Sample
The study design was a cross sectional survey. A total of 152 PWD living at home and their 128 informal carers were recruited from health and social services, and voluntary organisations in North East London (65 PWD and 54 carers), Cambridgeshire (81 PWD and 68 carers) and Liverpool (6 PWD and 6 carers). Inclusion criteria for PWD were: being aged 60 or over, having a diagnosis of dementia according to DSM-IV and living at home (not in institutions). A person was considered an informal carer (spouse, relative, friend or neighbour) when he/she was knowledgeable about the person with dementia and spent a minimum of 4 hours a week in direct contact (face to face) with them. Only one person was considered the nominated carer. A sample, similar to those obtained from previous community studies of dementia in terms of living situation, was recruited: 65% of participants living with another person and 35% living alone [9, 10].
At each centre, the manager or appropriate member of staff was requested to make a first approach either with the PWD's carers or the PWD themselves (depending on dementia severity and/or living situation) to give them the Information Sheet and to discuss if they were willing to be approached by the researcher regarding this study. Participants who had no objection were contacted by the researcher by phone and were given more information about the study as required. In addition, details of people who had attended the centre (PWD's name, carer's name, address, phone, etc.) were provided and a letter was sent to the carer and/or patient including information sheets about the study. One week after, the researcher contacted them by phone, answered any questions they might have, explained the study and looked for their willingness to participate. If the potential participant agreed to be involved, either the researcher or an interviewer arranged a day to carry out the interview at their homes.
Procedure
The study was carried out in accordance with the latest version of the Declaration of Helsinki. Ethical approval was granted by East London & the City HA Research Ethics Committee 3. All participants gave informed consent. Once the interviewer was at the PWD's or carer's home, they answered any further queries and sought informed consent as follows: written consent by signing a Consent Form was required from people with dementia and their caregivers. In order to achieve this, the interviewer approached potential subjects to explain the study and to inform them about their right to withdraw at anytime. Some PWD (11, 7.3%) were unable to provide written consent. When this occurred, the interviewer sought their assent (verbal consent). During this process, the interviewer made sure that he/she had taken as much time and care in explaining the information about this research as simply as possible. The interviewer avoided using long sentences and attempted to reduce any distractions. To find out if the participants have understood the information given, the interviewer observed their ability to ask any relevant questions and also requested the participant to repeat back the information and how it would relate to them. In addition, the interviewer clarified any doubts about the study and reiterated their right to withdraw at anytime.
Interviews were carried out by an experienced clinical psychologist and old age psychiatrists who were trained to undertake the interview. All the interviews with PWD were carried out at their homes. Interviews with carers were undertaken either at the PWD's home, their own home or at a health centre (e.g. memory clinic, day hospital). Whenever possible, the PWD and the carer were interviewed separately. However, some carers wanted to be present during the PWD's interview. In this situation, the interviewer emphasized the fact that he/she was interested in knowing both parties' views about the PWD's needs and quality of life; and, as they were unique human beings, both opinions do not necessarily have to be coincident and both were considered valid. Interviews were terminated immediately in presence of any sign of discomfort. In addition, if the conditions at home were not appropriate to undertake the interview with the carer, the interviewer arranged a next meeting in other location.
Using standardised instruments, PWD were interviewed about their needs, cognitive status and quality of life. This interview took an average of 30 minutes depending on dementia severity. Carers were interviewed about the PWD's sociodemographic details, needs, behavioural and psychological symptoms, functional status, quality of life, social networks, and services received. In addition, carers were assessed about their own sociodemographic details, depression, anxiety and burden. This interview took about two hours and a half.
Measures
Instruments administered to the person with dementia
Camberwell Assessment of Need for the Elderly (CANE) [11, 12]
The CANE is a comprehensive tool which offers a structured evaluation of needs in older people in 24 areas of social, psychological, physical, and environmental needs rated as no need, met need or unmet need. The CANE also asks about formal and informal support/services. The CANE has shown good levels of reliability (α = 0.99) and validity (correlated with the CAPE-BRS, r = 0.66; and the Barthel r = -0.53) [11]. It assesses the needs of older people from the perspective of the PWD, the carer, the staff and the researcher. Since ratings from the researcher were obtained for the complete sample (n = 152), in this article only researcher ratings were included. Researchers were trained by an expert (MO) to undertake the interviews using the Camberwell Assessment of Need for the Elderly (CANE) [12]. Pilot interviews were discussed and agreement in rating criteria was achieved. The CANE was selected because it has good psychometric properties and it has already been used to assess the needs of PWD [1, 13, 14].
Mini Mental State Examination (MMSE) [15]
This test assesses cognitive function including orientation, memory and attention. MMSE has been widely used in clinical and research practice [16]. The MMSE takes 5 to 10 minutes to administer. Its reliability (internal consistency) in community samples range from 0.54 to 0.77 and 0.96 in medical patients [17]. Regarding validity, MMSE has shown high correlations with several other test that measure different aspects of cognitive functioning ranging from 0.66 to 0.93 [17]. This brief screening tool was used to estimate the severity of PWD's cognitive impairment. This instrument was rated by the researcher in an interview with the person with dementia.
Quality of Life in Alzheimer's Disease (QoL-AD) [18]
The QOL-AD measures quality of life in PWD including areas such as physical health, energy, mood, living situation, memory, family, marriage, friends, self as a whole, ability to do chores around the house, ability to do things for fun, money and life as a whole. The scale allows both self-report ratings from the person with dementia and proxy-ratings from the caregiver. The QOL-AD has shown good levels of reliability and validity. In the original study, internal consistency was good (α = 0.88) [18]. Regarding convergent and divergent validity, QOL-AD showed a negative correlation with depression (-0.20) but no significant correlation was found with cognition (-0.09, p = 0.19) [19]. This measure was chosen because it is short and easy to administer, it assesses PWDs' and carers' perceptions about the person with dementia's quality of life, it can be used with people with MMSE scores as low as three [13] and it has been pointed out by the INTERDEM group as the instrument of choice to assess quality of life in PWD [20]. The QoL-AD PWD version was administered by interviewing the PWD and the carer version was self-administered by the carer.
Instruments administered to the carer to obtain information about the person with dementia
Camberwell Assessment of Need for the Elderly (CANE)
[11, 12]
(See above)
Quality of Life in Alzheimer's Disease (QoL-AD)
[18]
(See above)
Neuropsychiatric Inventory (NPI) [21]
The NPI is a structured interview designed to assess a broad range of behavioural and psychological symptoms commonly encountered in PWD [21]. This tool has shown high internal consistency reliability for the frequency/severity product scores (α = 0.88) and for the specific severity (α = 0.87) and frequency (α = 0.88) ratings [22]. The NPI has been indicated by the INTERDEM group as the measure of choice for assessing behavioural and psychological symptoms in dementia because it assesses a wide range of behaviours, it has shown sensitivity to behavioural changes and its comprises the assessment of carer's stress generated by the symptoms [20]. The NPI was rated by the researcher in an interview with the carer.
Physical Self-maintenance Scale (PSMS) and Instrumental Activities of Daily Living Scale (IADL) [23]
The PSMS assesses functional status through a rating made by the person or an informant about the person's ability to perform basic activities of daily living independently. The IADL scale has been designed to evaluate more complex daily tasks which reflect environmental adaptation. The IADL scale has shown good validity and reliability (from α = 0.87 to α = 0.91) [23]. This tool has been extensively utilised by researchers and clinicians to assess ability for instrumental functions. The PSMS/IADL has been widely used, it is easy to complete and has been recommended by the INTERDEM group as a measure of choice in dementia care research [20]. The PSMS and IADL were rated by the researcher in an interview with the carer.
Practitioner Assessment of Network Typology (PANT) [4]
The PANT was developed to assess older people's support networks. The instrument comprises 8 items about three main features: availability of local close kin, level of involvement of family friends and neighbours, and the level of interaction with the community and voluntary groups. Thus, networks are characterised into five main types:
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Local family dependent support network. Includes close local family ties with a few peripheral friends and neighbours. It is a small network (1-4). Older people in this network generally live very near to or in co-residence with an adult child, they are less likely to be in good health, and their community involvement is low.
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Locally integrated support network. It is the most common and the most robust. This network is composed by local family, friends and neighbours; it is larger than average (+7) and implies high levels of community involvement. This network is related to the fewest risks.
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Local self-contained support network. Reliance mainly on neighbours and occasional contact with at least one relative more than five miles distant. This network is average size (5-6). Community involvement, if any, is low. Risks are associated with concern for privacy.
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Wider community focused support network. It is characterized by the absence of local kin. This network includes mainly friends living within 5 miles, some neighbours, and family living more than 50 miles away. The size of this network is larger than average (+8). Community involvement is usually high.
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Private restricted support network. It is associated with absence of local kin other than the spouse. This network is composed by relatives who live more than 50 miles away and is smaller than average. Usually comprises two subtypes: independent married couples and older people who have withdrawn or become isolated from local involvement. It includes minimal contact with neighbours and no community involvement. Members of this network are most at risk.
The PANT was rated by the researcher in an interview with the carer.
Client Service Receipt Inventory (CSRI) [24]
This instrument collects retrospective information about the patient and the carer such as accommodation, medication, income and expenditure, hospitalisation and services received by the patient during the last three months [24]. The CSRI has been widely used and has proved useful to assess care receipt service and the associated costs. The CSRI was rated by the researcher in an interview with the carer.
Instruments administered to the carer to obtain information about themselves
Hospital Anxiety and Depression Scale (HADS) [25]
This self-administered instrument is divided into two subscales: anxiety (HADS-A) and depression (HADS-D) each one including seven items [25]. Internal consistency reports vary for HADS-A from 0.68 to 0.93, and for HADS-D from 0.67 to 0.90. Sensitivity and specificity for both subscales is about 0.80. Concurrent validity has been reported between 0.60 to 0.80 [26]. This measure was chosen because it does not include somatic items (which are not recommended when assessing anxiety and depression in older people), it can be used with younger and older carers [27] and it has been used in previous studies of dementia carers [13, 28]. The HADS was self-administered by the carer.
Zarit Burden Interview (ZBI) [29]
The Zarit Burden Interview is composed by 22 questions about the impact of the PWD's disabilities on the caregiver's life. For each item, caregivers are asked to indicate how often they have felt that way. Reliability has been estimated at 0.71 and 0.91, and validity has been estimated at 0.7 [30]. This measure was chosen because it has good psychometric properties, it is the most consistently used in research and it was developed specifically for carers of PWD [29]. The BI was self-administered by the carer.
Data Analysis
Statistical analyses were undertaken using the SPSS 15.0 software package and AMOS 7.0 [31]. The significance level used was p < 0.05. Since needs (met and unmet) were not distributed normally, non-parametric tests were performed. For a better understanding of the results, when comparing groups, means instead of ranks are shown.
In order to identify predictors of unmet need, a stepwise multiple linear regression was performed. In addition, in order to test the theoretical model a path analysis was carried out using AMOS 7.0. For this analysis, only the main variables of this study were considered: living situation (alone vs. with others), behavioural and psychological symptoms (NPI score), services received, unmet needs, social networks, quality of life (rated by patients and carers) and carers' mental health (depression, anxiety and burden). Variables skewed ≥1 ('Unmet needs' and 'NPI Score') were transformed [32]. Maximum likelihood method was used to estimate the model. Chi-square statistic for the model was reported. A non significant χ2 value indicates that the model does not occur by chance. The Normed Fit Index (NFI), and Comparative Fit Index (CFI) were reported. Values ≥ 0.90 indicate good fitting of the model [33]. Finally, the Root Mean Square Error of Approximation (RMSEA) which is sensitive to the number of estimated parameters in the model and penalizes the lack of parsimony was reported. A RMSEA value less than 0.05 with a narrow confidence interval (CI) denotes adequate parsimony [34].