Can a Made-for-Consumer Activity Monitor Assess Physical Activity in Adolescents and Young Adults After Lower Extremity Limb Salvage for Osseous Tumors?

Abstract

The purpose of this study was to test the validity of a consumer-oriented activity monitor in adolescents and young adults undergoing limb salvage for primary bone malignancies. A cross-sectional population of participants with an average age of 16 (range 12 to 22) years produced 472 days of activity monitoring during 25 evaluations periods alongside patient-reported outcome measures. Average daily steps ranged from 557 to 12,756 (mean=4711) and was moderately associated with the short-form (SF) 36 physical component subscale (r=0.46, P=0.04) as well as the SF6D health state utility measure (r=0.48, P=0.04), but not the SF36 mental component subscale (P=0.66) or Toronto extremity salvage score (P=0.07). Time from surgery was strongly correlated with average daily steps (r=0.7, P<0.001). A made-for-consumer activity monitor provided real-world data regarding the outcome of adolescent and young adult limb salvage, and evidence of validity in this population. Such lower cost, user-friendly devices may facilitate assessment of free-living activity and allow novel comparisons of treatment strategies. Level II-diagnostic.