Background: Low levels of physical activity are implicated in low life expectancies of people receiving maintenance haemodialysis. Accelerometers are increasingly being used to quantify activity behaviours of this population but guidance to quality-assure such data is lacking. The objective of this study was to provide data processing and reduction recommendations to ensure accelerometer-derived outcomes are sufficiently reliable for interpretative analysis. Methods: Seventy people receiving maintenance haemodialysis (age 55.9 ± 15.7 years, 34% women, 23% diabetic) from a single outpatient renal unit volunteered for the study. Participants wore Actigraph GT3x and ActivPAL monitors during waking hours over seven days. Reliability of accelerometer output (normalised to wear-time) was assessed via intraclass correlation coefficient (ICC). The Spearman-Brown prophecy formula was subsequently applied to the ICCs to derive the minimum required accelerometer wear-time for each behavioural outcome. Results: Monitor wear compliance was greater on dialysis compared to non-dialysis days (90% v 77%). Participants were significantly more active on non-dialysis days compared to dialysis days but there were no significant differences in estimated behaviours between days within the same condition. Average measure ICCs for all accelerometer outcomes were high (range 0.76-0.96). Computations indicated that habitual physical activity and sedentary behaviour could be estimated with a minimum reliability level of 0.80 from one dialysis day and two non-dialysis days, and at least eight hours monitor wear per day. Applying this rubric allowed 90% of participant data to be retained for further analysis. Conclusions: Regardless of accelerometer, one dialysis and two non-dialysis days data with a minimum of eight hours wear each day should enable habitual activity of people receiving maintenance haemodialysis to be characterised with acceptable reliability. These recommendations reconcile the tension between wear-time criteria stringency and retention of an adequately representative sample.

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The 4th European Congress of the ER-WCPT / Physiotherapy 102S (2016) eS43-eS65 eS63 Women showed an increase in 'duration' from work to leisure, contrary to men, where a decrease was observed. From work to leisure, men showed a larger increase in 'degrees' than women.Discussion and conclusions: This study showed that women experienced larger differences between the duration of forward bending during leisure and work compared with men. In contrast, men showed larger differences in the degrees of forward bending than women. These findings may be a reflection of gender specific differences in tasks during both work and leisure, like cleaning and gardening. Impact and implications: Diurnal direct measures may provide unobstructed valid recordings over several days on work-or leisure time specific exposures like forward bending [1] as a supplement to the general therapeutic practice encompassing higher quality and patient safety in (re)habilitation.Funding acknowledgement: The special pool for the social area partly financed this study. References[1] Villumsen M, Samani A, Jørgensen MB, Gupta N, Madeleine P, Holtermann A. Are forward bending of the trunk and low back pain associated among Danish blue-collar workers? A cross-sectional field study based on objective measures. Ergonomics 2015;58:246-58. [2] Mathiassen SE, Winkel J. Quantifying variation in physical load using exposure-vs-time data.Relevance: Habitual physical activity (PA) estimated objectively by accelerometry is predictive of longevity (Matsuzawa et al., 2012) and mobility (Kutsuna et al., 2010) of people receiving maintenance haemodialysis therapy (MHD). Additionally, PA is associated with cardiovascular risk factors and numerous indices of health status (Johansen et al., 2003; Masuda et al., 2009; Cupisti et al., 2011). A number of different accelerometers have been employed thus far in renal research and there is now a pressing need to standardise PA assessment tools.Purpose: The study objective was to examine the concordance of similar outcomes obtained from two different accelerometers in a clinical population characterized by low PA. The aim was to determine whether similar outcomes from different monitors could be employed interchangeably for PA surveillance.Methods/analysis: Seventy self-selected volunteers undergoing routine MHD wore ActivPAL and Actigraph GT3x accelerometers during waking hours over 7 days. Concordance of similar PA outcomes obtained from ActivPAL and Actigraph GT3x accelerometers was examined using correlational analysis, Bland-Altman limits of agreement (LOA) analysis, and tests for significant outcome value differences.Results: Strong correlations were observed for all similar outcomes from both monitors (range 0.84-0.95, p < 0.001). Actigraph estimates were significantly higher (p = 0.03) for minutes of sedentary time (bias +17.2 mins/day [LOA +107.1, −72.8]). Actigraph estimated time in total PA was lower than ActivPAL but not significantly different (bias -16.3 mins/day [LOA +73.4,, p = 0.054). Actigraph esti...