Associations between demographic characteristics, school schedules, activity choices, family functioning, and sleep behaviors were estimated using, nationally representative time-diary data from 2,454 children (ages 5.5 to 11.9 years) and adolescents (ages 12.0 to 19.1 years). For weekdays, African American adolescents, Asian children, and those with earlier school start times and longer travel times to school reported fewer sleep hours. More time spent watching television (for children), doing homework (for adolescents), and engaging in religious activities predicted fewer hours, whereas a longer time spent on meals predicted greater hours of weekday sleep. For younger children, greater parental warmth predicted more hours of weekday sleep, whereas for adolescents, stricter household rules were protective. On weekends, African American adolescents and Hispanic children slept less, and there were strong effects of activity choices including time spent on television, computer and video-games, sports, religious activities, socializing, and employment. In accounting for age-related decreases in sleep hours from childhood to adolescence, earlier school start times, greater hours of homework, greater paid employment, less time spent on meals, and fewer household rules were all significant mediators. Read more...

The objective of the present study was to evaluate the presence of pain and musculoskeletal pain syndromes in adolescents and associate them to computer and video game use. A cross-sectional study was performed on the entire adolescent population (n=833) of a private situated in the city of Sao Paulo. The research included a questionnaire and physical examination of the musculoskeletal system. Statistical analysis was carried out with Fisher, chi-square, Mann Whitney tests and logistic regression. A total of 791 adolescent was evaluated. A computer was used by 99% and video games by 58%. Pain was reported by 312 (39.4%) students: 23% complained of back pain, 9% of upper limb pain, 4% of diffuse pain and 4% of pain in the trapezium muscle. A clinical examination was carried out in 359 students, and one or more musculoskeletal pain syndromes were present in 56 students (15.6%): benign joint hypermobility syndrome in 10%, myofascial syndrome in 5%, tendonitis in 2% and fibromyalgia in 1%. In the multivariate analysis, the logistical regression showed that the independent variables in the prediction of pain were sex [odds ratio (OR): 2.19, 95% confidence interval (95% CI): 1.33-3.61] and age (OR: 1.17, 95% CI: 1.07-1.28) and that the prediction of musculoskeletal pain syndromes were sex (OR: 3.17, 95% CI: 1.69-6.22) and number of days a week using the computer (OR: 1.22, 95% CI: 1.05-1.42). However, the variations in the dependent variables by the mathematical regression models were low. Despite the frequent use of computer and video games among adolescents, this was not associated with the presence of pain and musculoskeletal pain syndromes. Read more...

Purpose. This study examined the prevalence rate of astigmatism and its epidemiological risk factors in Singapore school children. Methods. In a study of school children aged 7 to 9 years old in two schools in Singapore in 1999, a detailed questionnaire was administered to parents regarding reading or close-work habits, past history of close-work, family history, and socioeconomic factors. Cycloplegic refraction was performed five times in each eye. Defining astigmatism as worse than or equal to 0.5, 0.75, and 1 D cylinder in the right eye, the prevalence of astigmatism was calculated. Results. The study population consisted of 1028 children. The prevalence rate of astigmatism (worse than or equal to 1 D cylinder) was 19.2% (95% confidence interval, 16.8 to 21.6). This was not different between genders, ethnic groups, or age (p > 0.05). With-the-rule astigmatism was more common than against-the-rule astigmatism. The prevalence of astigmatism and myopia was 9.8% (95% confidence interval, 8.0 to 11.6). A high AC/A ratio was associated (p = 0.003) with astigmatism, even after exclusion of myopic children. On vectorial analysis, J(0) and J(45) were associated with the number of hours of playing video games, whereas J(45) was also associated with computer use. Only J(45) was associated to male gender, a high AC/A ratio, and a family history of myopia. Conclusions. The prevalence rate of astigmatism (greater than or equal to1 D) was 19%. Playing video games and computer use may be associated with astigmatism severity, although the presence of astigmatism (greater than or equal to1 D) was not associated with any nearwork factors. A family history of myopia was associated with oblique astigmatism severity. A high AC/A ratio is associated with astigmatism, and this requires further investigation. Read more...