Burden of physical activity on reduction of mortality risk and mitigation of health care costs of patients from National Health Service: 8-years follow-up

Abstract

Objective: To investigate, during eight years of follow-up, the effect of physical activity, obesity and chronic diseases on health care costs and all-causes mortality among adults aged 50 years and over. Methods: A cohort study was carried out in the city of Bauru-SP, Brazil, which in its first evaluation had the participation of 963 patients enrolled in five Basic Health Care Units. The study began in 2010 and the patients have been evaluated every two years: i) occurrence of deaths; ii) occurrence of diseases; iii) level of physical activity / sedentary lifestyle; (iv) smoking; v) overweight / obesity; vi) cost of health, vii) blood pressure and biochemical tests; viii) age, gender and economic condition, which are used as confounding factors. The comparisons along the follow-up for the numerical variables will be performed by analysis of variance (ANOVA) for repeated measures. Multivariate models for repeated measures ANOVA will be used, which will be adjusted by variables defined as "confounding variables". Because it involves more than two moments of analysis, effect size measurements will be estimated by eta-squared values (ES-r). For the categorical data, the McNemar test will indicate the behavior of the percentage values over the time analyzed. Since this is a historical series study with a categorical outcome that occurs during follow-up (mortality), the main analysis will be conducted using the Cox Regression. Hazard ratio (HR) values. All statistical procedures described above will be performed in the BioEstat statistical software (version 5.2) and the statistical significance will be set at values below 5%. Expected results: It is expected to quantify the burden of physical activity practice in mitigation of health care costs and reduction of mortality among adults attended in the National Health System. (AU)