Background

A single-disease model has prevailed over centuries of medical progress, but the era of population aging brings major challenges of managing multimorbidity in older adults that threaten to fragment care provision by necessitating multiple assessments and treatments [1]. Healthcare systems will be increasingly burdened by fragmented services, higher service volumes and escalating associated medical costs, and are hence transitioning from volume-based to value-based provision that emphasizes quality, expenditure and patient experience [2]. Consequently, the question of how best to measure healthcare quality and outcomes has become a research priority. Specific models of value-based healthcare, such as pay-for-performance, have shown effectiveness in certain diseases or chronic conditions but not overall [3]. Moreover, prevalent chronic comorbidities in older adults [1] make it hard to measure variations in health outcomes. More ‘function-centric’ aging medicine is crucial to handling the diversity and complexity of health care for older people and promoting healthy aging [4].

The International Consortium for Health Outcomes Measurement (ICHOM) has initiated an ambitious project to develop value-based health metrics for specific groups of people rather than discrete diseases/conditions. To establish a standard health outcome set and improve care and quality pathways for older adults, the ICHOM convened a global expert consensus panel to formulate evidence-based outcome measurement tools [5]. Without such tools, it is difficult for policymakers and health professionals to choose interventions effective in improving care quality [6]. The ICHOM Standard Set of health outcomes for older persons will be conductive to supplanting piecemeal care of older persons with a more holistic approach. ICHOM standard set for older adults might provide an operative definition for high value-based healthcare services and an opportunity for healthcare providers and policy makers to examine and refine services provisions.

Since the ICHOM Standard Set Older Person was published in 2018, important questions remain. For example, which patient subgroups require comprehensive assessments to evaluate their needs? Reporting these health metrics is the first step towards pragmatic application of this tool. This study explored the application of the ICHOM Standard Set for Older Persons health status among older multi-morbid community-dwelling adults in Taiwan.

Methods

Participants and study design

This cross-sectional study recruited older multimorbid community-living adults in New Taipei City, Yi-Lan County, and Hualien County, Taiwan, between July and December 2018. The inclusion criteria were: age ≥ 65 years and ≥ 3 chronic medical conditions. The study excluded people who: were unable to communicate adequately with study staff; had malignant tumors undergoing active chemotherapy; with life expectancy < 12 months; were institutionalized. Supplementary figure 1 showed details of recruitment process.

This study was designed and conducted in accordance with the principles of the Declaration of Helsinki. The Institutional Review Board of National Yang-Ming University approved the protocol (YM107042F). All participants provided fully informed written consent. The design and reporting format follow STROBE guidelines [7].

Value-based health metrics

The ICHOM Standard Set Older Person comprises three tiers (Supplementary Table 1) [5]. Absent valid Taiwanese versions of 4-item screening Zarit Burden interview- measured carer burden- and the Adult Social Care Outcomes Toolkit -measured autonomy and control- mitigated their applications in this study. Mortality was excluded because of present baseline data. Tier 1, achieved or retained health status, includes: all cause survival; death in a chosen place; and frailty. Participants were asked whether they had expressed a preferred place to die, and frailty was defined as clinical frailty scale ≥4 [8].

Tier 2, treatment burden and complications, includes: falls in the last 12 months; polypharmacy with ≥5 drugs [9]; and participation in decision-making, which comprised confidence in ability to manage their own health, discussion and planning of care, being treated with dignity and respect, coordination of care, and discharge to a chosen place. People in whom of these all components were affirmed were classed as having high participation in decision-making.

Tier 3, long-term consequences of care management and health sustainability, includes: loneliness, defined as ≥35 points on the University of California, Los Angeles (UCLA) loneliness scale [10, 11]; limitation of daily activities (disability), defined as Lawton instrumental activities of daily living scale < 8 (most independent) [12]; 6-m walk speed at usual pace, with < 0.8 m/s defined as slowness [13]; pain and emotional health measured by the Short-Form Health Survey (SF-36), with pain affecting activities of daily living considered pain, and the criterion for depression being ≥5/9 SF-36 depressive symptoms [14].

Based on items in Tiers 1, 2 and 3 (Supplementary Table 1), a score ranging from 0 to 10 was derived to represent the value-based health status of each individual; a highest tertile score of ≥8/10 was defined as high value-based health status.

Other variables

Physical performance, anthropometric characteristics, and health-related behaviors of all participants were recorded. Any tobacco or alcohol use in the last 6 months was classed as smoking or drinking, respectively. Exercise was defined as fitness activity for ≥30 min at least thrice weekly. Blood pressure, height and body weight were measured by standard procedures; body mass index was calculated as weight in kilograms, divided by height in meters squared (kg/m2). All participants were asked whether they had signed a Do Not Resuscitate order, which is an official agreement registered on national health insurance cards. Cognitive function was measured using The Montreal Cognitive Assessment (MoCA), adjusted by adding one point for those educated for ≤12 years (MoCAadj); MoCAadj ≥ 26 constituted normal cognitive function [15]. Charlson Comorbidity Index quantified disease burden and comorbidity burdens, with high burden defined as a score of ≥2 [16].

Statistical analysis

All analyses were performed with the SAS statistical package, version 9.4 (SAS Institute, Inc., Cary, NC, USA). A two-sided p-value < 0.05 was considered statistically significant. Numerical variables were expressed as mean plus/minus standard deviation and categorical variables as proportions. Descriptive characteristics were compared by Student t test or chi-square analysis, as appropriate. To maximize statistical efficiency, the value-based healthcare score was first treated as a continuous variable, then univariable and multivariable logistic regression analyses were used to investigate associations between corresponding variables and higher value-based healthcare status; p < 0.1 in univariable analysis was the entry criterion for multivariable analysis.

Results

Participant characteristics

The mean value-based healthcare score of 299 enrolled participants was 7.2 ± 1.8 and 89 (29.8%) had high value-based healthcare status (Fig. 1, Table 1). Although all participants had three or more chronic conditions, the mean Charlson Comorbidity Index score was only 1.1 ± 1.0 (Table 2). A minority of participants had chosen a place to die and signed Do Not Resuscitate agreements, but more than 90% reported a high level of participation in care plan decision-making. One-quarter experienced moderate loneliness and one in eight had depressed mood (Table 1).

Fig. 1
figure 1

Comparison of individual ICHOM Tiers and total value-based health care score by value-based health status, age, sex, and cognitive performance. ICHOM, International Consortium for Health Outcomes Measurement; ADL, activities of daily living; MoCAadj, Montreal Cognitive Assessment adjusted (one point added for education years ≤12)

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Table 1 ICHOM Standard Set Older Person outcome measures by value-based health status
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Table 2 Demographic and health-related characteristics by value-based health status
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Subgroup comparisons

People with high versus low value-based health status were significantly younger, and cognitively intact (Fig. 1, Table 2); body mass index, alcohol consumption and exercise habits were similar between low versus high care status groups. Figure 1, Tables 1, and 3 summarize the proportions of 299 people in different ICHOM Tier categories, both overall and stratified by, value-based healthcare status (high vs low), age (< 75 vs ≥75 years), sex, and cognitive performance (MoCAadj < 26 vs ≥26).

Table 3 Demographic data and ICHOM Standard Set Older Person outcome measures by sex, age, and cognitive performance status
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Linear and logistic regression analyses

Younger age, lower Charlson Comorbidity Index score, and higher MoCAadj score independently predicted high value-based healthcare status (Table 4). For every year increase in age, the likelihood of achieving high value-based healthcare status decreased by 5%. (Table 5). People with higher disease burden and cognitive impairment were 60 and 51% less likely, respectively, to attain high status (Table 5).

Table 4 Factors associated with high-value health status in univariable and multivariate linear regression analyses
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Table 5 Factors associated with high-value health status in univariable and multivariable logistic regression analyses
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Discussion

This is the first study of which we know to report the value-based healthcare status of older multimorbid community-living adults. We applied the ICHOM Standard Set for Older Person to evaluate the value-based healthcare status of ≥65-year-olds with multimorbidity; those who were younger, and cognitively unimpaired had higher levels of value-based healthcare status. Rates of participation in decision-making were high across all subgroups. Having high disease burden and impaired cognitive function were negatively associated with ability to achieve a high value-based healthcare score.

ICHOM Standard Set Older Person categorization into three tiers is based on Porter’s health outcome hierarchy [17]. Tier 1 includes peoples’ preferences for end-of-life care; choosing a place of death helps people to die at home, whereas people whose preference is unknown are more likely to be admitted to hospital for end-of-life care [18]. The proportion of Asian participants in this study expressing a preferred place of death or signing a Do Not Recuscitate Agreement was low compared with other studies [19]; this highlights an unmet need for advocacy to better prepare elderly Taiwanese people for death. The prevalence of frailty was similar to other reports [8, 20].

Approximately one-third of participants used ≥5 concurrent medications, consistent with a study of national health insurance claims by 59,042 Taiwanese people older than 65 years [21]; nevertheless there was a low incidence of adverse drug events or discomfort after taking medications, likely due to a low rate of inappropriate medication according to insurance claims data [21]. Although people prefer more participation in decision-making and expect to be treated with dignity and respect, not all patients want to make medical decisions [22]. More than 90% of people in our study participated in decisions about their care- and received collaborative, dignified and respectful medical management, compared with 60% in a systemic review of 44 studies [22]. Although falling is usually considered a health outcome, it was chosen as a standard value-based metric because it matters to older people, their carers, and physicians. A higher rate of falls among women than men in this study was consistent with a study of 1377 community-living Taiwanese, although not statistically significant [23].

The use of SF-36 in Tier 3 to measure depression and pain has the advantage of covering many outcomes to reduce complexity, but some experts advocate considering cost-free survey tools as well [5]. The prevalence of depression in this study population was similar to previous reports from dermatology and internal medicine, and lower than among surgery patients [24]. A meta-analysis study of 19 studies reported moderate to severe chronic pain in 10–14% participants [25], which was similar to our findings. Participation and social inclusion are key components of healthy aging; 26.8% prevalence of loneliness was consistent with previous reports [26]. Although measuring physical performance is not always easy in daily practice, the ICHOM included walk speed as a Tier 3 metric because it matters to older adults [27]; the mean speed of 0.9 m/s in this sample was much lower than reported in older healthy adults [28], reflecting that all participants were multimorbid.

The ICHOM Standard Set of outcome measures was the first tool developed for people who are older, rather than those with specific diseases or conditions. Based on findings from the study, stakeholders may devise tailor-made interventions for this population and examine their effectiveness accordingly. However, the ICHOM Standard Set does not include cognitive assessment; our results show that cognitive function per se was highly associated with high value-based healthcare status and might be considered amended in metrics of the ICHOM Standard Set. The ICHOM variables are a combination of self-reported and professional-assessed. Most of these variables are not routinely collected, even in an integrated geriatric health care clinic. That might burden collection of data from patients and professionals. For example, a Chinese version of the 4-item screening Zarit Burden interview was not available at the time this study commenced. Complexity and burden of assessments might be a barrier to scale up use of the standard set in Taiwan or other countries, Akpan et al. argued that free tools that encompass multiple outcomes to reduce numbers of measurable variables and complexity of tools would be help for clinical and public health implementation [5].

This study had limitations. First, the ICHOM Standard Set was designed to measure longitudinal changes of value-based health status; our cross-sectional study only presents a snapshot of baseline status. Second, convenient sampling instead of random sampling limits the representativeness and generalizability, although various dimensions studied had profiles similar to previous studies. Extrapolation of our study results to other populations may need further validation. Third, questionnaire items about falls and drug adverse events over the past year may result in recall-bias; this could be resolved by a prospective study, which is underway, and we intend to report in due course.

Conclusions

ICHOM Standard Set health outcome measures provide an opportunity to shift from a disease-centric medical paradigm to whole person care goals. The value-based health care profile in Taiwan indicates the importance of advanced age, chronic disease and cognitive impairment as barriers to achieving high value-based health status. Further longitudinal and intervention studies to examine the expedience of using ICHOM are warranted.