Table 5.

fT₄ concentrations of the first three follow-up samples, at 4.3, 9.2, and 17.0 days, by initial L-T₄ dose and minimal initial fT₄ deficit

Initial L-T 4 dose, µg/kg	Minimal initial fT 4 deficit, pmol/L
	<10 pmol/L	10–15 pmol/L	>15 pmol/L
5.0	–0.7 [−2.4; 1.1]	–2.3 [−3.9; −0.7]	–4.0 [−5.4; −2.5]
7.5	1.0 [−0.7; 2.7]	0.7 [−2.1; 0.8]	–2.3 [-3.7; −0.9]
10.0	2.7 [1.2; 4.1]	1.0 [−0.1; 2.0]	0.7 [−1.7; 0.5]
12.5	4.3 [l.9; 6.7]	2.7 [0.3; 5.1]	1.0 [−1.0; 3.0]
15.0	5.9 [3.6; 8.4]	4.3 [1.9; 6.7]	2.7 [0.7; 4.7]

fT ₄ concentrations are presented as mean [95% CI]. Minimal initial fT ₄ deficit: difference between −2 SD value of the 95% CI of the fT ₄ SSC range of the whole cohort, i.e., 16.6 pmol/L (1.28 ng/dL), and individual pre-treatment fT ₄. Fields with bold figures: increased risk of overtreatment, i.e., fT ₄ concentration >+2 SDS, relative to the individual SSCs of the patients. Reprinted from Bongers et al. [11] with permission from the authors.