Introduction
Objectives
The objectives of this part of the study were as follows:
To audit the quality of UDS traces submitted to the study office at the University of Birmingham Clinical Trials Unit as the reference standard for the patients in the BUS.
To assess whether or not recommended changes in UDS practice had been implemented following an initial audit among the recruiting centres for the BUS.
Methods
Urodynamic studies
Urodynamic studies were to be performed in a standardised manner as per the GUP guidelines from the International Continence Society6 and a SOP that had been produced for the study based on this (see Chapter 2, The reference standard: urodynamics). For patients at the main centre (Birmingham Women’s Hospital), according to the study protocol, patients were offered ambulatory UDS if they had a normal result from standard multichannel UDS.
Assessment of protocol compliance
An assessment of compliance with the UDS SOP for the BUS and with GUP was performed on 64 (20%) of the first 302 UDS traces received at the study office, between May 2011 and May 2012.
An expert panel, comprising a consultant in urogynaecology and a urogynaecology research nurse from the lead centre, assessed the traces independently. They were blinded to the investigator’s UDS diagnosis, the UDS operator and centre providing the trace, to minimise any bias in the assessment. All participating sites were audited regarding the urodynamic technique used throughout the study.
Traces were randomly selected by the BUS trial co-ordinator from traces supplied by each of the recruiting hospitals, as suggested by the DMC. The expert panel rereviewed UDS traces they had undertaken (the lead centre recruited 37% of all participants into the BUS) but were not aware of which traces were from the lead centre.
Following review, the requirements of the UDS SOP were reiterated to recruiting centres via e-mails and a newsletter and also discussed at BUS training days, which were held 3 months and 15 months into the recruitment period. A total of 6 months after the initial audit, a second audit (June 2012 to December 2012) was performed on a further 60 traces.
Audit standards for urodynamic studies
The traces were reviewed to assess the presence of the following criteria:
adequate subtraction prior to filling cystometry (i.e. initially bladder and rectal catheters should be zero when open to atmosphere, at the level of upper symphysis)
sitting position during filling cystometry (recommended as per study protocol)
the cystometry filling rate was 100 ml/minute to begin with (then slowed as and if necessary)
a cough pre-void
a cough post void
presence of one cough per minute to assess ongoing adequate subtraction of intravesical and abdominal pressures.
In addition, agreement of initial diagnosis between study investigator and expert panel was assessed. The expert panel determined a diagnosis of USI, DO, low compliance, VD or normal, or combinations of these diagnoses.
Results
Between May 2011 and December 2012, a total of 124 UDS traces were reviewed against the UDS SOP criteria, illustrates the result of the overall quality control check in UDS.
Comparison between audit and reaudit compliance of UDS traces
The initial urodynamic diagnoses given by the study investigator was consistent with the two assessors in the expert panel in 86% of cases, which improved, following the feedback given to all investigators, to 95% of cases. There was also improvement in the compliance with the repeated coughing, which was necessary to calibrate the traces. Despite reiterating that the sitting position is recommended for filling cystometry, compliance decreased following the second audit, although this could be a spurious finding from the small sample reviewed.
Out of 68 patients who had a normal UDS at Birmingham Women’s Hospital, 14 accepted the option of having an additional test in the form of ambulatory UDS and, of these, seven had a DO diagnosis.
Discussion
The results of this audit show that reiteration of SOP had a positive impact on the quality of UDS carried out within the BUS. Training and education through the use of e-mails, newsletters and study site visits significantly raised the compliance with the GUP guidelines and the study UDS SOP.
The strengths of this audit include anonymisation of the centre and UDS operator, availability of clear standards in the form of SOPs, predefined audit criteria and the closure of the audit loop via feedback. A larger audit, including all the UDS tests conducted in the BUS could have been carried out to provide greater reassurance, but the DMC were reassured that a representative sample of UDS tests was reviewed and the quality of the UDS was adequate.
Kraus et al.126 have identified that clinical trials using UDS as outcomes require additional standardised procedures to ensure that intersite variability is limited and kept to a minimum. To maintain reliability of urodynamic data, there should be standardisation of urodynamic technique, interpretation and performance. Multicentre urodynamic studies require a continuous quality control process, with audits, multidisciplinary team meetings and refresher training to reinforce the initial training. Our audit results demonstrate that ongoing education and training is paramount in the implementation of clinical guidelines and SOPs for UDS, and via regular communication with the recruiting centres, discrepancies were minimised, resulting in improved reliability of UDS diagnosis. Currently, urodynamic training in the UK is varied and ranges from bedside training, a certificate course, to individual study days. All centres should share the same course content in order to achieve standardisation.
There are a number of factors that may influence the detection of DO.127 For example, if a poor technique is implemented the results may become compromised or misleading. Emphasis should be made on the patient’s position during the filling cystometry phase of the UDS procedure. It is known that most patients with OAB caused by DO complain about their symptoms while in the sitting or standing position.127 A study by Arunkalaivanan et al.128 found that in 96 women with LUTS, 55% (n = 53/96) of them were diagnosed with DO while in the sitting position. In contrast, only 9% (n = 9/96) had the same diagnosis while in the supine position. Filling is often performed between 50 ml/minute and 100 ml/minute96 to improve the DO pick-up rate. In order to correlate symptoms and diagnosis, the filling rate specified within our SOP complied with the GUP guidelines.
Clinicians can maximise the chance of reproducing the patient’s symptoms by using provocation measures such as coughing, running hands under water and jogging.96,128
Conclusion
The results of this audit have demonstrated a positive change in urodynamic practice as a direct result of reinforcing the importance of adhering to guidelines of clinical practice and procedures, and that the UDS process was judged as adequate by the DMC. The results of the audit and a reminder about the SOP and GUP recommendations were shared with the BUS investigators via newsletters, e-mails, site visits and training days. Reiterating information and results can increase the level of adherence in the technique of performing the test. Ongoing audits of the technique and interpretations of UDS are necessary to maintain the high standards and reliability of the test.
