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From the University of Edinburgh (S.O'R., D.S., M.D.),
Neurosciences Trials Unit, Department of Clinical Neurosciences, The
University of Edinburgh, and the Edinburgh Health Care NHS Trust (S.M.), Royal
Edinburgh Hospital, Edinburgh, Scotland.
Correspondence to Martin Dennis, MD, University of Edinburgh, Neurosciences Trials Unit, Department of Clinical Neurosciences, The University of Edinburgh, Bramwell Dott Building, Western General Hospital, Crewe Rd, Edinburgh, UK EH4 2XU. E-mail MSD{at}skull.dcn.ed.ac.uk
MethodsOne hundred five hospital-referred stroke patients
completed both the GHQ-30 and HAD Scale 6 months after onset before a
blinded psychiatric assessment in which the Schedule for Affective
Disorders and Schizophrenia with some supplementary questions was used
to determine a DSM-IV (Diagnostic and Statistical
Manual of Mental Disorders, Fourth Edition) diagnosis. Measures
were compared in terms of sensitivity, specificity, and receiver
operating characteristic curves.
ResultsNo significant differences were found between the GHQ-30
and the HAD Scale in identifying those patients with any DSM-IV
diagnosis (P=0.95), grouped depression
(P=0.56), or anxiety (P=0.25) disorders.
The previously recommended cutoff points for identifying "cases"
for the GHQ (4/5) and for the HAD Scale (8/9 and 11/12) were found to
be suboptimal in this population.
ConclusionsThe GHQ-30 and HAD scale exhibited similar levels of
sensitivity and specificity. Data are presented, taking into
account the "cost" of false-positives and negatives, to allow a
choice of cutoff points suitable for differing situations.
Ideally, the diagnosis of psychiatric illness is made by standardized
psychiatric interview.12 13 However, this may be
impractical when screening large numbers of patients for treatable
psychiatric disease or in large-scale research studies. In these
situations, self-report questionnaires may be useful. Although several
have been used with stroke patients, there is still considerable
uncertainty regarding their suitability and the optimum cutoff points
for different uses. In clinical practice these measures may be useful
as screening tools to identify patients in need of further
intervention; however, in choosing suitable cutoff points, the
consequences of both false-negatives (ie, patients not receiving
treatment) and false-positives (ie, wasted resources) must be
considered. In randomized trials in which psychological outcomes are
important, the power of the study is reduced when outcomes are
misclassified; thus, an outcome instrument with a high accuracy is
essential.
The GHQ14 and the HAD
Scale15 are among the most commonly used measures
of psychiatric morbidity after stroke. The GHQ was designed as a
screening instrument to identify psychiatric disorders. It does not aim
to provide a diagnosis but rather to identify those in need of further
psychiatric assessment. We specifically chose the 30-item version
because items relating to physical illness have been removed to make it
suitable for use in our physically ill population. Unlike the
28-question version, it is not split into subscales for depression and
anxiety. We selected the HAD Scale for comparison because its authors
had specifically attempted to improve on the
GHQ.15 Substantially shorter than most versions
of the GHQ, it gives each patient a score on one of its two subscales,
anxiety and depression. The HAD Scale, which was designed for use in
nonpsychiatric hospital clinics, specifically avoids contamination by
excluding questions referring to physical
complaints.15
In this study we compared the accuracy of the GHQ-30 and HAD Scale in
the identification of patients with current psychiatric morbidity
assessed using a standardized semi psychiatric interview, the
SADS,16 with supplementary questions to generate
a DSM-IV diagnosis.
A psychology research associate (S.O'R.) visited patients in their own
homes 6 months after randomization and, as part of an extensive test
battery, administered the GHQ-30. The GHQ-30 is specifically concerned
with the subjects' health in the previous "few" weeks, specifying
that "we want to know about present and recent complaints, not
those you had in the past." The response options typically include
"not at all," "no more than usual," "rather more than
usual," and "much more than usual." Consequently, much discussion
has concerned whether the GHQ-30 misses chronic illnesses where
negative symptoms may be viewed as "usual" due to their longevity.
Because the present study was conducted 6 months after stroke,
patients were instructed to consider "usual" as their state of
health before their strokes. The GHQ-30 was scored in the conventional
0-0-1-1 format, where any response indicating a deterioration from the
usual is scored as 1. For the GHQ-30, the score taken is simply a total
of these scores, giving a range of 0 to 30.
A self-completion form that included the HAD scale was left for return
by mail. The HAD scale comprises 14 questions, of which half make up
the anxiety subscale and half the depression subscale. The scale refers
only to the patient's feelings during the previous week and makes no
reference to "usual" or past states. The response options for the
HAD Scale differ, but a typical choice would be "not at all,"
"occasionally," "quite often," and "very often." These are
scored 0-1-2-3, where a higher number indicates a more negative
response. The scores for each subscale are totaled, with a possible
score range of 0 to 21. The authors have specified that the subscales
should not be summed,18 19 although this has been
done.20
Two weeks later (mean, 14.2 days), a psychiatrist (S.M.) visited the
patients and, unaware of their scores on the GHQ-30 or HAD Scale,
administered the SADS to identify those with a current psychiatric
diagnosis. The SADS was chosen in preference to the comparable
Present State Examination21 because it allows
a more detailed assessment of affective disorders and has been used
previously to assess psychiatric morbidity in a stroke
population.22 23 It also provides a description
of both the current illness at its most severe and the level of
severity in the previous week, thus providing an index of change.
Supplementary questions were also administered to generate a
DSM-IV24 diagnosis. Because it is a possible
confounding variable in this physically ill sample, the fatigue
rating scale was excluded. All indications from use in both the
present and previous studies suggest that the SADS is both reliable
and valid.16
We calculated the sensitivity and specificity for each possible
threshold of both the GHQ-30 and the HAD Scale and plotted these on ROC
curves of sensitivity against 1- specificity. Comparisons of the areas
under different curves, a global measure of predictive power, were
carried out using the nonparametric method of DeLong et
al.25 The optimal cutoff points for each measure
for different "cost ratios" were calculated using the method
described by Sox.26
The SADS psychiatric evaluations of the 105 patients in whom data were
complete identified 30 patients (28.6%) with 40 psychiatric diagnoses
(Table
We compared the GHQ-30 and HAD Scale using ROC curves (Figure 1
The sensitivity and specificity rates for all cutoff points and grouped
diagnoses for the GHQ-30 are illustrated in Figure 1
The authors of the HAD scale unusually recommend two cutoff points, 8/9
for a high sensitivity and 10/11 for high specificity, for both their
anxiety and depression subscales, allowing the practitioner
to choose whether to include borderline cases.15
Using the 8/9 cutoff point in our patients for the depression subscale,
identifying depression only, produced a sensitivity of 0.45 and a
specificity of 0.85. A cutoff point of 10/11 produced a sensitivity of
0.35 and a specificity of 0.93. Improved sensitivity and specificity
were achieved in this sample using a cutoff point of 6/7 (sensitivity,
0.8; specificity, 0.79).
For the HAD anxiety subscale (identifying anxiety cases only), a cutoff
point of 8/9 produced a sensitivity of 0.5 and specificity of 0.87. A
cutoff of 10/11 produced a sensitivity of 0.42 and specificity of 0.92.
Again, as in the depression subscale, a better balance between
sensitivity and specificity was achieved using a cutoff point of 6/7
(sensitivity, 0.83; specificity, 0.68). Figures for the summed scale
are included in the present study only to facilitate comparison
with previous studies (eg, Reference 2020 , Figure 1
To further facilitate comparison and choice of cutoffs periods, we
calculated various cost ratios. Cost refers to the relative importance
in different situations of a measure possessing either high sensitivity
(ie, very few false-negatives) or high specificity (ie, very few
false-positives). For example, in some situations it may be deemed far
worse to miss a potentially treatable patient by using a measure with a
low sensitivity than it would be to further examine a patient who is
actually well by using a measure with a low specificity. The costs of
each cutoff point have been calculated through a range of a
false-negative (a patient missed), costing from one quarter to four
times the cost of a false-positive (a well patient assessed for further
treatment). That is the cost of a false-negative divided by the cost of
a false-positive. For example, it may be considered twice as costly to
miss a depressed patient than to assess a well patient for further
treatment, corresponding to a ratio of two. Note that the estimated
error cost depends not only on the sensitivity, specificity, and costs
of false-negative and false-positive errors but also on the prevalence
of the condition in the population. Explicitly,
Total
Cost=
where
This study identified a fairly representative sample of
hospital-referred stroke patients similar on all indices measured to
all the patients assessed at our hospital during the study period. The
necessity for patients to be hospital referred may have resulted in
extremely mild and severe strokes being underrepresented.
Patients who suffered severe cognitive impairment or who were unable to
communicate effectively were excluded; while we would acknowledge that
due to these impairments they might be at greater risk of depression,
self-report measures are clearly an inappropriate method of assessment
for this group. Furthermore, strokes that did not merit hospital
referral might have a correspondingly low frequency of mood disorders.
Thus, our sample may represent a "middle ground" of stroke
severity, but this is precisely the population in whom such measures
would be most appropriate in clinical and research practice. Also,
because the frequency of mood disorder varies over the months following
a stroke, it would be unwise to generalize our findings to situations
in which the frequency may be very different (eg, soon after
stroke).
Some might criticize our choice of the GHQ-30, which was designed to
measure the overall burden of psychiatric symptoms rather than (as is
the case with the 28-item version) to identify patients likely to have
specific psychiatric diagnoses. However, on balance we opted for the
30-item version since it was designed to be used in physically ill
people whose somatic symptoms might reduce the validity of other
versions. Even this version, however, refers to "sleep,"
"chatting," and "getting out," which might reflect physical as
well as psychiatric problems. This could in part account for the
increased rates of positive response in our population in comparison
with the general practitioner sample previously used for
validation.
Other methodological factors potentially confound our comparison of the
two measures. First, our two measures were delivered in different ways.
The GHQ-30 was administered by a research associate who read out each
question and recorded patients' answers for them. The GHQ-30 is
normally completed by patients independently but was not done so in
this case to achieve uniformity with the remainder of the structured
interview. The HAD Scale was left with patients for self-completion.
This was reflected in the substantially higher completion rate for the
GHQ-30 (92%) compared with the HAD Scale (77%). However, given the
different methods of delivery, our data cannot support the hypothesis
that the GHQ-30 is a more practical measure or one that would be
associated with a higher completion rate than the HAD Scale. Indeed, we
suspect that given its complexity and greater length, the response
rates to a self-completed GHQ-30 would be no better and possibly worse
than for the HAD Scale. Particularly relevant for a population 6 months
after stroke is the criticism that the GHQ-30 misses chronic cases
because of its reference to a "usual"
state.27 We hoped that our instructions to regard
"usual" as health status before stroke would partially overcome
this, but found that patients had difficulty remembering prestroke
health. Some patients, and particularly those who are depressed, might
have a rather negative view of their prestroke status, whereas others
might have an overly positive view of prestroke status. This could
distort our results in either direction and in an unpredictable
way.
The two scales were often completed a few days apart, which may
confound our comparisons if there were systematic changes in the
patients' psychiatric state over these few days. Significant bias
seems unlikely, especially since these patients were assessed at least
6 months after their stroke, when we considered mood likely to have
stabilized (a view supported by the psychiatric assessments, in which
no patients reported changes in their mental state within the preceding
fortnight). Ideally, the measures would have been completed at the same
time, but we judged that patients would be neither able nor willing to
complete three psychiatric measures at one time.
One previous comparison28 of the GHQ and the HAD
Scale in stroke reported that the 28-item version of the GHQ (n=66) was
superior to the HAD Scale (n=93) in detecting both anxiety and
depression. Similar studies have been conducted in other medically ill
populations. Lewis and Wessely20 found no
difference between the GHQ-12 and the summed HAD Scale in detecting
cases of minor psychiatric disorder in a sample of dermatological
patients. Wilkinson and Barczak,29 in a general
practitioner sample, found that the HAD Scale was generally
more sensitive and simpler to complete than the GHQ-28. Aylard et
al30 undertook a further validation of both the
HAD Scale and the anxiety and depression subscales of the GHQ-28 in a
hospital outpatient sample. They found both to be suitable for
preliminary screening, and suggested the use of a borderline range, a
score range where patients are "bordering" on being considered a
"case," in the GHQ.
When considering which measure should be recommended for what purpose,
it is useful to consider the balance of sensitivity and specificity at
different cutoffs points (eg, Figure 1
The recommended cutoff points for the GHQ-30 and HAD Scale appear
suboptimal in our group of stroke patients. When one considers which
cutoff is most appropriate for a given population or use, the
comparative cost of a false-positive or false-negative in those
circumstances might usefully be taken into account. For example, in a
clinical setting where it is most undesirable to miss treatable cases
and psychiatric resources are not too limited, a false-negative may be
deemed to cost four times more than a false-positive. Reference to
Figures 2
In conclusion, the GHQ-30 and HAD Scale appeared to differ little in
terms of their sensitivity and specificity for diagnosing mood
disorders 6 months after stroke, although the HAD Scale was
significantly shorter and, we suspect, may have been easier for
patients to complete. Recommended cutoff points may not offer the best
balance between sensitivity and specificity in this group of patients.
We hope that our data, and especially those referring to cost ratios,
will be useful to others who plan to use these measures to screen their
patients for psychiatric problems or who wish to use them as measures
of outcome in randomized trials.
Received December 17, 1997;
revision received January 29, 1998;
accepted February 2, 1998.
© 1998 American Heart Association, Inc.
Original Contributions
Detecting Psychiatric Morbidity After Stroke
Comparison of the GHQ and the HAD Scale
![]()
Abstract
Top
Abstract
Introduction
Subjects and Methods
Results
Discussion
References
Background and PurposeMood
disorders are common after stroke and may impede physical, functional,
and cognitive recovery, making early identification and treatment of
potential importance. We aimed to compare the accuracy of the General
Health Questionnaire (GHQ-30) and the Hospital Anxiety and Depression
(HAD) Scale in detecting psychiatric morbidity after stroke and to
determine the most suitable cutoff points for different
purposes.
Key Words: anxiety depression stroke
![]()
Introduction
Top
Abstract
Introduction
Subjects and Methods
Results
Discussion
References
Each year 127 000
strokes are treated in English hospitals, with an incidence of 2.9 per
1000 persons in England and Wales.1 In the first
year after stroke, mood disorders have been estimated to affect between
23% and 60% of patients,2 3 4 5 6 more than twice
the proportion in the general elderly population7
or in populations matched for physical
disability.8 Such figures are particularly
significant because depression is thought to impede physical,
functional, and cognitive recovery.9 10 11 If early
treatment were shown to improve any of these aspects of recovery, early
identification would clearly be important.
![]()
Subjects and Methods
Top
Abstract
Introduction
Subjects and Methods
Results
Discussion
References
We identified stroke patients as part of a randomized trial of a
"stroke family care worker,"17 in which
patients referred to our hospital with a clinical diagnosis of stroke,
confirmed by CT scan, were entered. Criteria for inclusion in the
randomized trial were assessment at the hospital within 1 month of
stroke onset, residence within 25 miles, consent to follow-up,
likelihood of survival, and acute stroke as the dominant illness.
![]()
Results
Top
Abstract
Introduction
Subjects and Methods
Results
Discussion
References
During the study period, 187 (71.4%) patients referred to our
hospital with acute stroke were randomized. Of these, 16 died, 19 were
severely cognitively impaired, and 7 refused to consent to follow-up,
leaving 145 patients (77.5%) who were followed up by both the
psychiatrist and psychologist at 6 months. The 145 subjects had a
median age of 68 (range, 18 to 90 years), and 75 (51.7%) subjects were
male. One hundred thirty-three patients (91.7%) completed the GHQ-30,
and 111 (76.6%) the HAD Scale. Data were complete for both measures in
105 patients (72.4%). The primary causes of incomplete responses were
inability to comprehend questions, refusal to answer specific
questions, and failure of patients to return the self-completion form
containing the HAD Scale (42% of those incomplete) or missing sections
by turning over two pages at once. To estimate the size of any
"nonresponse" bias introduced, we compared the baseline data of
those in whom data were complete (n=105) with the remainder of those
randomized (n=82). Patients in whom complete data were not collected
were significantly more likely to have been dependent before the
stroke, having suffered a severe stroke with cortical damage and
cognitive impairment.
; 7 patients had 2 diagnoses, and one had 4). The
psychiatric evaluation of the 40 patients who failed to complete the
study measures revealed that they were rather more likely to have a
psychiatric diagnosis. There were 14 patients (35%) with 19
psychiatric diagnoses: 11 patients (27.5%) had depressive disorders, 3
patients (7.5%) had anxiety, and 5 patients (12.5%) had a variety of
other disorders.
View this table:
[in a new window]
Table 1. Grouped Patient Diagnoses Defined by SADS With Supplementary
Questions to Generate a Current DSM-IV Diagnosis
). No significant difference was found
between the GHQ-30 and the HAD Scale total score to identify any DSM-IV
case (z=-0.07, P=0.95, Figure 1
). Neither was
there any significant difference between the ability of the GHQ-30 and
the HAD depression (z=-0.587, P=0.56) and
anxiety (z=-1.155, P=0.25) subscales to detect
cases of DSM-IV depression or anxiety, respectively.

View larger version (19K):
[in a new window]
Figure 1. ROC curve illustrating the ability of the GHQ-30
and the HAD summed Scale to identify any DSM-IV case at alternative
cutoff points. (Note that a perfect measure would have an area under
the curve of 1.0, whereas a measure with no diagnostic
value would have an area of 0.5, ie, the ROC curve would lie on the
diagonal.) GHQ cutoff points referred to in the text are labeled to
illustrate their position on the ROC curve. There was no significant
difference between the areas under the ROC curves
(z=-0.07, P=0.95).
. The recommended
cutoff point, derived from a general practitioner sample,
for the GHQ-30 is 4/5.14 Using this cutoff point
in the present sample of stroke patients to identify all diagnoses
produces a sensitivity of 0.9 and a specificity of 0.47. In this study,
to gain a sensitivity of 0.5, on which the recommended cutoff point was
based, a cutoff of either 13/14 or 14/15 would be necessary where the
sensitivity is 0.53 and 0.47, respectively, and specificity is 0.89 and
0.91, respectively. The ROC curve suggests that for both a high
sensitivity and specificity the best cutoff point is 8/9 in the
present population, with a sensitivity of 0.8 and specificity of
0.76.
), although totaling
of the scales was not recommended by the original
authors.15
(1-sensitivity)CFN +(1-
)(1-specificity)CFP
is the prevalence and
CFN and CFP are the costs
of false-negative and false-positive errors, respectively. This implies
that simply choosing a threshold that "balances" both sensitivity
and specificity in some way does not imply an assumption of equal error
costs. Based on this formula, the estimated optimal cutoff points for
various cost ratios are plotted in Figures 2
and 3
for
the GHQ and HAD, respectively.

View larger version (13K):
[in a new window]
Figure 2. Graph showing the optimum GHQ cutoff points for
identifying any DSM-IV case, depression, or anxiety, for a range of
cost ratios.

View larger version (13K):
[in a new window]
Figure 3. Graph showing the optimum HAD Scale cutoff points
for identifying any DSM-IV case, depression, or anxiety, for a range of
cost ratios.
![]()
Discussion
Top
Abstract
Introduction
Subjects and Methods
Results
Discussion
References
It is important for both clinicians and researchers to reliably
identify mood disorders after stroke. Poststroke depression is a common
and debilitating disorder that may slow rehabilitation and produce a
permanent negative influence on
recovery.2 4 5 6 9 10 11 Early screening and
identification of mood disorders may be important if an effective
treatment exists. In addition, large randomized controlled trials of
treatment that aim to influence psychological outcomes require reliable
self-report measures in which knowledge of both sensitivity and
specificity is necessary to compute the power of the study and to
facilitate the choice of cutoff point.
). However, because there was
little difference between the two measures, any choice may have to be
based on the measures' practicality, acceptability to patients, and
whether similar studies have used one or other, which might facilitate
future systematic review.
and 3
illustrates that at point 4 on the horizontal axis, the
optimal cutoff point for identifying depression is 9/10 for the GHQ and
6/7 for the HAD. We would suggest that to facilitate a decision
regarding cutoff points, potential users consider the comparative costs
within their frame of use and choose the optimum cutoff for their cost
ratio as specified in Figures 2
and 3
.
![]()
Selected Abbreviations and Acronyms
DSM-IV
=
Diagnostic and Statistical Manual of Mental
Disorders, Fourth Edition
GHQ
=
General Health Questionnaire
HAD Scale
=
Hospital Anxiety and Depression Scale
ROC
=
receiver operating characteristic
SADS
=
Schedule for Affective Disorders and Schizophrenia
![]()
Acknowledgments
We acknowledge the generous support and funding received from
the Scottish Home and Health Department, Stroke Association, and
Medical Research Council.
![]()
References
Top
Abstract
Introduction
Subjects and Methods
Results
Discussion
References
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