Pilot Validation Study of the Japanese Translation of the Brief Negative Symptoms Scale (BNSS)

Figures & data

Table 1 Demographic Characteristics of Subjects

	Age (Years)	Sex	Duration of Disease (Years)	Inpatient/Outpatient	Daily Dose of Antipsychotics^a
Case 1	33	M	8	Outpatient	1200
Case 2	47	M	30	Inpatient	1200
Case 3	36	F	12	Outpatient	1255
Case 4	41	M	18	Inpatient	1230
Case 5	22	F	9	Outpatient	160
Case 6	44	M	24	Outpatient	1000
Case 7	24	M	2	Outpatient	600
Case 8	44	F	10	Outpatient	300
Case 9	36	F	13	Outpatient	1000
Case 10	52	M	30	Inpatient	300
	37.9 (9.7)^b	M:F=6:4	15.6 (9.6)^b	In:Out=3:7	824.5 (439.1)^b

Notes: ^aChlorpromazeine quivalent (mg), ^bMean (standard deviation), Case 1 was used for rater training, and cases 2 to 10 were used for validation analysis.

Table 2 Descriptive Statistics and Cronbach’s Alpha

	Mean	SD	Skew	Kurtosis	Cronbach Alpha if Item Deleted
I. Anhedonia
1. Intensity of pleasure during activities	2.70	1.65	0.34	−1.09	0.95
2. Frequency of pleasurable activities	2.70	1.59	0.29	−0.90	0.95
3. Intensity of future pleasure	2.57	1.69	0.38	−1.00	0.95
Total subscale	7.96	4.78	0.36	−0.95
II. Distress
4. Lack of normal distress	2.28	1.35	0.18	−1.23	0.95
Total subscale	2.28	1.35	0.18	−1.23
III. Asociality subscale
5. Asociality:behavior	3.22	1.28	−0.18	−0.64	0.95
6. Asociality:inner-experience	3.14	1.55	−0.15	−1.24	0.96
Total subscale	6.36	2.53	−0.37	−0.82
IV. Avolition subscale
7. Avolition: behavior	2.17	1.16	0.33	−0.50	0.95
8. Avolition: inner-experience	2.43	1.30	0.05	−1.07	0.95
Total subscale	4.61	2.33	0.03	−1.04
V. Blunted affect subscale
9. Facial expression	2.74	1.42	0.34	−1.07	0.95
10. Vocal expression	2.30	1.59	0.52	−1.05	0.95
11. Expressive gesture	2.76	1.53	0.19	−1.13	0.95
Total subscale	7.80	4.23	0.38	−1.08
VI. Alogia subscale
12. Quantity of speech	1.70	1.19	0.99	0.47	0.95
13. Spontaneous elaboration	2.17	1.54	0.71	−0.72	0.95
Total subscale	3.87	2.53	0.79	−0.35	0.95
Total	32.88	15.18	0.20	−0.92	0.95

Abbreviation: SD, standard deviation.

Table 3 Inter-Rater and Test-Retest Reliability

	Inter-Rater Reliability		Test-Retest Reliability
	ICC^a	p	r^b	p
I. Anhedonia
1.Intensity of pleasure during activities	0.97	<0.001	0.85	<0.001
2.Frequency of pleasurable activities	0.97	<0.001	0.77	<0.001
3.Intensity of future pleasure	0.98	<0.001	0.86	<0.001
Total subscale	0.98	<0.001	0.86	<0.001
II. Distress
4. Lack of normal distress	0.96	<0.001	0.80	<0.001
Total subscale	0.96	<0.001	0.80	<0.001
III. Asociality subscale
5. Asociality: behavior	0.96	<0.001	0.80	<0.001
6. Asociality: inner-experience	0.98	<0.001	0.75	<0.001
Total subscale	0.98	<0.001	0.81	<0.001
IV. Avolition subscale
7. Avolition: behavior	0.96	<0.001	0.73	<0.001
8. Avolition: inner-experience	0.96	<0.001	0.78	<0.001
Total subscale	0.96	<0.001	0.79	<0.001
V. Blunted affect subscale
9. Facial expression	0.96	<0.001	0.90	<0.001
10. Vocal expression	0.95	<0.001	0.91	<0.001
11. Expressive gesture	0.96	<0.001	0.90	<0.001
Total subscale	0.97	<0.001	0.94	<0.001
VI. Alogia subscale
12. Quantity of speech	0.94	<0.001	0.82	<0.001
13. Spontaneous elaboration	0.90	<0.001	0.85	<0.001
Total subscale	0.93	<0.001	0.87	<0.001
Total	0.97	<0.001	0.94	<0.001

Notes: ^aICC: Intra class correlation coefficient, ^br: Pearson’s correlation coefficient.

Table 4 Convergent and Discriminant Validity of BNSS

BNSS	SANS Total		SANS Avolition/Apathy		SANS Asociality/Anhedonia		SANS Blunted Affect		SANS Alogia		SANS Attention		SAPS Total
	R^a	p	R^a	p	R^a	p	R^a	p	R^a	p	R^a	p	R^a	p
Total	0.87	<0.001	0.80	<0.001	0.72	<0.001	0.83	<0.001	0.74	<0.001	0.46	<0.001	0.17	0.678
Anhedonia	0.80	<0.001	0.75	<0.001	0.74	<0.001	0.67	<0.001	0.67	<0.001	0.49	<0.001	0.29	0.004
Distress	0.76	<0.001	0.70	<0.001	0.54	<0.001	0.73	<0.001	0.62	<0.001	0.47	<0.001	0.20	0.053
Asociality	0.66	<0.001	0.69	<0.001	0.59	<0.001	0.62	<0.001	0.52	<0.001	0.23	0.101	0.15	0.159
Avolition	0.77	<0.001	0.83	<0.001	0.76	<0.001	0.58	<0.001	0.61	<0.001	0.47	<0.001	0.35	<0.001
Blunted Affect	0.79	<0.001	0.64	<0.001	0.55	<0.001	0.85	<0.001	0.68	<0.001	0.38	0.002	<0.01	0.851
Alogia	0.65	<0.001	0.51	<0.001	0.41	0.001	0.73	<0.001	0.64	<0.001	0.25	0.101	<0.01	0.281

Note: ^aPearson’s correlation coefficient.

Abbreviations: BNSS, brief negative symptoms scale; SANS, Scale for the Assessment of Negative Symptoms; SAPS, Scale for the Assessment of Positive Symptoms.

Table 5 Factor Analysis

		Factors
		1	2
I. Anhedonia
	1.Intensity of pleasure during activities	−0.05	0.99
	2.Frequency of pleasurable activities	0.02	0.92
	3.Intensity of future pleasure	−0.12	1.00
II. Distress
	4. Lack of normal distress	0.60	0.25
III. Asociality subscale
	5. Asociality: behavior	0.54	0.33
	6. Asociality: inner-experience	0.63	−0.04
IV. Avolition subscale
	7. Avolition: behavior	0.07	0.75
	8. Avolition: inner-experience	0.14	0.73
V. Blunted affect subscale
	9. Facial expression	0.91	−0.01
	10. Vocal expression	0.58	0.34
	11. Expressive gesture	0.96	−0.04
VI. Alogia subscale
	12. Quantity of speech	0.87	−0.09
	13. Spontaneous elaboration	0.71	0.06
Eigenvalue		7.97	1.21
% of variance		61.28	9.30

Note: Items loading on the factor are in bold.