OBJECTIVES: Gastro-oesophageal reflux disease (GORD) is 'a condition which develops when the reflux of gastric content causes troublesome symptoms or complications'. Instrumental diagnostic tests generally used for GORD are 24-hour pH-metry and upper gastrointestinal (GI) endoscopy but barium study associated with provocative manoeuvres such as the water-siphon test (WST), has also been used for GORD. The aim of this paper was to estimate the accuracy of several tests in patients with GORD in a tertiary care setting, focusing on WST, which is rapid and non-invasive, simple to perform and well-tolerated by patients. METHOD: A total of 172 consecutive patients, sy…
Psychometric properties of the Brief Symptom Inventory-18 in a Spanish breast cancer sample
2007
Abstract Objective The objective of this work was to study the psychometric and structural properties of the Brief Symptom Inventory-18 (BSI-18) in a sample of breast cancer patients ( N =175). Methods Confirmatory factor analyses were conducted. Two models were tested: the theoretical model with the original structure (three-dimensional), and the empirical model (a four-factor structure) obtained through exploratory factor analysis initially performed by the authors of the BSI-18. Results The eligible structure was the original proposal consisting of three dimensions: somatization, depression, and anxiety scores. These measures also showed good internal consistency. Conclusion The results …
Unexpected high frequency of genital involvement in women with clinical and hostological features of oral lichen planus
2006
The main aims of this cross-sectional study were: (i) to assess the frequency of genital (vulval) lichen planus (VLP) and vulval lichen sclerosus (VLS) in women affected with oral lichen planus (OLP), regardless of the genital symptoms reported; and (ii) to verify whether any demographic, clinical, or histological features of OLP are associated with a higher risk of vulvo-vaginal involvement. Fifty-five women, presenting OLP, consecutively underwent gynaecological examination and, if they demonstrated positive clinical signs of VLP, underwent biopsy. After a drop-out of 14 subjects, 31/41 (75.6%) were found to have signs of genital involvement, of which 13/31 (44.0%) were asymptomatic. Foll…
A laparoscopic risk-adjusted model to predict major complications after primary debulking surgery in ovarian cancer: A single-institution assessment
2016
Abstract Objective To develop and validate a simple adjusted laparoscopic score to predict major postoperative complications after primary debulking surgery (PDS) in advanced epithelial ovarian cancer (AEOC). Methods From January 2006 to June 2015, preoperative, intraoperative, and post-operative outcome data from patients undergoing staging laparoscopy (S-LPS) before receiving PDS (n=555) were prospectively collected in an electronic database and retrospectively analyzed. Major complications were defined as levels 3 to 5 of MSKCC classification. On the basis of a multivariate regression model, the score was developed using a random two-thirds of the population (n=370) and was validated on …
Progestogens to prevent preterm birth in twin pregnancies:an individual participant data meta-analysis of randomized trials
2012
Abstract Background Preterm birth is the principal factor contributing to adverse outcomes in multiple pregnancies. Randomized controlled trials of progestogens to prevent preterm birth in twin pregnancies have shown no clear benefits. However, individual studies have not had sufficient power to evaluate potential benefits in women at particular high risk of early delivery (for example, women with a previous preterm birth or short cervix) or to determine adverse effects for rare outcomes such as intrauterine death. Methods/design We propose an individual participant data meta-analysis of high quality randomized, double-blind, placebo-controlled trials of progestogen treatment in women with …
Assessing Causality in normal and impaired short-term cardiovascular regulation via nonlinear prediction methods
2009
We investigated the ability of mutual nonlinear prediction methods to assess causal interactions in short-term cardiovascular variability during normal and impaired conditions. Directional interactions between heart period (RR interval of the ECG) and systolic arterial pressure (SAP) short-term variability series were quantified as the cross-predictability (CP) of one series given the other, and as the predictability improvement (PI) yielded by the inclusion of samples of one series into the prediction of the other series. Nonlinear prediction was performed through global approximation (GA), approximation with locally constant models (LA0) and approximation with locally linear models (LA1) …
Determinants of homonym and synonym rates of record linkage in disease registration.
1996
AbstractReliable record linkage is an essential component of the quality of population-based disease registration. Quality assessment of disease registries should, therefore, include quantitative approaches to describe the extent of record-linkage errors. The homonym and synonym rates have been proposed for this purpose. The homonym rate quantifies the proportion of distinct patients excluded from registration due to erroneous linkage with other patients. The synonym rate quantifies the proportion of unrecognized duplicate notifications on patients already registered in the registry. This paper provides an algebraic assessment of the determinants of both rates. It is shown how the homonym a…
Constant Hierarchic Patterns of Physical Functioning Across Seven Populations in Five Countries
1998
This research was aimed at identifying critical steps in the decline in physical function that often parallels aging. Six basic and nine instrumental activities of daily living (ADLs) were classified into four domains of disability characterized by specific underlying physical impairment. The hierarchical order of this classification was verified in two random samples representative of the older home-dwelling population. The concordance level of disability and results of performance-based measures of physical function were also tested. Finally, the cross-cultural reliability of the model was verified in seven population-based samples of older persons living in five European countries. In ol…
Method Effects: The Problem With Negatively Versus Positively Keyed Items
2012
Using confirmatory factor analyses, we examined method effects on Rosenberg's Self-Esteem Scale (RSES; Rosenberg, 1965) in a sample of older European adults. Nine hundred forty nine community-dwelling adults 60 years of age or older from 5 European countries completed the RSES as well as measures of depression and life satisfaction. The 2 models that had an acceptable fit with the data included method effects. The method effects were associated with both positively and negatively worded items. Method effects models were invariant across gender and age, but not across countries. Both depression and life satisfaction predicted method effects. Individuals with higher depression scores and lowe…
Evaluation of the postural stability of elderly persons using time domain signal analysis
2012
A force platform is widely used in the evaluation of postural stability in man. Although an abundance of parameters are typically retrieved from force platform data, no uniform analysis of the data has been carried out. In general, the signal analysis does not analyze the underlying postural event, i.e., whether the signal consists of several small corrections or large excursions. In the present work, we studied the postural stability of 4589 elderly persons from Iceland on a force platform under visual and non-visual conditions during stance on a solid surface. We analyzed the internal relationship between frequently used time domain variables. In addition, we conducted a factor analysis u…