The association between wearable activity monitor metrics and performance status in oncology: a systematic review

Purpose: The expanding armamentarium of wearable activity monitors (WAMs) offers new opportunities to supplement physician-assessed performance status (PS) with real-life patient activity data. These data could guide clinical decision making or serve as a measure of treatment outcome. However, information on the association between physical activity (PA) and sedentary behavior (SB) monitored with wearables (i.e., WAM metrics) and PS in patients with cancer is needed. Therefore, we conducted a systematic review to examine the association between WAM metrics and PS in patients with cancer.

Methods: We searched MEDLINE and Embase for studies that assessed the association between WAM metrics and performance status among adults with cancer. We extracted information on study design and population, WAM type and different activity metrics, outcome definitions, and results. Included studies were subjected to risk of bias assessment and subsequent best evidence synthesis.

Results: Fourteen studies were included in this review. All studies reported on different combinations of WAM metrics including: daily steps (n = 8), SB (n = 5), mean activity counts (n = 4), dichotomous circadian rest-activity index (n = 3), and time spent in moderate-to-vigorous PA (MVPA) (n = 3). Much heterogeneity was observed regarding study population, WAM used, and reporting of results. We found moderate evidence for a positive weak-to-moderate association between WAM-assessed PA and PS and a weak-to-moderate negative association between WAM-assessed SB metrics and PS.

Conclusion: Weak-to-moderate associations between WAM metrics and PS suggest that WAM data and physician-assessed PS cannot be used interchangeably. Instead, WAM data could serve as a dynamic and objective supplement measurement of patients' physical performance.