Functional Health In Nursing Care

Nursing Care and Functional Health

Functional Health Model,Weakness of Models,Health Indicators, Biomarkers, Psychosocial Factors.

What is Functional Health

    Functional health is a requirement for independent living and is the ability to engage in daily activities related to personal care and socially defined roles. Performance of these activities is integral to quality of life and to living independently and safely. Although functional health represents well being, most nomenclature reflects deficits in this health. 

   Terms include disability ( Nagi , 1991), frailty (Lawton, 1991), functional limitation (Johnson, RJ, & Wolinsky , 1993), and handicap (World Health Organization). Often these terms are used to refer to other concepts that lead to confusion in nomenclature and theoretical definitions. 

Functional Health Model

    The World Health Organization definition of disability lacks conceptual clarity and theoretical consistency, and this makes operationalization and establishing relationships difficult. 

    In the disablement model (Johnson & Wolinsky ), functional limitations are sometimes confused with factors affecting these limitations, and perceived health is used as a proxy for functional limitations. Leidy (1994) proposed nomenclature and definitions of functional status and other concepts related to this status that add to the conceptual confusion in this area. 

    In spite of the confusion related to nomenclature, Nagi's (1991) model of disability has been supported by extensive research and is useful to guide research, because disability in this model is conceptually clear, logically consistent, and useful in interpreting current and past research. 

    Disability (poor functional health) is the result of a sequence of factors with temporal relationships. Pathology or lifestyle contributes to functional impairments that are anatomic, physiological, and psychological abnormalities causing functional limitations at the level of the whole person (eg, poor memory or inability to get up from a chair). 

    Functional limitations then lead to disability, which is the inability to perform daily tasks or roles independently. Risk factors and external and internal factors were added to this model to increase its explanatory capacity (Pope & Tarlov , 1991; Verbrugge & Jette , 1994). 

    Another significant addition to Nagi's model was the notion that upperextremity limitations were more related to personal care activities of daily living, while lower extremity limitations were more relevant to instrumental activities of daily living (eg, shopping, housework, meal preparation) ( Verbrugge & Jette ). 

    Unique to Nagi's model is the notion of thresholds, where a certain amount of change must occur before change in a subsequent concept is observed. For example, impairments in mobility arose when the strength of leg muscles was below a certain threshold ( Rantanen et al., 1999; Rantanen et al., 2001).

Weakness of Models

    Lacking in these models is the influence of decision making on disability. Persons engage in activities that they believe they have the ability to do without risk of injury or excessive exertion. 

    Evaluative judgments about the environment and personal competencies affect decisions about what activities to participate in and how. Although the congruence between actual and perceived physical competencies is modest at best, little is known about how these affect disabilities (Roberts, BL, 1999).

    Since functional health is the ability to engage in everyday activities, a plethora of research has focused on daily activities related to personal care (ADLs) and tasks related to providing food and shelter and caring for the home (IADLs), because impairment in these contribute to excessive dependency, morbidity, mortality, and poor quality of life. 

    Health care costs and personal and social resources needed to manage disability are substantial, particularly as the baby-boom generation enters older adulthood when the proportion and number of older adults are expected to increase greatly as well as the associated financial, personal, and societal costs .

    In 2000, 41.9% of elders had at least one disability with nearly 60% of them being women (Waldrop & Stern, 2003). While only 9.5% had self-care deficits, 20.4% had difficulty going outside, and women were more disabled in this activity than men (23.0% and 16.8%, respectively). 

    Racial and ethnic differences exist, with only 40.4% of non-Hispanic whites being disabled compared to $2.8% of African Americans. In 1997, 38% of older adults reported severe disability with 14% and 22% requiring assistance with ADLs and IADLs, respectively (Administration on Aging, 2003). In the last year of life, dependency increases ( Covinsky , Eng , Lui, Sands, & Yaffe , 2003; Lunney , Lynn, Foley, Lipson, & Guralnik , 2003).

    ADLs are hierarchically structured by the complexity of the motor skills required (Spector, Katz, Murphy, & Fulton, 1987), IADLs are dependent on some of the same motor skills as ADLs but are more dependent on cognitive capabilities. ADLs and IADLs are highly related and may represent a continuum of the same construct (Johnson & Wolinsky , 1993; Thomas, VS, & Hageman, 2003).

Health Indicators

    Early empirical indicators were self-report, whose accuracy cannot be verified and can be biased by cognitive impairment, social desirability, or minimization of dependency. Although observational measures reflect what a person is able to do, they may not reflect what a person actually does. 

    Gait, dynamic and static postural stability, and muscle strength are physical factors affecting ADLs and IADLs ( Guralnik et al., 2000; Roberts , L., 1999), Upper-body function (eg.. muscle strength and range of motion of theorems) was related to ADLs, while lower-body function (eg, muscle strength of the legs) were associated with IADLS (Lawrence & Jette , 1996). 

    Although the effects of exercise on strength, balance, and mobility are well established, exercise has had little to no effects on ADLs or IADLS (Latham, Bennett, Stretton, & Anderson, 2004).

Biomarkers

    Recently, biomarkers of increasing dependency associated with frailty have emerged. Biomarkers of catabolic protein metabolism, pro-inflammatory cytokines, and other hormones were related to dependency, frailty, and loss of muscle mass and strength ( Chevalier , Gougeon , Nayar , & Morais , 2003; Ferrucci et al., 2002 ; Roubenoff , 2003). An understanding of their roles may lead to new assessment strategies and interventions.

Psychosocial Factors

    Relevant psychological factors include cognitive impairment and depression. Certain types of social support are factors that can contribute to dependency in daily activities (Seeman, Bruce, & McAvay , 1996), while men and women use different types of social support in response to limitations in ADLs and IADLS (Roberts, BL, Anthony , Matejc zyk , & Moore, 1994). 

    The role of the environment has not been well established, except for the increase in dependency noted during hospitalization and long-term residence in a nursing home. 

    Although there is evidence beginning that the relationship between actual abilities and perceptions of them is low, how these perceptions influence decisions people make about what activities to perform and how have not been well studied.

    More research is needed to identify thresh olds in factors related to functional health where declines in this health occur, and to identify factors and processes by which people make decisions about performing daily activities. This knowledge may provide directions for assessment in populations at risk of poor functional health and may lead to more sensitive assessment strategies. 

    A greater understanding of the interplay between environmental and personal factors with functional health may lead to multidimensional interventions that may be more effective than the one-dimensional interventions most often studied.