How well can you climb a flight of stairs: evaluating the relationship between self-reported and objective...

Subjective assessment of functional capacity is known to be variable. We investigated the association between patients' self-reported ability to climb a flight of stairs (FOS) using a graded index and their actual performance in doing so. We compared this with data on their Duke Activity Status Index (DASI) score, usual walking speed and physiological measures of both systemic and peripheral microvascular cardiovascular function. Fifty-eight patients undertook the study before a range of elective surgeries. Patient self-reported ability was strongly associated with their actual time to climb a FOS. Those reporting that this would be easy had a mean climb time of 17.4 s, which was significantly different to those reporting that it would be moderately hard (26.0 s, p = 0.001). Similar results were seen when the data were analysed according to usual walking speed of less than or greater than 1 m^-s. The median DASI scores were significantly different between the groups even after adjustment for age (easy vs moderately hard: adjusted mean difference of 16 points, p = 0.002, and moderately easy vs moderately hard 14 points, p = 0.004). Most systemic and peripheral measures of cardiovascular function were not different between groups. We conclude that patients' self-reported stair climb ability using a graded scale was associated with objectively measured performance. A graded index gives more information about functional capacity than a binary response. A DASI score, a 20 m walk test and a timed stair climb test were all closely correlated with each other.