The reproducibility of urodynamic studies of neurogenic bladders in spinal cord injury

OBJECTIVE: To evaluate the reproducibility (test-retest reliability) of urodynamic studies in neurogenic bladders of subjects with spinal cord injuries (SCI). DESIGN: Retrospective case series. SETTING: Urology department of a major rehabilitation center. SUBJECTS: Fifty individuals with SCI who had urodynamic studies performed from February 2000 to April 2000. MAIN OUTCOME MEASURES: Two trials (Time 1 and Time 2) of urodynamic studies done 5 minutes apart, with the following collected: bladder volume at first sensation, maximum cystometric capacity, presence of uninhibited contractions, opening pressure, maximum detrusor pressure, duration of bladder contraction, volume voided, and post-void residual (PVR) volume. The corresponding data were then compared. Statistical analysis was performed using the Lin's concordance correlation coefficient and kappa. RESULTS: Analysis of the data showed statistically significant levels of agreement between Time 1 and Time 2 with regard to the various corresponding parameters for both the filling and voiding phases. For 3 of the most important parameters-the opening pressure, maximum detrusor pressure, and duration of contraction-the Lin's concordance correlation coefficient (r(c)) was .86 (95% CI, .78-.95; p < .0005), .91 (95% CI, .86-.96; p < .0005), and .97 (95% CI, .95-.99, p < .0005), respectively. CONCLUSION: The study demonstrates good short-term intrasubject reproducibility of urodynamic studies in individuals with SCI.