Is Self-Reported Physical Fitness Useful for Estimating Fitness Levels in Children and Adolescents? A Reliability and Validity Study.

Background and objective: The assessment of physical fitness has become a necessary issue in epidemiological studies, since a reduction in fitness is directly associated with early mortality. Therefore, the development of simple, accurate, and inexpensive methods is necessary to measure physical fitness. This study aimed to determine the reliability and validity of the criteria and constructs of the International Fitness Scale (IFIS), Portuguese version, in Brazilian pediatric populations. Methods: A total of 190 children aged 3-10 years and 110 adolescents aged 11-17 years were enrolled in an observational study of reliability and validity. For reliability, the participants completed a questionnaire twice (with an interval of 15 days). To test the criterion validity, we analyzed the agreement between the questionnaire and physical tests (20-m shuttle run test, handgrip strength, standing long jump tests, 4 × 10-m shuttle run test, and back-saver sit and reach test), and the construct validity was estimated by agreement between the questionnaire and high blood pressure. The reliability was analyzed by kappa coefficients. The agreement between the testing and retesting of the questionnaire was evaluated by kappa coefficients. We applied a 2 × 2 table to estimate the specificity, sensitivity, and accuracy of the questionnaire. Results: The mean age of the children was 6.7 years (n = 190), and for the adolescents it was 14.6 years (n = 110). The questionnaire reliability showed an almost perfect score (κ ≥ 0.93 in children and κ ≥ 0.88 in adolescents). The questionnaire showed moderate criterion validity (κ ≥ 0.40 in children and adolescents) as well as moderate construct validity (κ ≥ 0.40) in the components of general conditioning, cardiorespiratory capacity, muscular strength, and speed/agility in children and in the components of cardiorespiratory capacity, muscle strength, and speed/agility in adolescents. The questionnaire was a sensitive method for measuring physical fitness. Conclusions: The Portuguese version of the IFIS is a reliable and valid method for measuring physical fitness in pediatric populations.

Measuring Socioeconomic Status and Environmental Factors in the SAYCARE Study in South America: Reliability of the Methods.

OBJECTIVE: This paper aimed to test the reliability of two questionnaires in studies involving children and adolescents (aged 3-18 years) in seven South American cities. One assesses socioeconomic status (SES) and the other measures environmental factors. METHODS: The SES questionnaire was composed of 14 questions, which included the presence of several consumer goods, domestic services, family income, parental education level, and current parental occupation status. The environmental questionnaire was composed of 15 questions to measure the social and infrastructure characteristics of the area of residence. Parents or guardians completed the questionnaires on behalf of their children. Adolescents answered the questions themselves for environmental factors, while those related to SES factors were answered by their parents or guardians. We analyzed the reliability of the questionnaires through kappa coefficient determination. Multilevel linear regression models were applied to calculate the correlation between the total household scores, the household income, and parents' education level. RESULTS: The environmental questionnaire showed good reproducibility in both age groups (k = 0.132-0.612 in children and k = 0.392-0.746 in adolescents). The SES questionnaire showed strong reliability in both age groups for all indicators (k = 0.52-1.00 in children and k = 0.296-0.964 in adolescents). CONCLUSIONS: Our multiple indicator questionnaires focused on environmental factors and SES in pediatric health surveys provided useful and easily applicable additional indicators to measure these important determinants of cardiovascular health.

The lipid accumulation product is a powerful tool to predict metabolic syndrome in undiagnosed Brazilian adults.

BACKGROUND & AIMS: Lipid accumulation product (LAP) is emergent predictor of central lipid accumulation linked to diabetes risk and cardiovascular disease. In this study, our aims were (i) to assess the accuracy of the LAP for predicting metabolic syndrome (MS) in subjects without diagnosis of cardiovascular disease (CVD) and type 2 diabetes mellitus compared with other classical anthropometric parameters and (ii) to estimate the optimal LAP cut-off point to predict MS in this population. SUBJECTS/METHODS: We conducted a cross-sectional study with representative undiagnosed subjects aged 20-79 years (n = 201; 37.8% men), selected by simple random sampling. In this study, subjects without previous diagnosis of CVD and type 2 diabetes mellitus, and those who did not make use of continuous medication were included. The independent variables were body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR) and waist-to-hip ratio (WHR) and LAP. MS was defined by American Heart Association and the National Heart, Lung, and Blood Institute (AHA/NHLBI); International Diabetes Federation (IDF); and a harmonized criteria between AHA/NHLBI and IDF. RESULTS: The prevalence of MS was 78.9% and 69.6% for men and women, respectively. LAP showed better area under the curve (AUC) for MS in three different criteria than those indexes based on body mass index, waist circumference, waist-to-height ratio and waist-to-hip ratio, even after adjusting for age and sex. In the harmonized criteria, the cut-off point of 34.2 cm.mmol/L for LAP showed the highest accuracy for MS (sensitivity 0.90, specificity 0.61, positive likelihood ratio of 2.31 and negative likelihood ratio of 0.17). CONCLUSIONS: LAP is a simple and accurate predictor tool for MS in undiagnosed adults. Moreover, it has significantly higher predictability than other screening tools commonly used to find subjects at risk of CVD and type 2 diabetes mellitus development, with the best performance at the 34.2 cm.mmol/L cut-off point.