RESUMO
The Reference values of systolic and diastolic Blood Pressure [BP] levels of school children aged 6-11 years by two different analytic strategies are presented and compared. From the cross-sectional study a total of 2064 children [52.3% boys and 47.7% girls] aged 6-11 years living in Shiraz [southern Iran] and considering their sex and height were used for this analysis. Polynomial Regression [PR] and Quantile Regression [QR] models based on Restricted Cubic Spline [RCS] were performed to calculate age and height specific reference ranges. To assess comparability of the two techniques, a chi-square goodness-of-fit within sex and age groups was preformed for each method. Both statistical methods generated reference values of systolic and diastolic BP using data from apparently healthy children. Analysis of data by two approaches reflected an increase in BP measurements with age and height in both sexes based on a nonlinear manner up to age 11. We found 50th and 95th percentile differences by two methods in BP level between the tallest and the shortest individuals, ranging from 2-7 mmHg. Using the QR model based on RCS offered the most flexible and better fit than PR model. The advantages of the QR led to a better adaptation of reference limits to the original data. This statistical approach might be preferable for the calculation of reference ranges in particular by non-normal distributed variables. Our results might help clinicians reach a consensus on the definition of hypertension in Iranian children living in Shiraz, south of Iran
RESUMO
Background and Objective: atopic diseases are one of the most common chronic conditions in children. A population based matched study was conducted to estimate the prevalence of atopic diseases and this study used to identify its correlations in primary school children aged 6-12 years in Shiraz [Southern Iran]
Materials and Methods: this case-control study was carried out in 2228 primary school children. The children were selected using 2-stage random sampling from the 4 educational distrincts of for each child. The consultant physician examined the children with positive result. After diagnosis of eczema, utricaria and allergic rhinitis control groups were selected by using matching method [Age, sex, school]. The correlations of atopic diseases were determined by conditional logestic regression
Results: the most important results were as follow: Prevalence of diagnosed allergic rhinitis, utricaria and eczema in primary school children estimated in order 5.2% [Boys: 5.2% and girls: 5.12%], 3.6% [Boys: 3.57% and girls: 3.7%] and 1.6% [Boys: 1.53% and girls: 1.7%]. There was no significant association between atopic diseases and birth order, social class, parent's education, parent's smoking and period of breast-feeding. An increased risk of childhood atopic diseases were associated with familiar history of allergic rhinitis [P<0.05], familiar history of utricaria [P<0.05] and familiar history of eczema [P<0.05]
Conclusion: our study confirmed that familiar atopic diseases were significant predictors of childhood allergic rhinitis, utricaria and eczema among school children in Shiraz