INTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, VOL. 7: 783-787 (1992)

THE NATURE OF WANDERING IN DEMENTIA: A GUTTMAN SCALING ANALYSIS OF AN EMPIRICAL CLASSIFICATION SCHEME

STEVEN M. ALBERT Polisher Institute, The Philadelphia Geriatric Center, 5301 Old York Road, Philadelphia, PA 19141, USA

SUMMARY Hope and Fairburn (1990) presented a typology of wandering behaviors based on the frequency of such behavior in a sample of community-dwelling, demented elders. They then linked the nine types of wandering behaviors to a set of etiological components to show that the apparently disparate types of behavior lumped together as ‘wandering’ may actually have distinct neurologic or neuropsychiatric origins. In fact, the distribution of the types of wandering behavior in the sample points to a single latent variable, with a hierarchical structure that demonstrates the centrality of purposeless behavior in the class of wandering behaviors. This is shown in a Guttman scalogram.

KEY woms-Wandering, dementia, classification.

In a study published in this Journal, Hope and Fair- burn (1990) presented descriptive information on the wandering behavior of 3 1 demented elders liv- ing in the community. They proposed a ‘typology of wandering’ consisting of nine different types of behavior: checkingkraining, pottering, aimless walking, activity with an inappropriate purpose, activity with an appropriate purpose but with excessive frequency, excessive activity, night-time walking, the need to be brought back home, and attempts to leave home. The report presented data on the distribution of these behaviors in the com- munity sample and also included a number of mea- sures associated with such behavioral disturbance, such as patient age, years of duration of dementing disease, and MMSE scores. Hope and Fairburn concluded their report by suggesting that the nine types of wandering behavior emerging from their Present Behavioral Examination (PBE) shared no common ‘essence’ but might reflect a more reduced set of ‘components’ linked to disease etiology. These included overall amount of walking activity, avoidance of being alone, diurnal rhythm distur- bance, navigational ability, and faulty goal- directed behavior.

Hope and Fairburn suggest that these compo- nents ‘are of particular importance to the range of behaviors covered by the term wandering’. They suggest a rough correspondence, as shown in Table 1, but they do not specify how each of the nine

types of wandering behavior relates to an underly- ing component; and in the case of wandering involving the need to be brought back home, the authors are apparently undecided on whether the behavior reflects difficulties with ‘navigational abi- lity’ or ‘faulty goal-directed behavior’. They indi- cate that in categorizing wandering behavior, it is hard to know how much stress should be put on activity and how much on the apparent goal of such activity.

Table 1. Hope and Fairburn (1990) classification

Etiologic component Wandering behavior type

Overall amount of walking

Avoidance of being alone Checking

Diurnal rhythm disturbance Night-time walking

Navigational difficulty

Faulty goal-directed behavior

Excessive activity activity

Trailing

Needing to be brought home?

Needing to be brought home? Attempts to leave home?

It is not out intent to subject this classification scheme to undue scrutiny, for the authors them- selves suggest it only as a provisional attempt to understand wandering in dementia. Instead, in this

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Received4 March 1992 Accepred I May I992

7 84 S . M . ALBERT

Table 2 . Guttman scale of wandering behaviors

Respon- dent*

Wandering behaviors?

9 26 1 18 1 6 1

28 + 19 + 1 +

25 + 20 1 16 1 8 1 3 1

14 1 29 1 7 1 2 I

12 1 17 1 1 1 1 15 + 22 + 10 + 24 + 23 + 27 +

5 1 4 1

13 0 9 0

21 0

Scale errors 10

4 + 1 + 1 + 1 1 1 + + + 1 + 1 1 + + 1 1 1 1 1 1 1 + + 0 0 0

11

7 1 1 1 1 1 + 1 1 + + + 1 1 1 1 + + + I 1 1 1 1 1 0 0 0 0 0

7

5 1 + 1 + 1 1 + 1 1 1 1 + 1 1 1 1 1 0 0 0 0 0 0 0 0 0

0 0

-

5

10 1 + 1 + + 1 1 1 + I 1 1 0 0 0 0 0 0 0 0 0 0 0 0 -

- 0 0 0

6

2 1 1 1 11 + 1 + + 1 0 0 0 0 0 0 0 0 0 0 -

-

0 -

-

0 0 0 0 0

7

8 + 1 1 1 1 + 1 1 0 0 0 0

0 0 0 0 0 0 0 0 0 0 0

-

-

-

0 0 0

5

3 1 + + + 1 1 0 0 0

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

-

- -

6

1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

0 0 0 0

0 0 0 0

-

-

2

Respondent scale score

6 0 0 0 0 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0 0 0 0 0

0

-

-

-

-

4

9 9 9 9 8 8 7 7 6 5 5 5 4 4 4 4 4 3 3 3 3 3 3 3 2 2 0 0 0

*Respondent numbers from Hope and Fairburn (1990, Table 2). ?Behaviors: 9, needs to be brought back home; 4, aimless walking; 7, excessive activity; 5, purpose not appropriate; 10, attempts to leave home; 2, checking; 8, night-time walking; 3, pottering; 1, trailing; 6, purpose appropriate, excessive frequency. 1, behavior present; +, behavior absent but expected in scaling solution; 0, behavior absent;-, behavior present but not expected in scaling solution.

short note we wish to draw attention to the struc- ture of the distributional data the authors them- selves present, and to show that further analysis of the distribution of these behaviors may shed light on the structure of wandering behavior in demented, community-dwelling elders.

Table 2 shows the Guttman scale for the 10 types of wandering behavior elicited in the Hope and Fairburn PBE for their 29 subjects. Ten behaviors are represented instead of nine, because the authors provide separate distributional information for ‘checking’ and ‘trailing’, which allows us to treat

them as distinct. On the other hand, the authors provide two levels of intensity for ‘excessive activity’ (+, + +), but for the purposes of the Gutt- man scale we treat them equally as an indication of the presence of such behavior.

A Guttman scaling analysis, or scalogram, offers a number of advantages for the analysis of distribu- tional data. First, Guttman scaling shows whether a set of items taps a single underlying domain. This allows us to determine whether each of the beha- viors recorded by Hope and Fairburn truly indi- cates a single construct, in this case ‘wandering’.

CLASSIFICATION OF WANDERING 785

Second, the Guttman procedure measures the extent to which a set of component behaviors repre- sents a cumulative scale, in which each of the beha- viors can be ordered (or ranked) according to the degree to which they tap the underlying construct. This indicative quality of the behaviors is evaluated in terms of the ‘difficulty’ of an item. That is, respondents who perform a more difficult or extreme behavior should also perform all the less extreme behaviors, and vice versa. Finally, this scal- ing approach is especially appropriate when items are recorded as simply present or absent, the format Hope and Fairburn used in recording wandering behaviors.

While a factor analysis could also be used to establish how well a set of items indicates a single domain, the Guttman procedure is preferable here because of the dichotomous recording of behaviors, and also because of its stringent requirement that items form a cumulative scale. Since the content of wandering behavior in dementia is still unclear (Cohen-Mansfield et af., 1989; Rindlisbacher and Hopkins, 1992), the Guttman procedure is perhaps more suitable than factor analysis because of this stringent demand that items demonstrate a single underlying dimension. The psychometric rationale for the Guttman scale is explained in more detail by Guttman (1 974) and Edwards (1957).

Thus, in this Guttman scaling analysis we wish to determine how well distributional data for the set of wandering behaviors indicate a cumulative, unidimensional scale. If the distributional data satisfy the demands of the Guttman scale, respon- dents who perform the more extreme or more indi- cative behaviors will also perform all the other behaviors less extreme on the scale. It follows that respondents, too, should be capable of being ranked according to how extreme their wandering behavior is with reference to the underlying con- struct. For each respondent, we can calculate a scale score, or ‘wandering score’, based on the degree to which their behavior is in accord with this hierarchical pattern of increasingly clear instances of wandering.

In the table, 1 means the behavior is present, while + means the behavior is not present but should be in a cumulative scale; 0 indicates the absence of the behavior, while - indicates the inap- propriate presence of the behavior given the demands of a cumulative scale.

Table 3 shows that the 10 types of wandering behavior can be ranked as a cumulative scale, but that the scale falls short of a perfect Guttman scale.

This 1 assessed by calculating the coefficient of reproducibility, a measure of the degree to which the behavior types correspond to a latent variable indicating wandering. Alternatively, the coefficient can be taken as a measure of the extent to which a respondent’s scale score predicts his or her actual response pattern (Nie et al., 1975). The coefficient is calculated by first summing the errors shown in the last row of the table. Errors represent cases in which a behavior was absent when it should have been present (marked with a +) or present when it should have been absent (marked with a -), in accord with the demand that respondents perform- ing the more extreme behaviors also perform the less extreme ones. Total errors (63) are then divided by the total number of responses (29 subjects X 10 behavior types) to give an error rate of 0.22 (63/290). This number is subtracted from 1. The coefficient of reproducibility, then, is 0.78, while the coefficient cutpoint for satisfactory scales, as indicated by Guttman, is 0.90 (Guttman, 1974). When one considers the small sample size used in this research, however, the degree of hierarchical organization evident in the distribution of the beha- viors is notable. Also, note that if we eliminate ‘aim- less walking’ from the scale, the behavior with the most scale errors (see table 2, last row), the coeffi- cient is increased to 0.81 (1 - 52/280), a score closer to acceptable reproducibility.

Whatever our qualms about the true ‘scalability’ of the items, we would argue that scaling these wan- dering behaviors is still valuable, for the Guttman procedure allows us to see which types of wander- ing behavior are more clearly fundamental or cri- terial in wandering behavior, as indicated by the empirical distribution of the behavioral data. Hope and Fairburn (1990) did not proceed in this way, but rather moved to external clinical criteria before fully exploring the empirical distribution of beha- vior types.

Looking, then, at the hierarchy of wandering behaviors shown in Table 2, we find that ‘needs to be brought back home’ (behavior 9) is the beha- vior most indicative of wandering. It is listed in the first column of the table because it is the beha- vior that best predicts whether a respondent has performed any of the other behaviors. Note that I6 of the 29 respondents have needed to be brought back home because of wandering. This is not the most frequent behavior, for 17 of the 29 respon- dents were noted as excessively active (behavior 7). However, ‘needing to be brought back home’ is listed first in the table because respondents per-

786 S . M . ALBERT

forming this behavior were likely to have per- formed all the other behaviors, in accord with the demand that behavior types follow a cumulative scaling pattern. Respondents who needed to be brought back home were likely to walk aimlessly (behavior 4), be excessively active (behavior 7), have an inappropriate purpose in their activity (behavior 5 ) , etc. Respondents who were exces- sively active (behavior 7 ) were only likely to have performed behaviors lower in the hierarchy, such as activity with an inappropriate purpose (behavior 5) , attempting to leave home (behavior lo), etc.

Thus, a demented elder who needs to be brought back home is very likely to have performed all the other wandering behaviors. This priority for need- ing to be brought back home is a welcome finding, for it is in accord with our intuitions and also with what we know about family caregivers who co- reside with demented elders (Albert, 1991). Need- ing to be brought back home is an undeniable exam- ple of wandering, which forces the caregiver to admit that a parent or spouse wanders. For exam- ple, police or neighbors may be involved in finding and ultimately bringing the parent home. The other behaviors do not have this undeniable quality. That is, the other behaviors are all intrahousehold events that allow variable constructions by family care- givers. Wandering out of the household to the point of needing to be brought home, then, can be seen as the most extreme form of wandering behavior. Note also that it is quite distinct from ‘attempts to leave home’ in tapping wandering as a latent construct.

On the other hand, the behavior designated ‘pur- pose appropriate, excessive frequency’ (behavior 6) is the poorest indicator of wandering behavior. Knowing that a demented elder performs this beha- vior does not allow one to predict that he or she performs any of the other behaviors. This is an indication (assuming the reliability of the coding) that repeated performance of activities that are otherwise appropriate is not a typical feature of wandering behavior. ‘Aimless walking’ (beha- vior 4), ‘excessive activity’ (behavior 7), and ‘pur- pose not appropriate’ (behavior 5) are all better indicators of wandering, as they closely follow ‘needs to be brought home’. Since these beha- viors all indicate excessive activity in the absence of an appropriate purpose, we may conclude that lack of an appropriate goal in activity, rather than excessive repetitions of an otherwise appropri-

ate activity, is the more central feature of wandering in dementia.

Note, also, that the behaviors stressed by two of Hope and Fairburn’s etiological components are actually relatively poor indicators of wandering. ‘Trailing’ (behavior I ) and ‘checking’ (behavior 2), which the authors link to fear of being alone, are relatively low in the hierarchy of wandering beha- viors. The same is true of ‘night-time walking’ (behavior 8), which Hope and Fairburn link to diurnal rhythm disturbance. These behaviors and the etiological factors they point to may be relati- vely minor in the wandering behavior characteristic of dementia for community-dwelling elders.

In general, then, the diagonal pattern evident across the table shows that the 10 wandering beha- viors roughly follow a cumulative, hierarchical pat- tern, as the Guttman scale demands.

Thus, subjecting the distributional data to scal- ing offers some insight into the relative priority of the different types of behavior in characterizing wandering. As a final check on the hierarchical ordering of the behaviors, we correlated scale scores for each respondent with age, duration of dementia, and MMSE, using the data provided by Hope and Fairburn. Scale scores in this case are simply the sum of 1 and + entries for each respon- dent across each row and are indicated in the last column of Table 2. Scale scores thus indicate the degree to which each respondent ‘wanders’ accord- ing to the underlying construct suggested by the distributional data. Excluding cases with missing data, Pearson correlations between scale score and age, duration of disease, and MMSE are 0.32,0.29, and - 0.34, respectively. These correlations are moderate (and fall short of significance), but are all in the proper direction.

To conclude, in this short note we have tried to show that the distributional information on types of wandering behavior presented by Hope and Fairburn (1990) can be scaled (though not per- fectly) and that this scaling solution shows that some of the behavior types surveyed are more indi- cative of wandering than others. The hierarchical ordering of behaviors clearly shows the priority of purposeless activity in wandering behavior, so that excessively frequent but appropriate activity is least informative in characterizing wandering behavior. Needing to be brought back home best predicts all the other behaviors, so that an elder who has been brought back home is likely to have engaged in all the other behaviors. The priority

CLASSIFICATION OF WANDERING 787

for this behavior makes sense, we have argued, in that it is the least deniable wandering behavior and the only one that necessarily involves others outside the household.

In short, Hope and Fairburn should be com- mended for their careful research on types of wan- dering behavior. However, attention to the distribution of the different types of behavior reveals a different picture of wandering than their own attempt to link the behavior types to etiologi- cal components. Future research on wandering behavior will be useful in testing this Guttman model on large samples. Also, since the Guttman scaling analysis implies that some kinds of wander- ing behavior are more extreme or indicative than others, it would be valuable to see if demented elders serially acquire these behaviors over the course of dementing disease (R. A. Hope, personal communication).

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Albert, S . M. (1991) Cognition ofcaregiving tasks: Multi- dimensional scaling of the caregiver task domain. Ger- ontologist 31, 726-134.

Cohen-Mansfield, J., Watson, V., Meade, W. etal. (1989) Does sundowning occur in residents of an Alzheimer’s unit? Int. J . Geriatr. Psychiat. 4,293-298.

Edwards, A. L. (1957) Techniques of Attitude Scale Con- struction. Appleton-Century-Crofts, New York.

Guttman, L. L. (1974) The basis for scalogram analysis. In Scaling: A Sourcebook for Behavioral Scientists (G. M. Maranell, Ed.). Aldine, Chicago.

Hope, R. A. and Fairburn, C. G. (1990) The nature of wandering in dementia: A community-based study. Int. J . Geriatr. Psychiat. 5,239-245.

Nie, N. H., Hull, C. H., Jenkins, J. G. et al. (1975) Statis- tical Package for the Social Sciences, 2nd edn. McGraw Hill, New York.

Rindlisbacher, P. and Hopkins, R. W. (1992) An investi- gation of the sundowning syndrome. Int. J. Geriatr. Psychiat. 7, 15-24.