Table 3. Content validity of the Vietnamese version of the UTBAS-6 scale (n=5)

Item	Clarity				Relevance
	A	I-CVI	Pc	K	A	I-CVI	Pc	K
1. I will never be successful because of my stuttering.	5/5	1.00	0.03	1.00	5/5	1.00	0.03	1.00
2. People will think I am incapable/incompetent due to my stutter.	5/5	1.00	0.03	1.00	5/5	1.00	0.03	1.00
3. People will think I am different.	5/5	1.00	0.03	1.00	4/5	0.80	0.16	0.76
4. I do not want to go out - people will not like me.	5/5	1.00	0.03	1.00	4/5	0.80	0.16	0.76
5. Even when I try to say something that is meaningful - I can’t say it straight away.	3/5	0.60	0.31	0.42	4/5	0.80	0.16	0.76
6. I will never finish my explanation - people will misunderstand me.	5/5	1.00	0.03	1.00	5/5	1.00	0.03	1.00
	S-CVI/Ave = 0.93S-CVI/UA = 0.83				S-CVI/Ave = 0.90S-CVI/UA = 1.00

A: The number of experts rated the item as a 3 or 4 on a 4-point scale
I-CVI: Item-content validity index; S-CVI: Scale-content validity index; S-CVI/Ave is averages of the item-level CVIs; S-CVI/UA: universal agreement among experts that was the proportion of items rated at level 3 or 4.
Pc: Probability of chance agreement
K: Modified kappa statistic coefficient