Postoperative results of ventilation tube insertion: a retrospective multicenter study for suggestion of grading system of otitis media with effusion

Table 1 Descriptive characteristics of the patients

	Grade 0 (n = 60)	Grade I (n = 32)	Grade II (n = 57)	Grade III (n = 152)	Grade IV (n = 410)	Grade V (n = 301)	p-value
Age (year)	7.0 ± 3.6^a	6.3 ± 3.6	5.3 ± 3.1	5.1 ± 3.0	4.9 ± 2.3	5.5 ± 3.0	< 0.001^b 0.046^c
Sex							0.591
Male	40	22	41	90	257	192
Female	20	10	16	62	153	109
Laterality							0.748
Right	27	16	33	80	200	150
Left	33	16	24	72	210	151
Preoperative OME duration (month)	-	3.6 ± 1.5	3.8 ± 2.0	3.9 ± 1.6	4.1 ± 1.9	4.1 ± 1.8	0.056

Note: Values are presented as mean ± standard deviation or number
VTI ventilation tube insertion, OME otitis media with effusion
^aAge at VTI in the contralateral ear because ear with grade 0 did not undergo VTI
^bp -value for difference in mean age from grade 0 to grade V
^cp -value for difference in mean age from grade I to grade V

ISSN: 1471-2431