Table 4. Summary of the secondary analysis mean difference findings between the citation numbers and the various characteristics for the 50 most-cited survey research publications in the neurosurgical literature.

*Denotes significance

Feature	Variables	Number	Mean Citation Numbers (±SD)	Mean Difference	P-value
Articles’ age (years)	≥15.5	25	199.8(±265.5)	88	0.0236*
	<15.5	25	111.8(±52.8)
Articles’ journals impact factor	≥2.82	26	190.4(±261.5)	54.7	0.1935
	<2.82	24	118.3(±59.2)
Articles’ number of Authors	>4	24	110.8(±54.3)	78.5	0.1544
	≤4	26	197.3(±260.4)
Articles’ number of centres	1	25	200(±266.4)	89.3	0.1053
	>1	25	111.3(±46.9)
Articles’ number of specialties	1	40	162.9(±214.6)	35.7	0.609
	>1	10	127.2(±74.6)
Articles’ number of countries	1	41	163.1(±212.2)	40.8	0.5743
	>1	9	122.3(±73)
Articles’ first authors countries	USA	32	175.1(±237.5)	53.6	0.3552
	Others	18	121.5(±66)
Participants’ numbers	≥222	22	210.3(±281.8)	87.9	0.1581
	<222	22	122.4(±53.8)
Participants’ response rates	≥51%	20	191.8(±278.6)	46.9	0.4572
	<51%	24	144.9(±117.1)
Participants’ specialties	General neurosurgery	23	153.9(±262)	3.500	0.9502
	Others	27	157.4(±115.3)
Participants’ selection	Associations/Groups	27	151.3(±116.7)	9.3	0.8664
	Others	23	160.6(±256.6)
Participants’ worldwide regions	North America	28	172.4(±252.4)	37.7	0.5022
	Others	22	134.7(±75)
Questionnaires’ number of items	≥12	25	169.6(±251)	29	0.6232
	<12	22	140.6(±119.1)
Questionnaires’ subspecialties	Spine surgery	14	175.9(±150.2)	28	0.6526
	Others	36	147.9(±210.8)
Questionnaires’ categories	Management	28	118.7(±52.1)	84.3	0.1297
	Others	22	203(±284.1)
	Training and career	9	93(±27.4)	76.4	0.2908
	Others	41	169.5(±212.4.5)
	Complications	8	347.9(±442.5)	228.7	0.0016*
	Others	42	119.2(±57)