Validation of self-reported physical activity by accelerometry among primary school children in Kilimanjaro, Tanzania: a pilot study

Mary Vincent Mosha,Elizabeth Kasagama,Heiner Grosskurth,Jim Todd,Suzanne Filteau,Philip Ayieko,Sia E Msuya

doi:10.12688/aasopenres.13118.1

Abstract

Background: Self-reports are commonly used to assess physical activity in children. Existing self-reports for physical activity have not been validated for use among primary school children in Kilimanjaro, Tanzania. In order to understand if primary school children can accurately report their physical activity, we examined the validity of self-reported physical activity against accelerometer measured physical activity. Methods: A community based cross-sectional study was conducted from May to July, 2018 among four primary schools in Moshi municipal and Moshi rural districts, Kilimanjaro, Tanzania. A total of 51 primary school children aged 9-11 years were enrolled using a simple random sampling technique. A self-reported questionnaire was used to collect physical activity related variables. In addition, children wore accelerometers for seven consecutive days to capture physical activity movements. Spearman's rank test and Bland Altman plots were used for assessing validity and agreement between self-reports and accelerometer moderate to vigorous physical activity (MVPA). Results: The mean age of the study participants was 10 (SD=0.8) years. Majority of the study participants were female 32 (63%). A moderate, positive correlation was found between self-reports and accelerometer MVPA (rho=0.36, p=0.009). Accelerometer had higher MVPA compared to self-reports. Children who reported walking to school had higher MVPA for both accelerometer and self- reports compared to children who use other means of transport to school, e.g. school buses (p < 0.001). Conclusions: This study found the moderate positive correlation between self-reports and accelerometers. Self-reports are prone to errors due to recall bias, and this interferes their validity. More research is needed to develop better self-reported measures with specific activities which can easily be recalled by children. Also, researchers have to be aware of self-reports validity limitation.

Highlights

Physical activity in children is key to better health
The validity of self-reports for assessing physical activity in primary school children have not been fully explored in our setting
It is unclear if children from Tanzania can accurately report their physical activity, or estimate minutes spent in physical activity

Summary

Introduction

Physical activity in children is key to better health. Active children gain health benefits including cardiorespiratory, muscular fitness and bone health. The World Health Organization (WHO) recommends an average of at least 60 minutes per day of moderate to vigorous activities for 5–17-year-olds, to gain benefits for their later life[2,3,4]. In Tanzania, 82.1% of school-going children are not meeting the recommended physical activity levels[7]. Self-reports are commonly used to assess physical activity in children. Existing self-reports for physical activity have not been validated for use among primary school children in Kilimanjaro, Tanzania. In order to understand if primary school children can accurately report their physical activity, we examined the validity of self-reported physical activity against accelerometer measured physical activity. Spearman’s rank test and Bland Altman plots were used for assessing validity and agreement between self-reports and accelerometer moderate to vigorous physical activity (MVPA).

Objectives

Results

Discussion

Conclusion