Association between accelerometry and physical activity levels measured by questionnaires in patients on hemodialysis

This study aimed to evaluate association of accelerometry data with physical activity levels (PAL) measured by three questionnaires and to investigate their ability to discriminate physically inactive from active patients on hemodialysis.

A cross-sectional study was conducted. PAL were assessed by accelerometry and questionnaires: Human Activity Profile (HAP), International Physical Activity Questionnaire (IPAQ), and 36-Item Short Form Health Survey (SF-36).

This study included 105 patients (59.2 ± 12.5 years, 60.0% male). Accelerometer data were significantly correlated with all questionnaire scores. Adjusted activity score (AAS) of HAP presented moderate to strong correlation with daily step count (ρ = 0.552, p < 0.001) and time in moderate and vigorous physical activity (ρ = 0.642, p < 0.001). AAS was associated with daily step count (R² = 0.29, p < 0.001) and time in moderate to vigorous physical activity (R² = 0.24, p = 0.001). Cutoff values for AAS of HAP, IPAQ, and physical component summary of the SF-36 for discriminating physically inactive from active patients were 63, 1139 and 44 (threshold of 5000 steps/day), respectively, and 55, 773 and 38 (threshold of 4260 steps/day), respectively.

PAL scores on questionnaires were associated with accelerometer data, mainly the HAP. Furthermore, this study established cutoff points for questionnaire scores to discriminate physically inactive from active patients.