Longitudinal trends in physical activity patterns in selected urban south Indian school children.

Background & objectives: There are very few studies describing the pattern of physical activity of children in India. This study was carried out to document patterns of physical activity in south Indian school children aged 8 to 15 yr and examine changes over a one year period. Methods: Physical activity was assessed using interviewer-administered questionnaires at baseline (n=256) and at follow up (n=203) in 2006 and 2007. Frequency and duration of each activity was recorded and metabolic equivalents (MET) assigned. Sedentary activity included activities with MET < 1.5, and moderate-to- vigorous physical activity (MVPA) with >3.0. For each activity, daily duration, intensity (MET), and the product of the two (MET-minutes) were computed. Children were categorized by age group, gender and socio-economic status. Height and weight were measured. Results: At baseline, sedentary activity was higher in children aged >11 yr, while intensity of MVPA was higher in boys than girls. Over one year, physical activity at school significantly decreased (P<0.001). There was also a significant decrease in MVPA MET-min (P<0.001) with interaction effects of age group (P<0.001) and gender (P<0.001). Interpretation & conclusions: There was a significant decline in moderate-to-vigorous physical activity over a single year follow up, largely due to a decrease in physical activity at school. There appears to be a gap between State educational policies that promote physical well-being of school-going children and actual practice.

Evaluating the suitability of prediction equations for lung function in Indian children: a practical approach.

OBJECTIVE: Although several prediction equations to evaluate peak expiratory flow rate (PEFR) of Indian children are available in literature, clinicians and researchers need to make a logical choice of which equation to use as reference. The aim was to demonstrate a practical approach to making such a logical choice by using prediction equations on our study population. METHODS: Eighteen linear regression equations generated on Indian children were chosen from available literature. PEFR measured on a Wright peak flow meter on 81 boys and 60 girls, aged between 8 and 13 years, was compared with the predicted values obtained from the equations. Data was systematically analyzed for the extent of over-estimation and under-estimation, correlation between the predicted and measured values and bias and limits of agreement using Bland-Altman plots. RESULTS: The correlation between observed and predicted values using the eighteen equations ranged between 0.616 and 0.797 (for all P < 0.001). The Bland-Altman plots indicated that for all but three equations in boys and three equations in girls, lower measured values of PEFR were associated with higher predicted values. A final choice of a reference prediction equation was based on a combination of factors which included a high correlation between actual and predicted PEFR values, the bias of the estimate, the limits of agreement and the extent to which equations over or under-estimated PEFR. CONCLUSION: A practical approach to evaluate the applicability of prediction equations on an independent data set has been demonstrated.