Visual symptoms after ABI: mental fatigue, anxiety and depression
The HADS includes 14 items; 7 items are depression grades
and 7 are anxiety grades (27). Each item is graded 0–3; the
maximum sum for anxiety is 21 and the same for depression.
A total score of 0–7 indicates no problems, 8–10 indicates pos-
sible anxiety or depression, and 11–21 indicates depression or
anxiety. In this study a cut-off value of 8 points was applied,
corresponding to possible symptoms of depression and anxiety.
Statistical analysis
All analysis was performed using SPSS 23. Mann–Whitney
U test and Kruskal–Wallis test were used to compare outcome
values between sex and diagnosis groups, respectively. Pearson χ 2
or Fisher’s exact tests were used for analysis of cross-tabulations
of frequencies. Binary logistic regression was performed with the
purpose of exploring factors affecting the likelihood that the pa-
tients had clinically significant mental fatigue (MFS ≥ score 15),
anxiety (HADS-A ≥ score 8) or depression (HADS-D ≥ score
8). The dependent variables (MFS, HADS-A, HADS-D) were
treated as dichotomous values based on the cut-off scores. The
binary logistic regression was conducted in 2 model blocks; the
null model with no predictors and the model with all independent
variables added according to the Enter method. The Nagelkerke
R 2 method was applied to calculate the explained variation.
Ethical considerations
The study was approved by the Regional Ethic Board of Stock-
holm, Sweden, (Dnr. 2013/157-31/3), were performed according
to the principles of the Declaration of Helsinki 1978.
RESULTS
The analysis and reporting of the results is based on the
patients who had complete data for VI, MFS, HADS-
A and HADS-D (n = 123). Of the 123 patients 100
patients (81.3%) had experienced some visual-related
symptoms according to the VI (median VI score 4,
range 1–15 while the rest of the patients (18.7%) did
not report any symptoms). Men scored median 3 (range
0–15) while women scored median 4 (range 0–10)
(Mann–Whitney U test, p = 0.026). No statistically
significant associations were found between age group
or diagnosis group and VI score (Kruskal–Wallis).
Sixty-four patients (52.1%) scored 15 or higher on
the MFS, indicating the presence of moderate (28.5%)
to severe (23.6%) mental fatigue. A total of 52 patients
(42.3%) scored 8 or more on HADS-A, indicating
“possible anxiety” (18.7%) or “anxiety” (23.6%).
A total of 42 patients (34.1%) scored 8 or more on
HADS-D, indicating “possible depression” (18.7%)
or “depression” (15.4%).
Analysis of the different diagnoses’ groups showed
MFS scores of 15 or higher in 66.7% of patients with
TBI, 66.7% of patients with SAH/infection/tumour,
and 55.6% of other, but only 36.8% of stroke patients.
Anxiety (HADS-A ≥8) was found in 40.4% of
stroke patients, 36.4% of TBI patients, 50.0% of SAH/
501
infection/tumour patients, and 55.6% of patients with
other diagnoses. A corresponding score for HADS-D
was found in 28.1% of stroke patients, 42.4% of TBI
patients, 33.3% of SAH/infection/tumour patients, and
44.4% of patients with other diagnoses.
Some of the questions in the VI showed a marked
difference between those who had or had not ex-
perienced symptoms of mental fatigue, anxiety or
depression. (Fig. 1) The questions that differed the
most concerned reading disturbances, blurred vision,
light sensitivity, needing more light while reading,
and a generally higher need for light to see well, or
an increased tendency to bump into objects (Fig. 1)
Univariate analyses of the VI score showed signi-
ficant associations with MFS and HADS. There were
also statistically significant associations between
demographics factors (sex, age-group, diagnosis) and
MFS and between HADS-A and HADS-D. It was
therefore decided to include demographics in addition
to VI score as independent variables in the logistic
regression models.
Mental fatigue
The logistic regression model was statistically signifi-
cant (χ 2 71.138, df = 8, p = 0.000). The model explained
58.6% of the variance (Nagelkerke R 2 ) and correctly
classified 82.9% of the cases. Increasing VI score and
HADS-D exceeding cut-off (≥ 8) were associated with
an increased likelihood of exhibiting mental fatigue
(Table II).
Anxiety
The logistic regression model was statistically signifi-
cant (χ 2 53.092, df=8, p = 0.000). The model explained
47.1% of the variance (Nagelkerke R 2 ) and correctly
classified 79.7% of cases. Diagnosis TBI, and HADS-D
Table II. Logistic regression predicting the likelihood of mental
fatigue (MFS≥ 15) based on sex, age group, diagnosis group,
Visual Interview score, HADS-A and HADS-D. Sex is for females
compared with males, diagnosis group is compared with stroke
Variable Wald Df
Sex, female
Age group
Diagnosis, stroke
Diagnosis, TBI
Diagnosis, SAH/Inf./Tum.
Diagnosis, other
VI score
HADS-A
HADS-D
Constant 1.227
2.378
4.933
2.916
3.575
0.129
6.598
3.388
11.361
2.226 1
1
3
1
1
1
1
1
1
1
Odds ratio Significance
1.822
0.567
3.150
3.781
1.467
1.261
2.927
10.347
0.217
0.268
0.123
0.177
0.088
0.059
0.720
0.010
0.066
0.001
0.136
TBI: traumatic brain injury; SAH: subarachnoid haemorrhage; HADS-A:
Hospital Anxiety and Depression Scale anxiety; HADS-D: Hospital Anxiety
and Depression Scale depression; VI: Visual Interview; MFS: Mental Fatigue
Scale; Inf./Tum.: Infection/Tumour.
J Rehabil Med 51, 2019