Classifying the probability of urinary incontinence in psychogeriatric nursing home patients

Urinary incontinence (UI) frequently occurs in psychogeriatric nursing home patients. In general the personnel involved in the care for these patients act on incontinence noted. Patients are not monitored or classified according to likelihood or severity of incontinence. This study was conducted to develop and validate a model for the classification of the likelihood of UI in demented nursing home patients. A multi-center cross-sectional study was conducted using data on clinical and functional status of 692 subjects. Subjects were subdivided in a Derivation set of 532 patients and a Validation set of 160 patients. The data were ascertained with questionnaires completed by physicians and nursing staff. All psychogeriatric wards (25) of four Dutch nursing homes were included. Using univariate logistic regression analysis on the derivation set we identified correlates of UI among 22 clinical and functional patient characteristics. Subsequently, we developed a classification model for prevalent UI, including independent patient characteristics by means of multivariable logistic regression. Next, we stratified patients into groups with varying likelihood's of UI based on the model developed. Subsequently, we transformed the model to an easy applicable classification rule for the identification of patient subgroups with high or low likelihood on UI. Finally, the rule was validated on the validation set. The independent multivariate factors associated with urinary incontinence were impaired ADL and mobility, diminished alertness and fecal impaction. After transforming the regression model to an easy classification rule, the scores ranged from 0 to 7. The area under the curve was 0.88 (95% Confidence Interval (CI): 0.85-0.91) in the derivation set. In the validation set a similar area under the curve was obtained (0.90 (95% CI: 0.85-0.95)). Among subjects with none of the associated factors the rule classified 0.5% as incontinent patients. In case all associated factors were present the proportion classified as incontinent increased to 91%. In conclusion, the developed classification rule provides means to stratifying nursing home patients according to their likelihood of being incontinent of urine.