Study design, materials and methods
A Retrospective study of Urodynamics traces was done in 167 women. Patients with bothersome lower urinay tract symotoms and mixed urinary incontinence, with normal Urodynamics study was used as Control.Abnormal Urodynamics included Bladder outflow obstruction, Derusor overactivity and Detrusor underactivity or a combination ,were included. Urodynamic values of Detrusor pressure at maximum flow pDet@Qmax and max flow ml/ sec (Qmax) were used to derive the Bladder contractility Index BCI, with the formula, pDet@Qmax+5(Qmax).
Interpretation of results
Bladder contractility Index in normal control group was 143.5+/- 55.8. The other group had contractility index of 116.+/-64. p value 0.017, which is statistically significant. AUROC 67%, p=0.0001. Cut off value of BCI was derived at 113.4, based on Youden Index, with a sensitivity of 73% and specificity of 57% .
Another observation made was a statistically significant p value of p=0.0001 between the normal group BCI= 143.5+/- 55 and Bladder outflow obstruction with hypocontractile bladder (or detrusor underactivity) with Impaired contractility BCI= 87+/- 37.AUROC 80% with a cut off value of BCI at 114.5, with a sensitivity of 70% and specificity of 83%.