Longitudinal study of associated factors with adolescent health: Method and sample profile

The aim of this work was to describe the methodological procedures of a longitudinal study on adolescent health, as well as to characterize the sample profile. This research enrolled a sample of 302 adolescents from Londrina - Parana. Two data collections were carried out with an interval of three years. Anthropometric indicators, blood pressure, heart rate, back pain, academic achievement, physical activity, sedentary behavior, eating habits, alcohol consumption, smoking, socioeconomic status, and motor tests were collected. There was a frequency of high blood pressure of 10.4%; body mass index in conditions associated with health risk of 22.4%; and spinal pain with moderate intensity of 22.1%. Sport and/or physical exercise practice (moderate-to-vigorous; ≥150 minutes/week) was 33.1%. High consumption of unhealthy foods and beverages ranged from 21.2% (coffee or tea) to 58.0% (fried foods). A high proportion (87.1%) reported never having smoked. The grades frequency ≥ seven varied between 21.4% (Biology) and 71.1% (Physical Education). Only 33.2% presented high academic achievement. The highest compliance with criteria was in the curl-up (76.4%) and the lowest in the 90o push-up (37.2%). This work will make it possible to verify the tracking of different behavioral and biological indicators related to health, as well as academic achievement. It will also allow the identification of the association between health outcomes and exposure factors prospectively, considering the influence of potential confounding variables. This information could contribute to the planning of public health interventions and policies.