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Validation and adaptation of the Norwegian version of Hayes Ability Screening Index for intellectual diffi culties in a psychiatric sample

ERIK S Ø NDENAA , Ø YVIND NYG Å RD , JIM AAGE N Ø TTESTAD , OLAV MARTIN LINAKER

S ø ndenaa E, Nyg å rd Ø , N ø ttestad JA, Linaker OM. Validation and adaptation of the Norwegian version of Hayes Ability Screening Index for intellectual diffi culties in a psychiatric sample. Nord J Psychiatry 2011;65:47–51.

© 2011 Informa H

Background: Intellectual disabilities (ID) among psychiatric patients have traditionally been neglected. A lack of convenient instruments and competency in ID may have worsened the conditions and treatment availability for these patients. Aims: Validation and adaptation of a screening instrument for ID (Hayes Ability Screening Index; HASI) in a psychiatric hospital setting. Methods: This is a cross-sectional study of 50 psychiatric patients in two Norwegian psychiatric hospitals comparing results of the HASI with the Wechsler Abbreviated Scale of Intelligence (WASI). Results: The HASI correlated well with the standard IQ test used ( r � 0.67, P � 0.001). At a stated cut-off score of 85, the HASI had a sensitivity of 100% and specifi city of 34%. Conclusions: The HASI is a valid and time-saving screening instrument for ID among psychiatric patients. The prescribed cut-off score, however, resulted in a large number of false positives.

• Intellectual disabilities, Psychiatric patients, Screening instrument.

Erik S ø ndenaa, Forensic Department Br ø set, Center for Research and Education in Forensic Psychiatry, P.O. 1803 Lade, 7440 Trondheim, Norway, E-mail: erik.sondenaa@ntnu.no; Accepted 14 April 2010.

International studies often discriminate between the

“administrative” and the “true” prevalence of intellec-

tual disability (ID) (1). Administrative prevalence usually

includes only people with the most severe disabilities

who are known because they receive services from the

administrations in the municipalities (2). The true preva-

lence also counts people having intellectual problems,

but without the need for health and care services adapted

for people with ID. A number of studies cited in

Roeleveld et al. (1), demonstrate a higher prevalence of

“true” ID compared with “administrative” ID. The

“administrative” prevalence was found between 0.23%

and 0.47% (3). The Norwegian administrative prevalence

is 0.45% (4). In contrast, Roeleveld et al. (1) found an

average “true” prevalence of ID in school children of

3%. The true prevalence in the Nordic countries is

slightly lower (5) as a consequence of the social and

welfare system, estimated at 1–2% of the population.

Hence, many people with ID are probably unknown to

the social and health authorities as well as to themselves,

and they may have undiscovered needs for services or

service adjustments.

ealthcare

There is an increased prevalence of psychiatric disor-

ders among people with ID. Several studies confi rm this

association: Richards et al. (6) found that depression,

anxiety and adjustment disorders are more prevalent

among people with ID than in the general population.

Greenwood et al. (7) noted a family association between

ID and schizophrenia. Among people with ID, the pooled

results of studies suggest rates of between 2% and 6%

for schizophrenia (7). These prevalence rates are about

four times higher than in the general population. Corbett

(8) found a 25% rate of personality disorders in a large

community sample of 402 persons with ID. People with

mild ID among psychiatric patients may not be identifi ed

and thus not treated in appropriately in the context of

their cognitive limitations (9).

No validated screening instruments for intellectual

capacity are available in Norwegian. The validated instru-

ments are time consuming, designed to be administered

by examiners who have psychological or psychometric

training, and in many cases designed to search for spe-

cifi c symptoms. For example, administration time for the

Kaufmann Brief Intelligence Test (K-BIT; 10) is 15–30

DOI: 10.3109/08039488.2010.486444

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min (11, 12). The Mini Mental State Examination

(MMSE) is commonly used to estimate the severity of

cognitive impairment in dementia (13). The administra-

tion time for the Wechsler Abbreviated Scale of Intelli-

gence (WASI; 14) is roughly half an hour and the test

may be too time consuming to be used as a screening

tool. The Wechsler Adult Intelligence Scale (WAIS-III;

15) is even more time consuming.

The Hayes Ability Screening Index (HASI) was devel-

oped by Susan Hayes (16) to serve as a valid and user-

friendly instrument to screen for ID within the criminal

justice system. People with reduced intellectual abilities

are overrepresented among habitual criminals (17), peo-

ple with mental disorders (18) and people with general

social problems (19). The HASI can be administered

quickly. Each subtest has a raw score, which is scaled

differently, summarized and added to the constant score

of 26. The whole battery, including administration and

scoring, is intended to be completed within 10–15 min.

This study aimed to validate the HASI with the WASI

used as the criterion for validity. Findings from a previ-

ous study using these two instruments in a prison sample

(20), suggested that in this context the number of false

positives could be reduced if the HASI cut-off score were

set at a lower level. Changing the cut-off score would,

however, raise copyright concerns. A study of the concor-

dance between the two instruments among psychiatric

patients could give the HASI legitimacy as a screening

instrument in this population.

Method Sample In total, 50 participants in two psychiatric hospitals in

the Norwegian county of S ø r-Tr ø ndelag were included in

the study. All were inpatients. There were 24 male and

26 female participants; 96% were ethnic Norwegians. The

participants’ ages ranged from 18 to 72 years (mean � 41.9;

standard deviation, s � 13.6). Two of the participants did

not complete the WASI, and were therefore withdrawn

from the analysis.

Instruments The HASI asks participants to self-evaluate whether they

think they may have a learning disability or be a “slow

learner”, collects some facts about spelling and the alpha-

bet, immediate verbal attention, divided attention, visuo-

spatial and constructional knowledge, and knowledge

about important issues of everyday living. The HASI has

been shown to correlate signifi cantly with the K-BIT

( r � 0.627) (10) and the Vineland Adaptive Behavior

Scales ( r � 0.497) (21, 22).

The HASI consists of four subtests: Background Infor-

mation, Backwards Spelling, Puzzle (adaptation of the

Trail-Making Test B) and Clock Drawing. The background

48

information subtest consists of four questions that are

sensitive to school diffi culties, the subject’s self-aware-

ness concerning their learning diffi culties, and the sub-

ject’s economic and social status. This subtest is based

on self-report. The task in Backwards spelling is to spell

a fi ve-letter word backwards. The original word in the

English edition (16) was “WORLD”. In the Norwegian

edition, the word “NORGE” (NORWAY) is used. Back-

ward spelling is a well-known test from many screening

batteries, including the Mini Mental State Examination

(MMSE). This task requires the ability to mentally rotate

words and pay attention. Clearly, some degree of liter-

acy in the Norwegian language is essential for this sub-

test. In the subtest “Puzzle”, the examinee draws lines

between a pattern of numbers and letters. This is an

adaptation of a well-known neuropsychological test best

known as the Trail Making Test (23). A variant of the

B-part of this test is used in the HASI, and is intended

to assess visual–conceptual and visual–motor tracking.

The test is based on the ability to maintain divided

attention, and is sensitive to effects of brain injury (24).

The last subtest in the HASI is the Clock Drawing test

(25). This test is often used as a part of a neurological

screening procedure, and demands visual–spatial and

constructional abilities. It is also sensitive to dementia.

The subject is asked to draw a large clock face, and to

put the hands of the clock at 3:40. The Clock Drawing

test correlates with other tests of non-verbal visuo-con-

struction such as the Rey–Osterrieth test (26) and the

Block Design test in the WAIS (27), and only marginally

with a verbal factor (27). A study by Ishiai et al. (28)

showed that clock drawings correlated highly (Spearman’s

rank correlation r s � 0.745, P � 0.01) with the verbal

Wechsler IQ test.

The WASI (14) was used as a criterion of validity in

this study. The WASI consists of two verbal tests

(“Vocabulary” and “Similarities”) and two performance

tests (“Block Design” and “Matrix Reasoning”). A Nor-

wegian translation (29) was used, but with US norms. A

study of the psychometric properties of the Norwegian

WASI translation found that mean T -scores and IQ

results, as well as intercorrelations of subtests and IQ

values, closely resemble results published with regard to

the US population (30). The WASI subtests correlated

signifi cantly with the WAIS subtests ( r � 0.85–0.93,

P � 0.001) in a Norwegian sample (31).

The HASI cut-off score for people aged 13–18 years

is set at 90 and for those aged over 18 at 85 (16). In

contrast with the WASI, the scores are not age-adjusted

in the HASI. Subjects with scores below the cut-off

score should be referred for further assessment. The

HASI does not report an IQ score, but a score that indi-

cates whether a person should be referred for further

assessment. The scores of the HASI cover the range

from 48.7 to 96.4 (16).

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125,00100,0075,0050,00

WASI-IQ score

12

10

8

6

4

2

0

Fre

qu

en

cy

100,0095,0090,0085,0080,0075,0070,0065,0060,0055,00

HASI

130,00

120,00

110,00

100,00

90,00

80,00

70,00

60,00

50,00

WA

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The Norwegian translation of the HASI included the

complete version (16). The translation was done by one

of the authors of this article. A preliminary trial was

conducted to detect problems in the structure of the

instrument, translation errors, diffi culties in understand-

ing, terms and expressions, which could cause cultural,

linguistic or ethical confl icts (32, 33). The fi nal Norwe-

gian version was retranslated into English by a profes-

sional translator and endorsed by the original author,

Susan Hayes, according to internationally accepted rules

for cross-cultural translation procedures (34).

Procedure Data collection took place during August 2007–April

2008. The data were collected by one psychologist and

one medical student. The psychologist administered the

WASI and the medical student administered the HASI.

All participants were tested with both the HASI and the

WASI. The instruments were administered in random

order. The participants were tested in a hospital setting.

After collection, all data were anonymized. Each sub-

ject gave written informed consent to participate. The

study was approved by the Regional Ethical Committee

for Medical Research.

Data analysis The data were analyzed using the SPSS software program,

version 14.0.

Results The average IQ in the sample as measured by WASI was

91.0 ( s � 18.3), with a minimum of 56 and maximum of

127. The distribution of the WASI IQ scores showed four

(8.3%) participants below 70, 12 (25%) between 70 and

80, 27 (56.3%) between 80 and 120, and fi ve (10.4%)

above 120 (Fig. 1). For male participants ( n � 23) the

average IQ score was 91.1 ( s � 19.0) and for the female

participants ( n � 25) it was 90.8 ( s � 17.9).

The average HASI score was 79.1 ( s � 8.1), with a

minimum of 59.3 and maximum of 96.4. The average

HASI scores for the male participants ( n � 24) was 78.2

( s � 8.1) and for the female participants ( n � 26) it was

79.9 ( s � 8.2).

The Pearson two-tailed correlation coeffi cient between

the WASI and the HASI scores was signifi cant ( r � 0.67,

P � 0.001). The correlation between the scales increased

( r � 0.71) when the subtest “Background information”

was eliminated from the HASI.

The HASI and the WASI scores were plotted together.

Figure 2 illustrates the distribution of the scores.

The internal consistency of the HASI was equivalent

to a coeffi cient of α � 0.67. The correlations between the

HASI subtests and the WASI were as follows: Backward

NORD J PSYCHIATRY·VOL 65·NO 1·2011

spelling 0.48, Puzzle 0.44 and Clock drawing 0.60. For

Background information, the correlation was 0.08. For

all the subtests except the “Background information”, the

correlations were signifi cant.

The HASI is meant to be over-inclusive, and at the

cut-off of 85 the sensitivity is 100% (95% CI 64.6–100%)

and the specifi city is 35.4% (95% CI 23.0–50.8%). Con-

fi dence intervals for proportions were calculated using

the Wilson (score) method. This methods performs well

even with small counts as we have (35). Sensitivity is

the proportion, or percentage, of those tested with the

condition (IQ � 70) that the test (HASI) correctly identifi es

as having it. Specifi city is the proportion, or percentage,

Fig. 1 . Distribution of the Standard scores of the WASI ( n � 48).

Fig. 2. Scatter-plot and cut-off for HASI (vertical) and cut-off for

WASI (horizontal).

49

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of those tested without the condition that the screening

test correctly identifi es as not having it.

Discussion This study attempted to ascertain whether the HASI could

serve as a useful and time-saving tool in a psychiatric

setting. An important purpose for a screening tool such

as the HASI is to reduce the number of individuals

referred unnecessarily for time-intensive, costly individual

assessments. In the copyrighted HASI, the cut-off is set

at 85. The authors of this article are not authorized to

recommend alterations to this cut-off, but the results from

the present sample propose that further research might

enable improvements in the utility of parts of the screening

instrument in a psychiatric setting.

The HASI was developed to indicate the possible

presence of ID, but not to be used for diagnostic pur-

poses (16). The HASI allows identifi cation of people

with a need for further assessment with full-scale neu-

ropsychological examinations. It is designed to be over-

inclusive, and may also identify individuals suffering

from a psychiatric illness or substance abuse disorder, or

who cannot speak the language properly (22). According

to Hayes (22), a cut-off score of 85 on the HASI was

originally found to be the optimum for discriminating

between participants with and without ID.

The possible correlation between the HASI and the

WASI is infl uenced by the fact that WASI measures IQ

throughout the range of scores, while the HASI has a

maximum score of 96.4. For participants with a WASI

IQ above 96.4, it will thus not be meaningful to deter-

mine the correlation with the HASI score. The HASI

was developed as a screening instrument for ID and it is

not sensitive to performance in the higher range of IQ

scores.

The HASI was sensitive to participants with an ID

and it was over-inclusive with many false positives. A

coeffi cient of α � 0.67 was obtained for internal consis-

tency, indicating that the scale measured a reasonably

consistent concept. According to Nunnally (36), a reli-

ability coeffi cient of 0.6 and more can be described as

moderate.

Concerning the subtest “Background information”,

several interesting results were found. In this part of the

test, patients are asked four questions concerning ID.

Several of the patients with ID denied or lacked insight

into their ID. Lyall et al. (37) found that the application

of questions related to ID was problematic because of

the negative connotations of ID. Several of the ID

patients in their study also denied their ID. In addition,

they did not report that they had attended a special-needs

school. Other studies have found that people may not

accept such labels as applicable to them and may defi ne

their own problems in different ways. This population

50

may have been in contact with professionals and may

have experienced that the information they gave could

have negative consequences. This might lead to evasive

answers. Other background items might possibly replace

the exciting items.

As a consequence of these issues, the subtest “Back-

ground information” did not correlate very well either

with the other HASI subtests, or with the WASI. Possi-

bly the subtest items should be studied and improved in

psychiatric populations.

The “Background information” subtest has demon-

strated signifi cant correlation with IQ in previous studies

(16, 20, 38), and the results based on the small sample

in the present study suggest the need for further research

on a larger sample. The limited sample also represents a

problem in measuring sensitivity and specifi city of the

screening instrument. Using the Wilson (score) method,

these calculations are meaningful even with small counts

as we have (35). The Wilson method is also generally

preferable when sensitivity or specifi city proportions are

close to or 100%, as found in the study (35). It is possi-

ble that inadequacies in the translation or differences in

the welfare system infl uenced the scores obtained using

the Norwegian version of the HASI. The HASI is copy-

righted and cannot be altered without specifi c permis-

sion. If such permission were granted, a modifi ed version

of the HASI should probably include a substitute for the

background information subtest.

As the HASI and the WASI correlate well, the HASI

may prove to be a useful and time-saving tool for psy-

chiatric services in identifying people with a need for

specially adapted treatment related to ID or other cogni-

tive defi ciencies. Employees in these services often lack

the competence as well as the tools and resources to

evaluate such problems properly. A further obstacle is

that most tests must be administered by certifi ed person-

nel. The HASI may be helpful in the process of identify-

ing people with cognitive defi ciencies, who should then

be referred for further assessment. It was designed to be

administered and scored by non-psychologists such as

correctional offi cers, police, probation and parole person-

nel, lawyers, welfare and mental health workers, drug

and alcohol workers, and medical practitioners, including

psychiatrists (16). This test may help to bridge the gap

between local services and the specialized health services,

and therefore make it easier for people with undetected

needs caused by ID to get appropriate help.

As a quick and highly available instrument, the HASI

can become an effective resource for detecting diffi cul-

ties. The fact that a large number of psychiatric patients

also have undetected ID (9) may diminish the value of

care and treatment decisions. A thorough prevalence

study of ID in specifi c psychiatric patient samples would

be valuable. Adaptation of the services offered to these

patients might stimulate progress in this fi eld.

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INTELLECTUAL DIFFICULTIES IN PSYCHIATRIC PATIENTS

Erik S ø ndenaa, Ph.D., Norwegian University of Science and Technol-ogy and St. Olavs Hospital. Ø yvind Nyg å rd, M.D. student, Norwegian University of Science and Technology. Jim Aage N ø ttestad, Dr.philos., Associate Professor, Norwegian University of Science and Technology and St. Olavs Hospital. Olav Martin Linaker, M.D., Professor, Norwegian University of Science and Technology and St. Olavs Hospital.

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Declaration of interest: The authors report no confl icts of

interest. The authors alone are responsible for the content

and writing of the paper.

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