Table 3. Agreement between ActiGraph and Fitbit Flex for categorizing step-defined daily physical activity.

No. of days (%)a	ActiGraph
Fitbit Flex	Inactive	Active
Inactive	320 (46.9)	11 (1.6)
Active	106 (15.5)	245 (35.9)
Total	426 (62.5)	256 (37.5)
Kappa (95% CI)	0.66 (0.61–0.71)

^a Physical activity categories are based on ActiGraph daily step counts: inactive <10,000 steps/day and active ≥10,000 steps/day [5].