Jonathan Myers1, Kevin T Nead2, Peter Chang3, Joshua Abella4, Peter Kokkinos5, Nicholas J Leeper6. 1. Division of Cardiology, Veterans Affairs Palo Alto Health Care System, Palo Alto, Calif; Stanford University School of Medicine, Stanford, Calif. Electronic address: drj993@aol.com. 2. University of Pennsylvania, Philadelphia. 3. National University Heart Centre, Singapore. 4. Division of Cardiology, Veterans Affairs Palo Alto Health Care System, Palo Alto, Calif. 5. Veterans Affairs Medical Center, Washington, DC. 6. Stanford University School of Medicine, Stanford, Calif; Division of Vascular Surgery, Stanford University, Stanford Cardiovascular Institute, Stanford, Calif.
Abstract
BACKGROUND: Inability to meet minimal guidelines on physical activity is associated with poor health outcomes, but quantifying activity can be complex. We studied whether a simple question regarding participation in regular activity improves risk classification for all-cause mortality. METHODS: Maximal exercise testing was performed in 6962 patients (mean age, 58.9 ± 11 years) for clinical reasons. Subjects also were assessed for participation in regular activity using a simple yes/no response to meeting minimal recommendations on activity. The incremental value of adding a simple physical activity assessment to clinical, demographic, and exercise test information to predict mortality was determined using Cox proportional hazards models, net reclassification improvement, and integrated discrimination index during a mean follow-up of 9.7 ± 4 years. RESULTS: Subjects who did not meet the minimal guidelines on activity had a lower exercise capacity (7.4 ± 4.3 vs 9.1 ± 3.6 metabolic equivalents, P < .0001) and a higher annual mortality rate (2.42% vs 1.71%, P < .001). Not meeting activity guidelines was associated with an age-adjusted 36% higher risk of mortality (hazard ratio, 1.36; 95% confidence interval, 1.22-1.51, P < .0001). Among clinical and exercise test variables, fitness had the highest C-index for predicting mortality (0.72, P < .001). The addition of physical activity classification to a model including traditional risk factors resulted in a net reclassification improvement of 22.8% (P < .001); adding fitness to the traditional risk factor model resulted in a net reclassification improvement of 43.5% (P < .001). CONCLUSIONS: The addition of a simple assessment of physical activity status significantly improves reclassification of risk for all-cause mortality among patients who are referred for exercise testing. Published by Elsevier Inc.
BACKGROUND: Inability to meet minimal guidelines on physical activity is associated with poor health outcomes, but quantifying activity can be complex. We studied whether a simple question regarding participation in regular activity improves risk classification for all-cause mortality. METHODS: Maximal exercise testing was performed in 6962 patients (mean age, 58.9 ± 11 years) for clinical reasons. Subjects also were assessed for participation in regular activity using a simple yes/no response to meeting minimal recommendations on activity. The incremental value of adding a simple physical activity assessment to clinical, demographic, and exercise test information to predict mortality was determined using Cox proportional hazards models, net reclassification improvement, and integrated discrimination index during a mean follow-up of 9.7 ± 4 years. RESULTS: Subjects who did not meet the minimal guidelines on activity had a lower exercise capacity (7.4 ± 4.3 vs 9.1 ± 3.6 metabolic equivalents, P < .0001) and a higher annual mortality rate (2.42% vs 1.71%, P < .001). Not meeting activity guidelines was associated with an age-adjusted 36% higher risk of mortality (hazard ratio, 1.36; 95% confidence interval, 1.22-1.51, P < .0001). Among clinical and exercise test variables, fitness had the highest C-index for predicting mortality (0.72, P < .001). The addition of physical activity classification to a model including traditional risk factors resulted in a net reclassification improvement of 22.8% (P < .001); adding fitness to the traditional risk factor model resulted in a net reclassification improvement of 43.5% (P < .001). CONCLUSIONS: The addition of a simple assessment of physical activity status significantly improves reclassification of risk for all-cause mortality among patients who are referred for exercise testing. Published by Elsevier Inc.
Authors: Nicholas R Lamoureux; John S Fitzgerald; Kevin I Norton; Todd Sabato; Mark S Tremblay; Grant R Tomkinson Journal: Sports Med Date: 2019-01 Impact factor: 11.136