Limitations of the Continence Item in Katz Activities of Daily Living Scale

Letter to the Editor

The potential increase in dependence in Activities of Daily Living (ADL) with global aging is an important public health issue. Evaluation of ADL is one of the major elements of comprehensive geriatric assessment. Dependence in basic ADL is associated with increased care burden for relatives of elderly people. Thus, an accurate assessment of basic ADL is crucial in clinical practice. Although there are various instruments to assess ADL, Katz ADL scale is among the most commonly used [1]. However, there is an important limitation of Katz ADL scale. One would be anticipated to become dependent on ADL in a gradual manner and generally following an order [2]. In this context, while more advanced basic ADL items like bathing and dressing would necessitate help before more simple and more frequently performed ones like continence and feeding. Dependence means inability of an individual to perform a particular item by him or herself. However, in the original version of Katz ADL scale, experience of incontinence episodes renders one as dependent in this ADL item. Considering the rather high prevalence of Urinary Incontinence (UI) in elderly people, we would erroneously define many completely independent individuals as dependent. In this context, many elderly individuals experience UI occasionally and can manage social and hygiene problems associated with UI by themselves. For instance, in a recent review, ‘bothersome incontinence’ was defined as “involuntary loss of urine that is a social or hygienic problem” [3]. So, why do we tar such an individual with the same brush as a demented patient with diapers? In a recent validation study of Katz ADL scale from Turkey, incontinence was far more common than other items and the item ‘continence’ had lower correlation with other items of this scale [2]. Another previous study suggested that the item continence had lower correlation with the total score and the lowest loading [4]. Furthermore, Katz ADL scale was modified by several authors, including by Katz himself, to exclude the item ‘continence’ because having incontinence did not necessarily mean being dependent on this activity [5,6]. However, the most commonly used Katz ADL scale is still the aforementioned original version, which does not exclude this item. We suggest that, it may be rational and clinically relevant to define dependence in continence item of Katz as needing care because of incontinence or inability to manage hygiene or social problems associated with it.

References

1. Katz S, Downs TD, Cash HR, Grotz RC. Progress in development of the index of ADL. Gerontologist. 1970; 10: 20-30.
2. Arik G, Varan HD, Yavuz BB, Karabulut E, Kara O, Kilic MK, et al. Validation of Katz index of independence in activities of daily living in Turkish older adults. Arch Gerontol Geriatr. 2015; 61: 344-350.
3. Abrams P, Andersson KE, Birder L, Brubaker L, Cardozo L, Chapple C, et al. Fourth International Consultation on Incontinence Recommendations of the International Scientific Committee: Evaluation and treatment of urinary incontinence, pelvic organ prolapse, and fecal incontinence. Neurourol Urodyn. 2010; 29: 213-240.
4. Mystakidou K, Tsilika E, Parpa E, Mitropoulou E, Panagiotou I, Galanos A, et al. Activities of daily living in Greek cancer patients treated in a palliative care unit. Support Care Cancer. 2013; 21: 97-105.
5. Branch LG, Katz S, Kniepmann K, Papsidero JA. A prospective study of functional status among community elders. Am J Public Health. 1984; 74: 266-268.
6. Al Snih S, Graham JE, Ray LA, Samper-Ternent R, Markides KS, Ottenbacher KJ. Frailty and incidence of activities of daily living disability among older Mexican Americans. J Rehabil Med. 2009; 41: 892-897.