Hypothesis / aims of study
Urodynamic studies (UDS) are essential in the management of patients with lower urinary tract dysfunctions, but are technically and clinically very demanding. Overall quality of UDS depends not only on good urodynamic practices (GUP), but also on real-time monitoring and correction of artifacts and post-test processing for proper interpretation. Questions exist regarding the influence of technique on the utility and perceived value of urodynamics. Despite the International Continence Society (ICS) has standardized GUP, quality problems still have been detected both in audits of multicenter studies and scientific publications [1,2]. Published urodynamic traces have undergone peer review and might therefore be regarded as examples of best urodynamic practice.
The primary objective of this study was to describe quality control of urodynamic traces recently published in scientific articles. A secondary objective was to describe the print size of those published urodynamic traces. To our knowledge this is the third study evaluating quality control of urodynamic traces published in scientific journals, and the first to asses it in voiding traces.
Study design, materials and methods
All articles published between January 2017 and December 2021 (5 years) from the journals "Neurourology and Urodynamics" (NAU), "International Urogynecology Journal" (IUJ), "Lower Urinary Tract Symptoms" (LUTS) and "International Neurourology Journal" (INJ) were reviewed (3,961 articles), selecting 35 articles with urodynamic traces (0.88%). Fifteen articles were excluded, 4 performed in children and 11 for other justified reasons. The urodynamic traces were classified according to curve type (filling cystometry, pressure-flow study and filling cystometry + flow-pressure study) and print size (full page width, greater than ½ page width, ½ page width and less than ½ page width). The minimum appropriate print size was arbitrarily considered as follows: ½ page width for traces showing filling cystometry or flow-pressure studies only, and full page width for traces showing both filling cystometry + pressure-flow study. One of the authors extracted the figures with their legends and 2 others experienced urodynamists independently assessed the quality control of each curve. Where there was discrepancy, agreement was reached by analysing them together. Eleven items of the Bristol UTraQ scoring system quality control [3] were assessed (Table 1). Student’s t test was used for the statistical analyses. The information was processed with jamovi, version 2.3 (The jamovi project 2022) and statistical significance was defined as P < .05.
Results
Twenty articles (NAU: 13, IUJ: 2, LUTS: 4, INJ: 1) with 48 urodynamic curves (NAU: 29, IUJ: 3, LUTS: 14, INJ: 2), corresponding to 44 filling cystometries and 33 pressure-flow studies, were analysed.
Table 1 shows the quality control audit of the published traces. Five items had 50% or less compliance. Scores for the pre-filling, filling and voiding items were met on average by 70.5%, 59.8% and 52.3%, respectively.
Nine articles (45%) explicitly stated that they followed the ICS GUPs (5 Schäfer’s 2002, 2 Rosier's 2016, and 2 both), 8 of NAU and 1 of LUTS. Only pre-filling scores were significantly better in the traces of articles that explicitly stated that they followed the ICS GUPs (3.18 ± 0.91 vs 2.60 ± 1.13 points, p=0.043); filling and voiding scores were not. Quality control of voiding items was significantly better in NAU urodynamic traces than in the other journals combined (2.47 ± 1.42 vs 1.57 ± 0.75 points, p=0,039); pre-filling and filling scores didn’t show differences.
Nine out of 20 (45%) articles reported patients’ position during UDS and in 12/25 (48%) traces of these articles pves and pabd were zeroed to atmosphere. Only 4/12 (33.3%) traces had pves, pabd and pdet values within physiological range for initial resting pressures (pves and pabd: 5–20 cmH2O if supine, 15–40 cmH2O if seated, 30–50 cmH2O if standing, pdet: −5 to +5 cmH2O).
Table 2 shows the print size of the traces expressed in the proportion of the total width they occupy on the page according to the type of trace. Twenty-three traces (47.9%) had a minimum appropriate print size and 9 articles (45%) had all their traces of appropriate print size.
Interpretation of results
Quality control of urodynamic traces published in recent scientific articles is very imperfect. Pves and pabd marked on the trace as being zeroed to atmosphere, good quality cough test carried out at the start of the test, good quality cough test done before voiding, “permission to void” indicated, and good quality cough test done after the final void had 50% or less compliance. Few articles reported patients’ position during UDS and very few of them had pves, pabd and pdet values within physiological range for initial resting pressures.
Less than half of the articles explicitly stated that they followed the ICS GUPs, and in them pre-filling scores were significantly better. There is some evidence that one of the studied journals had urodynamic traces of better quality than the others at least in one subgroup of items.
Two previous studies evaluated quality control of published filling cystometry traces [1,2]. The comparison of results is difficult because the evaluated parameters were not specified in the same way. However, we can say that there has not been a trend towards better quality control of published urodynamic traces over time.
The print size of the published urodynamic traces does not seem appropriate in more than half of the cases, highlighting the need of standardization.
These results show that GUP are not strictly applied even in environments regarded as examples of best practice, and should certainly draw attention of authors, reviewers and editors. The ICS must vigorously maintain their strategies of outreach and control of GUPs.