Investigation of the number of times needed to accurately measure the oral response times of community-dwelling elderly

Purpose: We investigated the number of times of needed to accurately measure the simple reaction time of a vocal response to auditory stimulus in physical measurements for the prevention of care of the community-dwelling elderly. Subjects: The subjects were 24 healthy elderly persons (5 men, 19 women) with no history of central nervous system diseases or orthopedic disorders who participated in a government sponsored exercise guidance and physical measurements program for the prevention of falls. Methods: With subjects in the sitting position, one practice trial was performed to accustom them to the task, then measurements were performed 10 times. Results: The intra-class correlation coefficients, ICC(1,1), of the 4th to the 7th measurements with the average of all 10 measurements was greater than 0.81; thus, the minimum number of measurement times needed for an ICC of greater than 0.81 is 4. Conclusion: The results suggest, that in physical measurements of elderly subjects, after a single practice, the fourth value of the oral response time can be used as a representative value.