Low interrater reliability of videourodynamic diagnosis of detrusor external sphincter dyssynergia

Objectives: Complex bladder dysfunction requires urodynamic testing, often under fluoroscopy termed videourodynamic study (VUDS), to assist the diagnosis and management. Videourodynamic study is an objective tool with high interrater reliability (IRR) for identifying detrusor overactivity. However, IRR has not been validated with disorders associated with neurogenic bladder (NGB). We aim to investigate the IRR of VUDS to diagnose detrusor external sphincter dyssynergia (DESD) among NGB patients and hypothesize a high IRR to DESD diagnosis on VUDS. Methods: Videourodynamics tracings with fluoroscopic images were rated either positive or negative for evidence of DESD by 4 raters (2 neurourologists, neurourology fellow, and urology postgraduate year 2 resident), in patients who underwent VUDS from 2013 to 2017. The study population had known NGB without previous bladder reconstruction. The IRR was determined using percent agreement and κ values. Results: The experts had a percent agreement of 82.1% (κ = 0.26). Expert 1 and expert 2 had a percent agreement of 63.6% (κ = 0.1497) and 68.9% (κ = 0.2967), respectively, when compared with the fellow. Sensitivity and specificity ranged from 28% to 75% and 64% to 93%, respectively. The negative predictive values ranged from 90% to 95%. Conclusions: The IRR to diagnose DESD on VUDS was much lower than expected, even among experts, and was likely multifactorial and partially owing to lack of clinical context and lack of standardized VUDS interpretation of the electromyogram. A high negative predictive value was found among all participants. Further research is needed to evaluate factors contributing to the low reproducibility of DESD diagnosis on VUDS.