Usefulness of chair stand time as a surrogate of gait speed in diagnosing sarcopenia

Determining gait speed as a measure of physical performance is recommended in diagnosing sarcopenia. Gait speed measurements require a certain amount of space (e.g. a 6-m course), and might not be feasible in clinical settings or heath checkup examination sites. We developed a formula to estimate chair stand time based on gait speed, and examined the validity (sensitivity and specificity) of using the estimated chair stand time cut-off point as a surrogate for the recommended gait speed cut-off point.Chair stand time was defined as the time it took to stand up from a standard chair five times. Gait speed was calculated from the time required for participants to walk a 6-m course at their usual pace.Simple regression analysis showed a significant negative relationship between chair stand time and gait speed (P < 0.0001), and the estimated formula was derived as follows: five times chair stand time = -8.41 × gait speed + 20.0 (R2 = 0.34). Therefore, the chair stand time cut-off point was estimated to be 13.3 s by inserting the recommended gait speed cut-off of 0.8 m/s in the above formula. Rounding off to make its use simpler, the estimated chair stand time cut-off was 13 s. The sensitivity and specificity of the estimated chair stand time cut off were 0.75 and 0.94, respectively.Chair stand time might be useful as a surrogate of gait speed when screening for sarcopenia. Geriatr Gerontol Int 2017; 17: 659-661.