Aims:
Katz index* assesses independancy of a person in performing activities of daily living
(bathing, dressing, toileting, transfering, continence, feeding). We evaluated the
use of Katz index for the prediction of inadequate bowel preparation among inpatients
undergoing colonoscopy.
Methods:
Post-hoc analysis of the data from a cohort inpatients undergoing colonoscopy in 4
tertiary Greek centers. To calculate Katz index each of the aforementioned domains
scores 1 point if patient performs the respective activity independantly (range 0
– 6; higher value indicates higher independancy level). We used the Area Under the
Curve (AUROC) to determine Katz index discriminative ability to predict inadequate
bowel prep.
Results:
Out of 261 patients (100 bedridden, 140 men, 70.7 ± 15.4 years old) 89 (34,1%) had
inadequate bowel preparation (BBPS< 6). Katz index was higher among ambulatory compared
to bedridden patients (p < 0.0001), but it did not differ between individuals with
adequate and inadequate bowel preparation (p = 0.08). Katz index showed a low discriminative
ability to predict inpatients with inadequate bowel preparation not only in the entire
cohort [AUROC (95% CI)= 0.44 (0.36 – 0.52), p = 0.11 but also in the groups of ambulatory
and bedridden patients [AUROC (95% CI)= 0.50 (0.39 – 0.60), p = 0.9 and 0.55 (0.43
– 0.67), p = 0.4 respectively].
Conclusions:
Katz index failed to predict satisfactorily inpatients (either ambulatory or bedridden)
with inadequate bowel preparation before colonoscopy.
*Katz, S, et al. Progress in the development of the index of ADL. The Gerontologist; 1970;10, 20 – 30.