Authors

  1. Wallace, Meredith PhD, APRN, BC
  2. Shelkey, Mary PhD, ARNP

Abstract

The Katz Index of Independence in Activities of Daily Living can help nurses detect subtle changes in health and prevent functional decline.

 

Overview: Created 45 years ago, the Katz Index of Independence in Activities of Daily Living has shown itself to be an important tool in measuring an older adult's capacity to care for her- or himself. When a nurse using the tool notes a diminishment in the patient's ability to perform any of six activities-bathing, dressing, toileting, eating, transferring, or remaining continent-further assessment may uncover a reversible cause, such as a chronic or acute condition requiring treatment. A video demonstrating the use of the Katz index is available for free online at http://links.lww.com/A241.

 

Article Content

Carmella Clyde, 89, lives in the Blue Haven Gardens nursing home. (This case is a composite based on our experience.) Her medical history includes hypertension, cardiovascular disease, and type 2 diabetes mellitus. She is typically alert, pleasant, and cooperative and needs minimal assistance in managing the six activities of daily living (ADLs): bathing, dressing, toileting, eating, transferring, and remaining continent. But one morning Ms. Clyde stays in bed through breakfast and skips most of her morning activities. Her daughter visits in the afternoon and finds her mother to be surprisingly unsteady during their walk. That night Ms. Clyde has an episode of urinary incontinence, and the next morning she falls on the way to the bathroom, banging her head on the floor. She's transferred to the local ED where she's found to have a heart rate of 150 beats per minute, blood pressure of 168/94 mmHg, urine that is positive for blood and nitrites, and an elevated white blood cell count of 12 x 103/mm3. Ms. Clyde is admitted on suspicion of urosepsis. Standard treatment-ciprofloxacin (Cipro) 250 mg by mouth twice daily and iv fluids (5% dextrose and 0.45% saline) infused at 50 mL/hour-is ordered.

  
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But nurses also decide to begin regular evaluation of Ms. Clyde's functional status; this will ensure her safety and identify decompensation caused by illness and inactivity. The enhanced care plan, emphasizing recovery of both health and function, will allow Ms. Clyde to return to the nursing home and resume the activities she enjoyed before her fall.

 

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Web Video

Watch a video demonstrating the use and interpretation of the Katz Index of Independence in Activities of Daily Living at http://links.lww.com/A241.

 

A Closer Look

Get more information on why it's important for nurses to assess functional status in older adults, as well as why the Katz index is the right tool for the job.

 

Try This: The Katz Index of Independence in Activities of Daily Living

This is the tool in its original form. See page 67.

 

Online Only

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THE KATZ INDEX

Changes in the functional status of older adults are common, have many causes, and can result from a variety of diseases. As in the case of Ms. Clyde, functional deterioration can signal underlying but as yet undetected illness or an exacerbation of illness. In many cases, a loss of function is treatable and reversible and, by alerting clinicians to the need for intervention, may avert more serious illness. Success depends upon careful monitoring and assessment. The Katz Index of Independence in Activities of Daily Living (referred to as the Katz index or the Katz ADL) is a tool for assessing an older adult's baseline ability to bathe, dress, use the toilet, transfer, remain continent, and feed her- or himself. It's also used for evaluating changes in response to illness. Designed 45 years ago to measure the functional status of nursing home residents, it is also used in residential care settings to measure nursing workload.1-3 The Katz index is easy to use and adaptable to most clinical settings. Ongoing evaluation of functional ability is no less important in acute care settings because of older patients' diminished immune function and higher incidence of chronic conditions such as cardiovascular disease and diabetes. Using the Katz index can help hospital nurses improve patient safety, detect subtle changes in health, and prevent functional deterioration. (For more information, see Why Assess Older Adults' Ability to Perform Activities of Daily Living? above.)

 

Why Assess Older Adults' Ability to Perform Activities of Daily Living?

There are 36 million people ages 65 and older in the United States, making up roughly 12% of the population, according to 2003 U.S. Census Bureau data.4 This figure is expected to more than double to 87 million-20% of the population-by 2050.5

 

According to the Federal Interagency Forum on Aging-Related Statistics, 13% of men and 20% of women ages 65 to 74 in 2002 reported that they were unable to perform at least one activity of daily living (ADL); the percentages rose to 35% of men and 58% of women among those 85 or older in the survey group.5 A 2005 survey by the MetLife Mature Market Institute found that 50% of nursing home residents require assistance with five ADLs.6

 

Functional decline in hospitalized older adults can have devastating consequences. A 2004 study of 1,147 adults in the United States ages 66 and older (mean age, 74 years) found that functional dependence significantly predicted later institutionalization.7 A similar study in 2005 of 2,805 older adults in Australia found that severe physical impairment correlated with a 59% increase in nursing home placement.8

 

Functional status and illness. Even normal aging undermines one's ability to function independently and increases the potential for illness and injury. (See "Functional Decline in Hospitalized Older Adults," January 2006.) For example, flexibility and bone strength diminish with age, making older people more vulnerable to musculoskeletal problems. Chronic illness can also undermine function. Age-related changes can occur in all body systems. In the respiratory system, for example, lung volume and rib cage expansion can diminish, which can cause a reduction in arterial oxygen pressure. According to the American Lung Association, "In 2004, influenza and pneumonia combined were ranked as the eighth leading cause of death in the United States and the fifth leading cause in people over 65."9

 

Functional decline may be the first sign of changing health status. Older adults with chronic conditions or acute illness often complain of fatigue, which can lead to a diminished ability to perform one ADL or more. Ferrucci and colleagues reported changes in older adults' functional status associated with at least eight diseases, including pneumonia and congestive heart failure.10 Functional decline is even more common in elderly people with cognitive impairment. Hakkinen and colleagues reported that prior to hip fracture, patients with reduced cognitive ability were more functionally dependent than those without dementia.11 Depression and other psychiatric illness can also erode functional ability.12

 

In the case discussed at the beginning of this article, Carmella Clyde's unwillingness to get out of bed or eat and her episode of incontinence turned out to be the first signs of an illness-urosepsis-that quickly became life threatening. A lack of response to her functional decline delayed diagnosis until she required hospitalization. Because of the strong link between changes in older adults' functional status and the onset of illness, Amella recommends an approach to care that goes beyond recording the medical history and vital signs to examine changes in patients' "mental, functional, nutritional, and social-support status."13

 

ADMINISTERING THE TOOL

Imagine that you're the nurse responsible for Ms. Clyde's discharge planning. Although she has responded to treatment and no longer needs acute care, her illness and the stresses of hospitalization have left her debilitated. The nursing home staff will need guidance on how to ensure the fullest possible recovery.

 

Ideally, use of the Katz index to assess patients' functional status begins on admission to an acute care facility and is repeated at regular intervals and in response to changes in health. Indeed, Medicare documents-the Minimum Data Set, for example-require documentation of functional status. Patients should be informed of the evaluation and told how and why it is done.

 

You tell Ms. Clyde that her ability to perform six basic activities-eating, dressing, bathing, getting in and out of the bed or a chair, using the toilet, and controlling her bladder and bowels-will be evaluated and that the results of this evaluation will be included in the discharge plan so the staff at Blue Haven Gardens can continue to support her recovery.

 

You quickly note some loss of strength in Ms. Clyde: she needs help getting out of bed and using the toilet and shower. On the positive side, she can feed and dress herself without difficulty and is continent.

 

The Katz index helps to organize these observations into a clinically useful framework, yielding numeric scores that sum up a patient's functional status. The instrument employs a dichotomous (yes-or-no) scale, with 1 point given for each ADL in which the patient is independent and 0 points given for each ADL in which the patient is dependent. The highest possible score is 6, signifying independence in all ADLs; the lowest is 0, meaning the patient needs help with every activity. Ms. Clyde can eat, remain continent, and dress independently, but she needs help in transferring, toileting, and bathing. This gives her a Katz index score of 3: moderate dependence.

 

ADAPTING THE KATZ INDEX IN DIFFERENT SETTINGS

The Katz index has been used successfully with long-term care residents, albeit with some adaptation. Older adults often have far more complicated needs than Ms. Clyde does, with clinical or cultural characteristics that require one's judgment in using the tool. Among the challenges are language barriers, dementia, and other conditions that interfere with communication or cognition.

 

Although the Katz index assesses ADLs that are not language dependent, interpreters may be needed to ask older patients to perform specific activities or to explain the basis for their refusal. Confusion, whether from dementia, delirium, or simple disorientation caused by illness, may mean that older patients can't follow instructions to dress, use the toilet, or bathe. The Katz index measures current functional ability in any patient, regardless of cognitive status. Any inability noted in the six ADLs, whether caused by mental or physical incapacity, must be given a score of 0 points. The central element in scoring the Katz index is patients' ability to demonstrate functional independence to a clinician. If they can't perform an ADL-for whatever reason-they must be scored as dependent in that category. Even patients with sensory impairment, amputation, or neurologic disorders are scored on current ability.

 

There may also be environmental challenges to using the Katz index. Some hospitals and skilled nursing facilities don't have bathing facilities or toilets readily available, making assessment in these areas difficult. Moreover, some nursing staff assist older adults with ADLs simply to save time, even when the patients are capable of performing them independently. It's critical that all nursing staff encourage older adults to remain as independent as possible. Using the Katz index in acute care settings may require a new institutional emphasis on the nursing staff's responsibility to support patients' functional independence. (To view the section of the online video discussing assessment, interpretation, and discharge planning, go to http://links.lww.com/A242.

 

COMMUNICATING THE KATZ INDEX RESULTS

The results of a functional assessment using the Katz index should be shared with the clinical team, the patient, and family members; they all have roles to play in improving function. Patients and family members in particular need a clear explanation of what the score means and what work the patient must do to achieve independence or, if that's not possible, to make good use of assistance. This usually requires an explanation of the categories assessed-for example, explaining remaining continent as "controlling your bladder and bowels" or transferring as "getting in and out of bed or up from a chair by yourself." It's also important to explain how functional status relates to living independently and how the plan of care aims to restore independence. The plan of care will likely involve ongoing nursing assessment and care to restore function and prevent further decline, as well as referral to physical and occupational therapists, if necessary.

 

Explaining Katz index scores to patients may require extra effort when particular barriers are present: insufficient fluency in English, hearing or other sensory impairment, aphasia, delirium, or dementia. Facing the patient, using pencil and paper or computer printouts, asking the patient to repeat what was said, and being alert for nonverbal indicators of comprehension may help to ensure that the Katz index results have been successfully communicated.

 

Nurses should be vigilant about ensuring that any changes in a patient's functional status are communicated to the clinical team and that the plan of care is modified as the patient's abilities improve or decline. In communicating results to a team whose members may not be familiar with the Katz index, a nurse may simply summarize the results. In the case of Ms. Clyde, who received a score of 3 on the Katz index, the nurse might say, "She has a moderate level of dependence." Specifically, the nurse may report deficits in the patient's ability to transfer, toilet, and bathe independently. Documentation in the chart would also include explanation for clinical staff unfamiliar with Katz scoring: "Patient scored 3 out of 6 on Katz ADL index, indicating moderate level of dependence, with deficits in ability to transfer, toilet, and bathe independently." (To watch the portion of the online video discussing nurses' role in preventing functional decline, go to http://links.lww.com/A243.

 

CONSIDER THIS

What evidence supports using the Katz index? Over the last several decades, numerous tools have been developed to assess patients' abilities to perform activities of daily living.14-16 The Katz index has emerged as an especially useful tool in assessing older adults; in determining nursing load in long-term care settings; and in predicting length of hospitalization, morbidity and mortality over time,1,17 and the need for future assistance.3 Because of its predictive value, the Katz index is often used to determine eligibility for assistance and benefits18,19 and by researchers studying older adults.

 

What are the psychometrics associated with the Katz index? There are few studies establishing psychometric properties of tools designed to measure patients' functional status. But the limited data available support the reliability and validity of the Katz index.

 

Reliability. The Katz index has shown good reliability, as evidenced by reliability coefficients ranging from 0.87 to 0.94.20

 

Validity. The Katz index has demonstrated accuracy in predicting functional outcomes over time among older adults in short-term care, hospitalized patients, and patients who have had a stroke.1,3,17 Hamrin and Lindmark reported convergent (or concurrent) validity as high, with a correlation of 0.95 between the Activity index and the Katz index.1

 

No specific studies of specificity and sensitivity of the Katz Index were found in the literature. For more information on the psychometric properties of the Katz index, go to http://links.lww.com/A410.

 

Watch It!!

Go to http://links.lww.com/A241 to watch a nurse assess an older adult's functional status and discuss how to intervene when abilities are compromised.

 

View this video in its entirety and then apply for CE credit at http://www.nursingcenter.com/AJNolderadults; click on the How to Try This series link. All videos are free and in a downloadable format (not streaming video) that requires Windows Media Player.

 

Online Resources

For more information on this and other geriatric assessment tools and best practices go to http://www.ConsultGeriRN.org-the clinical Web site of the Hartford Institute for Geriatric Nursing, New York University College of Nursing, and the Nurses Improving Care for Healthsystem Elders (NICHE) program.

 

Visit the NICHE site, http://www.nicheprogram.org, and the Hartford Institute site, http://www.hartfordign.org, for additional products and resources. The latter site includes a set of competencies expected of nurses who care for older adults in hospitals.

 

Go to http://www.nursingcenter.com/AJNolderadults and click on the How to Try This link to access all articles and videos in this series.

 

REFERENCES

 

1. Hamrin E, Lindmark B. Evaluation of functional capacity after stroke as a basis for active intervention. Scand J Caring Sci 1988;2(3):113-22. [Context Link]

 

2. Katz S, et al. Studies of illness in the aged. The index of ADL: A standardized measure of biological and psychosocial function. JAMA 1963;185:914-9. [Context Link]

 

3. Katz S, et al. Progress in development of the index of ADL. Gerontologist 1970;10(1):20-30. [Context Link]

 

4. He W, et al. 65+ in the United States: 2005. Washington, D.C.: U.S. Census Bureau; 2005 Dec. P23-209. Current population reports. Special studies; http://www.census.gov/prod/2006pubs/p23-209.pdf. [Context Link]

 

5. Federal Interagency Forum on Aging-Related Statistics. Older Americans 2004: Key indicators of well-being. Hyattsville, MD; 2004. http://www.agingstats.gov/Agingstatsdotnet/Main_Site/Data/Data_2004.aspx. [Context Link]

 

6. MetLife Mature Market Institute. The MetLife market survey of nursing home and nursing home care costs. Westport, CT: Metropolitan Life Insurance Company; 2004. [Context Link]

 

7. Bharucha AJ, et al. Predictors of nursing facility admission: a 12-year epidemiological study in the United States. J Am Geriatr Soc 2004;52(3):434-9. [Context Link]

 

8. McCallum J, et al. Patterns and predictors of nursing home placement over 14 years: Dubbo study of elderly Australians. Australas J Ageing 2005;24(3):169-73. [Context Link]

 

9. American Lung Association. Lung disease fact sheets. New York; 2006 Nov. http://www.lungusa.org/atf/cf/%7B7A8D42C2-FCCA-4604-8ADE-7F5D5E762256%7D/SOLDDC_. [Context Link]

 

10. Ferrucci L, et al. Hospital diagnoses, Medicare charges, and nursing home admissions in the year when older persons become severely disabled. JAMA 1997;277(9):728-34. [Context Link]

 

11. Hakkinen A, et al. Effect of cognitive impairment on basic activities of daily living in hip fracture patients: a 1-year follow-up. Aging Clin Exp Res 2007;19(2):139-44. [Context Link]

 

12. Mehta KM, et al. Cognitive impairment, depressive symptoms, and functional decline in older people. J Am Geriatr Soc 2002;50(6):1045-50. [Context Link]

 

13. Amella EJ. Presentation of illness in older adults. Am J Nurs 2004;104(10):40-51. [Context Link]

 

14. Bruett TL, Overs RP. A critical review of 12 ADL scales. Phys Ther 1969;49(8):857-62. [Context Link]

 

15. Law M, Letts L. A critical review of scales of activities of daily living. Am J Occup Ther 1989;43(8):522-8. [Context Link]

 

16. Sainsbury A, et al. Reliability of the Barthel Index when used with older people. Age Ageing 2005;34(3):228-32. [Context Link]

 

17. Brorsson B, Asberg KH. Katz index of independence in ADL. Reliability and validity in short-term care. Scand J Rehabil Med 1984;16(3):125-32. [Context Link]

 

18. Kane RL, et al. Using ADLs to establish eligibility for long-term care among the cognitively impaired. Gerontologist 1991;31(1):60-6. [Context Link]

 

19. Rowland D. Measuring the elderly's need for home care. Health Aff (Millwood) 1989;8(4):39-51. [Context Link]

 

20. Ciesla JR, et al. Reliability of Katz's Activities of Daily Living Scale when used in telephone interviews. Eval Health Prof 1993;16(2):190-203. [Context Link]