Timed Up & Go as a measure for longitudinal change in mobility after stroke - Postural Stroke Study in Gothenburg (POSTGOT)

Background: A frequently used clinical test to assess mobility after stroke is the Timed Up & Go. Knowledge regarding whether or not the Timed Up & Go is able to detect change over time in patients with stroke, whether improvements in mobility exist after the first three months and whether or not longitudinal change in mobility after stroke depend on the patients' age, is limited or unclear. The objectives were to investigate the distribution-based responsiveness of the Timed Up & Go (TUG) during the first three months after a first event of stroke, to measure the longitudinal change in TUG time during the first year after stroke and to establish whether recovery in TUG time differs between different age groups. Methods: Ninety-one patients with first-ever stroke were assessed using the Timed Up & Go at the 1st week and at 3, 6 and 12 months after stroke. The non-parametric sign-test, the parametric t-test and a mixed model approach to linear regression for repeated measurements (Proc mixed) were used for the statistical analyses. Results: The median TUG time was reduced from 17 to 12 seconds (p < 0.001) between the 1st week and 3 months. No further improvement was seen between 3 and 12 months after stroke. In a mixed model approach to linear regression, there was a significant age difference. Patients at age 80 and above tended to deteriorate in terms of TUG time between 3 and 12 months after stroke, while patients < 80 years did not (p = 0.011 for the interaction between age group and time). Conclusion: The Timed Up & Go demonstrates ability to detect change in mobility over time in patients with stroke. A significant improvement in TUG time from the 1st week to 3 months after stroke was found, as expected, but thereafter no statistically significant change was detected. After 3 months, patients >= 80 years tended to deteriorate in terms of TUG time, while the younger patients did not.