Frailty: a costly phenomenon in caring for elders with cognitive impairment

Dissecting the shared genetic architecture between Alzheimer's disease and frailty: a cross-trait meta-analyses of genome-wide association studies

Introduction: Frailty is the most common medical condition affecting the aging population, and its prevalence increases in the population aged 65 or more. Frailty is commonly diagnosed using the frailty index (FI) or frailty phenotype (FP) assessments. Observational studies have indicated the association of frailty with Alzheimer's disease (AD). However, the shared genetic and biological mechanism of these comorbidity has not been studied. Methods: To assess the genetic relationship between AD and frailty, we examined it at single nucleotide polymorphism (SNP), gene, and pathway levels. Results: Overall, 16 genome-wide significant loci (15 unique loci) (p meta-analysis < 5 × 10-8) and 22 genes (21 unique genes) were identified between AD and frailty using cross-trait meta-analysis. The 8 shared loci implicated 11 genes: CLRN1-AS1, CRHR1, FERMT2, GRK4, LINC01929, LRFN2, MADD, RP11-368P15.1, RP11-166N6.2, RNA5SP459, and ZNF652 between AD and FI, and 8 shared loci between AD and FFS implicated 11 genes: AFF3, C1QTNF4, CLEC16A, FAM180B, FBXL19, GRK4, LINC01104, MAD1L1, RGS12, ZDHHC5, and ZNF521. The loci 4p16.3 (GRK4) was identified in both meta-analyses. The colocalization analysis supported the results of our meta-analysis in these loci. The gene-based analysis revealed 80 genes between AD and frailty, and 4 genes were initially identified in our meta-analyses: C1QTNF4, CRHR1, MAD1L1, and RGS12. The pathway analysis showed enrichment for lipoprotein particle plasma, amyloid fibril formation, protein kinase regulator, and tau protein binding. Conclusion: Overall, our results provide new insights into the genetics of AD and frailty, suggesting the existence of non-causal shared genetic mechanisms between these conditions.

To Be Frail or Not to Be Frail: This Is the Question-A Critical Narrative Review of Frailty

Many factors have contributed to rendering frailty an emerging, relevant, and very popular concept. First, many pandemics that have affected humanity in history, including COVID-19, most recently, have had more severe effects on frail people compared to non-frail ones. Second, the increase in human life expectancy observed in many developed countries, including Italy has led to a rise in the percentage of the older population that is more likely to be frail, which is why frailty is much a more common concern among geriatricians compared to other the various health-care professionals. Third, the stratification of people according to the occurrence and the degree of frailty allows healthcare decision makers to adequately plan for the allocation of available human professional and economic resources. Since frailty is considered to be fully preventable, there are relevant consequences in terms of potential benefits both in terms of the clinical outcome and healthcare costs. Frailty is becoming a popular, pervasive, and almost omnipresent concept in many different contexts, including clinical medicine, physical health, lifestyle behavior, mental health, health policy, and socio-economic planning sciences. The emergence of the new "science of frailty" has been recently acknowledged. However, there is still debate on the exact definition of frailty, the pathogenic mechanisms involved, the most appropriate method to assess frailty, and consequently, who should be considered frail. This narrative review aims to analyze frailty from many different aspects and points of view, with a special focus on the proposed pathogenic mechanisms, the various factors that have been considered in the assessment of frailty, and the emerging role of biomarkers in the early recognition of frailty, particularly on the role of mitochondria. According to the extensive literature on this topic, it is clear that frailty is a very complex syndrome, involving many different domains and affecting multiple physiological systems. Therefore, its management should be directed towards a comprehensive and multifaceted holistic approach and a personalized intervention strategy to slow down its progression or even to completely reverse the course of this condition.

Is Co-Occurrence of Frailty and Multimorbidity Associated with Increased Risk of Catastrophic Health Expenditure? A Prospective Cohort Analysis in China

Purpose

The coexistence of multimorbidity and frailty is more likely to increase the risk of physical limitations, mortality and other adverse health outcomes in older adults than their individual occurrence. However, whether and how this coexistence is associated with catastrophic health expenditure (CHE) has not been well assessed. This study aimed to evaluate the independent and coexisting effects of frailty and multimorbidity on CHE.

Participants and Methods

A total of 4838 participants obtained from the China Health and Retirement Longitudinal Study (CHARLS) without CHE at baseline (2011) were included in the analytical sample. Marginal structural model (MSM) and time-varying Cox regression model were used to assess the independent and co-occurring impact of frailty and multimorbidity on CHE, respectively.

Results

Suffering from single chronic disease (HR, 1.26; 95% CI, 1.13-1.40; P < 0.001), multimorbidity (HR, 1.80; 95% CI, 1.63-1.99; P < 0.001) and frailty (HR, 1.32; 95% CI, 1.21-1.45; P < 0.001) were associated with a higher risk of CHE. Frailty co-occurring with a single chronic disease (HR, 1.28; 95% CI, 1.03-1.60; P = 0.027) or multimorbidity (HR, 1.91; 95% CI, 1.56-2.32; P < 0.001), and multimorbidity co-occurring with frailty also increased CHE risk (HR, 1.32; 95% CI, 1.17-1.48; P < 0.001) compared with single frailty or multimorbidity status.

Conclusion

Preventing, postponing, or reducing frailty, and enhancing standard management of chronic diseases are essential in reducing healthcare costs and preventing families from poverty. More efficient interventions for frailty and multimorbidity are urgently required.

Frailty and the impacts of the COVID-19 pandemic on community-living middle-aged and older adults: an analysis of data from the Canadian Longitudinal Study on Aging (CLSA)

BACKGROUND

frailty imparts a higher risk for hospitalisation, mortality and morbidity due to COVID-19 infection, but the broader impacts of the pandemic and associated public health measures on community-living people with frailty are less known.

METHODS

we used cross-sectional data from 23,974 Canadian Longitudinal Study on Aging participants who completed a COVID-19 interview (Sept-Dec 2020). Participants were included regardless of whether they had COVID-19 or not. They were asked about health, resource, relationship and health care access impacts experienced during the pandemic. Unadjusted and adjusted prevalence of impacts was estimated by frailty index quartile. We further examined if the relationship with frailty was modified by sex, age or household income.

RESULTS

community-living adults (50-90 years) with greater pre-pandemic frailty reported more negative impacts during the first year of the pandemic. The frailty gradient was not explained by socio-demographic or health behaviour factors. The largest absolute difference in adjusted prevalence between the most and least frail quartiles was 15.1% (challenges accessing healthcare), 13.3% (being ill) and 7.4% (increased verbal/physical conflict). The association between frailty and healthcare access differed by age where the youngest age group tended to experience the most challenges, especially for those categorised as most frail.

CONCLUSION

although frailty has been endorsed as a tool to inform estimates of COVID-19 risk, our data suggest it may have a broader role in primary care and public health by identifying people who may benefit from interventions to reduce health and social impacts of COVID-19 and future pandemics.

A review of caregiver costs included in cost-of-illness studies

INTRODUCTION

Economic evaluations typically focus solely on patient-specific costs with economic spillovers to informal caregivers less frequently evaluated. This may systematically underestimate the burden resulting from disease.

AREAS COVERED

Cost-of-illness (COI) analyses that identified costs borne to caregiver(s) were identified using PubMed and Embase. We extracted study characteristics, clinical condition, costs, and cost methods. To compare caregiver costs reported across studies, estimated a single 'annual caregiver cost' amount in 2021 USD.

EXPERT OPINION

A total of 51 studies met our search criteria for inclusion with estimates ranging from $30 - $86,543. The majority (63%, 32/51) of studies estimated caregiver time costs with fewer studies reporting productivity or other types of costs. Caregiver costs were frequently reported descriptively (69%, 35/51), with fewer studies reporting more rigorous methods of estimating costs. Only 27% (14/51) of studies included used an incremental analysis approach for caregiver costs. In a subgroup analysis of dementia-focused studies (n = 16), we found the average annual cost of caregiving time for patients with dementia was $30,562, ranging from $4,914 to $86,543. We identified a wide range in annual caregiver cost estimates, even when limiting by condition and cost type.

Education, wealth, and duration of life expected in various degrees of frailty

Multistate life tables are used to estimate life expected in three frailty states: frailty free, mild/moderate frailty, severe frailty. Estimates are provided for the combination of education and wealth by age, stratified by sex. Data consider 17,115 cases from the Health and Retirement Study, 2000-2014. Frailty is measured using a 59 item frailty index based on deficit accumulation. Estimates are derived using stochastic population analysis for complex events. Population-based and status-based results are reported. Findings confirm a hypothesis that the combination of higher education and wealth results in longer lives in more favorable degrees of frailty. Also, as hypothesized, wealth generally affords a greater advantage than does education among those with severe frailty at baseline. For instance, high wealth provides a 70-year-old woman with severe frailty at baseline 0.70 more total years and 0.81 more frailty free years then her counterpart with low wealth, compared to gains of 0.39 and 0.54, respectively, for those with high education. Unexpectedly, wealth also has a greater role among those frailty free at baseline. A 70-year-old woman frailty free at baseline with high wealth lives 3.19 more net years and 4.13 more years frailty free than her counterpart with low wealth, while the same comparison for high versus low education indicates advantages of 2.00 total and 1.96 frailty free years. Relative change ratios also indicate more robust results for wealth versus education. In sum, there is evidence that inequality in duration of life in degrees of frailty is socially patterned.

Frailty differences across population characteristics associated with health inequality: a cross-sectional analysis of baseline data from the Canadian Longitudinal Study on Aging (CLSA)

OBJECTIVE

To evaluate the pattern of frailty across several of social stratifiers associated with health inequalities.

DESIGN, SETTING AND PARTICIPANTS

Cross-sectional baseline data on 51 338 community-living women and men aged 45-85 years from the population-based Canadian Longitudinal Study on Aging (collected from September 2011 to May 2015) were used in this study.

PRIMARY OUTCOMES AND MEASURES

A Frailty Index (FI) was constructed using self-reported chronic conditions, psychological function and cognitive status and physical functioning variables. Social stratifiers were chosen based on the Pan-Canadian Health Inequalities Reporting Initiative, reflecting key health inequalities in Canada. Unadjusted and adjusted FIs and domain-specific FIs (based on chronic conditions, physical function, psychological/cognitive deficits) were examined across population strata.

RESULTS

The overall mean FI was 0.13±0.08. It increased with age and was higher in women than men. Higher mean FIs were found among study participants with low income (0.20±0.10), who did not complete secondary education (0.17±0.09) or had low perceived social standing (0.18±0.10). Values did not differ by Canadian province of residence or urban/rural status. After simultaneously adjusting for population characteristics and other covariates, income explained the most heterogeneity in frailty, especially in younger age groups; similar patterns were found for men and women. The average frailty for people aged 45-54 in the lowest income group was greater than that for those aged 75-85 years. The heterogeneity in the FI among income groups was greatest for the psychological/cognitive domain.

CONCLUSIONS

Our results suggest that especially in the younger age groups, psychological/cognitive deficits are most highly associated with both overall frailty levels and the gradient in frailty associated with income. If this is predictive of later increases in the other two domains (and overall frailty), it raises the question whether targeting mental health factors earlier in life might be an effective approach to mitigating frailty.

Unit costs for non-acute care in Ireland 2016—2019

Background: This paper presents detailed unit costs for 16 healthcare professionals in community-based non-acute services in Ireland for the years 2016—2019. Unit costs are important data inputs for assessments of health service performance and value for money. Internationally, while some countries have an established database of unit costs for healthcare, there is need for a more coordinated approach to calculating healthcare unit costs. In Ireland, detailed cost analysis of acute care is undertaken by the Healthcare Pricing Office but to date there has been no central database of unit costs for community-based non-acute healthcare services.

Methods: Unit costs for publicly employed allied healthcare professionals, Public Health Nurses and Health Care Assistant staff are calculated using a bottom-up micro-costing approach, drawing on methods outlined by the Personal Social Services Research Unit in the UK, and on available Irish and international costing guidelines. Data on salaries, working hours and other parameters are drawn from secondary datasets available from Department of Health, Health Service Executive and other public sources. Unit costs for public and private General Practitioner, dental, and long-term residential care (LTRC) are estimated drawing on available administrative and survey data.

Results: The unit costs for the publicly employed non-acute healthcare professionals have changed by 2–6% over the timeframe 2016–2019 while larger percentage changes are observed in the unit costs for public GP visits and public LTRC (14-15%).

Conclusions: The costs presented here are a first step towards establishing a central database of unit costs for non-acute healthcare services in Ireland. The database will help ensure consistency across Irish health costing studies and facilitate cross-study and cross-country comparisons. Future work will be required to update and expand on the range of services covered and to incorporate new data and methodological developments in cost estimation as they become available.

Health care costs of injury in the older population: a prospective multicentre cohort study in the Netherlands

Background

With the ageing population, the number of older trauma patients has increased. The aim of this study was to assess non-surgical health care costs of older trauma patients and to identify which characteristics of older trauma patients were associated with high health care costs.

Methods

Trauma patients aged ≥65 years who were admitted to a hospital in Noord-Brabant, the Netherlands, were included in the Brabant Injury Outcome Surveillance (BIOS) study. Non-surgical in-hospital and up to 24- months post-hospital health care use were obtained from hospital registration data and collected with the iMTA Medical Consumption Questionnaire which patients completed 1 week and 1, 3, 6, 12 and 24 months after injury. Log-linked gamma generalized linear models were used to identify cost-driving factors.

Results

A total of 1910 patients were included in the study. Mean total health care costs per patient were €12,190 ranging from €8390 for 65–69 year-olds to €15,550 for those older than 90 years. Main cost drivers were the post-hospital costs due to home care and stay at an institution. Falls (72%) and traffic injury (15%) contributed most to the total health care costs, although costs of cause of trauma varied with age and sex. In-hospital costs were especially high in patients with high injury severity, frailty and comorbidities. Age, female sex, injury severity, frailty, having comorbidities and having a hip fracture were independently associated with higher post-hospital health care costs.

Conclusions

In-hospital health care costs were chiefly associated with high injury severity. Several patient and injury characteristics including age, high injury severity, frailty and comorbidity were associated with post-hospital health care costs. Both fall-related injuries and traffic-related injuries are important areas for prevention of injury in the older population.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12877-020-01825-z.

Cost of Treatment and Care for People with Alzheimer's Disease: A Meta- Analysis

There is now a general attempt in developed countries to implement strategic plans to fight against Alzheimer's disease, for which treatment represents an increasing economic burden for the ageing society. At present, the costs of treatment and care for Alzheimer's Disease (AD) patients are not consistently tracked and logged, therefore, the economic burden is calculated based on the records kept by individual countries. The aim of this paper is to conduct a meta-analysis of the available data on the total costs of treatment and care for elderly AD patients with respect to the stage of the disease determined by the Mini Mental State Examination (MMSE). The Web of Science and PubMed databases were used for a systematic search. Two independent reviewers screened the identified records and selected relevant articles published in the period from 2007 to 2017. A meta-analysis of costs is performed in three categories related to the stages of Alzheimer's disease (mild, moderate, and severe). The resulting estimation of total costs per patient per year determined by the meta-analysis is 20,461$ total costs. The total costs in relation to the stage of the disease according to the MMSE scale are 14,675 $ for the mild stage, 19,975 $ for the moderate stage, and 29,708 $ for the severe stage. The meta- analysis confirms that the costs rise significantly with the severity of AD. These findings therefore, emphasize the severity of the economic burden carried out by the AD patients, their families, and the healthcare system, and this fact must be taken into account when planning health policy strategies for the years to come.

Gait speed and malnutrition in hospitalized patients and the quality of life of their caregivers

OBJECTIVE

To verify the age, nutritional status, and gait speed in hospitalized individuals, and their association with the quality of life of their caregivers.

METHODS

Observational cross-sectional study with 54 patients and their respective caretakers in a university hospital in the Brazilian Midwest. The analyses were carried out using the SPSS software, with p < 0.05.

RESULTS

The Social Relations domain had the highest mean score (71.45±18.64). The lowest score was in the Physical domain (57.80±12.01). According to a subjective nutritional evaluation, 72.2% presented some degree of malnutrition. Most were classified with low gait speeds (82%). There was a significant correlation between age and the Physical and General Quality of Life domains. The Environment domain was significantly correlated to the gait speed.

CONCLUSION

The age and the gait speed of the patient were related to the quality of life of the caregiver, but the nutritional state was not affected.

The Incremental Health Care Costs of Frailty Among Home Care Recipients With and Without Dementia in Ontario, Canada: A Cohort Study

OBJECTIVE

In this study, we investigated the incremental 1-year direct costs of health care associated with frailty among home care recipients in Ontario with and without dementia.

METHODS

We conducted a cohort study of 159,570 home care clients aged 50 years and older in Ontario, Canada in 2014/2015. At index home care assessment, we ascertained dementia status using a validated algorithm and frailty level (robust, prefrail, frail) based on the proportion of accumulated to potential health deficits. Clients were followed for 1-year during which we obtained direct overall and sector-specific publicly-funded health care costs (in 2015 Canadian dollars). We estimated the incremental effect of frailty level on costs using a 3-part survival- and covariate-adjusted estimator. All analyses were stratified by dementia status.

RESULTS

Among those with dementia (n=42,828), frailty prevalence was 32.1% and the average 1-year cost was $30,472. The incremental cost of frailty (vs. robust) was $10,845 [95% confidence interval (CI): $10,112-$11,698]. Among those without dementia (n=116,742), frailty prevalence was 25.6% and the average 1-year cost was $28,969. Here, the incremental cost of frailty (vs. robust) was $12,360 (95% CI: $11,849-$12,981). Large differences in survival between frailty levels reduced incremental cost estimates, particularly for the dementia group (survival effect: -$2742; 95% CI: -$2914 to -$2554).

CONCLUSIONS

Frailty was associated with greater 1-year health care costs for persons with and without dementia. This difference was driven by a greater intensity of health care utilization among frail clients. Mortality differences across the frailty levels mitigated the association especially among those with dementia.

Frailty and its association with the Mediterranean diet, life-space, and social participation in community-dwelling older people

Frailty is a common and vulnerable state in older people, which leads to a higher risk of adverse health outcomes. This cross-sectional study examined the association between frailty and its phenotypic components with the Mediterranean diet, life-space, and social participation in community-dwelling older people. 263 community-dwelling older people recruited from three community centers in Hong Kong completed the study (robust = 85, pre-frail = 120, frail = 58). The results showed that the Mediterranean diet (OR = 0.29), life-space (OR = 0.32), and social participation (OR = 0.31) were associated with frailty. All factors were preferentially associated with slowness. The Mediterranean diet and social participation were additionally associated with weakness and low activity, respectively. To reduce the risk of frailty among diverse populations of older people in community settings, eliminating foods considered detrimental in the Mediterranean diet is advocated. Older people's satisfaction with social participation should be taken into consideration. Environmental designs should accommodate slow-walking older people to maximize their life-space.

Frailty Phenotype and Healthcare Costs and Utilization in Older Women

OBJECTIVES

To determine the association of the frailty phenotype with subsequent healthcare costs and utilization.

DESIGN

Prospective cohort study (Study of Osteoporotic Fractures (SOF)).

SETTING

Four U.S. sites.

PARTICIPANTS

Community-dwelling women (mean age 80.2) participating in SOF Year 10 (Y10) examination linked with their Medicare claims data (N=2,150).

MEASUREMENTS

At Y10, frailty phenotype defined using criteria similar to those used in the Cardiovascular Health Study frailty phenotype and categorized as robust, intermediate stage, or frail. Participant multimorbidity burden ascertained using claims data. Functional limitations assessed by asking about difficulty performing instrumental activities of daily living. Total direct healthcare costs and utilization ascertained during 12 months after Y10.

RESULTS

Mean total annualized cost±standard deviation (2014 dollars) was $3,781±6,920 for robust women, $6,632±12,452 for intermediate stage women, and $10,755 ± 16,589 for frail women. After adjustment for age, site, multimorbidity burden, and cognition, frail women had greater mean total (cost ratio (CR)=1.91, 95% confidence interval (CI)=1.59-2.31) and outpatient (CR=1.55, 95% CI=1.36-1.78) costs than robust women and greater odds of hospitalization (odds ratio (OR)=2.05, 95% CI=1.47-2.87) and a skilled nursing facility stay (OR=3.85, 95% CI=1.88-7.88). There were smaller but significant effects of the intermediate stage category on these outcomes. Individual frailty components (shrinking, poor energy, slowness, low physical activity) were also each associated with higher total costs. Functional limitations partially mediated the association between the frailty phenotype and total costs (CR further adjusted for self-reported limitations=1.32, 95% CI=1.07-1.63 for frail vs robust; CR=1.35, 95% CI=1.18-1.55 for intermediate stage vs robust women).

CONCLUSION

Intermediate stage and frail older community-dwelling women had higher subsequent total healthcare costs and utilization after accounting for multimorbidity and functional limitations. Frailty phenotype assessment may improve identification of older adults likely to require costly, extensive care.

Frailty and healthcare costs-longitudinal results of a prospective cohort study

Objective

to investigate how frailty and frailty symptoms affect healthcare costs in older age longitudinally.

Methods

data were gathered from a prospective cohort study in Saarland, Germany (two waves with 3-year interval, n = 1,636 aged 57-84 years at baseline). Frailty was assessed by the five Fried frailty criteria. Frailty was defined as having at least three criteria, the presence of 1-2 criteria as 'pre-frail'. Healthcare costs were quantified based on self-reported healthcare use in the sectors of inpatient treatment, outpatient treatment, professional nursing care and informal care as well as the provision of pharmaceuticals, medical supplies and dental prostheses.

Results

while the onset of pre-frailty did not increase (log) total healthcare costs after adjusting for potential confounders including comorbidity, progression from non-frailty to frailty was associated with an increase in total healthcare costs (for example, costs increased by ~54 and 101% if 3 and 4 or 5 symptoms were present, respectively). This association of frailty onset with increased healthcare costs was in particular observed in the inpatient sector and for informal nursing care. Among the frailty symptoms, the onset of exhaustion was associated with an increase in total healthcare costs, whereas changes in slowness, weakness, weight loss and low-physical activity were not significantly associated with an increase in total healthcare costs.

Conclusions

our data stress the economic relevance of frailty in late life. Postponing or reducing frailty might be fruitful in order to reduce healthcare costs.

The increase in health care costs associated with muscle weakness in older people without long-term illnesses in the Czech Republic: results from the Survey of Health, Ageing and Retirement in Europe (SHARE)

Muscle weakness and associated diseases are likely to place a considerable economic burden on government health care expenditure. Therefore, our aim for this study was to estimate the direct and indirect costs associated with muscle weakness in the Czech Republic. We applied a cost-of-illness approach using data from the Survey of Health, Ageing and Retirement in Europe (SHARE). Six hundred and eighty-nine participants aged 70 years and over and without any long-term illnesses were included in our study. A generalized linear model with gamma distribution was used, and odds ratio (OR) was calculated in order to explore the effect of muscle weakness on direct and indirect costs. For both genders, muscle weakness had a statistically significant impact on direct costs (OR =2.11), but did not have a statistically significant impact on indirect costs (OR =1.08) or on total cost (OR =1.51). Muscle weakness had the greatest statistically significant impact on direct costs in females (OR =2.75). In conclusion, our study has shown that muscle weakness may lead to increased direct costs, and consequently place a burden on health care expenditure. Therefore, the results of this study could lead to greater interest in the prevention of muscle weakness among older people in the Czech Republic.

Associations of frailty with health care costs--results of the ESTHER cohort study

BACKGROUND

The concept of frailty is rapidly gaining attention as an independent syndrome with high prevalence in older adults. Thereby, frailty is often related to certain adverse outcomes like mortality or disability. Another adverse outcome discussed is increased health care utilization. However, only few studies examined the impact of frailty on health care utilization and corresponding costs. The aim of this study was therefore to investigate comprehensively the relationship between frailty, health care utilization and costs.

METHODS

Cross sectional data from 2598 older participants (57-84 years) recruited in the Saarland, Germany, between 2008 and 2010 was used. Participants passed geriatric assessments that included Fried's five frailty criteria: weakness, slowness, exhaustion, unintentional weight loss, and physical inactivity. Health care utilization was recorded in the sectors of inpatient treatment, outpatient treatment, pharmaceuticals, and nursing care.

RESULTS

Prevalence of frailty (≥3 symptoms) was 8.0%. Mean total 3-month costs of frail participants were €3659 (4 or 5 symptoms) and €1616 (3 symptoms) as compared to €642 of nonfrail participants (no symptom). Controlling for comorbidity and general socio-demographic characteristics in multiple regression models, the difference in total costs between frail and non-frail participants still amounted to €1917; p < .05 (4 or 5 symptoms) and €680; p < .05 (3 symptoms). Among the 5 symptoms of frailty, weight loss and exhaustion were significantly associated with total costs after controlling for comorbidity.

CONCLUSIONS

The study provides evidence that frailty is associated with increased health care costs. The analyses furthermore indicate that frailty is an important factor for health care costs independent from pure age and comorbidity. Costs were rather attributable to frailty (and comorbidity) than to age. This stresses that the overlapping concepts of multimorbidity and frailty are both necessary to explain health care use and corresponding costs among older adults.