Background Functional assessment in stroke patients is critical in both clinical practice and outcome studies. Ability in the areas relating to instrumental activities of daily living (IADL) that require increased interaction with the environment, whether household or community, appears to be a prerequisite for independent living in the community. The majority of the research in this area has been in the geriatric population. A literature review was undertaken to answer the following questions: What is a working definition of IADL? What are the criteria that determine inclusion with specific applicability in the stroke population? What are the reliability and validity of available measures in the stroke population? What is the relevance of IADL to functional outcome?
Summary of Review The findings at this time indicate that there is no consensus for a clear definition of IADL. The terminology used includes the original IADL as described by Lawton and Brody, extended ADL, social ADL, and advanced ADL. Four scales that were designed primarily for use in the stroke population were identified: the Nottingham Extended ADL (a self-report scale), the Hamrin Activity Index and the Frenchay Activities Index (both based on patient interviews), and the Household section of the Rivermead ADL Assessment (a performance index).
Conclusions There is some published evidence concerning the validity, reliability, utility, sensitivity, or hierarchical nature of these indexes, and further testing is needed. The items in each index, however, have inherent relevance with potential for use in future clinical research.
One of the practical outcomes of rehabilitation is to return patients to their chosen environments, usually their own home. The ability to live independently is one aspect of functional assessment that has not been developed as extensively as that of personal activities of daily living (ADL). There are now well-established measures of ADL that are valid, reliable, and of utility in the stroke population.1 Such measures include the Barthel ADL Index, the Katz ADL Index, and the Functional Independence Measure. Most of the research in the area of independent living has been and continues to be in the elderly population, looking at the ability of individuals to live in their own home. Necessary activities include but are not limited to domestic chores, household management, outdoor activities, and transportation. Restorative therapy or community resources are then accessed to allow the elderly to remain in their homes after stroke.
The phrase “instrumental activities of daily living” (IADL) was originally introduced in 1969 by Lawton and Brody in their seminal work Assessment of Older People: Self-Maintaining and Instrumental Activities of Daily Living.2 Rather than provide a definition of IADL, they described instead the schema of competence into which behaviors would fit, taking life maintenance as the lowest level. They measured this with the Physical Self-Maintenance Scale, which corresponds to the present general understanding of an ADL scale. Behaviors that indicated successively more complex levels of function were ascribed to the IADL scale.
IADL is generally well accepted as the descriptor for the behaviors as described. Other phrases encountered have included extended ADL,3 social ADL,4 advanced ADL (D.K.-H.C., personal communication, Occupational Therapy Department, Rehabilitation Institute of Michigan, 1994), and intermediate ADL,5 and this list probably is not exhaustive. Although there is a conceptual understanding of IADL, there is no agreement as to the exact categories or items to be included in such a measure that are most useful in clinical evaluation and outcome measurement. Different institutions have simply designed their own to serve their needs, an example being the RIC-FAS.6 Reuben et al5 have extrapolated the concept even further by describing a level of behaviors at which functional decline may be suggested before the loss of ADL and IADL. Part of the reason for this confusion is that the delineation between disability and handicap is not clear, and there is significant overlap. In an effort to resolve this without contributing yet another measure to the published literature, a review was undertaken to clarify the definition and measurement of IADL specifically within the stroke population. Such a measure would then identify who could return safely to independent living in the community, the community resources needed to make this possible, and when it clearly would not be advisable. To maintain uniform terminology, “IADL” will be used throughout this article.
Materials and Methods
Selection of Articles
A computer-assisted search of English language articles was undertaken in the following databases: MEDLINE from 1993 through 1966, CINAHL from 1993 through 1982, and CLINPSYCH from 1993 through 1980. Standard textbooks of rehabilitation medicine, neurorehabilitation outcome measurement, and occupational therapy were reviewed. A search of references of all relevant articles retrieved as well as bibliographic titles of text chapters was performed. Senior clinicians in the Department of Occupational Therapy of the Rehabilitation Institute of Michigan were consulted.
Criteria for Evaluation
The initial keyword used was IADL. The overwhelming majority of the published literature found was on geriatric population studies. Review of these articles provided a conceptual framework of IADL that generally agreed with the index originally espoused by Lawton and Brody; items of ADL such as self-care, sphincter control, basic transfers, locomotion, and elementary communication and cognitive processes were clearly not included. On the other end of the spectrum were articles on approaches that overlapped into IADL but considered the perspective of life satisfaction or quality of life. Such articles almost always identified themselves as such within the abstract or “Methods” sections. Articles from both ends of the spectrum were excluded. Some of the geriatric articles with descriptions of the subpopulations included subsets of stroke patients. None of these articles studied the stroke patients separately, nor were sufficient data provided to extrapolate the analysis. These articles were also excluded. The result of this phase of the search yielded one useful measure.
Recognizing that there may not be uniformity in terminology, the literature was then searched using stroke as the primary field and ADL, activity of daily living, and activities of daily living as the modifier. Articles found were then subjected to the exclusion criteria as described for ADL and quality of life. The result of this phase of the search yielded three useful measures.
The descriptors used by the individual authors for IADL were subsequently searched to elicit reliability and validity studies.
Four measures were identified that were designed and used within the stroke population (Table 1⇓).
The Rivermead ADL Assessment7 is the first published IADL measure that is directed specifically toward the stroke population. It is performance based and is scored on a three-point scale: 1, dependent; 2, independent but requires verbal supervision; and 3, independent. It has been used in young stroke patients (<65 years) and elderly stroke patients (>65 years).8
The Hamrin Activity Index9 is a patient interview, with or without family present, of what the patient did; it was used to assess premorbid and 1-year poststroke IADL. The interview was conducted either in the patient’s home or in the institution. It is scored on a four-point scale: 1, never do an activity; 2, can do it only with personal assistance; 3, can do it with some difficulty; and 4, do it on my own and regularly.
The Frenchay Activities Index10 is also based on a patient interview, with or without family, of what the patient did. It was used to assess premorbid IADL at 3 and 6 months before stroke and subsequently at 1 year after stroke, looking retrospectively at the past 3 and 6 months. It uses a four-point scale that has six versions ranging from 1 (never) to 4 (frequent).
The Nottingham Extended ADL scale3 is based on a self-reported questionnaire on level of activity actually performed. These questionnaires were mailed to patients’ homes 1 year after stroke. The scale uses two-point scoring that actually has four levels when answered by the patient: 0 (with help or not) and 1 (on my own or on my own with difficulty). The patients were coded as dependent (0) or independent (1) for statistical analysis.
The Frenchay Activities Index was the only measure that did not categorize the IADL items into different domains (Table 2⇓). The Rivermead ADL Assessment was the only measure to indicate the age of the population assessed. None of the articles defined IADL. The relevance on functional outcome was briefly discussed by Wade et al.4 They found the Frenchay Activities Index to be clinically useful and recommended it for use in stroke and geriatric rehabilitation and research. Table 3⇓ is a summary of published methodological studies on the different scales.
Early in the course of the review, it became clear that IADL as a keyword was insufficient to uncover all pertinent articles. The search subsequently was made more generic by using ADL as the keyword. This generated a large number of articles that bridged the span from impairment through handicap. Articles were culled by following the schema of competence as espoused by Lawton and Brody2 for activities that were above and beyond what is understood as ADL. Articles that appeared to place an undue emphasis on quality of life measures were rejected. In light of the difficulty of identifying outcome measures from a search of the literature, this author is confident that all scales that might reasonably be expected from this area have been included.
The above measures are difficult to compare because they examined different patient populations, the evaluation methods of the tests were different, and the test items and the scaling of the measures were different. Three of the studies were British, and one was Swedish. With these differing socioeconomic and cultural contexts, the generalizability of the measures and their applicability to a North American population are questionable.
It was not entirely clear why some items were included in certain measures and under certain domains and not in others. A method to retrospectively study this is factor analysis. Factor analysis was performed on the Frenchay Activities Index, which demonstrated either three factors (domestic, leisure/work, outdoor10 ; domestic, mobility/work, social/hobby4 ) or two factors (instrumental disability, handicap).12 The Hamrin Activity Index suggested a gender bias toward women performing better on the Household section, although studies of the Frenchay Activities Index did not show this as strongly. Guttman scaling was performed on the Rivermead and Nottingham measures and suggested a hierarchical nature to the items. Towle13 found that the hierarchical ranking of the Nottingham measure might not be consistent when depressed stroke patients were examined. Higher cognitive processing was not explored in tandem with some of the more complex activities; this may have been considered when the domains of reading books and writing letters were examined, although the relevance of these is subject to interpretation. Noticeably absent were the domains of managing one’s medical affairs as well as medication administration.
Notwithstanding the deficiencies in the above-mentioned scales, one must be wary of “measurement nihilism” in the challenge to rectify the situation. The methodological quality of each measure could be improved by further studies to refine the utility, reliability, and validity of the scale. It would be tempting to “tease out” and categorize the items in the physical, cognitive, and behavioral domains. If such were the case, then a concise scale could be designed so that testing a small number of items within each domain would predict capabilities for other items within the same domain. Another avenue to explore is the geriatric literature, where a vast source already exists, so that measures of value could be extracted. Comparison of the stroke IADL scales with the geriatric IADL scales would be the next step. Finally, the widespread applicability of identified geriatric IADL scales could be tested in the stroke population.
Four IADL measures were identified for use in the stroke population. Each measure has its own merits and deficiencies, as well as applicability, within the purpose and population for which the measure was designed. Further studies are needed to determine the relevance of these measures in a North American population.
I am grateful to and thank Marcel Dijkers, PhD, for assistance in the review of published statistical information relevant to scale reliability and validity. No commercial party having a direct or indirect interest in the subject matter of this article has conferred or will confer a benefit upon the author or upon any organization with which the author is associated.
- Received November 10, 1994.
- Revision received March 6, 1995.
- Accepted March 6, 1995.
- Copyright © 1995 by American Heart Association
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