Habitual Physical Activity and Sedentary Behavior as Predictors of Mortality in Older Adults: A Longitudinal Study With 5 Years of Follow-Up

Background: It is essential to study the various relationships between habitual physical activity (HPA), sedentary behavior (SB), and mortality. Objectives: To explore the predictive capacity of HPA and SB for all-cause mortality and assess the mortality risk associated with the cutoff points predicted. Methods: Prospective cohort study, comprising 332 older adults of both sexes. HPA and SB were assessed using the International Physical Activity Questionnaire. Receiver operating characteristic analysis was used to evaluate the predictive capacity of HPA and SB with mortality. Mortality risks were assessed by Cox regression, with a 95% confidence interval and hazard ratio estimation. Results: HPA and SB demonstrated good accuracy in predicting mortality, based on 150 and 40 min/week of HPA and 495 and 380 min/day of SB, respectively, for men and women. Based on the mentioned cutoff points, both behaviors were found to be associated with the risk of mortality for females, while for males, an association was observed only with SB. In the combined analysis, low HPA practice was identified as a risk factor for mortality, in both sexes. Conclusion: HPA and SB are good predictors of mortality, each with its own associated risks. Additionally, both exhibit different sensitivity and specificity values according to sex. Significance/Implications: We demonstrate that HPA and SB can be used as screening for end-of-life outcomes and can be used in public policies and specific cutoff points, especially for SB.