Prevalence of physical and verbal aggressive behaviours and associated factors among older adults in long-term care facilities

Prevalence of aggressive behaviour among residents in long-term care facilities varies widely from 7% to 91% [3‐7]. According to a recent literature review [8], it was estimated that on average 24% of cognitively impaired residents are agitated or aggressive. Based on our own review of studies published between 1999 and 2001, 24 to 95% of long term care residents display AB, 10 to 95% exhibit physical aggressive behaviour and 10 to 91%, verbal aggressive behaviour [9, 10]. In brief, prevalence rates of AB, although varying widely, may be very high.

Aggressive behaviour affects mainly older patients themselves and their informal and formal caregivers. It can also lead to increased health care costs. Older patients displaying ABs and other disruptive behaviours are more likely to receive psychotropic drugs and to be physically restrained [7]. The negative consequences of both interventions are well known and include worsening of cognitive impairment and reduced physical strength, endurance and flexibility [11]. AB is also associated with depression and loss of functional independence [12].

Family members and friends are affected by ABs in long-term care facilities [13, 14]. They can be embarrassed by these behaviours and eventually reduce the frequency of their visits.

Health care providers' stress is augmented by AB displayed by long-term care residents [7, 15]. ABs are more likely to occur during the activities of daily living (ADL) [16], more specifically when the older patients are mobilized, transferred, dressed, fed, bathed and groomed. AB compromises the delivery of care and can lead to psychological distress, emotional exhaustion, depression and occupational injuries among nursing staff [2, 17, 18]. Finally, increased health care costs arising from staff turnover and absenteeism are also associated with the prevalence of AB among older patients in long term care facilities [16].

Individual and environmental factors have been associated with AB among older adults. Among the individual factors, being of male gender and among the younger segment of the older adult population (65 to 70 years old) are the most consistent demographic characteristics associated with AB [19, 20]. Other individual factors include dementia (cortical and subcortical) and delirium, especially its hyperactive form [4, 5, 9, 21]. Among older patients with dementia, severity of cognitive impairment has been linked to AB. Older patients with severe cognitive impairment are associated with more frequent AB episodes [19]. Psychiatric diseases (depression, mania, schizophrenia, anxiety and post traumatic stress disorders) and some specific symptoms (delusions, illusions, hallucinations) have also been linked to AB [5, 19]. Personality traits, especially premorbid aggressive personality traits and aggression, are also risk factors for assaultive behaviour [2, 6]. Researchers underline the potential role of pain, discomfort, sensory deficiencies (vision, hearing) and unmet basic needs (nutrition, hydration, exercise, sleep, etc) that could also lead to AB [19, 21, 22].

Both social and physical environmental factors, such as social visitation and physical restraint, may trigger an outburst of AB and, as has previously been mentioned, ABs occur more frequently during ADL provided by nursing staff. Researchers have hypothesized that older patients react in this way because their personal space or privacy is perceived as violated and they feel threatened [2, 3, 23]. Thus, AB would appear to be a defensive reaction. This stresses the importance of both the personal communication skills and knowledge and understanding of nursing staff providing care to older patients in institutions.

Environmental factors may also lead to ABs when they cause pain (e.g. drawing blood samples), discomfort or frustration (e.g. locked doors) or when they are interpreted as threatening. Similarly associated factors include noise, uncomfortable temperature, inadequate lighting and moving older patients to unfamiliar places [5, 19].

To summarize, numerous factors have been associated with AB and since no one study has addressed all of them, it is difficult to determine those that are more important than others. This lack of knowledge concerning AB in long-term care facilities raises four important issues. First, studies on AB in long-term care facilities have generally been conducted on a small sized sample, some were case studies and few details are usually provided about methods for selecting participants [2, 10, 16, 20, 24, 25], i.e. many studies appear to be vulnerable to selection bias. Second, many have examined less than four of the risk factors for AB [10, 23‐27], although there are obviously some exceptions to this observation [6, 20]. Third, among those studies reporting prevalence rates for AB, few have described in detail the frequencies of specific ABs displayed in long-term care facilities [6, 28]. Fourth, results of recent studies that have separated AB into verbal and physical behaviours suggest that factors associated with these two behaviour types may be different [25, 27, 28]. Based on their results, we are of the opinion that there is a sound basis for dividing AB into two different categories, namely verbal and physical AB.

The main objective of this study was to describe the phenomenon of AB among older patients in long-term care facilities. Specific objectives were: 1 – to determine the prevalence of verbal and physical AB and the frequencies for each behaviour, and 2 – to identify the factors associated with a) both verbal and physical aggressive behaviours (BAB), b) physical aggressive behaviour (PAB) and, c) verbal aggressive behaviour (VAB).

In the original study, individuals were eligible if they were aged 65 or over and living in long-term care facilities, notably nursing homes, in the Quebec City area. Residents in six long-term care units within a large-scale psychiatric institution (n = 301) were excluded from this analysis (n = 2 332), as most of these residents had a life-long history of a psychiatric illness, usually used more psychotropic drugs and displayed AB in a context quite different from that of the average older patient in a long-term care facility.

Original data were collected from two sources as follows: first, structured simultaneous interviews with two nurses who were familiar with the residents in their health-care unit, and second, a systematic review of the medical files by research assistants. This strategy aimed at minimizing the risk that research assistants would influence the course of the interviews with nurses (information bias). Individual variables included in this study are: age, sex, length of stay, functional autonomy, cognitive status, psychological distress, isolation and withdrawal behaviour, sleep disturbance. Environmental variables are: social visitation, physical restraint and neuroleptic and benzodiazepine drugs.

Characteristics of the participants and ABs (verbal, physical and both) were described by frequencies and percentages. Bivariate analyses to determine crude odds ratios were used to evaluate the degree of association between independent variables and ABs (verbal, physical and both). Statistically significant variables in bivariate analyses were then assessed for multicolinearity according to the method outlined by Besley and colleagues [39]. The isolating and withdrawal behaviours and the functional autonomy variables correlated strongly with cognitive impairment and were discarded in the final model. Logistic regression analysis was used to examine the contribution of each independent variable to ABs (verbal, physical and both). All analyses were carried out using the Statistical Analysis System (SAS) software, version 8.0.

The first goal of this study was to determine the prevalence of verbal and physical aggressive behaviour among older residents in long-term care settings in the Quebec City area. In this study, aggressive behaviour (either physical or verbal) was displayed by 21% of the older residents and 11.2% of them exhibited both forms. In other studies, Cohen-Mansfield et al. [3] reported a prevalence rate for AB of 8 to 91% in institutional settings, Lyketsos and colleagues [40] found a prevalence rate of 23.7% for aggressive/agitated behaviour (Neuropsychiatric Inventory) among community-dwelling seniors and long term care residents, and Schreiner [23] reported a prevalence rate of 45.4% of physical or verbal aggressive behaviour (CMAI; last two weeks) among 391 cognitively impaired long term care residents. Marx et al. [6] reported a lower rate of 32% for aggressive behaviour (physical and verbal) in long-term care facilities (CMAI; last two weeks) and lastly, Giancola et al. [4] reported prevalence rates of 14 to 21% for physical aggressive behaviour and 10–14% for verbal aggressive behaviour in two nursing homes. While our results are in general agreement with these reported prevalence rates there is, nevertheless, substantial discrepancy between prevalence rates among studies. This is probably due in part to their use of different measures of AB [23, 40]. However we also cannot ignore the fact that some differences may be due to the varying quality of care provided in those long-term care facilities or to the inclusion criteria applied in the studies.

In our study, we found that 21% of older residents in long-term care settings displayed physical or verbal aggressive behaviour, confirming the significance of the phenomenon and the need to address it. Based on both their high frequency and their potentially distressing effect on both the resident and the caregivers, it appears that some specific behaviours, such as hitting and insults, deserve more attention from researchers. Such behaviour types have also been highlighted by researchers in previous studies [10, 23].

Although there is a relatively high prevalence of ABs (21%), the majority are not displayed often. Indeed, less than 3% are displayed "often" or "always". We understand from these low frequency levels that, in general, older residents do not favour one behaviour over another when exhibiting AB. There is also the possibility that specific contexts of care giving are more conducive to aggressive behaviour. However we were not able to take this into account in our study. For instance, AB during bathing has previously been observed in half of older patients with dementia [41], an observation that has led researchers to target specific care-giving contexts to tackle the problem among older patients with dementia. Sloane et al. [42] tested two experimental bathing interventions compared to a control group leading to impressive results. When compared to the control group, aggressive behaviour in the person-centred shower group and in the towel-bath group declined significantly (53% and 60% respectively). This would appear a likely avenue for future research, to target specific contexts where AB is more likely to occur in order to develop intervention suited to those contexts. Another study [43] was successful in decreasing agitation among older residents in institutions by targeting many factors and contexts (see Clinical implications). These results suggest that a broad approach to nursing care is also of value in the prevention of AB in long-term care facilities and that specific interventions should be developed targeting those care activities at increased risk for AB.

Our second study goal was to identify the factors associated with BAB, PAB and VAB. Overall, they were quite similar. This is somewhat in line with the results of previous research studies, although they yielded opposite results [27, 28]. Ryden et al. [27] found that among 116 residents, the use of psychotropic drugs, physical restraint and living on secured units were differently associated with VAB and PAB. In our study, use of benzodiazepine drugs was associated with VAB only and physical restraint only with BAB. It should be noted that Ryden's study focused exclusively on residents with frequent aggressive behaviours (9–10 aggressive behaviours a day, using the Ryden Aggression Scale-2), which is higher than the AB frequency in our study population. Using the CMAI, Schreiner [23] reported a higher prevalence of PAB among men than women (p = 0.05; n = 391), but did not observe such a difference for VAB, whereas we found men exhibited more PAB and VAB than did women. By examining patterns of co-occurrence of both ABs among residents (n = 240; 98% men; 32% had a psychiatric diagnosis), Souder et al [28] found PABs more likely to occur with non-aggressive physical behaviour, and unlikely to occur with verbally disruptive behaviours. These researchers did not look at other risk factors for AB. In our study, 11% of participants displayed BAB.

As can be concluded from these studies, much more research is needed in the field to determine whether the factors associated with BAB, PAB and VAB differ. Improved study comparability in the future requires research studies of comparable design and instruments. At present, differences in conclusions among studies could result from methodological differences, such as the instruments used, the Ryden Aggression Scale-2 [27], the CMAI [23], or the disruptive behaviour scale [28]. Nonetheless, certain results from our findings do deserve further attention. They are discussed below.

As shown in Tables 1, 4 and 5, AB was more likely to occur among older participants with mild-moderate or severe cognitive impairment than among those with no cognitive impairment. These findings are in agreement with those of Ryden et al. [27] and Marx et al. [6]. Menon et al. [26] also indicated that physical and verbal aggression increases with the severity of the cognitive impairment. According to Hall and O'Connor's literature review [19], the association between severity of cognitive impairment and aggressive behaviour has received strong support and may be caused by the communication deficiencies accompanying severe cognitive impairment.

This association between AB and cognitive impairment also provides support for the Progressively Lowered Stress Threshold (PLST) model [44, 45], according to which, a person with dementia has a declining ability to adjust to environmental demands as the cognitive losses progress. Demands not adapted to the resident's stress threshold become stressors directed at the resident, leading to the development of anxiety symptoms. If the caregiver does nothing to reduce these stressors, the resident will then display agitation such as verbal or physical aggressive behaviours. This model is useful for explaining the association between severe cognitive impairment and aggression and as such, it warrants further attention from researchers and clinicians since it brings insight to our understanding of AB [45]. Said model has also been found to improve the quality of care provided by caregivers in the community [46, 47] and therefore it would be important to also test its usefulness among older residents with severe cognitive impairment in long-term care facilities.

An interesting outcome of our study not in accordance with the PLST model is the non-linear association between cognitive impairment and VAB. According to the PLST, participants with severe cognitive impairment would have displayed more VAB than those with mild-moderate cognitive impairment. Our results in fact, showed that older residents with mild-moderate cognitive impairment were more likely to display VAB than those with severe cognitive impairment. Matteau et al. [25] explored the relationship between language deterioration and disruptive vocalization in demented residents (Alzheimer's, vascular or mixed type) living in nursing homes. They showed that those with language deficiencies were more likely to display frequent verbal behaviour in a large variety of distinct forms. Thus, disruptive vocalization could be a consequence of communicative difficulties [14, 24, 48]. Therefore, it is possible that among residents with severe cognitive impairment, their language limitations are so severe that they can no longer express their concerns through verbal agitation, including VAB. On the other hand, those residents with mild-moderate cognitive impairment, who possess residual verbal capacity, would be more prone to display their concerns via VAB, as was suggested by our results. As put forward by Hall and O'Connor [19], the association between communication impairment and VAB has implications for communication skill training for nursing staff.

The use of neuroleptics was significantly associated with PAB, and both benzodiazepine and neuroleptics were linked to VAB. Other studies [7, 10, 14, 20, 40] have found AB and psychotropic drugs such as neuroleptics and benzodiazepines to be associated. Conventional (e.g. haloperidol, thioridazine, chlorpromazine) and atypical (e.g. risperidone, olanzapine, quetiapine) neuroleptics are frequently used in the treatment of agitation and AB among older residents. Three meta-analyses concluded that, despite their wide use, neuroleptics might reduce the frequency of disruptive behaviour by only 18% [49] to 26% in older patients with dementia [50]. Lonergan and colleagues [51] report that haloperidol is not more effective than a placebo in controlling agitation among the elderly suffering from dementia and was slightly more effective than a placebo for AB. In addition, these drugs are associated with frequent adverse effects such as extra-pyramidal symptoms, drowsiness and anticholinergic manifestations [52, 53]. According to a one-year longitudinal study [54], researchers reported that change in disruptive behaviour occurs among nursing home residents regardless of the use of neuroleptic drugs, but that it occurs more frequently among those receiving neuroleptic medication. In fact, users of neuroleptics showed greater changes in both developing and resolving disruptive behaviour during the year than those not receiving the drugs. In short, given their limited effectiveness and the high risk of side effects, including permanent consequences such as tardive dyskinesia, the use of neuroleptic drugs should be a last resort

Benzodiazepines should also be used with caution among older residents. Liebson [9] reported that these drugs exacerbate cognitive deficits in cognitively impaired residents. Finally, we are not aware of any controlled clinical trial on the effectiveness of benzodiazepine for treating aggressive behaviour among older residents with dementia. It is worth mentioning that since sleep disturbance and psychological distress (both associated with AB) are indications for the use of benzodiazepine drugs, there are, undoubtedly, a certain percentage of participants who were taking these drugs to treat said symptoms and not AB. Nonetheless, future studies should be directed toward the development of new drugs and alternative treatments such as the towel bath [42] or staff training programs [55].

Physical restraints are sometimes used in an attempt to control aggressive or other risky behaviours. Their use results in loss of personal autonomy and self-esteem, and may lead to AB among residents. As found in a previous study [27], physical restraint (an environmental factor) was associated with AB among older residents. Tinetti et al. [56] reported that disruptive behaviour (which includes AB) was the reason most often cited for nursing staff's resorting to a physical restraint. However, physical restraint is not a solution for such behaviour [11]. Based on the reactance theory, we even suggest that physical restraint increases AB. Reactance theory, as proposed by Brehm, suggests that individuals pursue freedom and want control over their lives [57]. Any attempt to remove this sense of control or freedom from an individual will result in defensive behaviour. The removal of fundamental rights for a long period can lead to aggressive behaviour [58]. Therefore, one of the first interventions to be applied in the context of AB would be to reduce the use of physical restraints in long-term care settings.

Based on our results, we would like to suggest a preventive intervention program for AB inspired by the work of Inouye in the field of delirium [59]. Inouye et al. have been able to reduce the prevalence of delirium by implementing preventive interventions for every factor associated with delirium (e.g.: dehydration, malnutrition, sleep disturbance, hearing impairment, physical restraint, etc.). In the same way, it might be useful to adopt this approach for AB, since it too is associated with several factors. However a future study would need to test any such program to determine its relevance and effectiveness. According to our results, a multi-component intervention program would target the following five factors in order to reduce AB among older residents in long-term care facilities: cognitive impairment, sleep disturbance, psychological distress, benzodiazepine and neuroleptic drugs and physical restraints. Cognitive impairment, although it cannot be cured, can be alleviated somewhat through the use of an appropriate communication method. When the approach selected is suitable (validation therapy, reality orientation, reminiscence, etc.), it may reduce the occurrence of aggressive behaviours.

These multiple targets might discourage even the most well-intentioned caregivers and while it may appear that our recommendations are heavy artillery for treating AB with little real clinical application, a recent intervention study on agitation in long-term care [43] has been successful in targeting multiple risk factors for agitation, while remaining realistic in terms of clinical practice. We are of the opinion that this intervention, entitled BACE (Balancing Arousal Controls Excesses), appears promising, at least with regard to its approach to behavioural problems.

This study has some limitations. First, since it was cross-sectional in nature, the findings cannot be regarded as providing a cause-effect relationship. Second, aggressive behaviour, like all human behaviour, is influenced by individual (e.g. Parkinson's Disease, stroke) and environmental factors (e.g. staff's approach, environmental changes, quality of medical and nursing care), all of which could not be included in this study. Third, this study did not collect data on pain, a factor related to AB among long-term care residents. Lastly, this research is based on staff-reported data. The fact that the staff members in the institutions were very busy and had limited time available for the study may have affected the quality of the data collected. However, to reduce the impact of any potential bias, we interviewed two nurses simultaneously. Nevertheless, this work has two important strengths related to comprehensiveness: It should be noted in particular that our study population comprised all the residents in all the long-term care facilities in the Quebec City area (except for those in specialized psychiatric settings), and this resulted in a large sized sample. Finally, this study has made an important contribution by differentiating VAB and PAB when conducting analyses.