Table IV.

Mean ± standard deviation of the Brief-IT-QOD subscales scores in patients with OD and in asymptomatic subjects. Ranges are reported in parentheses. The results of Student’s t test are reported as well as those of Cohen’s effect size.

	Asymptomatic subjects	Patients with OD	P score	Cohen’s d
	(n = 303)	(n = 112)
QOD-P	1.6 ± 2.2	4.6 ± 3.4	P = 0.001	D = 2.793
	(0-8)	(0-12)
QOL-QOD	0.4 ± 1.6	4.3 ± 5.1	P = 0.001	D = 2.986
	(0-11)	(0-19)