Association between physical activity and mortality among community-dwelling stroke survivors

Objective:  To determine the relationship between physical
activity and mortality in community-dwelling stroke survivors.
Methods:  The Canadian Community Health Survey was used to obtain
self-reported physical activity (PA) across four survey years and was
linked to administrative databases to obtain prior diagnosis of stroke and
subsequent all-cause mortality.  PA was measured as metabolic
equivalents (METs) per week and meeting minimal PA guidelines was defined
as 10 MET-hours/week.  Cox proportional hazard regression models
and restricted cubic splines were used to determine the relationship
between PA and all-cause mortality in respondents with prior stroke and
controls, adjusting for sociodemographic factors, co-morbidities, and
functional health status. Results:  The cohort included 895
respondents with prior stroke and 97805 controls.  Adhering to PA
guidelines was associated with lower hazard of death for those with prior
stroke (adjusted hazard ratio [aHR] 0.46, 95% CI 0.29-0.73) and controls
(aHR 0.69, 95% CI 0.62-0.76). There was a strong dose-response
relationship in both groups, with a steep early slope and the vast
majority of associated risk reduction occurring between 0 and 20
MET-hours/week.  In the group of stroke respondents, PA was
associated with stronger associated risk reduction in those <75
years of age (aHR 0.21, 95% CI 0.10-0.43) compared to those >75
years of age (aHR 0.68, 95% CI 0.42-1.12). 
Conclusions:  PA was associated with lower all-cause mortality in
a dose-dependent manner among those with prior stroke, particularly in
younger stroke survivors.  Our findings support efforts towards
the implementation of PA programs for stroke survivors in the
community.