Activity levels among lower-limb amputees: Self-report versus step activity monitor

Objective: To determine the accuracy of self-reported activity by community-dwelling, lower-limb amputees. Design: Descriptive study. Setting: A regional prosthetics outpatient service. Participants: Seventy-seven unilateral lower-limb amputees at least 6 months after prosthetic rehabilitation. Interventions: Not applicable. Main Outcome Measures: Measured activity counts (in steps/min) and self-reported activity (rest, low, medium, high) in 15-minute intervals over 1 week were recorded for each participant. Results: Participants averaged 3063 +/- 1893 steps per day. Strong agreement (gamma >= 0.7) between self-reported and measured activity was found for only 34% of participants between the hours of 9:00 AM to 9:00 Pm. The measured and self-reported proportion of time spent in various states of activity also showed poor agreement (rest, r=.41; low level activity, r=.39; medium level, r=.26; high level, r=.40). There was no bias toward either over- or under-reporting. Conclusions: The majority of participants were unable to accurately self-report their activity levels (sleep excluded) as compared with measured activity levels. This may have important implications for prescribing appropriate prosthetics and for clinicians who provide patients with advice on promoting health.