Unravelling the complex interactions between self-awareness, cognitive change, and mood at 6-months post-stroke using the Y-shaped model

Figures & data

Figure 1. Participant inclusion and exclusion flowchart.

Flow chart comprising boxes and arrows illustrating the process of screening data according to inclusion and exclusion criteria.

Table 1. Summary of assessments administered at T1 and T2.

Assessment	T1 (M = 3.5 days, SD = 2.93)	T2 (M = 6.7 months, SD = 0.78)
NIHSS*	✓
Stroke hemisphere*	✓
Demographic information	✓
CFQ		✓
Barthel Index		✓
HADS		✓
OCS	✓	✓

Note: Demographics data include age, sex, and years of education; *Data was extracted from patient medical records at T1. NIHSS: The National Institutes of Health stroke scale; OCS: Oxford Cognitive Screen; CFQ: The Cognitive Failures Questionnaire; HADS: The Hospital Anxiety and Depression scale; BI: The Barthel Index.

Table 2. Clinical and demographic characteristics of included and excluded participants.

Variable	Included participants (N = 143)				Excluded participants (N = 110)
	M (SD)	Mdn	Range	n (%)	M (SD)	Mdn	Range	n (%)
Age	73.33 (13.73)	75	18–93	143 (100)	73.35 (13.17)	75	31–95	109 (99)
Sex				143 (100)				110 (100)
Male				74 (52)				61 (55)
Female				69 (48)				49 (45)
Education (years)	12.45 (3.34)	11	6–23	143 (100)	12.58 (3.42)	11	9–27	53 (48)
Stroke hemisphere				143 (100)				73 (66)
Right				66 (46)				38 (35)
Left				64 (45)				31 (28)
Both				13 (9)				4 (3)
NIHSS total	7.70 (7.91)	5	0–42	143 (100)	5.71 (4.87)	5	0–17	31 (28)
BI total	16.42 (4.44)	18	1–20	143 (100)	16.71 (4.50)	19	3–20	90 (82)
HADS-A	5.49 (4.08)	5	0–19	143 (100)	5.58 (4.23)	5	0–20	101 (92)
HADS-D	4.77 (3.98)	4	0–19	143 (100)	5.28 (4.14)	5	0–19	101 (92)
HADS total	10.26 (7.18)	9	0–34	143 (100)	10.86 (7.61)	10	0–36	101 (92)
CFQ total	29.39 (17.56)	27	1–92	143 (100)	32.58 (18.88)	31	0–93	99 (90)
Objective cognitive impairment (%) T1	29.75 (25.35)	20	0–92	143 (100)	31.46 (28.18)	25	0–100	110 (100)
Objective cognitive impairment (%) T2	23.50 (16.23)	17	8–83	143 (100)	26.56 (17.52)	18	0–83	97 (88)

Note. See main body for definitions of variables; n = sample total.

Figure 2. Scatterplot illustrating the relationship between awareness and OCI at T2.

Note: The vertical line through the x-axis denotes the cut-off OCI score (39.73) that defines the two groups, whereby OCI scores ≥ 39.73 indicates “moderate-severe cognitive impairment”.

A scatterplot with the X-axis denoting the percentage of OCS tests failed at T2, and the Y-axis denoting awareness score. Data points begin in the upper-left corner where awareness score is highest, and the percentage of OCS tests failed is the lowest. The pattern extends towards the lower-right corner where awareness is lowest and the percentage of OCS tests failed is highest. A vertical dashed line intercepts the graph on the X-axis at the value of 39.73, whereby data to the left comprise the 'mild-no cognitive impairment' group and data to the right comprise the 'moderate-severe cognitive impairment' group.

Table 3. Unadjusted and covariate adjusted descriptive statistics for awareness.

Objective cognitive impairment group	BI			Awareness (unadjusted)		Awareness (adjusted)
	N	M	SE	M	SE	M	SE
Mild-no impairment	120	16.78	0.38	54.17	1.01	54.23	1.02
Moderate-severe impairment	23	14.52	1.15	28.23	2.30	27.92	2.35

Table 4. Hierarchical multiple regression analyses of objective cognitive impairment at T1 as a moderator of the relationship between cognitive change and emotional distress (HADS total score) controlling for the effect of BI and awareness.

	b (CI)	SE b	β	t	p
Constant	−0.49 (−7.27, 6.29)	3.43		−0.14	.886
Cognitive change	0.19 (0.09, 0.30)	0.05	0.59	3.57	.001
Objective cognitive impairment at T1	0.22 (−0.13, 0.31)	0.05	0.79	4.83	.000
interaction	0.0020 (0.0002, 0.004)	0.0009	0.21	2.21	.000
BI	−0.42 (−0.35, −0.19)	0.12	−0.26	−3.64	.000
Awareness	0.37 (0.27, 0.47)	0.05	0.75	7.49	.000

Note: Adjusted R² = .369; 95% confidence intervals reported in parentheses. Cognitive change and objective cognitive impairment at T1 are centred variables. The interaction variable is defined as cognitive change × objective cognitive impairment at T1.

Figure 3. The conditional effect of cognitive change on HADS score as a function of objective cognitive impairment score at T1.

Note: Conditional effect of cognitive change represents the gradient between cognitive change and HADS score for a given OCI score at T1. Those with a higher OCI score at T1 are more sensitive to the effects of cognitive change on HADS. Upper and lower 95% confidence intervals are indicated by the dashed lines.

Graph with the X-axis denoting objective cognitive impairment, ranging from 0-100% and Y-axis denoting the conditional effect of cognitive change, ranging from 0-0.4. A line illustrating the gradient between cognitive change and HADS score for a given OCI score at T1 begins in the lower-left corner, where objective cognitive impairment is lowest, and extends towards the upper-right corner, where objective cognitive impairment is highest, suggesting that those with more severe acute cognitive impairment are more sensitive to the effects of cognitive change on HADS. Dashed lines either side of the gradient line indicates the upper and lower 95% confidence intervals.

Data availability statement

A minimal dataset that supports the findings of this study is openly available in OSF at https://osf.io/87kjv/10.17605/OSF.IO/87KJV