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Abstract The aim of the present study was to examine the relationships between behavioral disturbances and patient characteristics of inpatients with dementia nationwide. The five patient characteristics used were age, gender, years of education, cognitive status, and walking ability. The subjects consisted of 730 inpatients selected by systematic sampling from 180 units that have specialized psychiatric beds for acute/long-term care of dementia. Clinical staff members assessed the 730 patients with the Mini-Mental State Examination (MMSE), and filled out a questionnaire for long-term care insurance, including 19 items relating to behavioral disturbances and walking scale. Five meaningful factors were identified out of the 19 behavioral disturbances by factor analysis. Linear regression analysis revealed that the factor ‘psychotic/neurotic’ was not related to any patient characteristics; ‘aggression/negativistic’ was related to male gender and a lower MMSE score; and ‘dirty/destructive’ and ‘disorientation/fire management’ were related to a lower MMSE score and higher walking score. The factor ‘sexual behavior’ included only one behavior at a very low frequency. These findings suggest that different behavioral disturbance factors have different correlations with patient characteristics, while cognitive dysfunction has a relatively important role in behavioral disturbances of inpatients with dementia.
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Behavioral disturbances in patients with dementia are common, and are especially important for understanding the care burden of the family and clinical staff.1,2 Many previous studies have examined the etiological nature of such behaviors, especially their relationship to patient characteristics. For example, cognitive dysfunction (or dementia stage) was found to be associated with psychotic symptoms (i.e. delusions and/or hallucinations),3–7 agitation/aggression,8–13 and other behaviors such as wandering.9 In terms of gender, some studies reported a relationship between male gender and aggressive behavior.11,13,14 The length of education was also found to have an association with some behaviors.6,7,15 Although one study suggested the relationship between higher education and ‘frontal behavior’,6 lower educational level is generally related to some types of behavioral disturbances.7,15
However, most of these previous studies examined community dwellers, who had relatively mild levels of dementia and relatively high degrees of activity of daily living (ADL). Behavioral disturbances are just as important for care in the clinical setting as for functionality in the community because behavioral disturbances often result in institutionalization, after which clinical care needs to cope with it. Little is known about the prevalence of behavioral disturbances and their association with patient characteristics in inpatients with dementia.
In the present study we aimed to clarify the prevalence of behavioral disturbances and their association with patient characteristics in a nationwide sample of patients hospitalized in specialized psychiatric beds for acute/long-term care of dementia.
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The internal consistency reliability (Cronbach's α) of 19 behavioral disturbances was acceptably high (α = 0.84) in our sample.
Table 2 shows the prevalence of the 19 behavioral disturbances and the results of factor analysis. Prevalence varied from 5.3% (‘sexual behavior that annoys other people’) to 65.1% (‘once the client goes out, he/she cannot find his/her way back to hospital, institution, or home’). The factor analysis yielded five factors with eigenvalues >1 (explained variance: 57.9%). Each of these factors represented clinically interpretable domains. Factor 1 represented ‘psychotic/neurotic’ (explained variance: 14.4%), factor 2 represented ‘aggression/negativistic’ (explained variance: 13.1%), factor 3 represented ‘dirty/destructive’ (explained variance: 13.0%), factor 4 represented ‘disorientation/fire management’ (explained variance: 11.5%), and factor 5 was ‘sexual behavior’ (explained variance: 5.9%). Because factor 5 ‘sexual behavior’ included only one item, we excluded this factor from further analysis.
Table 2. Factor loadings of the behavioral disturbances in the 730 patients
|Behavioral disturbance used in long-term care insurance||% of answer 2 (sometimes yes)/ 3 (always yes)||Eigenvalue||%variance||Loading|
|Factor 1: psychotic/neurotic (α = 0.74)|| ||2.74||14.4|| |
| Feels persecuted such as believing things are stolen||39.3|| || ||0.76|
| Makes up stories and tells them to other people||37.7|| || ||0.76|
| Sees and hears things that other people do not||36.3|| || ||0.64|
| Repeats the same story or makes an unpleasant noise||35.3|| || ||0.56|
| Becomes nervous such as saying ‘I am going home’||40.1|| || ||0.56|
| Insomnia at night or reversal of day and night||45.6|| || ||0.35|
|Factor 2: aggression/negativistic (α = 0.78)|| ||2.48||13.1|| |
| Uses offensive language or becomes violent||38.8|| || ||0.82|
| Shouts||32.6|| || ||0.81|
| Resists advice or care||53.7|| || ||0.76|
| Becomes emotionally unstable and cries and laughs a lot||43.9|| || ||0.50|
|Factor 3: dirty/destructive (α = 0.71)|| ||2.48||13.0|| |
| Dirty behavior (e.g. playing with feces)||39.5|| || ||0.72|
| Puts inedible things into mouth||14.5|| || ||0.71|
| Destroys or tears things or clothes||18.1|| || ||0.65|
| Wanders||53.7|| || ||0.60|
| Collects various things or takes them without permission||25.9|| || ||0.57|
|Factor 4: disorientation/fire management (α = 0.76)|| ||2.19||11.5|| |
| Once the client goes out he/she cannot find his/her way back to hospital, institution, or home||65.1|| || ||0.83|
| The client cannot put out or deal with fire||46.4|| || ||0.82|
| The client should be watched because he/she insists on going out alone||48.1|| || ||0.73|
|Factor 5: sexual behavior|| ||1.12|| 5.9|| |
| Sexual behavior that annoys other people|| 5.3|| || ||0.91|
Table 3 shows the results of multiple regression analyses. The five variables explained only 1.4% of the factor variance for ‘psychotic/neurotic’; none of the adjusted beta variables reached a significant level. For the factor ‘aggressive/negativistic’, the five variables explained 8.3% of the variance, with gender (adjusted beta = −0.153, P < 0.05) and MMSE score (adjusted beta = −0.183, P < 0.01) being significant. For the factor ‘dirty/destructive’, the five variables explained 20.9% of the factor variance, with MMSE score (adjusted beta = −0.489, P < 0.01) and walking score (adjusted beta = −0.262, P < 0.01) reaching a significant level. For the factor ‘disorientation/fire management’, the five variables explained 9.3% of the variance, with MMSE score (adjusted beta = −0.160, P < 0.05) and walking score (adjusted beta = −0.328, P < 0.01) reaching a significant level.
Table 3. . Linear regression analyses with each factor score as a dependent variable
|Independent variables||Factor: adjusted beta|
|Psychotic/ neurotic||Aggression/ negativistic||Dirty/ destructive||Disorientation/ fire management|
|Age (years)|| 0.083||−0.101||−0.007|| 0.044|
|Gender (male = 1, female = 2)|| 0.035||−0.153*|| 0.028|| 0.049|
|Years of education||−0.002||−0.081|| 0.123|| 0.067|
|Walking score||−0.102|| 0.102||−0.262**||−0.328**|
|Adjusted R2|| 0.014|| 0.083|| 0.209|| 0.093|
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Not surprisingly, the prevalence of each behavioral disturbance in patients occupying specialized psychiatric beds for acute/long-term care of dementia was almost always higher than that of community dwellers.19 For example, the prevalence of ‘wandering’ is reportedly 9% among patients with dementia living in Tokyo and 53.7% among inpatients in our study.19 This result indicates that behavioral disturbances are strongly related to hospitalization (i.e. important causes of hospitalization). Therefore, reduction of behavioral disturbances, not of dementia itself, is an important role of special beds for dementia.
We extracted five factors (‘psychotic/neurotic’, ‘aggression/negativistic’, ‘dirty/destructive’, ‘disorientation/fire management’, ‘sexual behavior’) from 19 behavioral disturbances used in the assessment of eligibility for long-term care insurance; these factors were differently correlated with patient characteristics.
Contrary to our assumption, the factor ‘psychotic/neurotic’ was not related to any patient characteristics. This result differed from some previous studies in which patients who presented with psychotic symptoms had lower cognitive function.3–7 One reason for this disagreement might be the relationship between psychotic/neurotic behaviors and cognitive status. As some studies have suggested,12,15,20–22 such relationships might be curvilinear rather than linear; namely, peaking in the moderate stage and then declining in the severe stage. In other words, our linear regression analyses might have been inappropriate for examining a curvilinear relationship.
The factor ‘aggression/negativistic’ was the only variable that related to gender; male subjects tended to show a higher aggression/negativistic score. This result is congruent with those reported by Lyketsos et al. and Jagger and Lindesay.11,14 Additionally, lower MMSE scores were also associated with higher aggression/negativistic scores, in accordance with many previous studies.8–13 These findings suggest that premorbid personality traits may be intensified (or exaggerated) by cognitive dysfunction because male gender is more often related to aggressive personality traits than female gender.
The factor ‘dirty/destructive’ and ‘disorientation/fire management’ had significant relationships with MMSE score and walking score. Interestingly, lower MMSE and higher walking ability contributed to these factor scores. Several studies have pointed out that behavioral disturbances generally peak in the moderate to severe stage, but not in the most severe stage.12,15,20,21 As our results suggested, these findings might be explained in terms of the gap between cognitive dysfunction and walking level.
In relation to the MMSE score, we assume the factors aggression/negativistic, dirty/destructive, and disorientation/fire management reflected some kind of brain damage, such as frontal dysfunction. However, although many studies have examined neurological and biological correlates of psychotic symptoms in patients with dementia, few have addressed neurobiological correlates with the behavioral symptoms dirty/destructive and disorientation/fire management. Further study is needed to clarify how cognitive dysfunction causes such severe problem behaviors.
Of the five factors, ‘sexual behavior’ consisted of only one questionnaire item (i.e. sexual behavior that annoys other people). The frequency of this behavior was relatively low in our inpatient sample (only 5% were rated as sometimes yes or always yes), suggesting that this behavior had a different cause from the list of behavioral disturbances in the inpatient sample. The answer to the question about sexual behavior seemed to depend on the caregiver's subjective feeling toward the sexual-like behavior. In clinical settings, unlike community settings, sexual-like behavior might not be regarded as problematic by professional, trained caregivers. In that case, the low prevalence of sexual behavior in patients with dementia in clinical settings does not necessarily mean a low prevalence of such behavior in community-dwelling patients. Further study is needed to clarify the prevalence and correlates of sexual behavior in community-dwelling patients with dementia.
Several concerns must be raised regarding these results. First, variables used in the present study were too small to explain behavioral disturbances. It must be noted that R2 values in the present study were not high, especially the factor ‘psychotic/neurotic’. The present study did not include items on delirium (often a cause of some kinds of behavioral disturbances), on history of alcoholism, or on experience of stroke. Second, our data were cross-sectional, and could not add insights into valid longitudinal changes in each patient.
In conclusion, the present findings suggest that different behavioral disturbance factors have different correlations with the characteristics of inpatients with dementia. Cognitive dysfunction measured by MMSE contributed to three factors of behavioral disturbances: ‘aggression/negativistic’, ‘dirty/destructive’, and ‘disorientation/fire management’, suggesting that cognitive dysfunction is a relatively important correlate for behavioral disturbances in such patients.