Based on estimates gleaned from the regression model, the sample size was determined under the following assumptions: 1) 10-year old students would be sampled in school clusters with an average of 25 students per school, 2) the 5% significance level was desirable, and 3) at least 90% power was required to detect as significant a predictor that explains 3% of the variability in BMI.
Our study, using a national sample of in-school adolescents in Swaziland, found that the prevalence of truancy was 21.6% (Table 2).
The present study was undertaken to describe the magnitude of risky sexual behaviour and its association with Khat consumption and alcohol use among a national sample of in-school and out-of-school youth in Ethiopia.
Using a unique Internet methodology and a diverse sample of in-school adolescents in Rio de Janeiro, our study addressed gaps and limitations of prior inquiries by examining adolescent knowledge and perceptions of abortion methods outside of clinical settings.
We hypothesized that the PedsQL™ would be a suitable measure, and identify lower health-related quality of life compared to the healthy population sample, particularly in school and social functioning.
In Washington DC, where high levels of lead more than a decade ago in city water sparked a congressional investigation, consultants are finding that about one in every 200 drinking water samples in schools tests too high for lead (filters are generally added to the fountains in question).
Therefore, this work proposes a research aimed to obtain trip generator models for different land uses, through random sampling, in schools of the Libertador municipality, in Mérida-Venezuela.
Because the study required blood sampling in schools, we could not achieve a response rate as high as those attained in questionnaire-based studies.
However, it is difficult to conduct a blood test in epidemiological studies, because the test is very invasive and the handling of large number of blood samples in schools is too complex to perform.
The subgroup 'school-only test' included participants with no previous clinic based testing that provided a urine sample in the school based screening.
