The theoretical and practical determination of clinical cut-offs for the British Sign Language versions of PHQ-9 and GAD-7

Table 4 Reliable change indices for PHQ-9 and GAD-7 compared with PHQ-9 BSL and GAD-7 BSL

	English version (hearing population)		BSL version (Deaf population)
	PHQ-9	GAD-7	PHQ-9 BSL	GAD-7 BSL
Cronbach’s alpha	0.89 ([1] p608)	0.92 ([2] p1094)	0.81 ([13] p115)	0.88 ([13] p116)
Standard deviation of pre-therapy scores^a	N/A	N/A	5.52	4.49
Standard error of difference^b	N/A	N/A	3.40	2.20
Reliable change index	5.20 ([30] p599)	3.53 ([30] p599)	6.66^b	4.31^b

^an = 411 from those reaching caseness using the Equalising cut-off – see Table 5
^bfollowing Jacobson and Truax [32 p14]

ISSN: 1471-244X