purpose : to determine the prevalence of refractive condition and its risk factors among students in mashhad . methods : a total of 2510 students representing a cross-sectional of the population of mashhad were sampled using random cluster sampling strategy. primary and middle school students underwent cycloplegic refraction. the refractive errors of high school students were measured using non...

abstract  background: low birth weight neonates are confronted with some problems after  birth, they should be followed up and evaluated at different ages of life.the aim of this study was to determine the impact of birth weight on the risk of sensorineural hearing impairment on children.  method: this cross sectional and retrospective study determined the prevalence  of hearing problems in low...

PURPOSE The purpose of this study was to evaluate the effects of a school-based intervention program for middle school adolescent girls with depression. METHODS The study was a pretest-posttest repeated-measure design with a nonequivalent control group. Fifty eight students with depressive symptoms were recruited from two middle schools in Seoul, Korea. The data were collected from the interv...

Within-city variation in air pollution has been associated with childhood asthma development, but findings have been inconsistent. We examined whether perinatal air pollution exposure affected asthma onset during "pre-school and "school age" periods in a population-based birth cohort.65,254 children born between 1999 and 2002 in the greater Vancouver metropolitan region were followed until age ...

Long-Term Effects of School Size on Students’ Outcomes We estimate the effect of school size on students’ long-term outcomes such as high school completion, being out of the labor market, and earnings at the age of 30. We use rich register data on the entire population of Danish children attending grade 9 in the period 1986-2004. This allows us to compare the results of different fixed effect a...

Several studies have examined both physical characteristics and fitness of children and youth. The aim of the study was first, to find the tendency of changes in selected morphological characteristics of young male and female tennis players of various ages in the periods 1992-2000-2008; and second, to find the changes in selected variables of young tennis players and to compare them with the re...

background: the body mass index (bmi) is widely used to diagnose overweight and obesity. however, there are limitations on the use of bmi and development of alternative measures can be of clinical importance. this study aimed to compare specificity and sensitivity of weight for height (w/h), waist circumference (wc) and waist-to-height ratio (whtr) with bmi-for-age in diagnosing overweight and ...