Quality control in urodynamics: Analysis of an international multi-center study

To review the quality of urodynamic traces collected as part of a multi-center Phase II drug trial of a medication for overactive bladder (OAB), in order to assess adherence to the Good Urodynamic Practice (GUP) guidelines. To assess inter-rater reliability (IRR) for the numerical cystometrogram variables, and for the diagnosis of detrusor overactivity (DO).

Two central reviewers assessed 50 cystometrograms, recording the presence or absence of DO and assessing compliance with GUP guidelines. Three central reviewers independently assessed 20% of cystometrograms submitted, for numerical variables. IRR of central and peripheral assessments were compared with intra-class correlation (ICC) and Cohen's unweighted kappa statistics.

There was inconsistent adherence to GUP guidelines, because of differences in urodynamic equipment and practice. ICC between numerical variables assessed by the three central reviewers were excellent ranging between 0.830 and 0.997 (P all < or =0.001). ICC between numerical variables assessed by peripheral and central reviewers were good to excellent, ranging between 0.624 and 0.994 (P all < or =0.05). Central reviewers showed excellent agreement in the assessment of DO (kappa = 0.83). However central and peripheral reviewers showed poor agreement in the assessment of DO (kappa = 0.24).

Without standardization of equipment and training, adherence to GUP guidelines is problematic. Cystometric pressure and volume variables can however be reliably assessed in multi-center studies. DO cannot be reliably observed by interpreting the cystometrogram trace in isolation. Objective assessment of DO may therefore be unsuitable for multi-center studies reliant on central reporting of traces. Neurourol. Urodynam. 28:380-384, 2009. (c) 2008 Wiley-Liss, Inc.