The calculation and comparison of the Detrusor Contractility Parameter and Watts Factor.

AIMS

To test the significance of association between a validated index of detrusor contractility, v , the Watts Factor, and the Detrusor Contractility Parameter, t ; and to test whether t depends on outflow tract resistance as indicated by Bladder Outlet Obstruction Index (BOOI).

METHODS

Thirty-seven pressure-flow traces from 20 male and 17 female patients were analyzed and forms of the Watts Factor, t and BOOI were compared with v .

RESULTS

The Detrusor Contractility Parameter, t , is significantly associated with v for both women and men without a high degree of bladder outlet obstruction. The Watts Factor only had a significant association with v at the point of maximum flow in women.

CONCLUSIONS

The Detrusor Contractility Parameter (DCP) (t ), can be measured easily from the pressure flow curves of a urodynamic test. The Watts Factor at maximum urine flow, WF , can be readily calculated, but is only applicable to women. In both women and men without a high degree of bladder outlet obstruction, DCP is better associated with true detrusor contractility than any Watts Factor analysis.