Table 1.

Multi-wave Sampling Design for Childhood Obesity Endpoint

Original Strata	Final Strata	Obesity	Follow-up Time (yrs)	Maternal Gestational Weight Gain (kg)	$N_s$	$n_{(1),s}$	$n_{(2),s}$	$n_{(3),s}$	$n_{(4),s}$	$n_s$
A	1	0	(2, 5]	⩽ 5.14	190	7	0	0	0	7
B	2	0	(2, 5]	(5.14, 12]	1904	8	21	7	3	24
	3	0	(2, 5]	(12, 16]	1356			28	0	34
	4	0	(2, 5]	(16, 20.5]	526				27	37
C	5	0	(2, 5]	> 20.5	177	8	2	3	0	13
D	6	0	(5, 6]	⩽ 5.14	208	14	18	1	0	33
E	7	0	(5, 6]	(5.14, 8.6]	429	16	22	0	0	25
	8	0	(5, 6]	(8.6, 12]	1478		15	5	13	39
	9	0	(5, 6]	(12, 14]	846		18	21	20	44
	10	0	(5, 6]	(14, 16]	563				22	40
	11	0	(5, 6]	(16, 20.5]	588			22	8	35
F	12	0	(5,6]	(20.5, 24.3]	154	17	19	0	0	32
	13	0	(5,6]	> 24.3	71		24	0	0	28
G	14	1	(2, 2.5]	⩽ 5.14	49	17	0	0	0	17
H	15	1	(2, 2.5]	(5.14, 10]	140	20	19	16	3	28
	16	1	(2, 2.5]	(10, 12]	126			8	1	22
	17	1	(2, 2.5]	(12, 16]	205		12	8	5	29
	18	1	(2, 2.5]	(16, 20.5]	76				3	14
I	19	1	(2, 2.5]	> 20.5	33	17	0	0	0	17
J	20	1	(2.5, 3]	⩽ 5.14	13	12	0	0	0	12
K	21	1	(2.5, 3]	(5.14, 12]	129	12	13	0	2	19
	22	1	(2.5, 3]	(12, 20.5]	129		15	0	1	24
L	23	1	(2.5, 3]	> 20.5	19	12	0	0	0	12
M	24	1	(3, 4]	⩽ 5.14	21	10	0	0	0	10
N	25	1	(3, 4]	(5.14, 12]	175	13	25	0	5	20
	26	1	(3, 4]	(12, 20.5]	203			3	4	30
O	27	1	(3, 4]	> 20.5	28	13	0	0	0	13
P	28	1	(4, 5]	⩽ 5.14	22	9	0	0	0	9
Q	29	1	(4, 5]	(5.14, 20.5]	261	10	19	0	4	33
R	30	1	(4, 5]	> 20.5	24	11	4	0	0	15
S	31	1	(5, 6]	⩽ 5.14	14	8	0	0	0	8
T	32	1	(5, 6]	(5.14, 20.5]	167	8	2	3	4	17
U	33	1	(5,6]	> 20.5	11	10	0	0	0	10
Total					10335	252	248	125	125	750

$N_s$ is the population size in stratum $s,n_{\left(1\right),s}$ is the number sampled from the stratum in wave $1,n_{\left(2\right),s}$ is the number sampled from the stratum in wave 2 , and $n_{\left(3\right),s}$ and $n_{\left(4\right),s}$ are defined similarly. $n_s$ is the total number sampled from stratum $s$ over all waves of the phase 2 validation sampling.