How to explore the needs of informal caregivers of individuals with cognitive impairment in Alzheimer’s disease or related diseases? A systematic review of quantitative and qualitative studies

Background This study aims to review the methodologies used to identify the needs, the existing needs assessment instruments and the main topics of needs explored among caregivers of patients with mild cognitive impairment to dementia. Methods MEDLINE, PsycINFO, The Cochrane Library and Web of science were searched from January 1980 to January 2017. Research studies in English or French were eligible for inclusion if they fulfilled the following criteria: quantitative, qualitative and mixed method studies that used instrument, focus group or semi-structured interviews to assess the informal caregiver’s needs in terms of information, coping skills, support and service. Results Seventy studies (n = 39 quantitative studies, n = 25 qualitative studies and n = 6 mixed method studies) met the inclusion criteria and were included. Thirty-six quantitative instruments were identified but only one has been validated for the needs assessment of dementia caregivers: the Carer’s Needs Assessment for Dementia (CNA-D). The main areas of needs explored in these instruments were: information, psychosocial, social, psychoeducational and other needs. Conclusions No instrument has been developed and validated to assess the needs of informal caregivers of patients with cognitive impairment, whatever the stage and the etiology of the disease. As the perceived needs of caregivers may evolve with the progression of the disease and the dementia transition, their needs should be regularly assessed. Electronic supplementary material The online version of this article (doi:10.1186/s12877-017-0481-9) contains supplementary material, which is available to authorized users.


Background
The informal caregiver of people with cognitive impairment is often a spouse or a child, providing supervision, support and assistance with daily living activities during all stages of the disease to maintain the care recipient at home [1]. Prevalence of Mild Cognitive Impairment (MCI) ranges from 3 to 19% in adults older than 65 years [2]. In addition, the number of people with dementia in the world is expected to rise from 35.6 million in 2010 to an estimated 115.4 million in 2050 [3]. This will be associated with an increasing number of informal caregivers whose role represents a major societal and economic issue [4,5].
Cognitive impairment, progressive loss of autonomy and behavioural disorders associated with the evolution of Alzheimer's Disease and Related Diseases (ADRD) may lead to increased caregiver burden [6,7]. This burden may have physical, psychological, emotional, social and financial impact on the informal caregiver [8]. Several studies have shown that caring for people with dementia was associated with depression, anxiety, greater risk of hypertension and heart disease, decreased immunity and higher mortality [9][10][11][12][13].
The increasing frailty of the caregiver has been shown to predict an early institutionalization of the patient over time [14]. Despite caregivers of people with dementia often providing intensive levels of assistance, their use of support services is low. A review showed that one third of caregivers did not use any service and one fourth caregivers used only one service [15]. In addition, previous studies have shown a large number of unmet needs were correlated with a higher burden and an increase in caregiver strain and depressive symptoms [16][17][18][19][20][21][22][23]. To ensure the service utilization by the caregivers and to minimize their burden, the supply (support, services) and the demand (caregivers' needs) must be appropriate. Indeed, informal caregivers and professionals may differ in their perspectives to assess caregivers' needs and in prioritising subsequent interventions and supports [24]. The assessment of the caregivers' met and unmet needs represent a first step (i) to determine services or care plans for community-based programs and planning service delivery [25] (policy purposes); (ii) to refer caregivers to appropriate support and resources based on gaps-in needs identified and to ensure the service utilization (clinical purposes); and (iii) to design research programs for the caregivers (research purposes). This assessment can also be used when carrying out trials of interventions intended to improve caregiver outcomes including reducing unmet needs (Research purposes). Our research questions are: How to explore the caregivers' needs of individuals with cognitive impairment and what methods are used?
A previous systematic review conducted in 2012, has provided an overview of the existing needs assessment instruments among people with cognitive impairment [26], but no such studies have been conducted considering the need assessment of their informal caregivers.
Our objective was to perform a systematic review of the methodologies used to identify the needs, the existing needs assessment instruments and the main topics of needs explored among caregivers of ADRD patients with mild cognitive impairment to dementia.

Search procedure/methods
Electronic databases and key articles were searched for studies published in English and French between January 1980 and January 2017. The searches were carried out in MEDLINE, PsycINFO, The Cochrane Library and Web of Science in order to identify quantitative and qualitative studies. We used the following search strategies for the research (detailed in Additional file 1): (carer*/ caregiver*/ loved one*/ famil*) AND (dementia/ Alzheimer*/ frontotemporal/ lewy/ vascular dementia/ cognitive impairment/ memory) AND (need*/ expectation*) AND (quantitative*/ qualitative*/ questionnaire*/ item*/ scale*/ tool*/ instrument*/ interview*/ crosssectional/ focus group*/ structured/ verbatim* / survey). A manual search was performed at the end from the references of the included studies, from google scholar and using the 'Related articles' option on PubMed. The reference database used to retrieve records and for the screening was Endnote. This systematic review follows the PRISMA statement guidelines [27].

Eligibility criteria
We included quantitative and qualitative studies that used questionnaires, instruments, focus group or semistructured interviews to assess the needs (met and unmet needs) of informal caregivers. Informal caregivers were defined as unpaid, non-professionals who daily take care of individuals with mild cognitive impairment to dementia related to ADRD [1]. The included studies had to explore caregiver's needs in terms of information, coping skills, support and services. We also included studies that used both quantitative and qualitative methods (mixed methods studies).

Study selection
Two authors (T.N and C.M) independently screened the titles and abstracts of the citations identified by the search to determine which papers met the eligibility criteria. The final eligibility evaluation was performed utilizing the full paper. In cases with disagreements, discussions were held between authors until a consensus reached.

Data collection
One review author (T.N) extracted the data using a data extraction form, and a second author (C.M) verified the data. The following data were extracted: year of publication, country in which the study was performed, first author, number and main characteristics of caregivers (proportion of females and spouses and the mean age), the care recipient health condition, the instrument aim, and the main characteristics of the needs assessment method.

Selection of study
A total of 8265 studies were identified through database searching. A flow-chart of the selection process is illustrated in Fig. 1. We excluded 8080 studies including 2631 duplicates and 5450 articles after screening of the title and abstract. The remaining 185 full text articles were screened independently and five additional studies were identified by the authors from the references of the included studies. A total of 70 studies were included.

Study populations
A total of 11,122 informal caregivers was captured in the included studies: n = 9390 in quantitative studies, n = 1294 in qualitative studies, and n = 438 in mixed method studies (Tables 1, 2 and 3). In these studies, the caregiver needs assessment was performed according to the patient diagnosis in 19 studies, the stage of the disease in 45 studies or both in six studies. Nineteen studies were conducted among caregivers of Alzheimer's Disease patients, four in Frontotemporal dementia, two in Lewy Body disease, one in vascular dementia and one in ADRD (diagnosis unspecified). The stage of the disease the most explored in the caregiver needs assessment was dementia: 38 studies with dementia caregivers and seven with early-onset dementia caregivers. Only four studies were conducted among MCI caregivers.

Methodologies to identify the needs of informal caregivers
The sample of selected studies was composed of 39 quantitative studies, 25 qualitative studies and six mixed method studies. Tables 1, 2 and 3 summarize the methodology characteristics of the studies (quantitative, qualitative and mixed research).

Quantitative studies
A majority of the needs assessment instruments were especially developed for the research (28/39 studies) ( Table  1). Eleven studies have used validated instruments developed for the research or clinical use to assess the needs of elderly caregivers (6/11), dementia patient and caregivers (2/11), dementia caregivers (2/11) and nonspecific caregivers (1/11). Some of the validated instruments developed to assess the needs of patients with dementia, such as the Camberwell Assessment of Needs for the Elderly (CANE) [28], The Johns Hopkins Dementia Care Needs Assessment (JHDCNA) by Black et al. and the Care needs assessment pack for dementia (CarenapD) [29], include several questions concerning the caregivers'    [30]. This instrument with 35 items was not specifically developed to needs assessment. It explored the acquired knowledge and skills allowing to indirectly assess the dementia caregiver's needs.

Qualitative studies
Several methodologies were used to identify the needs of informal caregivers: semi-structured interviews (10/25     Table 2). The main objectives of these qualitative studies were to explore the experiences of caregivers with caring and community services, their information, training and support needs, their satisfaction with services and the gap between their perceived needs and the proposed services.

Mixed method studies
Six studies including quantitative and qualitative methodologies were conducted among informal caregivers ( Table 3). The majority of the studies consisted of quantitative survey associated with a semi-structured interview to explore the caregiver's experience and needs or to complete and to comment the quantitative data. The quantitative instruments were either developed for the study, or derived from validated instrument for nonspecific caregivers.

Main topics of needs explored in the quantitative and mixed method studies
From the 45 studies using quantitative methods (39 quantitative and six mixed methods research), 36 instruments were described (wholly or in part), four studies used the same validated instruments (CANE or JHDCNA) and four were not described. Table 4 summarizes the main items of needs explored among the different instruments. Twentyseven items were related to five areas of needs: information (e.g. on the disease and the treatment) psychological (e.g. emotional support for caregivers and their relative), social (e.g. financial issue and community services), psychoeducational (e.g. coping skills and caregiver training) and other needs (e.g. medication management and environment safety). The most explored topics of needs (≥50%) in caregiver needs assessment instruments were: information on the disease (78%), support for the caregivers (64%), coping for caring (56%), community services related to patient care (50%), financial issue (50%) and safety/supervision (50%).

Discussion
This article provides the first overview of existing needs assessments methods in caregivers of individuals with ADRD developed for clinical or research use. Despite the large number of studies include in the analysis, only one instrument was validated to assess the needs of dementia caregivers: the Carers' Needs Assessment for Dementia (CNA-D) [16]. Many quantitative instruments were used in research area to develop programs and interventions tailored to the caregivers' needs or in clinical area to identify their needs and to offer them appropriate support. Caregivers' needs for services or care plans and referring to support were included in many developed instruments. The items of corresponding needs were as follows: psychological and emotional support (64%), information about financial and legal issues (50 and 39%), information about respite and day care (39%) and community services related to patient care (50%) and home support (42%). Despite the diversity of the items present in the identified instruments, they allow to explore a larger number of topics such as information, skills, support and service needs, compared with qualitative methods. However, qualitative research produces large amounts of textual data in the form of transcripts and observational field notes about a predetermined topic [31]. Qualitative research methods have used in the social sciences and deserve to be an essential component in health and health services research. They allow exploring individually or in groups the perceived needs of caregivers. Unlike quantitative methods, qualitative methods allow to explore in depth specific needs (e.g. needs in an ethnic population, needs of interactions with physician and care providers, changing needs before, during and after diagnosis) and experiences of caregivers (e.g. experiences with support and services). Understanding these challenges may lead to improve the health care provision for informal caregivers. Thus, qualitative and quantitative approaches are complementary: qualitative work may be conducted as a preliminary to quantitative research, used to supplement quantitative work or used to explore complex phenomena or areas not amenable to quantitative research [32].
The caregiver plays a crucial role across all stages of the progression and identifying their needs should be performed by the health professionals at each stage to prevent or reduce their burden. Many studies have assessed the effectiveness of interventions on caregiver burden and psychological disorders [33][34][35][36]. The meta-analysis of Pinquart et al. including 127 interventions showed a significant but small effects on burden, depression, subjective well-being, and knowledge and/or coping abilities of the caregiver [34]. There is a lack of systematic investigations of the efficacy of treatment combinations using a needs assessment in caregivers of individuals with subjective cognitive impairment, MCI or dementia. To our knowledge no study has shown that caregivers receive the interventions matching their needs assessed as outcome with a validated instrument.
This current review has some limitations. The main restrictions concerned the searching process. Only studies published in scientific journals were included in the systematic review. The needs assessments of caregivers of individuals with cognitive impairment published in the "grey literature" were not explored. The searching process was also limited to a number of databases which covered both the clinical and psychosocial aspects of the study. Another limitation in the analysis of the different needs assessment instruments since the topic of explored needs were not always fully described in the included studies.

Conclusion
To reduce the caregiver burden and to facilitate the patient's home care, policymakers, service planners, health professionals and researchers must understand the needs of this growing population. This systematic review highlights the necessity to develop a validated instrument to assess the met and unmet needs of informal caregivers of patients with a cognitive impairment across all stages of the disease progression and whatever the etiology. As the perceived needs of caregivers may evolve with the progression of the disease and the dementia transition, the needs should be regularly assessed and taking into account the needs for information, coping skills, support and service.

Additional file
Additional file 1: Search strategies. This file provide the search strategies used in MEDLINE, PsycINFO, The Cochrane Library and Web of Science in order to identify quantitative and qualitative studies for the systematic review. (DOC 25 kb)

Funding
None.

Availability of data and materials
Detailed search strategies and lists of references included in this systematic review are available upon request.
Authors' contributions TN (PhD candidate) and CM (PharmD, PhD) performed the study selection, the data collection and wrote the main part of the article. The critical revision of the manuscript was made by VD (PhD, methodologist) and Pr. PK-S (MD, PhD, neurologist and geriatrician). All authors read and approved the final manuscript.

Competing interests
The authors declare that they have no competing interest.

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Ethics approval and consent to participate Not applicable.

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