Trends in the Assessment of Social Frailty in Community-Dwelling Older Adults: A Scoping Review

Assessment of social frailty is crucial; however, definitions and assessment methods lack standardization. This review examined social frailty in community-dwelling older adults, highlighted trends in the definitions and assessment items used to date, and identified issues in assessing social frailty. The PubMed and CINAHL databases were searched for articles related to social frailty published up to 2022, and 95 articles were included in this review. The Bunt classification was used to assess the trends in items considered indicative of social frailty. Existing rating scales for social frailty were used in 82% of studies, and cut-off values were defined in 62% of studies. Factors such as the level of education; social interaction (weekly outings); and feelings of abandonment, emptiness, and lack of social integration (absence of a partner and non-participation in social organizations or activities) were evaluated less frequently. This study revealed that subjective feelings, including the fulfillment of social needs and participation in social activities, are less commonly considered in the assessment of social frailty.


Introduction And Background
Frailty is a geriatric syndrome defined as a state of increased vulnerability to stress owing to decreased reserve capacity in older adults.Frailty comprises several elements, including physical, psychological, and social components [1], with particular emphasis on the social component.Social frailty is often interpreted as the lack of resources to meet basic "social needs."Theories explaining social needs include the selfdetermination theory [2], loneliness theory [3], and social production function (SPF) theory [4].Bunt et al. conducted a scoping review to structure and integrate social frailty based on the SPF theory.They extracted exhaustive components of social frailty, including subdivided elements from general resources, social resources, social behavior, and social needs fulfillment (Bunt classification) [5].Briefly, the assessment of social frailty included the evaluation of older adults' interactions with people around them, their living environment, their participation in social activities, and their environmental needs.Social frailty is problematic because of several reasons.For instance, a decrease in social interaction can trigger a deteriorating health status.Studies have reported a relationship between social frailty and the risk of developing diseases and depressive symptoms, and individuals with social frailty have a 2.31 times higher risk of developing depressive symptoms compared to those without social frailty [6,7].Additionally, a longitudinal study on older adults reported significantly higher all-cause mortality in 10-12 years among individuals with a history of lack of conversation with neighbors and reduced community participation.This suggests that social frailty may negatively affect physical and mental health status [8][9][10].Thus, social frailty is not only an expression of daily life and social isolation but is also considered a high-risk condition that causes mental and physical health problems in older adults.Makizako et al. evaluated older adults who did not exhibit physical frailty but were suspected of having social frailty, such as living alone, going out less frequently, and limited conversations with others for four years.They reported that the risk of developing new physical frailty was four times higher among older adults with elements of social frailty [11].Therefore, accurate and early assessment of social frailty is crucial to provide necessary interventions before it leads to serious health problems.Despite the recognized importance of assessing social frailty, a standardized method for the early identification of these issues is lacking.Although various assessment scales exist, the choice of components to be assessed varies according to the researcher.Furthermore, social frailty may not be adequately assessed owing to the lack of clear cutoffs for determining social frailty in the literature.Although Bunt et al. conducted a scoping review to validate the construct of social frailty, no report has addressed the status of social frailty assessments in community-dwelling older adults [5].Therefore, we conducted a scoping review of primary studies that assessed social frailty in community-dwelling older adults to identify the assessment scales and criteria used to determine social frailty.Additionally, we aimed to identify issues in the assessment of social frailty in community-dwelling older adults by highlighting trends in the elements extracted from each study based on Bunt et al.'s classification.

Review Material and methods
The PubMed and CINAHL electronic databases were searched for relevant studies.The search formula was "social frailty" AND (older OR elderly OR aged), and the search field was "All Fields" (search date: September 26, 2022).This report adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-Scr) guidelines (2018).The study was registered with the Open Science Framework in preparation for this paper (https://doi.org/10.17605/OSF.IO/3FTD5).The eligibility criteria were as follows: (1) studies assessing social frailty and (2) studies evaluating community-dwelling older adults (aged ≥60 years).The exclusion criteria were as follows: (1) the paper was not available, (2) the publication language was not English, (3) the article was not original, and (4) the study assessed hospitalized patients.Study eligibility was determined based on the title and abstract in the primary screening and information in the main text in the secondary screening.Screening was performed by two independent reviewers, and disagreements were resolved by a third reviewer.In articles selected after the screening, we assessed information on the use of existing assessment batteries, the classification of assessment components based on the Bunt classification, and the definition of social frailty.Studies were rated by two independent raters and discrepancies in ratings were resolved by a third rater.The results were summarized using descriptive statistics.

Bunt Classification
Social frailty has four components: general resources, social resources, social behavior, and satisfaction of social needs.These components are further subdivided as follows: General resources: living alone, level of education, lack of support, and financial difficulties; social resources: absence of a support person, neighbor, or close friend or presence of someone to rely on; social behavior: frequency of going out, social interaction, limitation of social activities, opportunities to talk to someone, visiting friends, social contact, frequency of contact with family and neighbors, frequency of contact with society, and lack of social integration; satisfaction of social needs: feelings of abandonment, emptiness, loneliness, or being useful to friends and family; lack of social relationships; and social support.

Results
Of the 159 articles on social frailty published up to September 2022, 95 articles that evaluated communitydwelling older adults were included in this review.The inclusion of papers in the scoping review is shown in the flowchart (Figure 1).Studies excluded at the eligibility stage are presented in the appendix.

Social Frailty Assessment Index and Criteria
Fourteen percent (13/95) of the studies did not use an existing assessment battery to assess social frailty; instead, they used their own assessment methods.Existing assessment batteries were used in 82 studies (86%), and three studies (3%) used multiple batteries simultaneously.Sixty-one studies (64%) used an existing assessment battery and clearly defined a cutoff point for determining social frailty.Additionally, among the 13 studies that used an original method to assess social frailty, nine used a clear cutoff for determining social frailty (Table 1  In studies that used existing assessment batteries, a total of 86 batteries were used; the Tilburg Frailty Indicator (TFI), Makizako's method, and Yamada's method were used in 29 (34%), 27 (31%), and 5 (6%) studies, respectively.The 8-item Social Frailty Scale, the Groningen Frailty Indicator, the Lubben Social Network Scale-6, and the Comprehensive Frailty Assessment Instrument were used in three studies (3%) each.The HALFT, Korean Frailty Scale, Functional Geriatric Evaluation, Fried score, PRISMA7, Frailty Phenotype, Clinical Frailty Scale, Biopsychosocial Frailty, University of California Los Angeles Loneliness Scale, California Los Angeles Loneliness Scale-3 items, and Modified Reported Edmonton Frail Scale were used in one study (1%) each.

Discussion
This scoping review examined current methods of assessment of social frailty in community-dwelling older adults.Additionally, trends in the current reporting of social frailty assessments and future issues were evaluated.

Rating Scales and Criteria for Social Frailty
In primary research on social frailty in community-dwelling older adults, existing assessment scales were used in > 80% of the studies.A total of 17 assessment scales were used, and no scale was established as a gold standard.The most commonly used scales were the TFI (34%) and the Makizako method (27%).The TFI is a frailty assessment tool developed by Gobbens et al. in the Netherlands and is divided into Part A, which indicates baseline characteristics, and Part B, which assesses frailty status.In Part B, 15 items, including physical, psychological, and social factors, are evaluated using a two-factor method, and a person is classified as frail if five or more items are applicable.The facts that the scale has been translated into several languages in several countries and that the validity of the overall assessment of frailty has been demonstrated (α = 0.79, κ = 0.79) are believed to contribute to the widespread use of the scale [12].Social frailty is defined based on the sub-items of living alone, lack of social relationships, and lack of social support, but definite criteria for determining social frailty are lacking.In primary studies using TFI, social frailty was determined based on the presence of two of the three sub-items [13,14].Makizako et al. [11] developed the Makizako method in Japan, which consists of five components: living alone, not going out frequently, not visiting friends, not being useful to friends and family, and not talking to someone daily.The presence of one of these factors is defined as presocial frailty, and the presence of two or more factors is considered social frailty [15,16].Other scales, such as the Yamada index [17] and SFI [18], are assessment methods based in part on the items listed in Bunt's scoping review, using items related to social needs satisfaction, social resources, general resources, and social behaviors and activities.Seventy-two percent of the studies using the Yamada scale were reported from Japan, suggesting a regional bias.Among the included studies, 60% used some type of cutoff to determine social frailty.Forty percent of the studies did not specify which items were used to determine social frailty or simply used scale scores for group comparisons but tended not to examine the clinical implications of the scores.In other words, authors tended to make relative assessments of social frailty, which may lead to arbitrary judgments and increase the risk of publication bias.The challenge is to clarify the criteria that should be used to assess social frailty.This is expected to lead to a multidisciplinary understanding of social frailty and the development of a gradation of social frailty.

Trends and Challenges in Assessing Social Frailty Factors
The most frequently asked question in the assessment of social frailty was "Does the patient live alone?"The importance of "living alone" in the assessment of frailty has long been debated.A series of studies on social support by Makizako et al. [7,11,15,19] reported living alone as an independent factor for social frailty.However, Sakurai et al. found that the presence of a roommate did not directly affect health status; nonetheless, poor social networking was the background for deterioration in health [20].Although the mechanism by which living alone induces frailty has not been fully elucidated [21], it should be evaluated in terms of whether support in times of need, such as from distant family members or neighborhood social services, can be easily obtained in the long term.The "Kashiwa Study (Japan)" of community-dwelling older adults reported that attention should be paid to the association between oral frailty (frailty related to dental and oral functions) and social frailty [22].In that study, participants who ate alone had less communication with family members, even if they did not live alone, and many of them had unbalanced diets and poor nutritional status.In other words, older adults who are isolated from their families may be at the threshold of physical and social frailty, even though they do not live alone; assessment of such cases is challenging.In general, the elements corresponding to the "satisfaction of social needs" tended to be evaluated less often.These elements evaluate how the individual feels in society and their expectations from the outside world.However, Bunt et al. reported that assessment of subjective aspects of social frailty was difficult [5].In a previous study, subjective factors, such as loneliness and alienation, which are difficult to assess objectively, tended to be excluded as they reduced the validity of the scale when creating rating scales.In addition, the items that extract the subjects' feelings might include aspects of psychological frailty, and because the boundary between psychological and social frailty is difficult to grasp, assessment of these items is difficult.However, regarding assessment for the early detection of the need for the use of social resources and the introduction of services, the subjective factor of the type of assistance required should be evaluated as a check for social frailty.This study identified key components of social frailty, such as the frequency of social interactions and the presence of support networks, which can be directly influenced by the types of assistance individuals perceive they need.
A limitation of this study is that it did not evaluate studies other than those included in the databases used in this study.The amount of information obtained can be increased by broadening the scope of the search.
Based on the results of this scoping review, we suggest the following: First, research reports should clearly describe the criteria for determining social frailty using existing or original rating scales.A clear presentation of the scoring criteria will lead to a multidisciplinary interpretation of the information.In addition, we believe that adding subjective factors, such as individual values and thoughts, to the actual assessment in community and clinical settings will facilitate the detection of social frailty risks.This approach will allow for a more comprehensive understanding of the social aspects influencing frailty.Therefore, in the future, supplementing the information by combining subjective factors that are difficult to express using existing rating scales with qualitative assessments, such as interviews, should be considered.It is necessary to conduct new studies to establish a gold standard for the assessment of social frailty.

Conclusions
This review showed that 60% of the studies used cutoffs to assess social frailty, and biases in the establishment of the cutoffs were evident.Particularly, subjective feelings and participation in social activities to fulfil social needs were infrequently included in the assessment of social frailty.Clarification of missing information will help identify signs of social frailty at earlier stages.Future studies should focus on defining the criteria for the evaluation of frailty and establishing a gold standard for assessment.* Where sources of evidence (see second footnote) are compiled from, such as bibliographic databases, social media platforms, and websites.† A more inclusive/heterogeneous term used to account for the different types of evidence or data sources (e.g., quantitative and/or qualitative research, expert opinion, and policy documents) that may be eligible in a scoping review as opposed to only studies.This is not to be confused with information sources (see first footnote).‡ The frameworks by Arksey et al. (6) and Levac et al. (7) and the JBI guidance (4, 5) refer to the process of data extraction in a scoping review as data charting.§ The process of systematically examining research evidence to assess its validity, results, and relevance before using it to inform a decision.This term is used for items 12 and 19 instead of "risk of bias" (which is more applicable to systematic reviews of interventions) to include and acknowledge the various sources of evidence that may be used in a scoping review (e.g., quantitative and/or qualitative research, expert opinion, and policy document).

Appendices
From

Additional Information
Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work.Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work.

FIGURE 1 :
FIGURE 1: PRISMA flowchart of the study selection for the scoping review.PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-Analyses

FIGURE 2 :
FIGURE 2: Proportions of elements classified as social frailty.

TABLE 1 : Frequency of use of each rating scale, presence of criteria for social frailty, and content of the ratings.
Eligibility criteria 6Specify characteristics of the sources of evidence used as eligibility criteria (e.g., years considered, language, and publication status), and provide a rationale.2Describeallinformation sources in the search (e.g., databases with dates of coverage and contact with authors to identify additional sources), as well as the date the most recent search was executed.Describe the methods of charting data from the included sources of evidence (e.g., calibrated forms or forms that have been tested by the team before their use, and whether data charting was done independently or in duplicate) and any processes for obtaining and confirming data Provide an explicit statement of the questions and objectives being addressed with reference to their key elements (e.g., population or participants, concepts, and context) or other relevant key elements used to conceptualize the review questions and/or objectives. 1 METHODS 2024 Iijima et al.Cureus 16(8): e66614.DOI 10.7759/cureus.66614Protocol and registration 5 Indicate whether a review protocol exists; state if and where it can be accessed (e.g., a Web address); and if available, provide registration information, including the registration number. 2 FUNDING Funding 22 Describe sources of funding for the included sources of evidence, as well as sources of funding for the scoping review.Describe the role of the funders of the scoping review.6

TABLE 2 : The PRISMA-ScR checklist.
JBI = Joanna Briggs Institute; PRISMA-ScR = Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews.

TABLE 3 : List of studies included in this research.
Assessing the Impact of a Community-Based Pro-active Monitoring Program Addressing the Need for Care of Community-Dwelling Citizens Aged More than 80: Protocol for a Prospective Pragmatic Trial and Adaptation of a Social Vulnerability Index for Measuring Social Frailty Among East African Women.Social Frailty as Social Aspects of Frailty: Research, Practical Activities, and Prospects.Term Life Care at Home: A Bottom up, Community-Driven Model for Long-Term Care Reform in Canada.Pandemic Control Measures: Impact on Social Frailty and Health Outcomes in Non-Frail Community-Dwelling Older Adults.