Reliability and Validity of the Japanese Adaptation of Human Activity Profile for Evaluating Physical Activity in Patients Undergoing Hemodialysis: A cross-sectional study

Background Physical inactivity is a significant risk factor for mortality in patients undergoing hemodialysis. Assessment of physical activity is crucial for clinical management and therapeutic decisions in this population. The Human Activity Profile (HAP) questionnaire is widely used to evaluate functional ability across various populations, including those with chronic diseases. Although the HAP is reliable and convenient for use in clinical settings, no validated Japanese adaptation is available. In this study, we aimed to create a Japanese version of the HAP and evaluate its reliability and validity in patients undergoing hemodialysis. Methods In this cross-sectional study, the Japanese version of the HAP was translated with the permission of the original author. Physical activity was assessed using both the HAP questionnaire and an accelerometer. The total steps and moderate-to-vigorous physical activity (MVPA) time were calculated using an accelerometer. Validity was assessed by evaluating the correlation between the HAP maximum activity score (MAS) and adjusted activity score (AAS) and objectively measured physical activity levels. Reliability was determined by re-administering the HAP questionnaire. Spearman's rank correlation coefficient and intraclass correlation coefficient (ICC) 2,1 were used to evaluate the validity and reliability, respectively. Results We included 32 Japanese patients undergoing hemodialysis (mean age 71.7 ± 9.2 years; 19 men). The Japanese version of HAP correlated with accelerometry data, excluding the MAS, and with the number of steps. The AAS moderately correlated with MVPA (ρ = 0.64, P < 0.001) and number of steps (ρ = 0.55, P = 0.003). The Japanese version of HAP indicated a high degree of reliability (ICC = 0.84). The cutoff points for HAP were set to identify participants engaging in < 4,000 steps per non-dialysis day, the minimum recommended physical activity level for patients undergoing hemodialysis, and objectively measure physical activity. The AAS cutoff value was determined to be 50, with an area under the curve of 0.81, a high predictive capability. Conclusions We demonstrated the robust reliability and validity of the Japanese version of the HAP questionnaire in patients undergoing hemodialysis. Given the strong reliability and validity of the Japanese HAP questionnaire, incorporating this assessment into standard care may be valuable for evaluating the physical activity of patients undergoing hemodialysis.