When aging adults survive the acute effects of cardiac and/or vascular disease, they are asked to adapt to lifestyle changes aimed at managing what now is chronic disease. Whether simple or complex, treatment guidelines will include recommendations for diet, weight management, and physical activity as well as medications to improve blood flow, cardiac performance, and risk factor profiles. The response to these recommendations will be influenced by patients' functional and cognitive abilities. Baseline assessment and repeated monitoring of functional and cognitive ability can assist healthcare providers caring for patients with cardiac and vascular disease understand their patients' ability to function in day-to-day living and assist in the determination of when and if, in the course of treatment, their patients will require intervention to maximize the benefits of treatment and more importantly maintain their independence.
The article begins with a discussion of tests of functional ability including self-report of the ability to engage in activities of daily living, observation of the performance of particular activities such as moving from a sitting position to a standing position, observation of stair climbing, and timed tests of mobility. Assessment of life space mobility and the use of global/single-item indicators to assess disability and physical activity are also highlighted. This is followed by discussion of ways in which cognitive ability is assessed, primarily assessment of mental status, and executive function (Table 1).
Functional Ability
Assessment of functional ability lends insight into how patients are able to carry out activities of daily living, specifically whether they can perform these activities independently. Patient self-report, clinician/researcher observation, and timing of particular tasks are common approaches to an assessment of functional ability.
Self-Report
The most widely used self-report of functional ability is the Katz Index of Activities of Daily Living (ADL).1,2 Patients are asked to rate their ability to perform basic activities of daily living: bathing, dressing, grooming, toileting, transfer, continence, and feeding as to how much help/assistance they need to perform each of the tasks (none, some assistance, complete assistance). Activities of Daily Living impairment increases in concert with the number of daily living tasks with which there is need for assistance. The psychometric properties of the ADL are well established, particularly with aging patients. The following psychometric statistics are reported: test-retest reliability of 0.95-0.98; correlation with the Mini-Mental State Examination(MMSE) of 0.75 and interrater reliability of 0.85-0.936.3-5 Its primary advantages are that it is readily understood and is easily administered in a restricted time frame. However, the ADL does not capture changes that patients may make in the way they do certain tasks or changes in the number of times they perform certain tasks, both indicators of beginning functional limitation.6
Instrumental Activities of Daily Living (IADL) is also widely used and has well-established psychometric properties.3-5 Richmond and colleagues report an internal consistency of 0.93 and interrater reliability of 0.85.5 The IADL evaluates the capacity to perform the tasks of daily life that also require cognitive skills such as the ability to use the telephone, shop for groceries, use transportation, prepare meals, engage in housekeeping, take medications, and handle finances.7 As the ADL, the IADL is readily understood by patients and can be completed in minutes. Differing scoring systems have evolved over decades of use. Some advocate restricting the response scale to 3 categories, whereas others use a more detailed response scale with up to 8 categories for each task. However, the IADL is scored and the interpretation is generally the same. Instrumental Activities of Daily Living impairment occurs when the individual needs assistance with 1/7 instrumental activities, and as the ADL as the number of tasks requiring assistance increases, the greater the functional impairment.
The intent of Life Space Assessment (LSA) is to determine patients' mobility within their homes and communities.8 Life space is conceptualized by level of life space ranging from beyond the room where one sleeps to beyond the place where one lives to the neighborhood, town, and beyond. For every life space level, the patients are asked whether they have been to that level in the past 4 weeks, how often they have been to that level (frequency), and whether they needed help to get there (an aid, equipment, or help from another person). The LSA is both valid and reliable. Given that mobility is an important aspect of functional independence, the primary advantage of the LSA is that it can be used to determine how well patients are able to navigate their immediate living space and areas beyond their immediate living space. The LSA can be administered in 5 to 10 minutes and is appropriate for a face-to-face assessment or telephone interview. Because the LSA assesses actual patterns of mobility, it extends the measurement of functional ability from the performance of specific tasks as is the case with ADL and IADL to a better understanding of what patients are actually able to do or not do given the need to move from place to place in order to do what it is they need to do. Test-retest reliability has been established between baseline and 2-week follow-up with a correlation of 0.86 (95% confidence interval = 0.82-0.97).9
Single-item Indicators
Single-item indicators can also be considered for use in the assessment of functional ability, supplying additional information and often validating other information on functional limitations or level of physical activity. Scores on single items are highly predictive of declining functional ability. The question "during the past 30 days, about how many days did poor physical or mental health keep you from doing your usual activities such as self care, work or recreation" is highly related to functional limitation(s).10 Likewise, asking women to report "usual physical activity" using 3 options, highly active (5 points), moderately active (3 points), or inactive (1 point) is a reliable and valid option for assessing the level of physical activity.11 Physically active aging adults are stronger, more flexible, have greater endurance, and have better coordination than those not physically active.12 Higher levels of physical activity have also been linked to lower resting heart rate, higher high-density lipoprotein cholesterol, and lower systolic blood pressure,12 which are important considerations for patients with cardiac and vascular disease.
Observation
The Physical Performance and Mobility Examination (PPME) is appropriate for use with both hospitalized and community-dwelling older adults.13 The PPME is easy to use and score, either as pass-fail or using a 3-point scale. Actual performance of 6 tasks (bed mobility, transfer skills, multiple stands from chair, standing balance, step up, and ambulation) is assessed. The psychometric properties of the PPME are well established. Test-retest reliabilities for the pass-fail version range from 0.53 to 1.00, and for the 3-point scale version, the test-retest reliabilities range from 90 to 1.00. Construct validity of the PPME is supported by stable correlations with self-report of activities of daily living, instrumental activities of daily living, and mental status ranging from .31 to .46. A primary advantage of the PPME is that there is opportunity for the examiner to directly observe patient performance, rather than rely solely on self-report. However, the PPME may not be appropriate for use in its entirely in every situation, as, for example, bed mobility cannot be evaluated in settings without beds. In addition, there will be patients who will be unable to perform the tasks in succession because of pain, fatigue, or shortness of breath.
Assessing stair climbing ability is important for those whose living situations require the use of stairs to enter the place of residence or to move about within it. Observational Stair-Climbing Performance Examination is designed to assess 6 parameters of stair climbing performance: handrail use, walking style, medial/lateral position on stairs, sideways, hesitation at initial transition from landing, and upper body movement.14 The interrater reliability of the Observational Stair-Climbing Performance Examination ranged from 0.60 for frontal plane motion during stair ascent and descent to 1.00 for walking style. Handrail use also had high interrater reliabilities of 0.92 for ascent and 0.88 for descent. Medial lateral position on the stairs and sideways positioning scores were 0.7 or greater. However, hesitation scores and instability of the upper body in the frontal plane were lower and ranged from 0.60 to 0.66. Advantages are that the Observational Stair-Climbing Performance Examination can be completed in 5 to 10 minutes and, more importantly, that the examiner can directly assess how a patient uses the stairs. Thus, when there is difficulty in using the stairs, the examiner can determine what modifications to suggest when using the stairs.
Timed Tests of Mobility
The 6-Minute Walk Test15 mimics the submaximal energy expenditure required for common daily activities. The test is safe, simple, and easy to perform, requiring no special equipment. Patients who walk less than 300 m in 6 minutes are more likely to suffer impairment that will influence their ability to engage in activities of daily living than those who walk more than 300 m in the 6 minutes. There are absolute contraindications to the 6-Minute Walk Test: unstable angina or myocardial infarction in the previous month, uncontrolled hypertension, and resting heart rate of greater than 120 beats per minute. Although the 6-Minute Walk Test can be adapted to a variety of settings and is appropriate for use with aging patients with diagnoses of cardiac and vascular disease, 6 minutes of walking may not always be reasonable for every patient or realistic, given the constraints of the setting. To address such concerns, at least in part, a 2-Minute Walk Test was developed, tested, and used with cardiac surgery patients.16 The 2-Minute Walk Test was shown to be sensitive to change after cardiac surgery and was significantly related to the physical function subscale of the SF-36 (r = 0.48; P = .001). Further supporting the validity of the 2-Minute Walk Test, significant differences in performance were noted between those NYHA class I and II compared with those classified as NYHA class III or IV (P = .04).
Cognitive Ability
The MMSE17 is the most frequently used bedside test of cognition. The MMSE has well-established psychometric properties, including internal consistency of 0.68 to 0.96, test-retest reliability of 0.79 to 0.97, sensitivity of 0.87 to 1.00, and specificity of 0.82 to 1.00.18 The MMSE is robust across settings and retains its psychometric properties despite gender, race, ethnicity, and social class. The MMSE consists of 11 questions grouped into 5 categories, each category representing a particular cognitive domain: orientation, registration, attention, recall, and language.17 Points for correct responses to each question vary (1-5 points) according to the number of parts in the questions. Scores range from 0 to 30, scores of 23 or below are indicative of impairment. Since its development, the MMSE has been used extensively to assess cognitive function in aging men and women in hospitals, long-term care facilities, and community settings and has become one of the gold standards in cognitive assessment. Requiring 5 to 10 minutes to complete, the MMSE can be realistically used in most settings, even those with high patient volume.
Executive Function
Assessment of executive function adds additional dimensions to the assessment of cognitive ability. The term executive function is synonymous with those tasks relative to frontal lobe function including a wide range of abilities that integrate, organize, and maintain other cognitive processes such as memory and attention.19 The definition of executive function continues to evolve; however, most agree that executive functions include abilities such as sequencing of behavior, flexibility, planning, and organization of behavior.20 Executive function is complex, making it difficult to distinguish what cognitive processes are actually involved.21 What is important is that executive function is linked to activities of daily living, particularly IADL performance, which involves physical tasks and those cognitive processes involved in the execution of the tasks.
Research has shown that elders without cognitive impairment are better able to engage in activities of daily living compared with those more cognitively impaired who require assistance. Age-related declines in executive function, defined by processes involved with complex goal-directed activities such as cooking, dressing, and housework, predict change in functional status.22 Declines are not easily detected by the MMSE but clock drawing is one approach to assessing executive function.23 Although there are variations as to what is said to the patient, the time the patient is asked to affix to the clock, and the scoring of the test, all variations ask the patient to first draw the face of a clock on a predrawn circle. This test usually takes only a few minutes and has been shown to be a quick screening tool for executive dysfunction. Clock drawing involves executive control functions that guide complex goal-directed behavior, similar to those demands required for independent living skills.24
Discussion
The intent of this article was to present ways in which the assessment of functional and cognitive ability can be approached in patients with cardiac and/or vascular disease. The tests reviewed are summarized in Table 2. It is our hope that readers take the opportunity to review these approaches and that when deciding to adopt particular assessments into patient care protocols, that consideration be given to the characteristics of individual patients. Following are instances of how we have applied the measures of functional and cognitive ability in particular patients. These examples are composites of patients we have known.
Mrs S. is an elderly woman, 88 years of age. After experiencing an episode of prolonged chest pain, she called 911 and was taken to the emergency department. From the emergency department, she went to the cardiac catheterization laboratory where she had angioplasty. She had no previous history of heart or vascular disease but stated that she was experiencing increased pain due to arthritis. At her follow-up appointment at the cardiology clinic, she reported that she was now able to resume her usual activities but the arthritis pain (hips and knees) had progressively increased to the point that it was now difficult to walk or to climb stairs. She was mentally alert, discussing the upcoming presidential election. Given that she reported decreased ability to change positions due to arthritis pain, and the fact that she would continue to be followed, baseline assessments for Mrs S. included LSA, PPME, and a 2-minute walk. These assessment measures were used to develop an individualized activity prescription for Mrs S. and to monitor her progress.
The second case is of Mr J., a 74-year-old former college athlete and major league baseball player who had coronary artery bypass grafting surgery 10 years prior to before his admission. Since his coronary artery bypass grafting, he reported that he exercised 4 to 5 days per week, followed a low-fat diet, and maintained normal weight and blood pressure. On the day of admission to our medical center, he collapsed when leaving the fitness center after an extensive workout that included a weight training routine and running 5 miles on a treadmill. Following extensive cardiac testing, an implantable defibrillator was inserted. Mr J. was discharged 2 days later. At his first follow-up visit (cardiology clinic) 3 weeks after the implantable defibrillator insertion, Mr J. reported that he felt physically alright but that he was suffering memory lapses. Baseline assessments of functional status for Mr J. included the PPME, Observational Stair Climbing Examination, and the 6-Minute Walk Test. Cognitive status was evaluated using the MMSE and the Clock Drawing Test. Recommendations forwarded to his cardiologist included that Mr J. be reevaluated on these parameters at each subsequent appointment.
These case examples illustrate the need to develop an appreciation of the impact of declining functional and/or cognitive status when caring for aging patients with cardiac and/or vascular disease, particularly when declining status threatens independence in day-to-day living and patients' ability to follow the treatment regimen. Whether cognitive decline precedes, occurs in tandem with, or follows functional decline remains at issue. What is known is that when either declines, there are or will be problems of decline in the other.25
Limitations in ADL increase exponentially with advancing age, hospitalization, and increasing disease burden.26 In patients with cardiac and/or vascular disease, disease burden waxes and wanes in concert with acute exacerbations of the primary illness requiring hospitalization and each additional comorbid illness. Hospitalization, although sometimes necessary, has its own set of notable problems, including loss of independence as a function of increased dependence in ADL.27-29
Recently, nurse investigators published a conceptualization of cognitive deficits in chronic heart failure.30 Based on an exhaustive review of the literature, this model incorporates symptoms of chronic heart failure; contributing factors such as age, comorbid conditions, hypertension, and depression; covariates such as medications, gender, and education; and particular cognitive deficits that have been observed in studies of patients with chronic heart failure. Additional conceptualizations are sorely needed, including conceptualizations of functional decline as related to patients with cardiac and/or vascular disease, as well as broader conceptualizations that incorporate both functional and cognitive decline.
Acknowledgment
Dr Holm was awarded an American Academy of Nursing/John A. Hartford Foundation Building Geriatric Nursing Capacity Fellowship (2002-2004). Dr Foreman served as her sponsor, teacher, and mentor.
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