Journal of Rehabilitation Medicine 51-1CompleteIssue | Page 24

Temporal stability of psychological factors post-stroke
21
Table II. Temporal stability of psychological factors
Changes over time 0.5 SD a
2 months post-stroke 2 years post-stroke
Psychological factors
Score range
n
Mean (SD)
Mean (SD)
Effect size %worse
t
Correlations b
%equal %better
Proactive coping [1–4] 301 3.1 (0.5) 2.9 (0.7) 6.83** –0.42 46.8 33.6 19.6 0.55**
Self-efficacy
Extraversion
Optimism [10–40]
[0–12]
[0–12] 301
305
298 31.5 (6.4)
7.2 (3.2)
8.2 (2.1) 30.8 (6.4)
6.3 (3.3)
6.9 (2.1) 2.20* c
5.64**
9.33** –0.11
–0.28
–0.58 28.6
34.1
41.6 51.5
51.1
47.7 19.9
14.8
10.7 0.52** c
0.64**
0.42**
Passive coping
Neuroticism
Pessimism [7–28]
[0–12]
[0–12] 304
305
294 10.5 (2.8)
3.6 (3.1)
4.4 (2.8) 10.9 (3.2)
4.4 (3.5)
4.9 (2.3) 0.12
0.27
0.19 28.9
34.8
35.0 48.4
47.5
43.2 22.7
17.7
21.8
–0.87 c
–5.12**
–3.38**
0.61** c
0.64**
0.49**
*p  < 0.05, **p  < 0.01. a % worse, % equal and % better refer to categories of 0.5 SD change of the psychological variable score over time.
b
Correlations between 2 months post-stroke and 2 years post-stroke.
c
Based on transformed data.
and more pessimism in comparison with 2 months
post-stroke. The largest effect sizes were found for
optimism (Glass’s Δ = –0.58) and proactive coping
(Glass’s Δ = –0.42). Furthermore, looking at changes
over time (“worse”, “equal”, “better”), 28.6–46.8%
participants showed changes in a negative direction and
10.7–22.7% improved across all psychological factors.
At 2 years post-stroke, all psychological factors cor-
related significantly with each other. The correlations
ranged between weak and strong. The highest corre-
lation was again found between proactive coping and
self-efficacy (r = 0.71). Overall, correlations at 2 years
were somewhat stronger compared with 2 months.
Dimensions among psychological factors
Associations among psychological factors
For all psychological factors moderate or strong cor-
relations were found between scores at 2 months and 2
years post-stroke, ranging between 0.42 and 0.64 (Table
II). In Table III correlations among the various psy-
chological factors within each time-point are reported.
At 2 months post-stroke, all psychological factors
correlated significantly with each other, except for
extraversion with neuroticism. The correlations ranged
between very weak to strong. The highest correlation
was found between proactive coping and self-efficacy
(r = 0.62).
The correlations among the psychological variables at
both time-points were best described by the extraction of
2 factors using principal axis factoring as EFA extraction
method (Table IV). After factor extraction and oblimin
rotation, the factor correlation was 0.58 and –0.70 at 2
months post-stroke and 2 years post-stroke, respectively.
The pattern matrices of both time-points, consisting of
the factor loadings after oblimin rotation, are shown in
Table V. For interpretation purposes, factor loadings on
factor 1 at 2 months post-stroke were inverted.
At 2 months post-stroke, factors 1 and 2 are labelled
as “maladaptive psychological factor” and “adaptive
Table III. Correlations of psychological measures at 2 months post-stroke (below the diagonal) and at 2 years post-stroke (above the
diagonal)
Psychological factors
1. Proactive coping
2. Self-efficacy a
3. Extraversion
4. Optimism
5. Passive coping a
6. Neuroticism
7. Pessimism
1
2 a
3 a
4
5 6 7
–
0.62** 0.71**
– 0.50**
0.45** 0.47**
0.46** –0.54**
–0.56** –0.46**
–0.47** –0.30**
–0.34**
0.27**
0.41**
–0.46** 0.27**
0.44**
–0.39** –
0.21**
–0.19** 0.43**
–
–0.41** –0.40**
–0.56**
– –0.28**
–0.53**
0.68** –0.29**
–0.37**
0.34**
–0.40**
–0.15** –0.31**
–0.24** –0.09
–0.14* –0.39**
–0.28** 0.59**
0.26**
–
0.26**
0.38**
–
*p  < 0.05, **p  < 0.01. Correlation coefficient is Pearson’s correlation. a At 2 months post-stroke based on transformed data due to non-normality.
Table IV. Exploration of factor structures at 2 months post-stroke and 2 years post-stroke
Criterion for factor extraction Two months post-stroke Two years post-stroke N of extracted factors
Eigenvalues 1
3.03 2
1.02 1
3.76 2
0.86
K1 criterion (eigenvalues ≥ 1.0)
Scree plot
Residual correlations ü
[–0.06; 0.14] [–0.07; 0.09] ü
[–0.07; 0.14] [–0.04; 0.06]
Small [–0.1; 0.1]
p-value, goodness-of-fit test 0.00 0.08 0.00 0.10
Non-significant
Bold indicates that the criterion is met.
J Rehabil Med 51, 2019