Mohammed T. Abou-Saleh

166 PRINCIPLES AND PRACTICE OF GERIATRIC PSYCHIATRYDIAGNOSIS AND ASSESSMENTWhen choosing an ADL instrument, three questions need to beasked:Question 1: for what purpose is it to be used?Possible uses could be:(a) To describe and document any need for assistance inperforming ADL.(b) To differentiate among different levels of disability.(c) To follow and record changes in ADL performance over time.(d) To predict outcome, survival, length of hospital care, type andquality of living, etc.(e) To evaluate rehabilitation programmes, hospital, home andday care, etc.Question 2: for whom is it intended?(a) For individuals, for groups with certain medical diagnoses orreceiving different types of care or for populations?(b) For mainly healthy persons or for the mildly or severelydisabled?(c) For patients living in institutions or in their own homes or forpatients with or without cognitive impairment?Most published instruments are shown to be reliable and valid forparticular purposes and for particular patient categories. Thesame instruments may be unsuitable for use in other circumstances,e.g. instruments that include personal items only are oftenadequate for the more seriously disabled patients living ininstitutions, whereas instruments including instrumental itemsare necessary for use with more healthy populations living in theirown homes. For patients with serious cognitive impairment, theADL instrument has to depend on observation or test situations.The assessment has to take into consideration the patient’s owndependence on active assistance as well as the patient’sdependence on supervision, and whether or not activity is initiatedby another person. The quality of ADL performance has also tobe assessed; for example, if the patient dresses him/herselfindependently, does he/she dress him/herself adequately andappropriately for the situation?Question 3: are the results of ADL assessment expected to becompared with other ADL assessments?If so, it is necessary to choose an ADL instrument that has beentested and documented as to its reliability and validity for thechosen purpose and the specified patient category. If a group ofpatients is to be compared with normal subjects, data onnationally representative samples must also be available forcomparison.It may be difficult, if not impossible, to find one ADLinstrument to fit all purposes. In any case, it is usually better tochoose one of the well-known instruments and then supplement itwith items that seem important in that specific situation, than tostart the immense work of creating a new instrument. It is alsobetter to use a plain ADL instrument instead of a multidimensionalone, if the purpose is simply to study ADL ability.Time and staff resources are also limiting factors when choosingan ADL-instrument. Self-administered questionnaires are lessexpensive to administer, but require patients who understand thequestions and can respond adequately. The number of subjectswho drop out may be high, so some validation of the answers isnecessary. This type of instrument is mainly used in studies ofelderly general populations, who are expected to be reasonablyhealthy.Observations of the patient’s actual ADL performance can becarried out during a nurse’s daily work, when documentation willtake only a few minutes. Training of the observers is usuallyrequired, along with tests of inter-observer reliability.Test situations that use professional observers are the mostexpensive measures. Even if the test situation does not correspondexactly to real life, it can still be of value for specific purposes, e.g.when occupational therapists analyse the kind of impairment thatis hindering performance or how rehabilitation should be undertaken;or in methodological studies, such as in a study of therelationship between severity of dementia and ADL performance5 .In clinical practice, occupational therapists usually combineself-report information concerning the disabled patient’s ownvalues, personal causation, interests, roles, habits and skills withobservations and test situations 6 .HOW GOOD ARE THE ADL ASSESSMENTS?The quality of an ADL instrument depends on the followingfactors:1. Its representativeness: i.e. whether the items reflect theactivities of a person’s normal daily life.2. Its reliability: viz. its reproducibility and stability, so that theresults can be reproduced by other observers or by the sameobserver at different times, so that changing results reflectchanges in the patient’s ADL status.3. Its validity: i.e. whether the results are meaningful to others;whether they can be understood and used to compare withother data reflecting different levels of disability; and whetherthey may predict outcome.These aspects of instrument quality are generally easy to test,but the problem is the lack of a norm or gold standard forcomparison. The closest approximation to such a norm is theKatz Index of ADL 7 , which is based on a cumulative scale ofpersonal items reflecting improvement and deterioration amongdisabled patients, and designed to correspond with ADLdevelopment in the small child.Other instruments may include more or less the same items as inKatz Index, such as Barthel’s Index 8 , but problems arise when theauthors put arbitrary nominal values on different levels of ADLability, which are ordinal in character, and then summarize theassessments. The results may be affected by systematic statisticalerrors, but more importantly they may obscure the understandingof actual ADL status and undermine the possibility for interstudycomparisons using different instruments. For example, if a patientscores 75 out of 100 possible points, this will not reveal in whichitems the patient is dependent. Furthermore, one patient with 75points may not be as disabled as another person with an equalnumber.Quite another way of handling ordinal data is shown by thedevelopment of Katz’s Index of ADL. In the 1950s, a multidisciplinaryteam in Cleveland, Ohio, followed patients who wererecovering from a hip fracture by assessing in which order theyregained the ability to perform ADL. They found six items thatusually followed in sequence: first the patients regained independencein feeding, followed by continence, movement of the body(e.g. getting out of bed), going to the toilet, dressing and bathing.A patient who was independent in bathing could be expected to beindependent in the other five items, too, and a person who wasdependent in feeding was also dependent in the other items. Theauthors defined each item carefully, and found that dependenceon another person, either by active assistance or supervision,decided whether or not the subject was dependent.The authors had discovered a hierarchical or cumulative orderbetween these six personal activities of daily life, which formed thebeginning of an ADL ‘‘staircase’’ where each step upwardscorresponded to an improvement in the patient’s condition. Later,it was shown that patients with other diagnoses, such as stroke