Search results for " sample"
showing 10 items of 456 documents
Overrating Classifier Performance in ROC Analysis in the Absence of a Test Set: Evidence from Simulation and Italian CARATkids Validation
2019
Background The use of receiver operating characteristic curves, or “ROC analysis,” has become quite common in biomedical research to support decisions. However, sensitivity, specificity, and misclassification rates are still often estimated using the training sample, overlooking the risk of overrating the test performance. Methods A simulation study was performed to highlight the inferential implications of splitting (or not) the dataset into training and test set. The normality assumption was made for the classifier given the disease status, and the Youden's criterion considered for the detection of the optimal cutoff. Then, an ROC analysis with sample split was applied to assess the disc…
Intestinal symptoms and Blastocystis load in schoolchildren of Paranaguá Bay, Paraná, Brazil
2017
ABSTRACT The symptomatology of Blastocystis cannot be attributed to any particular subtype, although can be related to a high Blastocystis infection load. One stool sample from each of 217 schoolchildren of Vale de Sol Paranaguá Bay (Paraná, Brazil) was collected. Three milliliters of each fixed stool sample were processed applying the formalin-ether concentration technique. After obtaining the overall prevalence of intestinal parasites, quantification was carried out in Blastocystis positive samples. A total of 75/217 (34.6%) children suffered from intestinal symptoms (abdominal pain and/or persistent diarrhea), of whom 41.3% (31/75) presented moderate/heavy Blastocystis load with a statis…
Prevalence of cytomegalovirus infection in Italy
1991
SUMMARYBetween 1987 and 1989, the prevalence of antibody to cytomegalovirus (CMV) was determined, by the ELISA method, in serum samples from 1494 apparently healthy subjects, 3–18 years old. Subjects were selected by a systematic cluster sampling from five geographical areas in Italy. The overall prevalence of antibody was 64·2%, increasing from 54·4% in 4–6-year-olds to 73·3% in subjects 17–18 years old (P < 0·01). Prevalence of antibody was significantly higher in females (P < 0·05) and in subjects residing in the South of Italy (P < 0·01). A significant association was found with sociodemographic factors. Subjects belonging to a household with six or more persons had a 1·5-fold …
The Prevalence of sexual abuse in institutions : Results from a representative population-based sample in Germany
2018
The lifetime prevalence of sexual abuse in institutional settings in Germany was examined in a sample representative of the general adult population (N = 2,437). Participants completed a survey on whether they had ever experienced such abuse, its nature (contact, noncontact, forced sexual, intercourse), the type of institution (e.g. school, club), and the relationship of perpetrator to victim (peer, caregiver, staff member). Overall, 3.1% of adult respondents (women: 4.8%, men: 0.8%) reported having experienced some type of sexual abuse in institutions. Adult women reported higher rates of all types than did men, with rates of 3.9% versus 0.8% for contact sexual abuse, 1.2% versus 0.3% for …
Stabilization of asthma prevalence among adolescents and increase among schoolchildren (ISAAC phases I and III) in Spain.
2004
Background: Most studies show a steep increase in asthma prevalence in the last decades, although few studies had applied the same methodology. Recent reports point out the possibility that the epidemic has come to an end. We have studied the prevalence of asthma in a very large sample of children, repeating the study eight years apart. Methods: Repeated cross-sectional studies using the International Study of Asthma and Allergies in Childhood (ISAAC) protocol in a sample of Spanish schoolchildren 6–7 (parent-reported) and 13–14 (self-reported) years old in 1994–95 (phase I) and 2002–2003 (phase III). The number of participants was 42 417 in phase I and 42 813 in phase III. The participat…
Sprint mechanical variables in elite athletes: Are force-velocity profiles sport specific or individual?
2019
Purpose The main aim of this investigation was to quantify differences in sprint mechanical variables across sports and within each sport. Secondary aims were to quantify sex differences and relationships among the variables. Methods In this cross-sectional study of elite athletes, 235 women (23 ± 5 y and 65 ± 7 kg) and 431 men (23 ± 4 y and 80 ± 12 kg) from 23 different sports (including 128 medalists from World Championships and/or Olympic Games) were tested in a 40-m sprint at the Norwegian Olympic Training Center between 1995 and 2018. These were pre-existing data from quarterly or semi-annual testing that the athletes performed for training purposes. Anthropometric and speed-time sprin…
Recognition memory deficits in mild cognitive impairment
2012
There is no agreement on the pattern of recognition memory deficits characteristic of patients diagnosed with mild cognitive impairment (Mel). Whereas lower performance in recollection is the hallmark of Mel, there is a strong controversy about possible deficits in familiarity estimates when using recognition memory tasks. The aim of this research is to shed Iight on the pattern of responding in recollection and familiarity in MCl. Five groups of participants were tested. The main participant samples were those formed by two Mel groups differing in age and an Alzheimer's disease group (AD), which were compared with two control groups, Whereas one of the control groups served to assess the p…
The palliative-supportive care unit in a comprehensive cancer center as crossroad for patients' oncological pathway
2016
Aim The aim of this study was to assess how an admission to an acute palliative-supportive care unit (APSCU), may influence the therapeutic trajectory of advanced cancer patients. Methods A consecutive sample of advanced cancer patients admitted to APCU was assessed. The following parameters were collected: patients demographics, including age, gender, primary diagnosis, marital status, and educational level, performance status and reasons for and kind of admission, data about care-givers, recent anticancer treatments, being on/off treatment or uncertain, the previous care setting, who proposed the admission to APSCU. Physical and psychological symptoms were evaluated at admission and at ti…
The EUropean Network of National Schizophrenia Networks Studying Gene-Environment Interactions (EU-GEI)
2020
Funder: FP7 Ideas: European Research Council; doi: http://dx.doi.org/10.13039/100011199; Grant(s): HEALTH-F2-2010-241909
One‐quarter of chronic hepatitis D patients reach HDV‐RNA decline or undetectability during the natural course of the disease
2021
BACKGROUND Spontaneous HDV-RNA fluctuations, assessed by nonstandardised in-house assays, have been reported during the course of chronic hepatitis delta (CHD). AIMS To evaluate changes in serum HDV-RNA concentrations in untreated CHD patients and correlate these changes with other HBV markers. METHODS A total of 323 consecutive serum samples from 56 CHD patients (detectable HDV-RNA) followed for >3 years were retested for HDV-RNA levels by a sensitive technique using the first WHO international HDV-RNA standard. Quantitative HBsAg, HBV-DNA, and HBV-RNA were also determined. RESULTS Most participants were male, middle-aged, white European, and HBeAg-negative (82%). Almost half had liver cir…