The older population worldwide is growing at an unprecedented rate. In 2019, nine percent of the world's population was 65 years and over and this is projected to rise to 16% by 2050 (1). The increasing life expectancy is driven by public health developments and medical advancements (2). Older adults generate numerous societal benefits including contributing to paid and volunteer work, supporting loved ones and have the ability to pass experiences onto younger generations strengthening capacity (3). However, aging also presents challenges, as longer survival is associated with higher prevalence of chronic diseases, longer periods of demand for care and consequent burden on health and social support systems (1).

Patterns of aging amongst Indigenous People indicate faster growth than for non-Indigenous populations (2). Despite Indigenous populations having a relatively younger age structure (4), projections show that the number of older Indigenous Peoples is expected to significantly increase in the coming years. By 2051 the number of Aboriginal and Torres Strait Islander Australians aged 45 years and over is expected to increase from 167,170 in 2016 to 511,263 (5). Similarly, the number of First Nations seniors in Canada has doubled from 56,030 in 2006 to 121,665 in 2016 (6).

Indigenous Peoples worldwide tend to experience higher rates of age-related diseases than their non-Indigenous counterparts (4, 7). Overall, chronic diseases account for 70% of the health gap between Indigenous and non-Indigenous Australians (8); and frailty (9) associated with both aging and chronic illness has widespread implications for public health (10). These poorer health outcomes can be attributed to the long-term effects of colonization, intergenerational trauma and marginalization (11).

Frailty is a challenging expression of aging. It can be viewed as an individual's biological age rather than their chronological age (12) and has been characterized as a state of increased vulnerability to poor health outcomes as a result of age-related decline in reserve and function across multiple physiological systems (9, 13). A plethora of frailty tools exist in use within research and clinical practice (14) however, there is currently no consensus on an operational definition of frailty.

One widely used approach to frailty screening is the Fried Frailty Phenotype (FFP) (15), which assesses performance across five criteria including unintentional weight loss, self-reported exhaustion, physical inactivity, weakness (grip-strength) and slow walking. The presence of ≥ 3 criteria categorize a person as frail and one to two categorize an individual as pre-frail. A similar tool, the Edmonton Frail Scale (EFS) also assesses the frailty phenotype across nine components. Responses fall into five categories ranging from not frail to severely frail (16). The Frailty Index (FI) is another commonly used approach (12) defining frailty as accumulation of deficits, whereby a higher number of deficits the individual has indicates greater severity of frailty. This multidimensional approach includes deficits not only in the physical domain, but includes health conditions, cognition, disability, and psychosocial domains.

However, defined, frailty is consistently associated with poor outcomes including functional decline, aged-care admission, hospitalization and death (12, 17, 18). Both frailty and pre-frailty (the intermediate state between frail and robust) are prevalent among older adults in the general population. A systematic review of community-dwelling adults 65 years and over estimated frailty prevalence of 10.7% and pre-frailty 41.6% (19). It is important to note that given the lack of consensus on how to measure frailty and the varied diagnostic criteria, population prevalence can demonstrate significant variation making direct comparisons difficult.

Indigenous and non-Indigenous populations experience health differently. The World Health Organization defines health as a “state of complete physical, mental and social well-being and not merely the absence of disease or infirmity” (20). In contrast, Indigneous Peoples definition of health is more holistic and incoporates elements of physical, mental, spiritual and social well-being along with the broader health of family and the community as a whole; connection to land and culture are also important factors (21–23). This has important implications when characterizing and assessing frailty within Indigenous populations.

Given the potentially devastating impact of frailty and its associated adverse outcomes, there are implications for health service delivery, including screening and the development of prevention strategies. Therefore, to inform culturally appropriate strategies to prevent or delay the onset and progression of frailty it is important to estimate the prevalence of frailty within Indigenous populations and to establish whether the tools currently in use to measure frailty are culturally appropriate. As a first step to developing an understanding in this area we aimed to summarize the existing literature using standardized scoping review methodology.

The overall question for this scoping review was: What does the literature report on the extent of the problem, types of assessments and strategies to combat frailty within Indigenous populations?

Specifically, we aimed to map the (i) existing literature on the characteristics of frailty in Indigenous Peoples; (ii) tools that are being used to measure frailty and their characteristics; and (iii) strategies/interventions that have been developed to manage frailty in these populations.

We searched MEDLINE, Prospero, Joanna Briggs Institute (JBI) and Open Science Framework and did not find any systematic reviews with a focus on frailty within Indigenous populations. Furthermore, our preliminary search found a paucity of research in this area. Therefore, we decided to conduct a scoping review as an appropriate way to map the existing literature (24). Scoping reviews are particularly relevant when the topic has not been extensively investigated, making it difficult to conduct a systematic review. This review sought to examine the range of research in this area, identify gaps in the literature, and provide insight into topics that may benefit from further evidence synthesis (25, 26).

This review followed scoping review methodology by Arskey and O'Malley (25) and advancements from the Levac et al. (24) framework and JBI (27). We did not exclude studies based on design and did not conduct quality appraisal.

Our review was registered in Open Science Framework on 8th October 2020 https://osf.io/u2f4p/.

In total nine articles (30–38) met our inclusion criteria (Figure 1).

This scoping review has highlighted the scarce evidence available regarding the understanding, impact and measurement of frailty within Indigenous populations in the context of settler-colonies. After an extensive literature search, nine articles met the inclusion criteria. Despite efforts made to include Indigenous perspectives of frailty (Table 2), this limited evidence highlights multiple shortcomings including inconsistent approach to measurement; not using standard instruments to estimate frailty prevalence; common absence of comparison of frailty results with mainstream population groups; and lack of monitoring of frailty prevalence over time. Across the included articles, there is no consensus pertaining to target age group for estimation of frailty. In addition, the lack of standardization of a frailty measurement tool and absence of commentary on appropriateness for Indigenous populations limits the validity of the estimates and comparison between articles. Several frailty definitions were used and therefore the true Indigenous frailty prevalence was difficult to determine and compare across Indigenous population groups (9). There was also a vast difference in frailty prevalence both within countries and globally. This may be a consequence of not only differences in populations, but varying frailty definitions and inclusion of different age groups and underlying comorbidities.

What we could determine from the limited evidence available is most studies found Indigenous Peoples to have higher rates of frailty and younger onset compared to their non-Indigenous counterparts. We also found Indigenous women were more likely to experience frailty compared to Indigenous men. This is consistent with findings from non-Indigenous populations (39). Furthermore, the Indigenous women sample size included in the articles was larger than the male cohort, which could potentially have skewed the results.

Two of the earliest included articles did not report on the use of a formal frailty tool. This is not surprising as frailty is a relatively new concept within the literature but detracts from the validity of results. The remaining seven articles that used a formal frailty tool were all published between 2016 and 2020. One-time prevalence of frailty could be informative when there is no prior source of data, but time-trends would have more utility to plan healthcare and community resources to cater for the changing needs of individuals and of the population.

Our search did not find any interventional articles to manage or address frailty within Indigenous populations or those at risk of frailty. Interventions such as strength and resistance training and nutritional supplements have been found to prevent or delay frailty onset (40). Future studies could investigate the feasibility, acceptability and effectiveness of these approaches in Indigenous populations to fill this important knowledge gap.

Context also play an important role in gaining true insights into prevalence. All included articles were in community-dwelling settings, apart from one based in hospitalized patients (34). Hospitalized patients are more likely to be in poorer health and experiencing higher rates of frailty. Whereas, community-dwelling individuals may have lower levels of frailty as they are in better health and able to manage independently in their daily lives (36). Others have found high frailty prevalence in hospitalized patients (41).

A number of the included articles highlight the correlation between frailty and other chronic diseases (32, 33). Chronic diseases are responsible for almost two-thirds of the estimated burden of disease within Indigenous Australians (8). Furthermore, the prevalence of multimorbidity in Indigenous Peoples was found to be nearly 2.6 times that of non-Indigenous population and the adjusted hazard of mortality within twelve months was 2.4 times as high, and 1.5 times that of the non-Indigenous population after adjusting for the number of morbidities (42). Whilst chronic diseases were found to contribute to a higher prevalence of frailty, highlighting the importance of screening for frailty in routine care. The reported associations between dementia, diabetes, and frailty or that of frailty and mortality found in our review cannot be used to infer causality due to the cross-sectional nature of these studies.

Frailty may present earlier within Indigenous Peoples due to overall poorer health and social outcomes across the life-span (43) and contribute to the lower life expectancy amongst Indigenous populations. This is consistent with findings related to other age-related conditions such as dementia (7), and should be an incentive to identify and evaluate programs with social and health components to prevent or reduce frailty and its early onset.

After reviewing all articles, it was evident that Indigenous perspectives had not been considered when defining frailty or incorporated into the design of the discussed frailty measurement tools. The included definitions and tools are based on Western models and largely adopt a deficit-based approach. While some included studies appeared to have attempted some level of cultural adaptation and training of people to administer surveys, and a study reporting the use of a culturally appropriate questionnaire (31). Deficit-based understandings of health are inconsistent with strength-based Indigenous models of well-being. Current deficit-based approaches are key limitations in assessing frailty, as aging becomes framed in a negative light. In addition, there is a need to highlight the importance of strength and resilience of Indigenous Peoples (44) along with promoting culturally safe and supportive healthcare. Instruments with face validity and culturally appropriate domains need to be developed.

Holistic approaches to defining and assessing frailty are required for this to be closely aligned with Indigenous definitions of health and perspectives on aging, incorporating social, emotional and cultural well-being of the community as a whole (21). Social and cultural factors that reflect the experiences of Indigenous Peoples including early life experiences, social capital, cultural connectivity, language, and engagement in traditional culture (45, 46) could also be considered in future research investigating frailty in Indigenous populations. Frailty tools could also be strengthened with assessment items including characteristics such as resilience, vitality, individual and community strengths as opposed to the current deficit frameworks. A standardized setting-specific measurement framework and approach across Indigenous populations in various locations or services would help inform a more accurate understanding of the true frailty prevalence within this population. Indigenous Peoples are well positioned to drive these developments (47), drawing upon Indigenous knowledge, experiences and ways of knowing.

Addressing modifiable lifestyle risk factors across the life-course may help lower the risk of frailty, delaying or preventing onset (48). Culturally appropriate programs across the lifespan, including targeting age-related conditions in earlier life may have the potential to reduce the prevalence of early onset of frailty (13). Further research is essential, reflecting Indigenous knowledge to help with firstly understanding the current environment and potentially lead to informing culturally appropriate strategies. Indigenous views and understanding of frailty as well as co-designed approaches to screening is urgently needed.

Socioeconomic circumstances and frailty are heavily intertwined. Addressing the underlying social and cultural determinants (46), which result in the differences experienced between Indigenous and non-Indigenous populations, should be investigated. It is worth examining whether factors such as higher educational attainment and improved employment opportunities through the life-course may lower frailty risk in later life.

Overall, a sophisticated multi-sector focus is required to tackle the determinants of frailty, strongly underpinned by research and collaboration with Indigenous communities. This would create a strong foundation to plan and better care for the aging Indigenous population.

To our knowledge this is the first review to map what the literature reports around frailty within Indigenous populations. Despite the large health burden frailty seemingly has on Indigenous Peoples, there was little definitive evidence of the true frailty prevalence, approaches to frailty screening and potential points of intervention to manage or prevent the onset of frailty amongst Indigenous Peoples. Improvements are urgently needed in the quality of evidence around frailty and its apparent earlier onset amongst this population. Furthermore, this review highlights an urgent need for further research to determine the factors contributing to these higher rates of frailty within Indigenous populations and recommends that Indigenous views of frailty must be incorporated into existing research as co-designers of frailty instruments and strategies and interventions to address this important public health priority.

The original contributions presented in the study are included in the article/Supplementary Material, further inquiries can be directed to the corresponding authors.

ETL conceived the idea. ETL and LH screened the articles and led the initial draft and all authors made critical revisions to the manuscript. All authors participated in the discussions that led to the design of this review and contributed substantially to the development of this work and reviewed, and provided final approval of the version to publish.

ETL was supported by a UNSW Scientia PhD Scholarship.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.