A method for assessing off-loading compliance

Background: Off-loading excessive pressure is essential to healing diabetic foot ulcers. However, many patients are not compliant in using prescribed footwear or off-loading devices. We sought to validate a method of objectively measuring off-loading compliance via activity monitors. Methods: For 4 days, a single subject maintained a written compliance diary concerning use of a removable cast walker. He also wore a hip-mounted activity monitor during all waking hours. An additional activity monitor remained mounted on the cast walker at all times. At the conclusion of the 4 days, the time-stamped hip activity data were independently coded for walker compliance by the compliance diary and by using the time-stamped walker activity data. Results: An intraclass reliability of 0.93 was found between diary-coded and walker monitor-coded activity. Conclusions: These results support the use of this dual activity monitor approach for assessing off-loading compliance. An advantage of this approach versus a patient-maintained diary is that the monitors are not susceptible to incorrect patient recall or a patient's desire to please a caregiver by reporting inflated compliance. Furthermore, these results seem to lend support to existing reports in the literature using similar methods.