Reliability and agreement of urodynamics interpretations in a female pelvic medicine center

To estimate the reliability and interobserver consistency of urodynamic interpretations of female bladder and urethral function.

Three urogynecologists and three female urologists at a tertiary care medical center reviewed masked, abstracted clinical and urodynamic information from 100 charts, selected for adequate completeness from a consecutive series of 135 women referred for urodynamic testing. For each of the 100 cases, the reviewers assigned International Continence Society filling and voiding phase diagnoses, and overall clinical diagnoses. Raw agreement proportions and weighted kappa chance-corrected agreement statistics (kappa) were used jointly to describe both reliability and interobserver agreement. Reliability was estimated from duplicate reviews, masked and separated by at least 4 months, of each case by each physician. Interobserver agreement was estimated from comparisons of all pairs of responses from different physicians.

For clinical diagnosis of stress incontinence (present, absent, indeterminate), the within- and across-physician weighted kappa's were, respectively, 0.78 and 0.68. Corresponding results were 0.40 and 0.13 for detrusor overactivity without incontinence, 0.58 and 0.38 for detrusor overactivity with incontinence, and 0.51 and 0.26 for voiding dysfunction. Standard errors of each kappa were between 0.023 and 0.043.

In our group, lower urinary tract diagnoses of stress urinary incontinence from both clinical and urodynamic data demonstrated substantial reliability and interobserver agreement. However, by conventional interpretation of kappa-statistics, reliability of diagnoses of detrusor overactivity or voiding dysfunction was only moderate, and interobserver agreement on these diagnoses was no better than fair. Urodynamic interpretations may not be satisfactorily reproducible for these diagnoses.