Table 2.

Population characteristics in the 12 studies from the literature comparing TT vs TT/PND

Study (LE)	Study design	No of patients	Mean age TT vs TT/PND (years)	T classiffication	Follow-up TT vs TT/PND (months)
Lang et al. [17] (LE 2)	Meta-analysis	3,331	–	T1, T2, T3, T4	50.8 vs 45.2
Wang et al. [28] (LE 4)	Meta-analysis	2,318	46.7 vs 50.5	T1, T2, T3, T4	12–144 vs 3–159 ns
Barczynski et al. [10] (LE 4)	Retrospective	640	52.7	T1, T2, T3, T4	128 vs 126 ns
Popadich et al. [13] (LE 4)	Retrospective	606	48 vs 44	T1b, T2, T3, T4	50 vs 32 ns
Sywak et al. [36] (LE 4)	Retrospective	447	42.6 vs 39.1	T1b, T2	70 vs 24.5 ns
Zuniga et al. [32] (LE 4)	Retrospective	266	41.5 vs 42.9	T1, T2, T3, T4	6.1
Hartl et al. [12] (LE 4)	Retrospective	263	46 vs 47	T1b, T2, T3	74 vs 83 ns
Costa et al. [27] (LE 3)	Retrospective	244	52 vs 46	T2, T3, T4	47 vs 62
So et al. [35] (LE 4)	Retrospective	232	49.8 vs 49.2	–	45.4 vs 44.7 ns
Raffaelli et al. [20] (LE 3)	Prospective	186	42 vs 43.2	T1, T2, T3	25 vs 25.5 ns
Lang et al. [19] (LE 4)	Retrospective	185	50 vs 52	T1, T2, T3, T4	31.9 vs 28.2
Hughes et al. [18] (LE 4)	Retrospective	143	41.2 vs 46.8	T1a, T2	27.5 vs 19 ns
Moo et al. [16] (LE 4)	Retrospective	81	49.2 vs 45.7	T1, T2	37.2 vs 37.2

LE level of evidence, TT total thyroidectomy, PND prophylactic neck dissection, ns not signifcant