Classification of Neurocognition in Japanese Patients with Schizophrenia: A Cluster Analysis

Table 1

Demographics and psychiatric symptoms by clusters (n = 133).

	Overall		Cluster 1		Cluster 2		Cluster 3		Cluster 4		F
	n = 133		n = 16		n = 44		n = 42		n = 31
	Mean	SD	Mean	SD	Mean	SD	Mean	SD	Mean	SD
	n		n		n		n		n
Demographics
Sex
Male/Female	72/61		8/8		23/21		22/20		19/12			0.834
Treatment site
Inpatient/Outpatient	70/63		16/0^a		32/12^a		12/30^b		10/21^b			<0.001
Age (years old)	50.7	15.4	60.8	13.3^a	59.5	13.6^a	43.6	13.1^b	42.6	12.1^b	17.846	<0.001
Age of onset (years old)	26.1	9.4	25.9	8.2	27.6	10.5	26.9	10.3	23.2	6.4	1.462	0.228
Duration of illness (years)	24.5	14.5	34.9	12.6^a	31.9	14.5^a	16.7	10.1^b	19.4	12.3^b	16.084	<0.001
Length of stay (months)	92.7	137.2	278.6	148.1^a	128.5	158.6^b	23.0	40.8^c	40.5	60.0^c	24.335	<0.001
FGA (mg)	239.5	475.0	445.6	756.7	222.6	536.6	147.8	278.9	281.1	388.3	1.648	0.182
SGA (mg)	436.5	378.6	390.4	422.0	383.4	319.5	504.4	386.9	443.6	422.9	0.818	0.486
Total chlorpromazine equivalent (mg)	676.0	541.2	836.1	670.4	606.1	592.7	652.2	425.3	724.7	537.5	0.819	0.486
Biperiden (mg)	2.0	2.6	1.8	3.3	2.1	3.1	1.7	1.9	2.2	2.6	0.269	0.848
Diazepam (mg)	12.6	12.8	17.2	16.8	11.7	11.7	11.9	11.3	12.5	13.7	0.810	0.491
Psychiatric symptoms
Positive scale	13.1	4.2	14.8	4.4	13.9	3.9	12.3	4.6	12.2	3.7	2.340	0.076
Negative scale	18.8	7.1	23.6	7.4^a	20.7	7.8^a,b	16.5	5.9^b	16.5	5.3^b	6.861	<0.001
General psychopathological scale	29.5	7.1	35.8	6.7^a	31.5	7.0^a,b	27.1	5.8^b,c	26.5	6.3^c	10.633	<0.001
PANSS total	61.3	15.0	74.1	12.6^a	66.1	15.0^a	56.0	13.2^b	55.2	12.3^b	10.870	<0.001

^a,b,c,dthe different letters mean significant differences between letters. ^αgender and treatment site were analysed by chi-square test. ^βrest of variables was analysed by one-way analysis of variance. FGA:first-generation antipsychotics. SGA:second generation antipsychotics.