Ambulatory activity in stroke survivors associated with functional outcome and quality of life: an observational cohort study.

Abstract

Physical activity is beneficial in stroke prevention and recovery. Understanding activity dynamics and its effect on outcome after stroke is important to improve recommendations and develop interventions. We examined serial changes in daily ambulatory activity (AA) averaged over 1 week in people with subacute to chronic stroke and its association with functional outcome (modified Rankin scale [mRS]) and quality of life (EQ-5D-3L). This observational study examined AA in stroke survivors with no to moderate disability (US National Institute of Stroke Scale [NIHSS] score) who were mostly community dwelling and had cryptogenic stroke based on data from the Continuous Cardiac Monitoring to Assess Atrial Fibrillation After Cryptogenic Stroke study. The participants underwent long-term AA monitoring by accelerometric activity data obtained from an insertable cardiac monitor without receiving any specific encouragement regarding physical activity. We analysed AA changes and assessed the association between baseline AA and mRS/EQ-5D-3L scores. A small group of participants had follow-up data for 2 years, which allowed for analysing long-term serial changes. We included 186 participants (mean [SD] age 61.3 [11.2] years, 67% male, mean 39 [28] days after stroke). AA increased during the subacute phase in individuals with mild (NIHSS score 1-4, p<0.001) and moderate (NIHSS score 5-10, p=0.013) disability but not in the non-impaired group. Baseline AA was inversely associated with NIHSS score (p<0.001) and was associated with mRS score (p=0.001) and weakly correlated with EQ-5D-3L score at 6 months (p=0.032, r=0.22). For the 45 participants with follow-up data (mean age 64.5 [9.7] years, 80% male, mean 34 [21] days after stroke), AA remained stable. AA increased in stroke survivors with impairments but remained stable in those whose symptoms had resolved. AA during the early subacute period was associated with mRS and EQ-5D-3L scores at 6 months. Insertable cardiac monitoring offers a feasible method for monitoring activity over prolonged periods in people after stroke. Its increased use may offer an opportunity to overcome the limited reliability and validity of many existing measures. ClinicalTrials.gov (NCT00924638).