Table 1.

Characteristics of included studies

Study ID	Country	Type of study	Pathology	Number of patients	Number of analyzed PTG
Abboud 2008 [4]	Lebanon	Intraoperative	Various thyroid disease	574	2219
Akerstrom 1984 [5]	Sweden	Cadaveric	Healthy	503	2032
Alveryd 1968 [6]	Sweden	Cadaveric	Healthy	352	1405
Arnalsteen 2003 [7]	France	Intraoperative	MEN1	79	340
Botelho 2004 [8]	Brazil	Cadaveric	Healthy	19	76
Butterworth 1998 [9]	UK	Intraoperative	SHPT	60	241
de Andrade 2014 [10]	Brazil	Intraoperative	SHPT	166	664
Edis 1987 [11]	Australia	Intraoperative	SHPT	20	73
Ghandur 1986 [12]	USA	Cadaveric	Healthy	166	502
Gilmour 1938 [13]	UK	Cadaveric	Healthy	428	1713
Gomes 2007 [14]	Brazil	Intraoperative	SHPT	35	143
Heinbach 1933 [15]	USA	Cadaveric	Healthy	25	86
Hellman 1998 [16]	Sweden	Intraoperative	MEN1	50	206
Hibi 2002 [17]	Japan	Intraoperative	SHPT	822
Hojaij 2011 [18]	Brazil	Cadaveric	Healthy	56	220
Kawata 2008 [19]	Japan	Intraoperative	SHPT	44	163
Lappas 2012 [20]	Greece	Cadaveric	Healthy	942	3796
Milas 2003 [21]	USA	Intraoperative	PHPT	828	3250
Nanka 2006* [22]	Czech Republic	Cadaveric	Healthy	101	280
Numano 1998 [23]	Japan	Intraoperative	SHPT	570	2377
Okada 2016 [24]	Japan	Intraoperative	SHPT	131	457
Pacini 1983 [25]	Italy	Intraoperative	PHPT and SHPT	42	163
Périé 2005 [26]	France	Intraoperative	SHPT	20	80
Pool 1916 [27]	USA	Cadaveric	Healthy	25	60
Prazenica 2015 [28]	Czech Republic	Intraoperative	Various thyroid disease	788	1937
Pyrtek 1964 [29]	USA	Cadaveric	Healthy	100	391
Wang 1976 [30]	USA	Cadaveric	Healthy	160	645

SHPT secondary hyperparathyroidism, PHPT primary hyperparathyroidism

*Study included only in location analysis