Table 1.

TSH distribution using the ELISA for the entire cohort and by NRG

	TSH (μIU/ml)
	n	Mean	sd	Median	Minimuma	Maximum	2.5th percentileb	97.5th percentileb
All	1861	1.81	2.78	1.35	<0.04	88.7	0.25	5.67
Males	895	1.58	1.67	1.22	<0.04	26.3	0.44	4.40
Females	966	2.01	3.49	1.47	<0.04	88.7	0.06	6.50
NRG-1c	1448	1.54	0.82	1.35	0.32	4.98	0.52	3.73
Males	779	1.43	0.78	1.22	0.33	4.80	0.50	3.73
Females	669	1.67	0.84	1.49	0.32	4.98	0.54	3.76
NRG-2c	1186	1.45	0.73	1.30	0.32	4.79	0.53	3.37
Males	673	1.39	0.73	1.21	0.36	4.79	0.52	3.38
Females	513	1.53	0.72	1.40	0.32	4.05	0.53	3.37
NRG-3c	766	1.48	0.74	1.32	0.36	4.79	0.54	3.37
Males	480	1.41	0.73	1.24	0.36	4.79	0.54	3.28
Females	286	1.61	0.75	1.47	0.38	4.05	0.55	3.37

^aThere were 18 female subjects and one male subject with TSH by ELISA less than 0.04. 

^bPercentiles were estimated nonparametrically, not from fitted Gaussian or lognormal distributions. 

^cNRG-1 excludes those with thyroid disease, on thyroid hormone, and on medications that may affect thyroid function (lithium, amiodarone, glucocorticoids, Dilantin, Tegretol). NRG-2 additionally excludes those with positive antithyroid peroxidase or positive antithyroglobulin, and NRG-3 additionally excludes those with thyroid ultrasound abnormalities.