Relationship between physical activity and step count of patients receiving dialysis: A pilot study

Abstract

【Background/Objective】Evaluation of physical activity have been recommended as part of routine care in hemodialysis patients. There are many direct ways to evaluate physical activity measured by a 3-axis acceleration sensor. Although, direct way to evaluate physical activity limit the feasibility or practicability. Therefore, it may be useful to simply measure the amount of physical activity through an interview with a questionnaire since this may be completed during the time required for dialysis treatment. The aim was to explore the relationship between the amount of indirectly measured physical activity (self-reported by questionnaire) and physical activity measured directly by an accelerometer. 【Method】Single center pilot study design was employed. Twenty-seven patients receiving outpatient dialysis completed the study. A 3-axis accelerometer assessed the number of steps, which was considered a direct measurement of physical activity. Indirect assessment of physical activity was measured using the International Physical Activity Questionnaire (IPAQ short form, IPAQ-SF) to find the total metabolic equivalents (METs). The relationship between the number of steps and METs was analyzed. 【Results】In all patients, no significant correlation was observed between the number of steps and total METs on both non-dialysis and dialysis days. However, when dividing the number of steps by 3700 steps on non-dialysis day, the ‘over 3700 steps’ group had a strong correlation between the number of steps and total METs on non-dialysis day (r = 0.81, p < 0.05). 【Discussion】This study showed that the relationship between indirect evaluation of physical activity by a questionnaire (IPAQ-SF) and direct evaluation of physical activity (step count) in hemodialysis patients. The IPAQ-SF may only be applicable to indirectly measure physical activity in elderly patients receiving dialysis who have activity levels over 3700 steps on non-dialysis days.