Risk Factors for Disagreement between Self and Proxy Reports on Physical Activity of Children and Young Adolescents

Abstract

Background Although easy accessible and relatively cheap movement instruments have been developed and are used in population studies on physical activity among children, self-report very often is the main source of information. Sometimes information on PA coming from self and proxy respondents are pooled together for later analysis. However, the comparability of information received based on self- and proxy-reports remains unclear. Objectives The main aim of the study was to assess the level of agreement of data gathered from schoolchildren and their mothers concerning physical activity of youths and to identify factors associated with disagreement. Methods A cohort of 91 children (66 % girls), aged 7-15 years, and their mothers were studied using a questionnaire in a cross-sectional study. Information gathered included average leisure time physical activity during the summer and winter weeks over a year prior to the interview. Results Children, compared to their mothers (proxies), reported higher average weekly time spent on general seasonal activity, seasonal team games, time spent on TV/movie viewing, and book reading. The observed level of Lin's concordance correlation coefficient for agreement varied from 0.32 for TV/movie viewing to 0.79 for non-seasonal activity. Sedentary lifestyle (> 25.5 h in sedentary activity/week) was identified as a factor associated with disagreement in reports on general seasonal activity (OR = 5.47, 95 % CI: 1.78-16.83) and on seasonal team games (OR = 5.42, 95 % CI: 1.74-16.88). Moreover, increase in categories of BMI percentiles was associated with increased risk of disagreement in these activities (p for trend 0.037, 0.041; respectively). Conclusions The comparability of information on the level of children's and young adolescents' leisure time physical activity depends on the nature of this activity. Sedentary lifestyle and increased body mass index may be responsible for disagreement in some types of physical activity. The use of parental proxy reporting as supplementary source of information on the level of physical activity of children should be applied, if ever, with caution.