eTable 1. Included studies and their characteristics (in alphabetical order).

Reference	Country	Study design	Study period	Number of patients with empty sella	Age (mean ± SD)	Symptoms	Initially imaging, followed by endocrinologic diagnostics	Radiological method	Radiological diagnostic criteria empty sella present	Study quality*1
Cannavo 2002 (23)	Italy	Case-control study*2	Not available	43	48 ± 12	Headache, impaired vision	Yes	MRI	Yes	8
Colao 2013 (24)	Italy	Case-control study*3	Not available	94	50.1 ± 9.3	Not available	Yes (78%)*4	CT, MRI	Yes	10
Lupi 2011 (22)	Italy	Case-control study*5	2006–2009	85 (PES), 16 (SES)	48 ± 1	Headache, impaired vision, sexual dysfunction, oligomenorrhea, rhinoliquorrhea*6	Yes	MRI	Yes	10
Zuhur 2014 (21)	Turkey	Prospective cohort study	2011–2012	81	49.9 ± 14.5	Headache, fatigue, arthralgia, myalgia, nausea, weight loss, sexual dysfunction, amenorrhea*7	Yes	MRI	Yes	9

*¹ Based on the quality assessment criteria of Guyatt et al. (GRADE working group) (18, 19) (0 = low to 10 = high quality)

*² 43 patients (10 men, 33 women) with PES and 40 controls (9 men, 31 women) without goiter or prior intake of thyroid hormone

*³ 94 patients (39 men, 55 women) with PES, of which 78% had an incidental finding, and 94 controls from a cohort of 1484 individuals with normal pituitary function, matched for age (± 1 year), body mass index, and sex

*⁴ In 78% incidental, in 22% imaging for pituitary disorder

*⁵ 85 patients (18 men, 67 women) with PES and 214 healthy controls (48 men, 166 women) with normal findings on examination and normal pituitary function, as well as 16 patients with autoimmune hypophysitis, of these at least 14 histologically confirmed

*⁶ No differentiation between PES, SES, and hypophysitis

*⁷ A non-incidental finding has to be assumed in <10% CT, computed tomography; MRI, magnetic resonance imaging; PES, primary empty sella syndrome; SD, standard deviation; SES, secondary empty sella syndrome