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Exploring costs, cost components, and associated factors among people with dementia approaching the end of life: A systematic review

Abstract Introduction Understanding costs of care for people dying with dementia is essential to guide service development, but information has not been systematically reviewed. We aimed to understand (1) which cost components have been measured in studies reporting the costs of care in people with dementia approaching the end of life, (2) what the costs are and how they change closer to death, and (3) which factors are associated with these costs. Methods We searched the electronic databases CINAHL, Medline, Cochrane, Web of Science, EconLit, and Embase and reference lists of included studies. We included any type of study published between 1999 and 2019, in any language, reporting primary data on costs of health care in individuals with dementia approaching the end of life. Two independent reviewers screened all full‐text articles. We used the Evers' Consensus on Health Economic Criteria checklist to appraise the risk of bias of included studies. Results We identified 2843 articles after removing duplicates; 19 studies fulfilled the inclusion criteria, 16 were from the United States. Only two studies measured informal costs including out‐of‐pocket expenses and informal caregiving. The monthly total direct cost of care rose toward death, from $1787 to $2999 USD in the last 12 months, to $4570 to $11921 USD in the last month of life. Female sex, Black ethnicity, higher educational background, more comorbidities, and greater cognitive impairment were associated with higher costs. Discussion Costs of dementia care rise closer to death. Informal costs of care are high but infrequently included in analyses. Research exploring the costs of care for people with dementia by proximity to death, including informal care costs and from outside the United States, is urgently needed.


INTRODUCTION
Dementia is currently the fifth leading cause of death globally, 1 and the number of people dying with dementia in the world is projected to increase from ≈2 million deaths in 2016 to more than 7 million in 2060. 2 When approaching death, people with dementia experience a rapid increase in the incidence of fatigue, pain, and dizziness; 3 potentially burdensome hospital admissions; 4 and emergency department visits. 5 Assessing the economic impact of illness on society is key to understanding resource needs, identifying main cost components, explaining the variability of costs, and identifying management pathways to inform policy. 6 Two published systematic reviews have examined aspects of dementia care costs, including hospital, outpatient, drugs, informal, and indirect costs. 7,8 In Quentin et al., direct and indirect costs for patients with severe dementia were almost twice the costs for people with mild dementia. 7 In Schaller et al., the main drivers of total dementia costs were nursing home expenditures and informal costs due to home-based care. 8 Neither systematic review examined end-oflife care costs.
Understanding the costs of care at the end of life is particularly important as health-care costs have been shown to increase by proximity to death. 9 A systematic review of studies exploring the cost of caregiving among people receiving palliative care at the end of life found informal caregiving could account for 27% to 80% of total costs and have a significant impact on families and carers. 10

METHODS
We undertook a systematic review of primary studies reporting costs of care for people with dementia approaching the end of life. The review protocol was registered with PROSPERO (registration number CRD42020166337).

Eligibility criteria
Studies were included if they reported direct or informal health-care costs for individuals who died with dementia (for retrospective studies) or who are likely to be approaching the end of life based on clini-

Search strategy
The search strategy included the concepts of "dementia," "end of life," and "health-care costs." Medical subject headings (MeSH) index terms were used together with free text to capture relevant articles.
The terms recommended by the Cochrane Dementia and Cognitive Improvement Group for dementia were used. The complete search strategy is available in Table S1 in supporting information.

Inclusion criteria Exclusion criteria
Type of study -Any type of study with primary data or secondary data analysis -Articles that used modeling techniques also could be included if they used primary data

Selection process
The study selection and de-duplication processes were managed in in case no agreement was reached.

Risk of bias in individual studies
The methodological quality of included articles was assessed using the Evers' Consensus on Health Economic Criteria (CHEC) checklist. 11,12 One reviewer (JL) assessed all included studies and discussed scores with a second reviewer (DY). Studies were not excluded based on quality appraisal results, as one of our aims was to understand the breadth of studies describing costs of care at the end of life.

Data analysis
A data extraction form was developed in Microsoft Excel (version 2101), piloted, and used ( were reported by components of care, we calculated the cost by adding the separated means. All costs were inflated and converted to 2019 US dollars (USD) using purchasing power parities (PPP) conversion rates provided by the World Bank. 13 To make costs more comparable across studies, we calculated the mean costs per person per month for each study ( = the mean costs per person/the study period [in months] considered). We classified studies according to whether they measured direct costs, informal costs, or both. Costs of care were defined according to Gardiner et al. (Table 2). 14 We report both the average costs per For question 3, studies were grouped based on whether they reported sociodemographic, illness-related, or health-care servicerelated factors associated with the cost of care for people with dementia at the end of life. A preliminary descriptive paragraph on each study was produced by one reviewer (JL) and discussed with three other reviewers (KS, IH, DY). A summary of the main points was then agreed. 15

Characteristics of included studies
After removing duplicates, 2843 articles were retrieved from databases and hand searches. One hundred eighty-eight articles were included for full-text screening; 19 fulfilled the inclusion criteria and were considered for the analysis (Figure 1).

Quality appraisal of included studies
The mean quality score of all included studies on the CHEC checklist was 82.8% (proportion of "yes" answers). The lowest score was 64.3% and 12 studies scored more than 80% (Table S3 in

Question 1: Which cost components have been measured in studies reporting the costs of care in people with dementia approaching the end of life?
Types of costs measured included hospital, community care, hospice, long-term care facility (nursing or residential home) expenses and informal costs (Table 3). Of the 19 included articles, 16 included respectively. When only direct costs of care were considered, the costs of care for people with dementia were higher than for those without dementia in the last 6 months, 16 12 months, 24,29 and nonsignificant in one study in the last 5 years of life. 23 When both informal and direct costs were considered, the cost of care was higher for those with dementia than for those without dementia. 22 We found three studies exploring the cost of dementia care by proximity to death. In Pyenson et al., Medicare costs for people with AD and general dementia in the last year of life was three times higher than 8 years before death. 29  for other conditions, 16,17,24,29,34 probably explained by lower rates of hospital admissions. 35,36 In contrast, when including informal costs, the costs were substantially higher for individuals with dementia. 22  -Cost differences: One study reported cost differences between people with and without dementia rather than the total cost. 23 -Average costs: One study reported the average cost for people with an expenditure, 16 while most of studies reported the average for the whole population and in others it was not clear. death, 18,24,29 and with findings from studies in other conditions. 9 This could reflect an increase in health-care needs due to a rise in symptom burden among people with dementia close to death, 3 and is also consistent with studies that have found an increase in potentially avoidable hospital admissions 4 and emergency department visits 5 among these patients closer to death. Further research is needed to explore more directly how costs increase toward the end of life, and to understand the extent to which this represents low-value care.

TA B L E 3 Characteristics of included studies and information regarding total cost
In this review there were differences in the end-of-life period and types of cost components considered in each study, making comparisons between studies challenging. Some of these differences are likely to be explained by disparities among health-care systems, or changes of costs over time that are not addressed by adjusting for inflation. Factors identified as contributing to the variability of the costs reported include (1) those related to the study design, (2) those related to the study population, and (3) the type of costs considered (Table 4).  45 Informal care use has been shown to be endogenous and a substitute of formal care received at home by older people. 46 However, this tends to disappear as the level of disability of the older person increases and it is not necessarily a substitute for care received in a long-term care facility or other health-care service. 47,48 Future research needs to investigate the effects of hospital costs on economic burden on family and the reciprocal relationship between informal care and total care costs

Strengths and limitations
To

CONCLUSIONS
Published data on costs of dementia care for people approaching the end of life suggest direct costs increase before death, but more information on costs by proximity to death is needed. Informal costs of care represent a substantial component of total costs but have been rarely measured, and there is little information from countries outside the United States. Understanding informal costs and costs from outside the United States must be a priority given the fast-projected increase in the number of people who will die with dementia over the next 40 years.

CONFLICTS OF INTEREST
The authors declare that there are no conflicts of interest.