It's a non-dialysis day... do you know how your patient is doing? a case for research into interdialytic activity

Hemodialysis (HD) patients are less active than their healthy counterparts; this is associated with higher mortality. Healthcare workers observe their patients only during HD, which accounts for about 7% of the week. Knowing more about what occurs in between sessions, particularly with respect to physical activity, may improve patient care and prognosis. Yet without a standard method to measure interdialytic activity, it is difficult to compare the effect of interventions. However, it is unclear how interdialytic activity can be accurately measured. Since activity associated with quality of life is multi-dimensional, objective and subjective tools should be used in conjunction. While commercially available tracking devices can be seamlessly incorporated into everyday life and can increase awareness of user's activity, their validation is needed in the HD population. Fertile topics for research should include the relationship between objective and subjective measures in HD patients, and the investigation of physical activity in non-ambulatory HD patients.