Evaluation Of Subjective Cognitive Function Using The Cognitive Complaints In Bipolar Disorder Rating Assessment (COBRA) In Japanese Adults

Figures & data

Table 1 Socio-Demographic And Clinical Data

Patient Details	Mean (SD)	n (%)
Age (years) (n=584)	41.71 (12.10)
Sex, male, n (%) (n=584)		249 (42.6)
Sex, female, n (%) (n=584)		335 (57.4)
Married, n (%) (n=580)		383 (65.5)
Years of education (n=585)	14.60 (1.82)
Currently employed, n (%) (n=581)		571 (97.6)
Psychiatric history, n (%) (n=585)		68 (11.6)
Current psychiatric treatment, n (%) (n=575)		23 (3.9)
Family history of psychiatric treatment, n (%) (n=531)		58 (9.9)
Drinking, n (%) (n=584)		379 (63.4)
Smoking, n (%) (n=584)		114 (19.5)
PHQ-9 (n=585)	4.05 (4.23)
SDS work, (n=580)	2.04 (2.52)
SDS social (n=580)	1.72 (2.44)
SDS family/home (n=580)	1.52 (2.38)
SDS total (n=580)	5.28 (6.61)
PF (n=580)	49.99 (5.64)
RP (n=580)	50.22 (5.14)
BP (n=580)	49.87 (8.69)
GH (n=580)	49.27 (8.14)
VT (n=580)	49.89 (6.71)
SF (n=580)	49.12 (7.83)
RE (n=580)	49.59 (6.13)
MH (n=580)	49.22 (7.56)
PCS (n=580)	49.00 (6.30)
MCS (n=580)	48.44 (7.76)
COBRA (n=581)	8.32 (6.60)

Abbreviations: PHQ-9, Patient Health Questionnaire-9; SDS, Sheehan disability scale; PF, physical functioning; RP, role physical; BP, bodily pain; GH, general health; VT, vitality; SF, social functioning; RE, role emotional; MH, mental health; PCS, physical component summary; MCS, mental component summary; COBRA, Cognitive Complaints in Bipolar Disorder Rating Assessment.

Table 2 Spearman Correlations (ρ) Between COBRA Scores And PHQ-9, Or QoL Measures

	COBRA
PHQ-9 (n=581)	0.407**
SDS work (n=579)	0.363**
SDS social (n=579)	0.378**
SDS family/home (n=579)	0.334**
SDS total (n=579)	0.390**
PF (n=579)	−0.266**
RP (n=579)	−0.294**
BP (n=579)	−0.208**
GH (n=579)	−0.315**
VT (n=579)	−0.290**
SF (n=579)	−0.324**
RE (n=579)	−0.381**
MH (n=579)	−0.333**
PCS (n=579)	−0.210**
MCS (n=579)	−0.341**

Note: **P < 0.01 (two-sided).

Abbreviations: COBRA, Cognitive Complaints in Bipolar Disorder Rating Assessment; PHQ-9, Patient Health Questionnaire-9; SDS, Sheehan disability scale; SF-8, Medical Outcomes Study-Short Form Health Survey; PF, physical functions; RP, role physical; BP, bodily pain; GH, general health; VT, vitality; SF, social functioning; RE, role emotional; MH, mental health; PCS, physical component summary; MCS, mental component summary.

Table 3 Stepwise Multiple Regression Analysis Of The SDS Total Score

Independent Factors	Partial Regression Coefficient (B)	95% Confidence Interval	Standardized Partial Regression Coefficient (β)	p
(Constant)	0.861	0.122 to 1.600	–	–
PHQ-9	0.808	0.696 to 0.921	0.519	<0.001
COBRA	0.138	0.065 to 0.211	0.136	<0.001

Notes: Adjusted R² = 0.345, F = 151.5, p < 0.001. Dependent factor: SDS total score. Two independent factors: PHQ-9 and COBRA scores.

Abbreviations: COBRA, Cognitive Complaints in Bipolar Disorder Rating Assessment; PHQ-9, Patient Health Questionnaire-9; SDS, Sheehan disability scale.

Figure 1 Results of covariance structure analysis in the structural equation model with depressive symptoms (PHQ-9), subjective cognitive function (COBRA), and quality of life (SDS) in 585 adult volunteer subjects from the community.

Notes: Rectangles indicate the observed variables. The oval indicates the latent variable. The numbers beside the arrows show the standardized path coefficients (minimum −1, maximum 1).
Abbreviations: PHQ-9, Patient Health Questionnaire-9; COBRA, Cognitive Complaints in Bipolar Disorder Rating Assessment; SDS, Sheehan disability scale.

Figure 2 Results of covariance structure analysis in the structural equation model with depressive symptoms (PHQ-9), subjective cognitive function (COBRA), and quality of life (SF-8) in 585 adult volunteer subjects from the community.

Notes: Rectangles indicate the observed variables. The numbers beside the arrows show the standardized path coefficients (minimum −1, maximum 1).
Abbreviations: PHQ-9, Patient Health Questionnaire-9; COBRA, Cognitive Complaints in Bipolar Disorder Rating Assessment; SF-8, Medical Outcomes Study-Short Form Health Survey; PCS, physical component summary; MCS, mental component summary.

Table 4 Relationships Between COBRA Scores And PHQ-9, SDS Work, SDS Social, SDS Total, SDS Family/Home, PCS, And MCS Scores

			N	Average Rank		Rank Sum
PHQ-9	COBRA ≦14		480	271.14		130,146
	COBRA >14		101	385.4		38,925
	Total		581
SDS work	COBRA ≦14		479	272.3		130,431.5
	COBRA >14		100	374.79		37,478.5
	Total		579
SDS social	COBRA ≦14		479	271.11		129,862
	COBRA >14		100	380.48		38,048
	Total		579
SDS family/home	COBRA ≦14		479	272.67		130,607.5
	COBRA >14		100	373.03		37,302.5
	Total		579
SDS total	COBRA ≦14		479	270.39		129,517.5
	COBRA >14		100	383.93		38,392.5
	Total		579
PCS	COBRA ≦14		479	299.82		143,616
	COBRA >14		100	242.94		24,294
	Total		579
MCS	COBRA ≦14		479	306.97		147,036.5
	COBRA >14		100	208.74		20,873.5
	Total		579
	PHQ-9	SDS Work	SDS Social	SDS Family/Home	SDS Total	PCS	MCS
Mann–Whitney U	14,706	15,471.5	14,902	15,647.5	14,557.5	19,244	15,823.5
Wilcoxon W	130,146	130,431.5	129,862	130,607.5	129,517.5	24,294	20,873.5
Z	−6.265	−5.793	−6.35	−5.944	−6.32	−3.093	−5.341
p	<0.001	<0.001	<0.001	<0.001	<0.001	0.002	<0.001
Grouping variable	COBRA ≦14, COBRA >14

Note: Analysis was conducted using Mann–Whitney U-tests.

Abbreviations: COBRA, Cognitive Complaints in Bipolar Disorder Rating Assessment; PHQ-9, Patient Health Questionnaire-9; SDS, Sheehan disability scale; SF-8, the 8-item-containing Short-Form Health Survey; PCS, physical component summary; MCS, mental component summary.

Table 5 Chi-Square Test Describing The Association Between COBRA Scores And Demographic Data

	Chi-Square	p
Sex	0.553	0.457
Married	4.712	0.03
Current employed	1.1	0.294
Psychiatric history	5.977	0.014
Current psychiatric treatment	5.089	0.024
Family history of psychiatric treatment	3.016	0.082
Drinking	0.513	0.474
Smoking	1.56	0.212

Notes: Chi-square test: COBRA scores ≦14, COBRA scores >14, degree of freedom: 1.