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Journal of Alzheimer’s Disease 40 (2014) 221–226 DOI 10.3233/JAD-131850 IOS Press
Predictors of Institutionalization in Dementia: A Three Year Longitudinal Study Henry Brodatya,b,∗ , Michael H. Connorsa,b , Jing Xua,b , Michael Woodwardc and David Amesd,e on behalf of the PRIME study group a Dementia Collaborative Research Centre, School of Psychiatry, University of New South Wales, Sydney, Australia b Centre
for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, Australia of Melbourne, Austin Hospital, Melbourne, Australia d National Ageing Research Institute, Australia e University of Melbourne Academic Unit for Psychiatry of Old Age, Melbourne, Australia c University
Abstract. Patients with dementia often require institutionalization when they can no longer care for themselves. The study examined demographic and clinical variables that predict the time until institutionalization in patients with dementia attending memory clinics. Of 970 patients recruited from nine memory clinics around Australia, 779 patients had dementia at baseline. Measures of dementia severity, cognition, functional ability, neuropsychiatric symptoms, caregiver burden, and medication use were completed for all patients. Patients were followed for three years. Overall, 197 (25.3%) of the patients with dementia were institutionalized within three years. Lower cognitive ability, lower functional ability, and more neuropsychiatric symptoms at baseline predicted a shorter time until institutionalization, as did use of antipsychotic medication. In addition, greater deterioration in cognitive ability, functional ability, and neuropsychiatric symptoms over the initial three months predicted a shorter time to institutionalization. The findings confirm that clinical features of dementia at baseline predict the time to institutionalization, as do greater changes in symptoms over three months independent of baseline levels. Keywords: Alzheimer’s disease, dementia, institutionalization, longitudinal, nursing home, survival analysis
INTRODUCTION Dementia leads to the progressive loss of cognitive and functional abilities. As a result, patients often require institutionalization when they and their caregivers are no longer able to cope with the demands that this places on them. Although patients vary in the course of their dementia, a reliable estimate of the likely time to institutionalization is important for planning purposes. Such an estimate, for example, allows clinicians to recommend appropriate care, patients and ∗ Correspondence to: Henry Brodaty, Dementia Collaborative Research Centre, Level 3, AGSM Bldg (G27), University of New South Wales, Sydney 2052, Australia. Tel.: +61 2 9385 2585; Fax: +61 2 9385 2200; E-mail: [email protected].
caregivers to make the necessary preparations, and policy makers to forecast overall demand for aged care services. For estimates to be reliable and useful, it is necessary to identify features of patients that influence or predict institutionalization. Three broad classes of variables may be of particular relevance. First, pre-existing characteristics of patients, including their relationships to caregivers, may predispose some patients to earlier institutionalization. For example, older age, being unmarried, and living alone predict earlier institutionalization [1–3]. Second, clinical features of dementia affect the extent to which patients require care and so may also predict institutionalization. For example, more severe dementia, greater cognitive impairment, greater functional impairment, more severe neuropsychiatric
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symptoms, and caregiver burden predict early institutionalization [1–3]. Finally, clinical interventions, such as medications for Alzheimer’s disease, may delay or reduce cognitive decline, thereby delaying the need for nursing home admission [4–6]. Two recent studies, however, found that these medications were associated with greater cognitive decline [7, 8]. Other medications, such as antipsychotics and benzodiazepines, are associated with shorter survival time in patients with dementia [9, 10], and so could also potentially be associated with earlier institutionalization. While much research has examined baseline characteristics of patients that predict institutionalization, comparatively little research has examined whether the rate of change in cognition, functional abilities, and neuropsychiatric symptoms over time predict institutionalization. There is also limited research on patients with dementia seen in memory clinics, as opposed to other health care settings, and no recent data available for patients in Australia. The current study examined a large sample of patients with dementia from memory clinics across Australia. Following previous research, we hypothesized that the following variables would be associated with earlier institutionalization: older age, living alone, lower cognitive ability at baseline, lower functional ability at baseline, greater severity of dementia, greater levels of neuropsychiatric symptoms, faster decline in cognition over three months, faster decline in functional ability over three months, and greater increase in neuropsychiatric symptoms over three months, and taking antipsychotic or benzodiazepine medication. MATERIALS AND METHODS Design Participants were drawn from the PRIME study in Australia [11]. This study was a three-year non-prescriptive, observational study examining relationships between predictors and outcome variables in patients attending memory clinics. Overall, the study recruited 970 patients with dementia or mild cognitive impairment. All patients were receiving specialist assessment or treatment at one of nine memory clinics in Australia. These memory clinics were in four of the eight states and territories of Australia and included both regional and capital city centers. Patients were followed up at 3, 6, 12, 24, and 36 months by a research nurse and/or their specialist clinician. Ethics approval was obtained from institutional ethics committees associated with individual referring cen-
ters (National Institute of Health clinical trials registry number: NCT00297271). Participants The current paper focused on the 779 patients with dementia. These patients had received a diagnosis of dementia from a specialist clinician according to DSM-IV criteria. Patients were classed as having Alzheimer’s disease, vascular dementia, frontotemporal dementia, mixed dementia, or other type of dementia. To be included in the study, patients had to live in the community and have less than 40 hours/week nursing care to ensure that they were not equivalent to patients in nursing homes. Patients also had to be fluent in English, have a caregiver who consented to the study, and provide written informed consent either themselves or through a legal guardian/proxy. There was no requirement for patients to be taking any particular medication. Patients were excluded if they were acutely ill or had any life-threatening illness that was likely to prevent them from completing the study. These patients were excluded to ensure that only patients that were likely to be seen in memory clinics, rather than in emergency or other parts of the health care system, were studied. Instruments Demographic and diagnostic data were collected at baseline. All other measures were completed at each visit. Dementia severity was assessed using the Clinical Dementia Rating scale (CDR) [12] and scored using the sum of boxes method [13]. Cognition was assessed using the Mini-Mental State Examination (MMSE) [14]. Neuropsychiatric symptoms were assessed using the Neuropsychiatric Inventory (NPI) [15]. Function was assessed using the Functional Autonomy Measurement System (SMAF) [16]. Caregiver burden was assessed using the Zarit Burden Interview (ZBI) [17]. Statistical analyses Analysis using the Cox proportional hazard model was performed to determine whether baseline variables could predict institutionalization. The following variables were included as predictors in the model: age, sex, educational level, dementia type, baseline dementia severity (CDR), baseline cognitive ability (MMSE), baseline functional ability (SMAF), baseline neuropsychiatric symptoms (total NPI), living alone, baseline caregiver burden (ZBI), medication
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Table 1 Patients’ characteristics at baseline Overall Age Sex Male Female Education Primary school or less High school Some post secondary College/university Post-graduate Dementia type Alzheimer’s disease Vascular dementia Mixed dementia Dementia with Lewy bodies Frontotemporal dementia Other dementias Dementia Severity & Clinical Features MMSE SMAF NPI CDR ZBI Relationship to Caregiver Lives alone Cared for by family Medication ChEI/Memantine Antipsychotic Benzodiazepines Changes (3 Months) MMSE SMAF NPI CDR ZBI
78.03 (7.50)
Institutionalized 78.83 (7.31)
Not institutionalized 77.76 (7.55)
408 (52.4%) 371 (47.6%)
105 (53.3%) 92 (46.7%)
303 (52.1%) 279 (47.9%)
98 (12.7%) 399 (51.6%) 110 (14.2%) 129 (16.7%) 37 (4.8%)
21 (10.7%) 111 (56.3%) 26 (13.2%) 32 (16.2%) 5 (2.5%)
77 (13.2%) 288 (49.5%) 84 (14.4%) 97 (16.7%) 32 (5.5%)
521 (66.9%) 51 (6.5%) 129 (16.6%) 16 (2.1%) 31 (4.0%) 31 (4.0%)
135 (68.5%) 7 (3.6%) 39 (19.8%) 7 (3.6%) 4 (2.0%) 5 (2.5%)
386 (66.3%) 44 (7.6%) 90 (15.5%) 9 (1.5%) 27 (4.6%) 26 (4.5%)
21.51 (5.28) –18.13 (11.23) 14.48 (16.08) 5.25 (3.49) 23.97 (15.77)
18.43 (6.05) –24.57 (12.01) 19.04 (18.61) 7.18 (4.15) 28.40 (15.56)
98 (12.6%) 732 (94.0%)
21 (10.7%) 187 (94.9%)
77 (13.2%) 545 (93.6%)
676 (86.8%) 188 (24.1%) 162 (20.8%)
179 (92.7%) 85 (44.0%) 45 (23.3%)
497 (85.4%) 103 (17.7%)** 117 (20.1%)
–0.38 (3.02) –1.78 (5.91) 0.43 (14.11) 0.56 (2.10) 1.81 (11.01)
–0.87 (3.33) –2.95 (7.55) 3.02 (17.92) 1.13 (2.56) 4.25 (13.60)
22.54 (4.56)** –15.92 (10.05)** 12.83 (14.74)** 4.59 (2.96)** 22.44 (15.57)**
–0.20 (2.89)* –1.35 (5.12)** –0.54 (12.27)** 0.34 (1.86)** 0.91 (9.75)**
Standard deviations or percentages are in brackets. Asterisks indicate difference between patients who were institutionalized and not institutionalized is significant; *p = 0.05; **p < 0.01. ChEI, cholinesterase inhibitor; CDR, Clinical Dementia Rating scale; MMSE. Mini-Mental State Examination; NPI, Neuropsychiatric Inventory; SMAF, Functional Autonomy Measurement System; ZBI, Zarit Burden Interview.
types (anti-psychotics, benzodiazepines), change in MMSE at three months (i.e., 3 months from the baseline assessment), change in SMAF at three months, and change in NPI at three months. Medications for Alzheimer’s disease, such as cholinesterase inhibitors and memantine, were not included as predictors given the large proportion of patients in this sample taking these medications. RESULTS Patient characteristics and institutionalization Of the 779 patients, 197 (25.3%) were institutionalized over the three year period at a mean time of 19.7 months (SD = 10.9) after index assessment. A further
70 (9.0%) patients died within the three year period without being institutionalized. Demographic features of the patients and clinical measures are summarized in Table 1. Patients in this sample were representative of patients with dementia living in the community in Australia, though there was a smaller proportion of patients with severe dementia in this sample than what is estimated in the wider population [18]. In brief, patients who were institutionalized had significantly more severe dementia, lower cognitive ability, lower functional ability, more severe neuropsychiatric symptoms, and greater caregiver burden at baseline than patients who were not institutionalized. A greater proportion of patients who were institutionalized were receiving antipsychotic medications than patients who were not institutionalized. Patients who
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H. Brodaty et al. / Predictors of Institutionalization Table 2 Predictors of time to institutionalization
Demographics Age Sex (female) Education (high school) Living alone Diagnosis Alzheimer’s disease Baseline Measures Cognition (MMSE) Function (SMAF) Neuropsychiatric (NPI) Severity (CDR) Caregiver burden (ZBI) Medication Benzodiazepines Antipsychotics Changes at 3 Months Change in MMSE Change in SMAF Change in NPI
Parameter estimate
Standard error
p
Hazard ratio
95% CI for Hazard ratio
0.18 –0.11 0.14 0.52
0.17 0.18 0.18 0.29
0.29 0.54 0.46 0.07
1.20 0.89 1.14 1.68
(0.86, 1.69) (0.62, 1.28) (0.80, 1.64) (0.96, 2.95)
0.30
0.19
0.11
1.36
(0.94, 1.96)
–0.07 –0.05 0.02 –0.02 –0.00
0.02 0.01 0.01 0.04 0.01
Journal of Alzheimer’s Disease 40 (2014) 221–226 DOI 10.3233/JAD-131850 IOS Press
Predictors of Institutionalization in Dementia: A Three Year Longitudinal Study Henry Brodatya,b,∗ , Michael H. Connorsa,b , Jing Xua,b , Michael Woodwardc and David Amesd,e on behalf of the PRIME study group a Dementia Collaborative Research Centre, School of Psychiatry, University of New South Wales, Sydney, Australia b Centre
for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, Australia of Melbourne, Austin Hospital, Melbourne, Australia d National Ageing Research Institute, Australia e University of Melbourne Academic Unit for Psychiatry of Old Age, Melbourne, Australia c University
Abstract. Patients with dementia often require institutionalization when they can no longer care for themselves. The study examined demographic and clinical variables that predict the time until institutionalization in patients with dementia attending memory clinics. Of 970 patients recruited from nine memory clinics around Australia, 779 patients had dementia at baseline. Measures of dementia severity, cognition, functional ability, neuropsychiatric symptoms, caregiver burden, and medication use were completed for all patients. Patients were followed for three years. Overall, 197 (25.3%) of the patients with dementia were institutionalized within three years. Lower cognitive ability, lower functional ability, and more neuropsychiatric symptoms at baseline predicted a shorter time until institutionalization, as did use of antipsychotic medication. In addition, greater deterioration in cognitive ability, functional ability, and neuropsychiatric symptoms over the initial three months predicted a shorter time to institutionalization. The findings confirm that clinical features of dementia at baseline predict the time to institutionalization, as do greater changes in symptoms over three months independent of baseline levels. Keywords: Alzheimer’s disease, dementia, institutionalization, longitudinal, nursing home, survival analysis
INTRODUCTION Dementia leads to the progressive loss of cognitive and functional abilities. As a result, patients often require institutionalization when they and their caregivers are no longer able to cope with the demands that this places on them. Although patients vary in the course of their dementia, a reliable estimate of the likely time to institutionalization is important for planning purposes. Such an estimate, for example, allows clinicians to recommend appropriate care, patients and ∗ Correspondence to: Henry Brodaty, Dementia Collaborative Research Centre, Level 3, AGSM Bldg (G27), University of New South Wales, Sydney 2052, Australia. Tel.: +61 2 9385 2585; Fax: +61 2 9385 2200; E-mail: [email protected].
caregivers to make the necessary preparations, and policy makers to forecast overall demand for aged care services. For estimates to be reliable and useful, it is necessary to identify features of patients that influence or predict institutionalization. Three broad classes of variables may be of particular relevance. First, pre-existing characteristics of patients, including their relationships to caregivers, may predispose some patients to earlier institutionalization. For example, older age, being unmarried, and living alone predict earlier institutionalization [1–3]. Second, clinical features of dementia affect the extent to which patients require care and so may also predict institutionalization. For example, more severe dementia, greater cognitive impairment, greater functional impairment, more severe neuropsychiatric
ISSN 1387-2877/14/$27.50 © 2014 – IOS Press and the authors. All rights reserved
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symptoms, and caregiver burden predict early institutionalization [1–3]. Finally, clinical interventions, such as medications for Alzheimer’s disease, may delay or reduce cognitive decline, thereby delaying the need for nursing home admission [4–6]. Two recent studies, however, found that these medications were associated with greater cognitive decline [7, 8]. Other medications, such as antipsychotics and benzodiazepines, are associated with shorter survival time in patients with dementia [9, 10], and so could also potentially be associated with earlier institutionalization. While much research has examined baseline characteristics of patients that predict institutionalization, comparatively little research has examined whether the rate of change in cognition, functional abilities, and neuropsychiatric symptoms over time predict institutionalization. There is also limited research on patients with dementia seen in memory clinics, as opposed to other health care settings, and no recent data available for patients in Australia. The current study examined a large sample of patients with dementia from memory clinics across Australia. Following previous research, we hypothesized that the following variables would be associated with earlier institutionalization: older age, living alone, lower cognitive ability at baseline, lower functional ability at baseline, greater severity of dementia, greater levels of neuropsychiatric symptoms, faster decline in cognition over three months, faster decline in functional ability over three months, and greater increase in neuropsychiatric symptoms over three months, and taking antipsychotic or benzodiazepine medication. MATERIALS AND METHODS Design Participants were drawn from the PRIME study in Australia [11]. This study was a three-year non-prescriptive, observational study examining relationships between predictors and outcome variables in patients attending memory clinics. Overall, the study recruited 970 patients with dementia or mild cognitive impairment. All patients were receiving specialist assessment or treatment at one of nine memory clinics in Australia. These memory clinics were in four of the eight states and territories of Australia and included both regional and capital city centers. Patients were followed up at 3, 6, 12, 24, and 36 months by a research nurse and/or their specialist clinician. Ethics approval was obtained from institutional ethics committees associated with individual referring cen-
ters (National Institute of Health clinical trials registry number: NCT00297271). Participants The current paper focused on the 779 patients with dementia. These patients had received a diagnosis of dementia from a specialist clinician according to DSM-IV criteria. Patients were classed as having Alzheimer’s disease, vascular dementia, frontotemporal dementia, mixed dementia, or other type of dementia. To be included in the study, patients had to live in the community and have less than 40 hours/week nursing care to ensure that they were not equivalent to patients in nursing homes. Patients also had to be fluent in English, have a caregiver who consented to the study, and provide written informed consent either themselves or through a legal guardian/proxy. There was no requirement for patients to be taking any particular medication. Patients were excluded if they were acutely ill or had any life-threatening illness that was likely to prevent them from completing the study. These patients were excluded to ensure that only patients that were likely to be seen in memory clinics, rather than in emergency or other parts of the health care system, were studied. Instruments Demographic and diagnostic data were collected at baseline. All other measures were completed at each visit. Dementia severity was assessed using the Clinical Dementia Rating scale (CDR) [12] and scored using the sum of boxes method [13]. Cognition was assessed using the Mini-Mental State Examination (MMSE) [14]. Neuropsychiatric symptoms were assessed using the Neuropsychiatric Inventory (NPI) [15]. Function was assessed using the Functional Autonomy Measurement System (SMAF) [16]. Caregiver burden was assessed using the Zarit Burden Interview (ZBI) [17]. Statistical analyses Analysis using the Cox proportional hazard model was performed to determine whether baseline variables could predict institutionalization. The following variables were included as predictors in the model: age, sex, educational level, dementia type, baseline dementia severity (CDR), baseline cognitive ability (MMSE), baseline functional ability (SMAF), baseline neuropsychiatric symptoms (total NPI), living alone, baseline caregiver burden (ZBI), medication
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Table 1 Patients’ characteristics at baseline Overall Age Sex Male Female Education Primary school or less High school Some post secondary College/university Post-graduate Dementia type Alzheimer’s disease Vascular dementia Mixed dementia Dementia with Lewy bodies Frontotemporal dementia Other dementias Dementia Severity & Clinical Features MMSE SMAF NPI CDR ZBI Relationship to Caregiver Lives alone Cared for by family Medication ChEI/Memantine Antipsychotic Benzodiazepines Changes (3 Months) MMSE SMAF NPI CDR ZBI
78.03 (7.50)
Institutionalized 78.83 (7.31)
Not institutionalized 77.76 (7.55)
408 (52.4%) 371 (47.6%)
105 (53.3%) 92 (46.7%)
303 (52.1%) 279 (47.9%)
98 (12.7%) 399 (51.6%) 110 (14.2%) 129 (16.7%) 37 (4.8%)
21 (10.7%) 111 (56.3%) 26 (13.2%) 32 (16.2%) 5 (2.5%)
77 (13.2%) 288 (49.5%) 84 (14.4%) 97 (16.7%) 32 (5.5%)
521 (66.9%) 51 (6.5%) 129 (16.6%) 16 (2.1%) 31 (4.0%) 31 (4.0%)
135 (68.5%) 7 (3.6%) 39 (19.8%) 7 (3.6%) 4 (2.0%) 5 (2.5%)
386 (66.3%) 44 (7.6%) 90 (15.5%) 9 (1.5%) 27 (4.6%) 26 (4.5%)
21.51 (5.28) –18.13 (11.23) 14.48 (16.08) 5.25 (3.49) 23.97 (15.77)
18.43 (6.05) –24.57 (12.01) 19.04 (18.61) 7.18 (4.15) 28.40 (15.56)
98 (12.6%) 732 (94.0%)
21 (10.7%) 187 (94.9%)
77 (13.2%) 545 (93.6%)
676 (86.8%) 188 (24.1%) 162 (20.8%)
179 (92.7%) 85 (44.0%) 45 (23.3%)
497 (85.4%) 103 (17.7%)** 117 (20.1%)
–0.38 (3.02) –1.78 (5.91) 0.43 (14.11) 0.56 (2.10) 1.81 (11.01)
–0.87 (3.33) –2.95 (7.55) 3.02 (17.92) 1.13 (2.56) 4.25 (13.60)
22.54 (4.56)** –15.92 (10.05)** 12.83 (14.74)** 4.59 (2.96)** 22.44 (15.57)**
–0.20 (2.89)* –1.35 (5.12)** –0.54 (12.27)** 0.34 (1.86)** 0.91 (9.75)**
Standard deviations or percentages are in brackets. Asterisks indicate difference between patients who were institutionalized and not institutionalized is significant; *p = 0.05; **p < 0.01. ChEI, cholinesterase inhibitor; CDR, Clinical Dementia Rating scale; MMSE. Mini-Mental State Examination; NPI, Neuropsychiatric Inventory; SMAF, Functional Autonomy Measurement System; ZBI, Zarit Burden Interview.
types (anti-psychotics, benzodiazepines), change in MMSE at three months (i.e., 3 months from the baseline assessment), change in SMAF at three months, and change in NPI at three months. Medications for Alzheimer’s disease, such as cholinesterase inhibitors and memantine, were not included as predictors given the large proportion of patients in this sample taking these medications. RESULTS Patient characteristics and institutionalization Of the 779 patients, 197 (25.3%) were institutionalized over the three year period at a mean time of 19.7 months (SD = 10.9) after index assessment. A further
70 (9.0%) patients died within the three year period without being institutionalized. Demographic features of the patients and clinical measures are summarized in Table 1. Patients in this sample were representative of patients with dementia living in the community in Australia, though there was a smaller proportion of patients with severe dementia in this sample than what is estimated in the wider population [18]. In brief, patients who were institutionalized had significantly more severe dementia, lower cognitive ability, lower functional ability, more severe neuropsychiatric symptoms, and greater caregiver burden at baseline than patients who were not institutionalized. A greater proportion of patients who were institutionalized were receiving antipsychotic medications than patients who were not institutionalized. Patients who
224
H. Brodaty et al. / Predictors of Institutionalization Table 2 Predictors of time to institutionalization
Demographics Age Sex (female) Education (high school) Living alone Diagnosis Alzheimer’s disease Baseline Measures Cognition (MMSE) Function (SMAF) Neuropsychiatric (NPI) Severity (CDR) Caregiver burden (ZBI) Medication Benzodiazepines Antipsychotics Changes at 3 Months Change in MMSE Change in SMAF Change in NPI
Parameter estimate
Standard error
p
Hazard ratio
95% CI for Hazard ratio
0.18 –0.11 0.14 0.52
0.17 0.18 0.18 0.29
0.29 0.54 0.46 0.07
1.20 0.89 1.14 1.68
(0.86, 1.69) (0.62, 1.28) (0.80, 1.64) (0.96, 2.95)
0.30
0.19
0.11
1.36
(0.94, 1.96)
–0.07 –0.05 0.02 –0.02 –0.00
0.02 0.01 0.01 0.04 0.01
