Confidence Interval

Background Bullying has public health importance. It has been reported that both the victims and perpetrators of bullying are more likely to have suicidal ideation and other suicidal behaviours. Moreover, bullying can be a precursor for school violence and can contribute to poor academic performance. The purpose of the study was to raise awareness on the subject in China. We, therefore conducted an analysis of secondary data to determine the prevalence and correlates of having been bullied among in-school adolescents. Methods The data was taken from the Beijing Global School-Based Health Survey conducted in 2003. A weighted analysis to reduce bias due to differing patterns of non-response was conducted using statistical software (SPSS version 14.0). We conducted a backward logistic regression analysis to determine independent predictors for being bullied. Results Out of a total of 2,348 in-school adolescents who participated in the survey, 20% (23% males, and 17% females) reported h...

Low back pain (LBP) in children and adolescents was considered for many years to be rare and an indication of serious disease [1]. In the last two decades, epidemi-ological studies have shown that the prevalence of ... Ismail Bejia Nabiha Abid Kamel Ben Salem Mondher Letaief ...

To determine (i) the extent to which recommended lifestyle healthy behaviors are adopted and the existence of positive attitudes to health; (ii) the relative influence of socio-demographic variables on multiple healthy lifestyle behaviors and positive attitudes to health; (iii) the association between healthy lifestyle behaviors and positive attitudes to health. Two distinct healthy behavioral measures were developed: (i) healthy lifestyles based on physical activity, no cigarette smoking, no/moderate alcohol drinking, maintaining a "healthy" weight and having no sleeping problems and (ii) positive health attitudes based on having positive emotional attitudes, such as: self-perceived good health status, being calm, peaceful and happy for most of the time, not expecting health to get worse and regular health check-ups. A composite healthy lifestyle index, ranging from 0 (none of behaviors met) to 5 (all behaviors met) was calculated by summing up the individual's scores...

To analyze the clinical efficacy of cidofovir combined with highly active anti-retroviral therapy (HAART) in AIDS-related progressive multifocal leukoen-cepalopathy (PML), a multicenter observational study was performed. Consecutive HIV-positive patients with histologically or virologically proven PML and at least 4 weeks of treatment after diagnosis were examined: 27 patients were treated with HAART, whereas 16 patients were treated with HAART plus cidofovir 5 mg/kg intravenously per week for the first 2 weeks and every other week thereafter. JC virus DNA was quantified in cerebrospinal fluid (CSF) by PCR. Baseline virologic, immunologic, and clinical characteristics as well as HIV RNA and CD4 responses to HAART were homogeneous between the groups. The median follow-up was 132 weeks. In one case (6%), cidofovir was permanently discontinued because of severe proteinuria. One-year cumulative probability of survival was 0.61 with cidofovir and 0.29 without (log rank test P = 0.02). After adjusting for baseline CD4 counts, JC viral load in CSF, Karnofsky, and use of HAART prior to the onset of PML, the use of cidofovir was independently associated with a reduced risk of death (hazard ratio, 0.21, 95% confidence interval, 0.07–0.65; P = 0.005). A randomized study will definitively establish whether cidofovir confers significant advantage over HAART alone in AIDS-related PML.

Respiratory infections cause significant mortality in developing countries but are frequently undiagnosed. Reasons for this are unclear. We observed 1,081 outpatient consultations with patients less than five years of age in Tanzania. In 554 patients with cough or difficulty breathing, the absolute percentages examined were 5% for respiratory rate counted, 14% chest exposed, and 25% stethoscope used. Decisions to conduct particular examinations did appear to follow clinical logic, with odds ratios of 4.28 for counting respiratory rate (95% confidence interval [CI]=1.75-10.47), 2.57 for exposing the chest (95% CI=1.67-3.95), and 18.91 for using a stethoscope (95% CI=9.52-37.57) in patients with cough or difficulty breathing. Non-clinical variables, including salary level, were also associated with examinations, and history taking was more common among clinicians originating outside the hospital area. Although respiratory examinations are relatively more common in those with cough or ...

Lead-210 assay and dating are subject to several sources of error, including natural variation, the statistical nature of measuring radioactivity, and estimation of the supported fraction. These measurable errors are considered in calculating confidence intervals for 210Pb dates. Several sources of error, including the effect of blunders or misapplication of the mathematical model, are not included in the quantitative analysis.

Two pairs of confidence intervals for a proportion, similar to that of Larson, are compared. It can be shown through computer simulation experiments that, for certain values of p, the confidence interval obtained by the approximation is superior.

A standard contrast enema for Hirschsprung's disease can sometimes be inconclusive in delineating a transition zone especially in neonates and infants. The aim of this study was to determine the utility and diagnostic accuracy of a plain abdominal radiograph transition zone (PARTZ) in predicting the level of aganglionosis. A prospective observational study of neonates and infants with biopsy proven Hirschsprung's disease was carried out from March 2004 through March 2006. All patients underwent a plain abdominal radiograph and a contrast enema followed by a rectal biopsy. The transition zone on a plain radiograph (PARTZ) and contrast enema (CETZ) were compared with operative and pathology reports. Results were analyzed by chi square test and expressed as their p values and 95% confidence intervals. PARTZ and CETZ suggestive of…

NKX3.1, a member of the NK class of homeodomain proteins, is expressed primarily in the adult prostate and has growth suppression and differentiating effects in prostate epithelial cells. A C-->T polymorphism at nucleotide 154 (NKX3.1 C154T) is present in approximately 11% of healthy men with equal distribution among whites and blacks. In a cohort of 1253 prostate cancer patients and age-matched controls, the presence of the polymorphism was associated with a 1.8-fold risk of having stage C or D prostate cancer or Gleason score > or =7 (confidence interval, 1.01-3.22). The NKX3.1 C154T polymorphism codes for a variant protein that contains an arginine-to-cysteine substitution at amino acid 52 (R52C) adjacent to a protein kinase C phosphorylation site at serine 48. Substitution of cysteine for arginine 52 or of alanine for serine 48 (S48A) reduced phosphorylation at serine 48 in vitro and in vivo. Phosphorylation of wild-type NKX3.1, but not of NKX3.1 R52C or NKX3.1 S48A, dimin...