Table 1.

Characteristics of the included primary studies identified in the systematic review that reported on diagnostic outcomes

First author		Year		Location		Study type		Study duration (months)		Total patients		Mean age (range) (years)		Proportion of women		Number of operative patients		Reference Standard	Reference standard positive appendicitis
S Serinsoz30		2021		Turkey		Retrospective, centre unknown		24		70		32 (11–71)		63%		40		Surgical results; unclear for non-operated patients	37/70 (53%)
G Islam31		2021		India		Prospective, single-centre		18		67		24 (6–70)		37%		39		Histopath; or clinical follow-up	45/67 (67%)
A Inoue32		2019		Japan		Retrospective, single-centre		10		51		35 (6–90)		53%		25		Surgery; or clinical follow-up and CT	35/51 (69%)
M Repplinger33		2018		USA		Prospective, single-centre		30		198		32 (12–81)		58%		Not reported		Expert panel; Histopath or clinical follow-up	64/198 (32%)
S Byott34		2016		England		Prospective, single-centre		60		468		Median 27 (7–59)		74%		116		Surgical, histological, and clinical follow-up	38/468 (8%)
I Petkovska35		2016		USA		Retrospective, single-centre		24		253		Not reported		Not reported		Not reported		Expert panel; surgical results; or clinical follow-up	35/253 (14%)
H Gielkens36		2016		Netherlands		Prospective, single-centre		18		112		Median 22 (12–55)		100%		51		Histopath; or clinical follow-up	29/112 (26%)
M Leeuwenburgh37		2014		Netherlands		Prospective, multi-centre		6		223		35 (18–84)		62%		128		Expert panel; surgical findings, histopath, and clinical-follow-up	117/223 (52%)
S Avcu38		2013		Turkey		Prospective, single-centre		12		55		36 (17–83)		43%		40		Histopath; unclear for non-operated patients	40/55 (73%)
First Author	Year		Location		Study type		Study duration (months)		Total patients		Mean age (range) (years)		Proportion of women		Number of operative patients		Reference Standard			Reference standard positive appendicitis
B Zhu39	2012		China		Prospective, single-centre		24		41		42 (range not reported)		56%		41		Surgery/histopath			36/41 (88%)
E Inci40	2011		Turkey		Prospective, single-centre		11		119		27 (17–72)		36%		92		Histopath; unclear for non-operated patients			79/119 (66%)
E Chabanova41	2011		Denmark		Prospective, single-centre		Not reported		48		37 (18–70)		60%		48		Surgery/histopath			30/48 (63%)
L Cobben42	2009		Netherlands		Prospective, single-centre		22		138		Not reported (6–80)		58%		64		Histopath; or clinical follow-up			62/138 (44.9%)
A Singh43	2008		USA		Retrospective, multi-centre		72		67		34 (11–69)		91%		Not reported		Surgical results; unclear for non-operated patients			12/67 (18%)
N Nitta44	2005		Japan		Prospective, single-centre		Not reported		37		37 (16–69)		51%		31		Surgery/histopath; clinical follow-up			29/37 (43%)
L Incesu46	1997		Turkey		Prospective, single-centre		22		60		20 (14–71)		55%		39		Surgery/histopath; or clinical follow-up			34/60 (57%)