Introduction

Ageing and the accompanying long-term diseases in the older population potentially pose a threat to self-sufficient functioning of older adults in their own environment. Following a downward spiral, the progressive deterioration in physical capacity associated with ageing may lead to physical frailty and for instance a higher risk on falling. Subsequently, this physical decline causes limitations both in functional performance and (instrumental) daily life activities. In the end, someone’s ‘Functional Independence’ (FI), is at stake (Ardali et al. 2017; Clark and Manini 2010; Freedman et al. 2002). FI has been described as the ability of an individual to perform activities of daily living (Curzel et al. 2013). Several studies have shown that older adults with limitations in their FI make disproportionate use of hospital services (Mortenson et al. 2018). Early insight into factors limiting individuals’ FI may contribute to better preservation of daily life activities and to use less of health care services. It may also facilitate older people in living independently, in their own environment for as long as possible (Angus et al. 2005). Moreover, monitoring FI is in line with current health care policy promoting self-sufficiency to maintain quality of life in older people. Finally, focusing on patient’s FI may include a shift from the relatively expensive secondary health care towards less expensive primary care (Bodenheimer 2005; Coulter (1995); Freedman et al. 2002; Huber et al. 2011).

At this moment, different instruments are already available for clinical healthcare professionals to asses factors limiting FI and to evaluate someone’s FI in daily life activities (Edwards et al. 2017). Examples are the Functional Independence Measure, the Barthel index and the Katz Index of independence in activities of daily living (Glenny and Stolee 2009; Mahoney and Barthel 1965; Wallace et al. 2007). Those instruments are commonly used in clinical practice by several professionals who are involved in the issue of FI. Physiotherapists, occupational therapists, nurses and physicians use those instruments to specifically assess the physical aspect of FI. However, from an integrated health care perspective, it is likely that FI exceeds the physical domain. According to such an integrated health care model as the International Classification of Functioning, Disability and Health (ICF) it is likely that in addition to physical capabilities, personal and environmental interactions are equally important in maintaining FI of older people (Ustun et al. 2003; de Carvalho et al. 2018). At this moment, a clear definition of such an integrated concept of FI is lacking (Collins 2017). To optimize interprofessional collaboration to prevent a decline in FI, a uniform, integral definition is required (Sangaleti et al. 2017). We report the results of a scoping review and present an interprofessionally supported definition of FI and an ICF-structured overview of factors influencing FI in community dwelling older people.

Methods

A scoping review was conducted, combining an explorative literature search with expert consultations, to develop a broad, interdisciplinary definition of FI. The five-stage framework for producing a scoping literature review, proposed by Arksey and O’Mally, was used as guidance (Arksey and O’Malley 2005; Colquhoun et al. 2014) The subsequent steps will be described below.

  1. 1)

    Identifying the research question

The research questions were twofold: (1) to determine a clinically applicable, interprofessionally supported definition of FI in the community dwelling older people. (2) to determine which factors help to identify FI and the relationship between these factors. The overall aim was to create a comprehensive overview of FI for clinical practice, fitting to the integrative ICF framework.

  1. 2)

    Identifying relevant studies

To create a literature based definition of FI., a medical information specialist (LS) performed an extensive search in medical electronic databases MEDLINE, CINAHL and PsycINFO. The extended search strategy was presented in Table 1. Databases were searched from the date of database start until May 2017, an update of the search in MEDLINE was conducted in July 2019. Clinicians seem to commonly focus on physical factors limiting independence. Hence to get insight into the relationship and contributing factors the term “physical” needed to be combined with “independence” or a related term. In addition, the search was carried out for a vulnerable population. ‘Vulnerable’ was attributed by people with several chronic diseases who are at risk for diminished FI. The search was limited to publications written in English, Dutch or German.

Table 1 Search strategy scoping review on Functional Independence July 2019
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  1. 3)

    Selecting the studies

Articles were considered eligible for inclusion when both an independence component and a physical component were described. Moreover, potentially eligible studies included a vulnerable population for losing FI as in suffering from a long-term disease, frailty or older of age. The operationalization of the independence component, physical component and vulnerability was presented in Table 1. Considering the explorative aspect of the review, all research papers were considered for inclusion. In general no exclusion criteria were applied.

Prior to the selection process, duplicates were removed. Selection of eligible studies was performed following a drop-out procedure, starting with scanning of the study titles only, (Mateen et al. 2013) followed by screening of the abstracts and in the end of the full-text articles against the selection criteria. The selection procedure was performed independently by two authors (EM and JAB).

After each selection stage, differences in inclusion between the authors were resolved in a consensus meeting. Articles not available as full text were excluded, although corresponding authors were contacted when full text was not available online.

  1. 4)

    Charting the data

To provide an overview of the included studies, study characteristics were extracted by identifying a study’s authors, publishing date, study type, research design and the description or definition of FI (Table 2). Subsequently, the first author identified text fragments concerning FI by extensively reading the text, extracting the fragments from the included articles and identifying terms concerning FI by open coding and axial coding the text fragments according to the grounded theory (Corbin and Strauss 1990). The gathered codes were plotted in a wordcloud (Fig. 2) to identify the most commonly mentioned codes. Subsequently, these codes were used to form a preliminary, literature-based definition of FI. Furthermore, a list of key-terms related to FI was gathered, mentioned in the medical literature, to detect potential factors contributing to FI.

Table 2 Data extraction table scoping review on Functional Independence
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  1. 5)

    Adding a clinical view and analyzing the data

To enhance the preliminary definition and to ensure its applicability in clinical practice, relevant stakeholders in the community were consulted. Prior to consultation of stakeholders, the results of the literature review were structured by researchers and lecturers who are involved in the domain of functional independence (n = 7). Initially, this group was asked to reach consensus on the definition of FI in a guided focus-group discussion facilitated by the first author. Second, to gain insights into related factors of FI, the list of key-terms found in the literature was presented to the group. To involve the participants in developing an overview of related factors we used two different Participatory Learning Action techniques. With the direct ranking technique we asked participants which terms they thought contributed mostly to the definition of FI (de Brún et al. 2017). Participants were allowed to skip terms from and add terms to the list. To categorize these key terms, we used the card sort method, to democratically let the participants divide the key-terms into different main themes (Mukherjee 2002). This eventually led to a first overview of related factors influencing FI.

Subsequently, a stakeholder consultation was organized to assure the clinical relevance of the FI concept for clinical daily practice. This online consultation took place in the autumn of 2019 and involved community dwelling older persons (N = 4) and varying healthcare providers in community care such as occupational therapists (n = 2), physical therapists (n = 2), (district) nurses (n = 4), physician (n = 1).Participants were recruited by inviting professionals who are linked to two local networks of community-care professionals through a personal e-mail. In addition, social media was used to recruit community-care professionals as well. Professionals were eligible to participate when they were involved in treatment of older people in the community. Participating professionals were requested to recruit community-dwelling older people from their professional practice. After agreement on participation participants received a personal link to provide access to the online environment which required a password. Participants were asked what their personal association was with each contributing factor to the concept of FI. Answers were discussed in the group until consensus was reached. Finally, they were asked if the factors influencing FI were adequate and if they found factors missing. Data-analyses were performed by using Atlas.ti. (version 8). First open source labeling (Corbin and Strauss 1990) was done by the first author. Second, the first two authors separately categorized these labels, outcomes were compared and discussed. Finally, the categories were added to the already obtained results and a graphic representation of FI was formed by these authors. The graphical representation adhered to the ICF framework where possible.

Results

Study Selection

The search strategy initially resulted in a total of 1905 unique articles. After the screening process, 25 studies were eligible for inclusion. The most common exclusion criterion was a single focus on independence in general or physical output, instead of describing a physical component in relation to independence (Fig. 1).

Fig. 1
figure 1

Flow Diagram scoping review on Functional Independence 2019

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Charting the Data

Ten studies were published over the last decade, 11 between 2000 and 2010 and only one of the studies was performed during the 90’s. Most studies (N = 12) were cross-sectional, almost half of the included studies (n = 11) focused on older adults (>65 years). The most commonly used words for describing the combination of the physical component and independence in the literature were ‘independency’, ‘ability’, ‘functional’ and ‘participation’ (Fig. 2). Further categorization by the first author, led to a preliminary definition of FI as “functioning physically independent in activities of daily life”. Furthermore, the list of key-terms (available on request) mentioned in relation to the definition of FI gathered from the literature, showed terms concerning different domains as physical capacity, social participation, psychological functioning and personal environment. By way of illustration: “Mobility” (Faul et al. 2009), “Self-management” (Lee et al. 2016), “Psychological state (Jenkins and Gortner 1998a)” and “Circumstances” (Cardol et al. 2002).

Fig. 2
figure 2

Wordcloud search results from the scoping review on Functional Independence

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Adding a Clinical View and Analyzing the Data

Definition of FI

In addition to the preliminary definition of FI based on literature review, stakeholders mentioned the importance to include a safety-component with respect to FI based on their clinical expertise. Furthermore, participants asked for a further specification of ‘independent’; it raised questions on the classification of independence when a medical instrument was used. Also the term ‘daily functioning’ was considered to be liable to personal interpretation. Participants finally agreed on the following definition of FI: “Functioning physically safe and independent from other persons, within one’s own context”.

The Comprehensive Overview of FI

Elaborating on the definition of FI, stakeholders categorized and prioritized the key terms from the literature that were associated with FI. As a result, three domains considered to be of equal importance to FI: “physical capacity”, “coping” and “context”. Next to these domains, stakeholders suggested adding “empowerment” and “health literacy” as additional factors contributing to FI. Furthermore, stakeholders recommended to operationalize the factor “context” into home environment, social environment and neighborhood. With respect to the sustainability of FI, participants emphasized that FI seems to be a dynamic condition as persons can suddenly become dependent from another person due to for instance a traumatic event but then again regain their independent functioning by recovery or rehabilitation. Finally, FI should be seen as a disease-independent construct, which focusses on the ability of persons to stay independent, apart from disorders or diseases demanding salutogenesis (Mittelmark & Bull). The comprehensive overview of FI is graphically presented in Fig. 3.

Fig. 3
figure 3

The graphic presentation shows the contributing factors of Functional Independence

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Discussion

This scoping review aimed to determine a clinical relevant definition of FI and an overview of influencing factors of FI in community-dwelling older people. As a result from the literature review and stakeholder consultation, FI could be interpreted as an interplay of physical capacity and behavioral and cognitive factors such as coping, empowerment and health literacy, that enables an older person to function physically safe and independent from other persons, within one’s own context. Therewith, FI could not be seen as a discriminant outcome (functional independent versus functional dependent) but rather as a sliding scale. Someone’s level of FI depends on someone’s level of physical capacity influenced by personal and environmental factors. One important part of the definition of FI is ‘safety’. As prior studies in older adults reported that falls are a major public health issue among community dwelling older adults worldwide (Hartholt et al. 2012; Kannus et al. (1999); Marks and Allegrante 2004), this study stresses the importance of safety when considering one’s FI (Collins 2017). Second, we have identified personal factors like coping, empowerment and health literacy as relevant to the concept FI. Although insufficient empowerment skills and poor health literacy are not directly associated with a loss of independent functioning they are associated with poorer health outcomes (Berkman et al. 2011; Wolf et al. 2005). In addition coping, empowerment and health literacy interact: poor health literacy causes a lack of empowerment (Edwards et al. 2012).

Results from this study are in agreement with the holistic view on a persons’ health related disability’s (Huber et al. 2011; Jette 2006). It enriches previous views on FI, which focused exclusively on the physical component of FI (Lamb and Keene 2017). Although we mentioned physical capacity as one of the most important contributing factors to FI, aligned with other multi-component concepts focusing on independency as the ICF (Ustun et al. 2003) and Integrated Care for Older PEople (ICOPE) guidelines (Briggs and Araujo de Carvalho 2018), the graphical presentation shows FI itself should be seen as physical performance being influenced by contextual factors, both personal and environmental factors. Furthermore the identified domains associated with FI are comparable to, for example, the physical literacy statement which also mentions the influence of cognitive and behavioral factors as knowledge and motivation besides physical competence as influencers of maintaining an active lifestyle (Tremblay et al. 2018).

Strengths and Limitations

One of the strengths of the current study was the design of the study. The scoping review design combined a literature search with a clinical view of relevant stakeholders, which is particularly suitable to explore a quite new concept like FI. Moreover, development in co-creation with the end users increases the chance of implementation in daily practice (Arksey and O’Malley 2005). The fact that FI was an unrecognized term gave the study a broad explorative character, with a broad search strategy and lacking exclusion criteria. Though, a number of limitations should be mentioned. First, as we did not filter on type of research paper, a significant amount of ‘grey’ literature was considered for inclusion. Unfortunately, a part of the identified articles were unavailable as full-text articles and consequently should have been excluded. Due to practical restrictions the stakeholder consultation had to be held online instead of in person, this limits the expression of emotions and can emerge misunderstanding. However, this was convenient, participants could provide input at the time which suited best, it made interaction between participants possible while not all persons had to be in a discussion simultaneously. Previous research on independency of community dwelling older people confirms the influence of contextual factors, mentioning spouses as caregivers and environmental obstacles in the home environment and neighborhood (Baker 2005; Stoller and Earl 1983).

Recommendations

This scoping review delivers a clinical and scientifically relevant definition of FI and an overview of factors contributing to FI in older people. This has several implications for clinical practice, health policy, health education and further research. The most important recommendation concerns interprofessionalism as the construct exceeds the border of a single profession and single ICF domain. Maintaining FI asks for a sufficient level of physical capacity, adequate coping, sufficient health literacy and empowerment, adapted to an older adult’s context, and, therefore, professionals are recommended to look for interprofessional collaboration when supporting community-dwelling older people. This recommendation suits to current health policy which focuses on providing patient-centered care from a holistic perspective (Cieza et al. 2004; Gobbens and van Assen 2017; Liu 2017; Tomey and Sowers 2009). As at this moment interprofessional collaboration in the community care is still in its infancy, there is a call for financial investment, theoretical development and practical facilitation of this concept.. One of the ways to facilitate interprofessionalism both in an educational setting and clinical setting is developing a generic measurement tool to determine and monitor the level of FI in community dwelling older people.

Conclusion

This scoping review resulted in an interprofessionally supported definition of FI as “Functioning physically safely and independent from another person, within one’s own context”. For maintaining functional independent, sufficient physical capacities are needed but also personal and environmental factors like an adequate coping style, empowerment skills and a sufficient level of health literacy. Future research is recommended on operationalizing those factors in measurable quantities to facilitate professionals in community care to determine and monitor older people’s FI in a joint manner.