Detrusor Activity Index: Quantification of Detrusor Overactivity by Ambulatory Monitoring

Abstract

Ambulatory urodynamic monitoring has been developed and evaluated during the last decade, and its appreciation is growing rapidly. We investigated the usefulness of this technique to quantify detrusor activity, and developed a parameter to quantify the grade of detrusor overactivity. We investigated 167 female patients with lower urinary tract symptoms and 61 asymptomatic volunteers. Detrusor behavior was classified according to the medical history findings and independently based on urodynamic investigation. The possible categories were termed overactive or not overactive. Subjects who were classified consistently formed the 2 reference groups, which were used in the statistical analysis of logistic regression. By logistic regression a scoring rule was developed. The individual score (detrusor activity index 0 to 1) is a measure of detrusor activity during the filling phase. At a cutoff point of 0.41 the sensitivity equaled specificity of 85% in our patient and volunteer groups. The scoring rule can be applied clinically as a test to detect and quantify detrusor overactivity in patients with urinary incontinence.