PAS
News
PAS
News
Any news about the Psychogeriatric Assessment Scales will be posted on this page. A newsletter was sent to all registered users of the PAS in 1995. This appears below. Please note that many on the topics in this newletter have since been incorporated in subsequent editions of the PAS itself
PAS
Newsletter 1
ContentsThe PAS was published in November 1994 with the assistance of a grant from the Commonwealth Department of Human Services and Health. Over the subsequent 10 months, approximately 800 copies of the PAS have been requested from all over the world and over 150 people in Australia have become Registered Users.
Questionnaire
on use of the PAS
The Commonwealth Department of Human Services and Health has asked us to gather more information on the users of the PAS, their assessment activities and the type of work they do. Enclosed is a questionnaire which requests this information. We would appreciate if you filled out this questionnaire immediately and returned it in the envelope provided. Your responses will help in planning what further support is needed by PAS users.
Training
Courses
The grant from the Commonwealth also provided a small amount of funding to run PAS training courses. So far these half-day courses have been run in Canberra, Armidale, Townsville, Mildura, Warrnambool and Shepparton.
Arrangements have also been made to run a training course for remote areas of Western Australia using satellite broadcasts. These broadcasts have been organized by the ACAT Training Programme in WA based at Osborne Park Hospital and will take place in October and November.
Compact
response sheet for the PAS (the µPAS)
A number of users of the PAS have suggested that we develop a compact response sheet which uses less paper than the PAS interview forms. In response to this suggestion, we have developed the uPAS (pronounced micro PAS) which involves a single sheet of paper for recording the subject's answers and another sheet for the informant's answers. As with all PAS materials, the uPAS can be freely photocopied.
The uPAS is recommended only for experienced users of the PAS. Beginning users should always use the full interview forms until they are thoroughly familiar with all aspects of the scale. A copy of the uPAS and the instructions for using it are enclosed with this newsletter. The uPAS is now included as part of the materials sent out to new users of the PAS.
The µPAS has been incorporated into the Online User's Guide and the test materials and printable version of the User's Guide on the PAS Download page.
PAS
materials for non-English speakers
The PAS is designed for subjects and informants who are native speakers of English or are fluent in English as a second language. However, work is underway to develop versions of the PAS in several languages other than English. Dr Francisco Bagulho, a Melbourne psychogeriatrician, is working on versions of the PAS for Australians of Greek and Italian-speaking background. In these versions, the instructions are kept in English, but the script of what the interviewer says is in the other language.
Dr Reinhild Mulligan, a psychogeriatrician from Geneva in Switzerland, is developing French and German versions. These are designed for use in Europe rather than for migrants to Australia and involve a translation of the complete PAS materials.
If you are interested in further information on the availability of the PAS in these languages, write to the PAS Project about your requirements. We would also be interested in hearing from individuals who have the expertise and interest to develop versions of the PAS in other languages.
For the latest information about any translations of the PAS see the Download page.
Technical
information on the development of the PAS
Users of the PAS do not need to know the details of the extensive psychometric work and validity studies which underpin the scales. However, some users have expressed interest in knowing more about this work. Enclosed is a brief summary of the work which in now included as a Technical Appendix in the materials sent out to new users. Further psychometric and validity studies of the PAS have recently been completed and support the original findings. These will be published in the scientific literature over the coming year.
The PAS User's Guide gives all the information that is needed for using the PAS. It is not necessary for most users to know the technical details of how the PAS was developed. Such information is primarily of interest to researchers who may want to do further psychometric work on the PAS. Below is a summary of the research on which the PAS is based. A full technical report on this work is available in the following journal article:
JORM, A.F., MACKINNON, A.J., HENDERSON, A.S., SCOTT, R., CHRISTENSEN, H., KORTEN, A.E., CULLEN, J.S. & MULLIGAN, R. (1995) The Psychogeriatric Assessment Scales: A multi-dimensional alternative to categorical diagnoses of dementia and depression in the elderly. Psychological Medicine, 25, 447-460.
The PAS items were taken from the Canberra Interview for the Elderly (CIE). This is a standardised interview for the diagnosis for dementia, depression and related disorders by ICD-10 and DSM-III-R criteria. The CIE involves an interview with an informant as well as one with the subject. Responses are scored by a computer program to produce the diagnoses. The aim in developing the PAS was to produce a set of short scales made up of the best of the CIE items.
CIE data were available from an epidemiological study of 1045 persons aged 70+ living in Canberra or the adjacent town of Queanbeyan. This sample involved people living in the community as well as in institutions, with approximately equal numbers of males and females. There were 683 subjects who had relatively complete data on both the subject and informant sections of the CIE. Data from these subjects were analysed by principal components analysis followed by varimax rotation. A scree plot was used to determine that 5 factors should be rotated. These were labelled: Cognitive Impairment, Depression, Cognitive Decline, Behaviour Change and Stroke. The items loading highest on the Cognitive Impairment and Depression factors were all from the subject interview of the CIE, while the highest loading items for the Cognitive Decline and Behaviour Change factors were from the informant interview. The items loading on the Stroke factor were a mixture of both subject and informant items.
Items with loadings of 0.3 or greater on a factor were regarded as candidates for inclusion in a scale. Final selection of items was based on a two-parameter latent trait analysis. Items from each factor were analysed separately, confirming the unidimensional nature of the factor and giving separate slope and threshold parameters for each item. Items were selected to have steep slopes (i.e. to be highly discriminating items) and to have a range of thresholds (i.e. to cover a range of severity). The Stroke items were split into separate subject and informant scales, each having parallel items.
Reliability was assessed in the Canberra general population sample as well as with two clinic samples. The first clinic sample consisted of 76 geriatric and psychogeriatric patients from Sydney and the second consisted of 60 patients from Geneva (who had the questions administered in French). The patients in the two clinic samples had the items administered twice a few days apart, allowing the assessment of test-retest reliability. Internal consistency reliability was assessed in all three samples using Cronbach's alpha. Test-retest reliability was found to be high for all the scales, with alpha generally lower, reflecting the fact that alpha is an estimate of the lower bound of reliability. Reliability was generally higher for the informant scales than for the subject scales.
Validity was assessed against clinical diagnoses of dementia and depression using receiver operating characteristic (ROC) analysis. Diagnoses were available from the CIE computer program as well as from independent clinicians using the ICD-10 and DSM-III-R criteria. The Cognitive Impairment and Cognitive Decline scales were found to perform well as screening tests for dementia, while the Depression scale performed well as a screening test for depression. The Behaviour Change scale was non-specific, being affected by both dementia and depression. The Stroke scales performed well at discriminating vascular from non-vascular (mainly Alzheimer) types of dementia.
Further evidence of validity came from correlations with other commonly used scales. In the Canberra sample, the Cognitive Impairment scale correlated 0.80 with the MMSE and 0.45 with the IQCODE. The Cognitive Decline scale correlated 0.48 with the MMSE and 0.78 with the IQCODE. The Depression scale correlated 0.67 and 0.60 respectively with the Goldberg depression and anxiety scales. The Stroke scales correlated 0.71 and 0.65 with the Hachinski Ischemic Score.
Percentile rank norms were developed from the Canberra general population sample. Data on PAS scores were weighted by age group, sex and place of residence (community or institution) to match the structure of the population living in Canberra and Queanbeyan in 1990. The norms cover the whole population, including cases of dementia and depression. The main difference between the Canberra population and the rest of Australia is the higher level of education. However, only the Cognitive Impairment scale is affected by education, with a correlation of 0.18 in the Canberra sample.
The cutoffs on the PAS Summary Profile were set to detect around 80% of diagnosed cases of dementia and depression. To get sufficiently large groups for this analysis, cases were pooled from the Canberra, Sydney and Geneva samples. Individuals were included as a case if they satisfied either the ICD-10 or DSM-III-R criteria. The average profiles for cases of dementia and depression were also developed from these pooled data. The average profiles for cases of vascular and Alzheimer's dementia were based only on the Canberra data, as specific types of dementia were not diagnosed in the Sydney and Geneva studies.
This and other technical information about the PAS has been incorporated into the Online User's Guide and the printable version on the PAS Download page.