TABLE 2.

Independent sample t-tests for LDL overall, by stature, stratified by gender, and then by median age

Group	N	Mean (SD)	t-value	DF	P	Cohen’s d
Top quartile	16,248	89.74 (24.88)	13.52	31,577	<0.0001	0.15
Bottom quartile	15,331	93.58 (25.69)
For females only
Top quartile	9,019	88.00 (24.29)	17.31	17,006	<0.0001	0.27
Bottom quartile	7,989	94.60 (25.38)
For males only
Top quartile	7,229	91.90 (25.44)	1.36	14,569	0.175	0.02
Bottom quartile	7,342	92.48 (25.98)
For females below median age
Top quartile	5,091	88.96 (24.65)	12.37	8,957	<0.0001	0.26
Bottom quartile	3,868	95.49 (24.85)
For females above median age
Top quartile	3,928	86.75 (23.76)	12.64	8,047	<0.0001	0.28
Bottom quartile	4,121	93.76 (25.85)
For males below median age
Top quartile	3,442	93.51 (25.47)	−1.01	6,617	0.315	0.02
Bottom quartile	3,177	92.88 (25.41)
For males above median age
Top quartile	3,787	90.44 (25.33)	2.98	7,950	0.0029	0.07
Bottom quartile	4,165	92.17 (26.40)