TABLE 5.

Choosing the threshold for moderate-to-vigorous intensity physical activity by examining the false positives and false negatives based for approach 3 (slow and brisk walking)

Accelerometer (counts·30 s-1)	True Positive (N)	True Negative (N)	False Positive (N)*	False Negative (N)**	Error Rate (%)	Validation Error Rate (%)*** (5th, 95th Percentile)
1100	29	73	43	0	29.7	21.7,37.4
1150	32	73	40	0	27.6	19.8,34.9
1200	42	72	30	1	21.4	14.2,28.2
1250	49	72	23	1	16.6	9.6,22.0
1300	53	72	19	1	13.8	7.9,19.8
1350	58	72	14	1	10.3	6.0,16.7
1400	59	72	13	1	9.7	5.6,13.9
1450	64	71	8	2	6.9	3.5,11.5
1500	66	70	6	3	6.2	2.5, 9.4
1550	67	65	5	8	9.0	4.0,13.8
1600	69	65	3	8	7.6	2.7,12.5

^*Counts measured under the protocol for slow walk that were above the threshold for moderate intensity activity were considered as false positive.

^**Counts measured under the protocol for brisk walk that were below the threshold for moderate intensity activity were considered as false negative.

^***Based on 100 bootstrap samples, each half the size as the original sample.