Abstract
Keywords
Unpaid caregivers in Canada form the backbone of care provided to older adults in the community. About 18% of Canadians act as informal caregivers (e.g., family/friends—referred to simply as “caregivers” throughout the remainder of this article) to older adults (Canadian Institute for Health Information, 2010). Many caregivers provide this support willingly and find it to be a positive experience (Kruithof et al., 2012); however, as care needs increase, many also find it stressful, making it difficult to continue. In particular, caregivers report that their caregiving responsibilities can negatively affect their ability to manage their working lives and their social/leisure activities (Health Quality Ontario, 2016).
Caregiver burden has been described as a negative affective outcome which results as a perceived inability to meet the demands of the caregiving role (Garlo et al., 2010; Miller et al., 2012). It encompasses the physical, psychological, emotional, social, or financial problems experienced by caregivers (Zarit et al., 1980). Caregiver burden is correlated with a deterioration in the caregiver’s mental (Duggleby et al., 2016) and physical health (Vitaliano et al., 2003) and is a strong risk factor for the care recipient’s admission to a long-term care (LTC) facility (Cepoiu-Martin et al., 2016; Gaugler et al., 2009; Rockwood et al., 2014; Verbeek et al., 2015). Furthermore, the Alzheimer Society of Canada forecasts a 7% increase in dementia among older adults living in the community over the next 30 years (Alzheimer Society of Canada, 2010). This fact, together with population aging and an increase in the number of older adults living with chronic conditions, will result in more families and friends providing care to their loved ones making it critical to identify caregivers who may be experiencing the early signs and symptoms of burden.
Several assessments exist to measure caregiver burden (Vitaliano et al., 1991) with the Zarit Burden Interview (ZBI) being used most often (Mosquera et al., 2016). The original ZBI has 22 items and was developed for use with caregivers of individuals with Alzheimer’s dementia (Zarit et al., 1980). It has documented validity and reliability (Bachner & O’Rourke, 2007; Hebert et al., 2000), and higher scores are correlated with an increased risk of admission to an LTC facility (Miller et al., 2012). It is considered to be the most useful instrument based on its validity, ease of use, and ability to predict change over time (Van Durme et al., 2012).
A shorter 12-item version is also widely used and was chosen for the purposes of this study. This shorter version has strong internal consistency (Bedard et al., 2001; O’Rourke & Tuokko, 2003), is highly correlated with the longer version (Bedard et al., 2001) and with dementia severity (Branger et al., 2016), and has demonstrated predictive validity for caregiver depression (O’Rourke & Tuokko, 2003). The 12-item version has also been evaluated among older adults with advanced cancer and among older people with no cognitive challenges (Higginson et al., 2010; Iecovich, 2012), and in both studies, the results were positive in terms of internal consistency and validity.
Given the increasing demand for home care and individual preferences to remain at home and “age in place,” there is the potential for increased reliance on caregivers. This can lead to the caregiver experiencing negative health-related outcomes (Duggleby et al., 2016). As such, there is a growing need to find efficient ways to assess caregivers and flag those, within the home care sector, who may be at risk.
In Canada, the Resident Assessment Instrument for Home Care (RAI-HC) is being used in seven provinces/territories, in multiple states in the United States, and in multiple countries around the world (e.g., the United Kingdom, Belgium, Germany, Australia). The RAI-HC is a standardized assessment that is useful in assisting home care clinicians in care planning and in making decisions regarding placement in LTC. Completing these assessments represents a significant investment in time and human resources for the participating region or country. As such, it is important to find ways in which to maximize the efficient use of these data. One way to do this is to create electronic decision-support tools for use by clinicians. This would then eliminate the need to complete additional caregiver burden assessments thus reduce the assessment burden for both clinicians and informal caregivers. This study sought to develop and validate a new decision-support tool, termed the Caregiver Risk Evaluation, or CaRE, to estimate the risk of caregiver burden among home care clients, using items from the RAI-HC.
Design and Methods
Population, Setting, and Study Context
This study utilized secondary data collected for home care clients using the RAI-HC, a government-mandated assessment in both the Winnipeg Regional Health Authority (WRHA) in Manitoba and Island Health (located on Vancouver Island, BC) (British Columbia Ministry of Health, 2016; Toews, 2016). It contains just over 300 items, including domains such as cognitive and sensory functioning, communication, diagnoses, and functional abilities. Individual items on the RAI-HC are valid and reliable (Landi et al., 2000; Poss et al., 2008). Assessments are completed in a client’s home by trained assessors (typically a registered nurse) following guidelines published by interRAI, the nonprofit group that holds the copyright to the instrument. The assessor interviews the client and their caregiver, can consult with other health care professionals (e.g., primary care physician), or observe client’s abilities, as needed. Assessments are completed every 6 to 12 months after admission to the home care service, or after a significant change in clinical status.
Home care in Canada typically offers services such as health promotion, rehabilitation, support and maintenance, and end-of-life care (Accreditation Canada and the Canadian Home Care Association, 2015). All provinces and territories provide home care to their residents; however, policies vary regarding eligibility and service intensity, as home care is not covered under the national Medicare program. In general, a referral from a physician is not required to receive home care. In most regions, a trained case manager (usually a registered nurse) will complete a needs assessment and determine the level and intensity of care based on their clinical judgment. It is possible that the family could assume some financial responsibility for care that is not covered by the publicly funded system. This would likely depend, in large part, on the level of home care provided and whether the family felt that this was adequate.
Within Island Health, the ZBI was routinely used in the two sites involved in the study (e.g., Victoria, Campbell River), regardless of the cognitive status of the home care client. As it was used as part of routine clinical practice, consent from informal caregivers was not required. However, this was not the case within WRHA. During the study, a designated staff member approached the home care client’s primary caregiver about the project to see if they would be interested in completing the ZBI. They were selected based on the fact that their relative was receiving home care and the RAI-HC assessment was scheduled to be completed in the near future. This was done to ensure that the RAI-HC was completed within approximately 1 month of the ZBI. No home care clients were excluded based on their cognitive status. As completion of the ZBI was not part of the WRHA’s normal clinical practice, individual consent was obtained from each primary caregiver.
Description of Key Outcome Measures
The main outcome measure was the score on the ZBI, which was used as the dependent variable in all decision tree analyses. The client’s primary caregiver completed the 12-item ZBI. Each item is scored from zero to four for a maximum score of 48. Higher scores indicate greater levels of perceived burden (Bedard et al., 2001). A secondary outcome was the client’s status at 12 months following the RAI-HC assessment. Based on the literature, we anticipated that there would be a relationship between the risk of admission to an LTC facility (dependent variable) and the level of risk for caregiver burden, based on the CaRE algorithm. Both health authorities tracked client status to determine if the person was still receiving home care at that time, had died, or was placed in an LTC facility. The health authorities sent de-identified RAI-HC data, linked with both the items on the ZBI, and also linked to the client’s status at 12-months, to the research team.
Sample
The sample included 344 unique home care clients (226 from WRHA and 118 from Island Health), aged 65 years and older. Within WRHA, a total of 297 caregivers were approached and 230 consented and completed the ZBI, either in person or over the phone. Within Island Health, the ZBI was completed as part of normal practice, either in person or on the telephone. Evidence suggests that reliability is good when using either type of administration (Lin et al., 2017; Tremont et al., 2013). Four clients in the WRHA did not have a timely RAI-HC assessment to link to the ZBI and were removed from the study. If a client had multiple RAI-HC assessments within Island Health, the assessment that was closest in date to the completion of the ZBI was selected. Data collection took place between April 2010 and March 2016.
Health Index Scales and Other Items From the RAI-HC
There are six validated health index scales generated from items within the RAI-HC that were used in the analysis. Higher scores on these scales indicate a greater degree of impairment.
Activities of Daily Living Self-Performance Hierarchy (ADL-SHS) is a 6-point scale that measures performance on items such as toilet use and personal hygiene. A cut point of two or greater indicates at least mild functional impairment. The ADL-SHS has been validated against the Barthel Index (Morris et al., 1999).
Instrumental Activities of Daily Living (IADL) Involvement Scale is a 21-point scale that assesses items such as independence in housework, managing finances, and medication management. A cut point of 14 or higher was used to indicate at least moderate impairment in performing these tasks, in line with previous studies (Guthrie et al., 2018; Williams et al., 2018).
Cognitive Performance Scale (CPS) is comprised of four items (cognitive skills for daily decision-making, short-term memory, making self understood, and eating) and ranges from zero to six, where a cut point of two or more represents at least mild cognitive impairment. The CPS has been validated against the Mini-Mental State Examination (MMSE) (Morris et al., 1994) and the Montreal Cognitive Assessment (Jones et al., 2010).
Depression Rating Scale (DRS) is a 14-point summative scale that has been validated against the Cornell Scale for Depression and the Hamilton Depression Scale (Burrows et al., 2000). A score of 3+ is typically used as a cut point as it can accurately predict a clinical diagnosis of depression (Martin et al., 2008). In the current analysis, we considered this cut point, but also others (e.g., DRS of 0 vs. 1+), as any score above zero indicates the presence of signs/symptoms of depression.
Pain Scale measures the frequency and intensity of pain on a 4-point scale ranging from 0 (no pain) to 4 (daily/severe) pain, where a cut point of two or greater indicates daily pain (Fries et al., 2001).
Changes in Health, End-Stage Disease and Signs and Symptoms (CHESS) scale assesses the level of health instability. The scale ranges from 0 (no instability) to 5 (severe health instability), and for each one-point increase on the CHESS scale, there is nearly a twofold increased risk of death (Hirdes et al., 2003). A score of two or more was used to indicate the presence of at least moderate health instability (Hirdes et al., 2008).
The Method for Assigning Priority Levels (MAPLe) score represents a decision-support tool to prioritize the need for community-based care or LTC. It can also be generated directly using items from the RAI-HC (Hirdes et al., 2008). The MAPLe can range from one to five, with higher scores indicative of higher priority/greater urgency. We collapsed the MAPLe score into two groups as a number of the groups had small sample sizes (<5). A score of four or higher was used to identify clients with a higher priority/greater urgency.
Several other individual items on the RAI-HC provide detailed information regarding the client’s primary caregiver, including their relationship to the client (spouse/child/neighbor), whether they reside with the client (yes/no), whether they experience feelings of distress, anger or depression, whether the caregiver or the client feels that the client would be better off in another living environment, and the number of informal care hours provided in the past week. We examined several dichotomous variables, including the presence of responsive behaviors (e.g., wandering), urinary incontinence (yes/no), and a diagnosis of dementia (i.e., a diagnosis of Alzheimer’s disease or another type of dementia). We also examined whether the client experienced an overall change in their care needs compared with 90 days ago, or since their last assessment (no change/improved and receiving less support/deteriorated and receiving more support).
Development of the Algorithm and Analyses
The algorithm was created in four main steps as outlined below.
Step 1
Demographic characteristics, the health index scales, the MAPLe score, characteristics of the caregiver, diagnoses, and whether there was a change in the client’s health status were examined in relation to the ZBI score. The t tests and a one-way analysis of variance (ANOVA) were used to calculate p values and determine statistical significance as the dependent variable (ZBI score) is a continuous measure. All significant variables, based on a two-tailed alpha level of .05, and those identified in the literature, were considered for inclusion in the algorithm.
Step 2
The algorithm was created using interactive decision tree software, such that each branch is informed from an explanatory variable, drawn from candidate items on the RAI-HC assessment, as described above. The dependent variable was the score on the ZBI. Decision trees are well-suited to analytic situations where interactions among explanatory variables are expected, such that subgroups of cases, based on a particular characteristic, can be modeled separately from others (Batra & Agrawal, 2018; Gulati et al., 2016).
The tool in SAS Enterprise Miner (SAS Institute Inc., 2016) presents the variables for a given potential split by rank order of the Gini coefficient, which provides a measure of the degree of inequality of the resulting groups. At each step in the tree development, the software automatically recommends splits for independent variables being considered, but one can override these suggestions. As such, the development of the algorithm was guided both by the statistical properties of the model and by clinical relevance through input from home care clinicians and informal caregivers (described in Step 3).
To protect from over-fitting that can occur with small datasets that may contain nonrepresentative sampling, a random 25% sample of the cases was held back to provide some independent confirmation of each split. The results of this 25% validation sample varied depending on the splitting variable and location in the various decision trees that were constructed. As the splitting process is manually controlled, the operator sees the evidence for a given split before accepting it, or considering a different splitting variable. For splits where both 75% and 25% samples showed similar results, this was taken as evidence that the choice was appropriate and unlikely to be influenced by a few chance observations. In the case where the 25% sample differed, this was cause to consider another item for this split. Just over a dozen tree variants were produced which were examined by the investigators for their face validity and explanatory power.
Step 3
We held four separate discussion groups with home care clinicians and caregivers to elicit feedback on the potential variables that should be included in the final algorithm. A total of 32 case managers and eight caregivers participated.
Based on the preliminary tree models, 23 potential variables, from the RAI-HC, were presented to the home care clinicians and caregivers who provided feedback on each, namely whether or not they felt they were important and if anything critical was missing from the list. These discussions highlighted the importance of cognitive impairment, incontinence, responsive behaviors, hours of informal care and impairments in ADLs (e.g., bathing, dressing), and IADLs (e.g., telephone use, managing medications). Three of these areas (i.e., ADL impairment, IADL impairment, and responsive behaviors) were related to the ZBI score but were not kept in the final algorithm. This is likely explained by the fact that they added little explanatory power above and beyond the CPS, a measure of cognitive impairment, which was included in the final algorithm. They also felt the age and sex of the client and certain diagnoses were not as important, and none of these variables were included in the final algorithm.
Step 4
The research team used all of this input to create the final version of the algorithm. The final CaRE algorithm contained nine terminal nodes, which clearly fell into four distinct categories based on the mean Zarit score (mean Zarit score near 10, near 14, near 20, and near 25), which are provided for each node in Figure 1. This suggested a four-level scale (low risk, moderate, high, and very high). A larger sample might have produced a tree with more nodes, allowing for a scale with additional distinct points, but given the limitations of the sample, a 4-point scale was considered to be reasonable. A summary of how the items were used to create each of the four risk group is shown in Table 1.

Schematic representation of the CaRE algorithm.
Description of the Items in the Algorithm and How They Are Used to Populate the CaRE Risk Groups.
Note. CaRE = Caregiver Risk Evaluation.
A check mark indicates that the item was used in the creation of that particular CaRE risk group.
We anticipated that there would be a relationship between the risk of admission to an LTC facility (dependent variable) and four-level CaRE algorithm. To examine this, we calculate the odds ratio (OR) and 95% confidence interval (CI) for LTC admission as a function of the CaRE risk groups, both unadjusted, and after adjusting for age, sex, and health authority. All analyses were completed using SAS Enterprise Guide, version 7.1 (SAS Institute Inc., 2016) and SAS Enterprise Miner, version 13. A two-tailed alpha level of .05 was used to determine statistical significance. The study followed the Transparent Reporting of a multivariable prediction model for Individual Prognosis or Diagnosis (TRIPOD) guidelines (Collins et al., 2015). The design of the study was reviewed and approved by the Research Ethics Board at Wilfrid Laurier University (REB #4085), the Health Research Ethics Board at the University of Manitoba (REB#: HS21587), the WRHA Research Access and Approval Committee (RAAC #2015-025), and the Health Research Ethics Board in Island Health (REB#: H2014-115).
Results
The mean time between a client’s RAI-HC and ZBI assessment was 36.7 days (SD = 37.4 days). Just under half of the sample were aged 85+ (48.0%), 61.6% were female, and 39.4% were married. Across four of the health index scales (i.e., CPS, DRS, IADL, and ADL-SHS), clients with impairments in these areas had higher scores on the ZBI. For the other two scales (i.e., Pain Scale and CHESS), there was no significant association. The MAPLe score was also significantly related to the ZBI score (p < .0001). Higher scores on the ZBI were significantly associated with the caregiver co-residing with the client; the caregiver was a spouse; the caregiver was experiencing distress, anger, or depression; and the primary caregiver felt the client would be better off living in another environment. Caregivers providing at least 7 hours per week of care had higher ZBI scores versus those providing less care (Table 2).
Relationship Between Demographic Characteristics and Other Health Measures for the Home Care Clients and the Score on the ZBI.
Note. ZBI = Zarit Burden Interview; CPS = Cognitive Performance Scale; DRS = Depression Rating Scale; ADL-SHS = Activities of Daily Living Self-Performance Hierarchy Scale; CHESS = Changes in Health, End-Stage Disease and Signs and Symptoms; MAPLe = Method for Assigning Priority Levels; CaRE = Caregiver Risk Evaluation.
This cut point was chosen to be in line with the way in which the variable is presented in the CaRE algorithm.
The final CaRE algorithm included whether or not the caregiver experienced distress, anger, or depression as the initial split and captured information about the caregiver’s living situation, whether the caregiver was a spouse of a child, hours of informal care, symptoms of depression, and cognitive impairment. The mean ZBI score across the nodes ranged from 9.0 to 24.9. The final model explained 22.8% of the variation in the ZBI score, which was the highest level of explained variance of any of the decision tree models that were considered.
Compared with the low-risk CaRE group, clients in the very high-risk group were more likely to experience difficulties completing ADLs (33.3% vs. 8.6%), and the primary caregiver and the client were both more likely to feel that the client would be better living in a different environment (51.2% vs. 9.6%). A similar pattern was also found for the MAPLe score. In the low-risk CaRE group, only 51.8% of clients fell within the high MAPLe category (score of 4–5), compared with 95.6% in the very high-risk group (Table 3). Finally, we found a higher proportion of clients in the very high-risk group were residing in LTC after 12 months (37.8%) compared with 15% in the low-risk group (Table 4). After adjusting for age, sex, and health authority, the odds of LTC admission for clients in the very high-risk group was 5.16 times greater than for those in the low-risk group (OR = 5.16; CI = [2.05, 12.9]; Table 5).
Comparison of Selected Variables by CaRE Risk Group.
Note. CaRE = Caregiver Risk Evaluation; ZBI = Zarit Burden Interview; ADL-SHS = Activities of Daily Living Self-Performance Hierarchy; CPS = Cognitive Performance Scale; DRS = Depression Rating Scale.
Outcome Status 12-Months Post RAI-HC Assessment by CaRE Risk Group.
Note. RAI-HC = Resident Assessment Instrument for Home Care; CaRE = Caregiver Risk Evaluation; LTC = long-term care.
12-month outcome status was missing for two clients.
Includes clients no longer receiving home care services, clients admitted to assisted living/hospital.
Odds of Admission to LTC as a Function of CaRE Risk Group.
Note. LTC = long-term care; CaRE = Caregiver Risk Evaluation.
Discussion and Implications
The CaRE algorithm represents a new decision-support tool for home care, generated directly from items within the RAI-HC. It was developed with significant input from home care clinicians and caregivers, and differentiates the level of risk of caregiver burden for caregivers in home care. It represents a new measure that can be used along with other outputs from the RAI-HC (e.g., health index scales) to guide care planning and service provision. Like other scales and algorithms generated from the RAI-HC, it should be considered as a measure to support, but not as a replacement for clinical judgment. Case managers using the CaRE score should do so in conjunction with the client, their family, and other formal service providers to ensure a client-specific response tailored to the unique needs and preferences of the caregiver and care recipient dyad.
As the RAI-HC is currently used widely in Canada, and internationally, the CaRE algorithm represents a very efficient way for these providers to assess the risk of caregiver burden without administering additional caregiver assessments. This is not only an efficient use of the existing information, but would also minimize assessment burden for home care clients and their families. Finally, the CaRE algorithm opens the door to cross-national comparisons of caregiver burden, and its correlates, among those countries routinely using the RAI-HC.
The items within CaRE were chosen based on both clinical input and feedback from caregivers and represent issues that are supported in the literature. For example, client depression (deAlmeida Mello et al., 2017; Hirdes et al., 2012; Mohamed et al., 2010), the caregiver co-resides with the client (deAlmeida Mello et al., 2017; Kim et al., 2012; Melis et al., 2009; Pauley et al., 2018), cognitive status (deAlmeida Mello et al., 2017; Oldenkamp et al., 2016), and the number of hours of informal support (Kim et al., 2012; Park et al., 2015; Pauley et al., 2018; Sutcliffe et al., 2016) are embedded in the CaRE algorithm and are also well-established risk factors for caregiver burden or distress. The algorithm is strongly associated with the risk of future LTC placement, even after adjusting for client age, sex, and the health authority where care was received. In algorithm development, the first split is key. Although we evaluated many possible variables for this initial split, we decided to use the item identifying whether or not the caregiver feels distressed, angry, or depressed. This is evidence of the validity of this single item with respect to caregiver burden.
A key strength of our approach is the use of input from multiple sources. The creation of the CaRE algorithm was undertaken using rigorous statistical methods, in conjunction with input from the existing literature and the opinions of caregivers and home care professionals. However, a possible limitation to this work is our limited sample size from two regions of Canada. In our sample, roughly 42% had a diagnosis of dementia, about twice the rate among long-stay home care clients in Canada. When compared with a very large sample (n = 163,527) of home care clients in Ontario (Williams et al., 2018), ours was very similar on demographic characteristics, such as age, sex, and marital status, but our sample was more likely to have a CPS score of two or higher (69% vs. 53%) and was somewhat less likely to co-reside with their primary caregiver (43% vs. 51%).
Using RAI-HC data from across Canada (n = 131,000), the Canadian Institute for Health Information found strong relationships between caregiver distress and the CPS score, hours of informal support, and with the DRS score. All relationships had unadjusted ORs of two or higher (Canadian Institute for Health Information, 2010). So, although our sample may not truly represent home care in Canada, other research strongly supports the variables included in the algorithm. In future studies, we plan to assess the validity of the CaRE algorithm in the large sample of long-stay home care clients in Canada, and where feasible, using RAI-HC data from other countries.
Conclusion
The CaRE algorithm represents a new decision-support tool generated from items within the RAI-HC assessment. It differentiates home care clients based on the level of risk for caregiver burden and can potentially reduce or eliminate the need for additional caregiver assessments. It represents an efficient method to identify enhanced risk for caregiver burden and can act as a “flag” to home care and other professionals to enable them to understand which families may be in need of additional care, education/training, respite support, or other services. By quickly identifying the caregivers who are most at risk and linking them with the necessary supports and services, this could maximize the likelihood of the person remaining in their own home and reducing the need for admission to LTC. Future research could use this algorithm to flag caregivers who may be at risk as part of a larger intervention study or randomized trial.
Footnotes
Acknowledgements
The authors gratefully acknowledge the financial support provided by the Alzheimer Society of Canada. We also offer our sincere thanks to the staff and clinicians within Island Health and the Winnipeg Regional Health Authority who gave generously of their time and helped to make this project possible.
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Ethical Approval
The design of the study was reviewed and approved by the Research Ethics Board at Wilfrid Laurier University (REB #4085), the Health Research Ethics Board at the University of Manitoba (REB#: HS21587), the WRHA Research Access and Approval Committee (RAAC #2015-025), and the Health Research Ethics Board in Island Health (REB#: H2014-115).
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the Alzheimer Society of Canada (Grant Number 15-10).
