INTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, VOL. 2: 1-2 (1987)

EDITORIAL Surveying old people: some practical problems

Old people all over the world are standing up to be counted. Their psychiatric morbidity is being documented in dozens of surveys both in indus- trially advanced nations and now also in develop- ing nations where the worrying implications of future demographic changes have begun to sink in. We include in this issue a study from Scotland (Bond, J . p. 39-56) and no doubt there will be many more reports in future issues of this journal from other parts of the world.

How useful are these surveys? There are of course two primary aims of epidemiology. One is to assess accurately the prevalence of the problem and the need for appropriate medical and social services. Local data have an impact on planning in statutory authorities that cannot be substituted by simply extrapolating figures from surveys from outside the area. Planners often believe there is something special about their own locality and local data gives compelling evidence of need. The second and perhaps more important aim is the identification of risk factors for specific forms of psychiatric disorder with the long-term goal of prevention and treatment. Although tremendous strides have been made in the last 20 years, we know a great deal more about aetiological risk factors for depression than we do for the dementias. The establishment of reliable diagnos- tic criteria for both affective and organic psych- oses has successfully delineated the magnitude of the problem and its likely increase over the next few decades. However, there are still fun- damental difficulties in the clinical classification of dementias which need to be resolved before we can embark on any sound aetiological theory testing. Nevertheless, we are now in a position of being able to compare overall prevalence of dementias in different societies.

If surveys are conducted using an instrument which has been employed in other studies, then we may begin to explore possible environmental causes. So far, however, comparability of survey data across national frontiers has not often been achieved, with one or two notable exceptions, for example the US/UK New York-London study by Gurland ef al. (1983). Epidemiologists should perhaps add new sections onto well-established schedules when they wish to expand or refine data collection rather than devise a completelv new

instrument, but few researchers seem to be able to restrain their creative muse when embarking on their own local survey.

Surveying is a time-consuming and expensive business, even in those developed countries which have publicly recorded census data on the structure of the local population readily available. In many developing countries such data on the overall size and structure of the local population does not exist and the researcher must first do his own enumeration census before selecting his sample. This practical obstacle to research is one which we tend to forget in developed countries. However, we have other practical difficulties, some minor, some major, which are rarely discussed in the research literature but can have an important influence on the validity of the data. Much of this will have as much relevance for market research organizations surveying the sale of a particular brand of tonic wine amongst the elderly as for psychiatric epidemiologists. How- ever, unlike a market research interviewer who stands on the doorstep, pencil and pad in hand, with a few brief questions, we are generally concerned with gaining access for a prolonged interview about very personal data and therefore must take extra care to ensure full cooperation.

First, let us consider the issue of response rate amongst the elderly. Traditionally this has been said to be excellent. In general the elderly are cooperative about accepting medical investiga- tions and answering questions about their health and usually welcome interviewers who are clearly asking questions about matters directly relevant to their lives. Many surveys report 85-90% response rates. For example, a social services community survey in 1976 in Newcastle-upon- Tyne achieved 86% response rate (Hoinville, 1983) and a survey of Abbeyfield House residents reported 69% cooperation (Morton-Williams, 1979). We should therefore expect a high response rate. However, in more recent urban studies cooperation has not been quite so good. For example, 81% of the elderly of London cooperated in the US/UK cross-national project whereas among elderly New Yorkers the re- sponse rate was only 71% (Gurland ef al., 1983). We may suspect that the elderly New Yorker was rather less trusting of those knocking on the door.

2 E. M U R P H Y

However, there is some evidence that the urban elderly in Britain are increasingly uncooperative and fearful. This makes it all the more important to use trained, skilled interviewers who are unthreatening, which, by the way, means where- ver possible of similar ethnic background, middle- aged, female and friendly! In multi-ethnic urban societies, such as is the rule in British, American and Australian cities, this can pose formidable difficulties in conducting the survey and in interpreting data from interviews conducted in an atmosphere of mutual incomprehension.

Sometimes it is difficult to reach the elderly person because of the paternalistic protectiveness of those who care for them. These uncooperative ‘gatekeepers’ - matrons of homes, managers of institutions and occasionally relatives - can be obstructive in preventing access. There are two ways of dealing with this issue. One method is by very careful preliminary preparation of those with caring responsibility, usually successful but not always. The other, to be used with some caution and due regard to ethical considerations, is to sidestep the issue altogether and not ask permis- sion from those who have no right to refuse access.

The aged live mostly at home but an important small proportion reside in institutions. Since psychiatric illness is the single most important cause of institutionalization in the elderly, clearly any total survey which omits this group is likely to produce low prevalence rates. However, it is not always easy to collect an appropriate sample which includes the relevant institutionalized proportion. For example, the Editor chose East Ham, a small working-class area of East London, for a survey of 200 elderly people (Murphy, 1982). I chose that area because I knew the local general practitioners would be helpful and had an ‘agekex’ register to help selection of subjects. Unfortunately, East Ham has no residential facilities for the elderly. If residential care is required, the clients are admitted to homes in a neighbouring district. This sort of movement at the point of institutionalization makes it difficult to get a truly cross-sectional sample. Surveys should therefore state clearly whether institutions are included and whether or not any institution is part of the total ‘economy’ of residential possibili- ties for that population.

Furthermore, deciding on what is an institution can be quite difficult. In the leafier middle-class areas of London or in the south coast retirement towns, and also in similar areas in the United States, there are numerous small guest houses and hotels used by old people as permanent

residences where considerable care is being provided by domestic staff and yet which are not registered with the local authority as rest homes. Groups of sheltered flats have traditionally been regarded as single dwelling units, not institutions, but now some of these flats are staffed by care assistants providing 24-hour supervision. Are not these institutions too? Some thought must be given as to whether to include these types of dwelling.

The elderly are a minority, albeit a sizeable minority, in our society. A truly random sample of elderly people at home, painstakingly convert- ing a list of random addresses into a sample of households containing at least one elderly person, is a very time-consuming and tedious business. Many researchers in Britain have used general practice lists, since well over 95% of the elderly in Britain are registered with a GP. But lists are notoriously inaccurate because of delay and mistakes in information about death and moves reaching the GP. As many as 14 or 15% of the elderly on a list may have died, moved away or be registered twice over (Fernando, 1977). Further- more, GPs who cooperate in such surveys in urban areas are often the ‘better’ GPs with a partly selected list of ‘clued-up’ patients. Thus there is a risk that psychiatrically disturbed patients may be under-represented.

Random sample methods, however, have one major disadvantage. The population shrinks at 85 years and older and the ‘very very old’ in their late 80s and 90s are therefore poorly represented. There is some suggestion that these grand survivors may actually be mentally healthier than those in their 70s, particularly in regard to depressive illness. Few studies have sup- plemented their random samples with larger cohorts of the very aged groups although this type of age-weighted sampling could be important in assessing the problems of this group.

ELAINE MURPHY

REFERENCES

Fernando, F. (1977) Survey of the elderly in Clackman- non. SCPR methodological report, City University, London.

Gurland, B. et al . (1983) The Mind and Mood of Ageing. Croom Helm, London.

Hoinville, G . (1983) Carrying out surveys among the elderly. J . Market Rex SOC., 25, 22S237.

Morton-Williams, J . (1979) Survey in Abbeyfield Houses. SCPR report, City University, London.

Murphy, E. (1982) Social origins of depression in old age. Brif. J . Psychiaf., 141, 135-142.