Protocol for the value of urodynamics prior to stress incontinence surgery (VUSIS) study: a multicenter randomized controlled trial to assess the cost effectiveness of urodynamics in women with symptoms of stress urinary incontinence in whom surgical treatment is considered AbstractBackground: Stress urinary incontinence (SUI) is a common problem. In the Netherlands, yearly 64.000 new patients, of whom 96% are women, consult their general practitioner because of urinary incontinence. Approximately 7500 urodynamic evaluations and approximately 5000 operations for SUI are performed every year. In all major national and international guidelines from both gynaecological and urological scientific societies, it is advised to perform urodynamics prior to invasive treatment for SUI, but neither its effectiveness nor its cost-effectiveness has been assessed in a randomized setting.

Background: To put statistically significant changes in patient reported outcome measurement (PROM) questionnaires into a clinical perspective, the concept of the minimal clinically important difference (MCID) can be used. Aim: To determine the MCID for the summary score for sexually active (SA) women of the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire, IUGA-Revised (PISQ-IR), a validated instrument which assesses sexual functioning (SF) for patients suffering from a symptomatic pelvic floor disorder. Methods: Patients participating in a multicentre prospective cohort study comparing pessary therapy with surgery for a symptomatic pelvic organ prolapse (POP) filled in the PISQ-IR at baseline and 12 months' follow-up. We used both an anchor-based as well as a distribution-based method to calculate the MCID for both treatment groups. The Patient Global Impression of Improvement (PGI-I) questionnaire and PISQ-IR question 19a about satisfaction with sexual functioning were used as anchors. For the distribution-based approach we used the effect size (ES). Outcomes: MCID for the SA summary score of the PISQ-IR.Results: Data of 243 women were used to calculate the MCID. In the pessary group, Kendall's tau-b correlation coefficients between the PISQ-IR summary score and both anchors were below the cut-off of 0.21, which implies the anchors cannot be used to calculate an MCID. In our surgery group, the PISQ-IR question 19a met the anchor criteria and 0.31 points increase in the PISQ-IR summary score was equal to an improvement of 1 point on question 19a about satisfaction with sexual functioning. Clinical implications: Future research on this subject should focus on clinical relevance of results rather than statistical significance only. Strengths & Limitations: Our main strength is the fact that we used both anchor-based and distribution-based methods to determine our MCID. Secondly, we set out to determine an MCID for both treatment groups separately, which relatively enhances the generalisability of our results. A limitation is that we were not able to estimate an MCID for the pessary group. Conclusion:We estimated the MCID for the PISQ-IR SA summary score to be 0.31 in our surgery group.

Dear Editor,We read with interest the publication by Lone et al.[1], where they prospectively compared the effectiveness of a vaginal pessary or surgery in women with symptomatic pelvic organ prolapse (POP). They concluded that "women can be reassured that by choosing a pessary as their first option for treatment of POP, the outcome at 1 year in terms of prolapse symptoms, urinary and bowel function, and quality of life can be as effective as that of surgery". In our opinion this conclusion is too strong for several reasons.First, the analysis was not performed according to intention to treat: women who changed their decision after randomisation and switched from pessary therapy to surgery (n=8) as well as women who discontinued the use of the pessary (n=12) were excluded. By excluding women who are dissatisfied with pessary treatment, improvement after pessary therapy will be overestimated. Moreover, in total for 36 % (104/287) of the women no change in score since baseline could be calculated at 1 year. Therefore, selective loss to follow-up cannot be excluded.Second, both pessary therapy and surgery showed statistically significant improvement in prolapse symptoms, urinary and bowel function, and quality of life. Although the decline in bothersome symptoms is described, no interpretation of when an improvement is considered relevant for the patient is given. In the surgery group there is more decline for almost all symptoms, but these differences are not statistically significant. However, the on average much smaller decline within a woman is statistically significant and therefore called important. Given the relatively small sample size of the study, a potentially clinically relevant difference might not be detected, but can also not be excluded.In our opinion, the cost-effectiveness of a primary treatment strategy of pessary or surgery for moderate to severe prolapse still deserves further evaluation [2], preferably in a well-powered randomised trial. We recently started the PEO-PLE study in the Netherlands, which is a multicentre pragmatic cohort study with an embedded randomised trial comparing the (cost) effectiveness of pessary therapy versus surgery (NTR 4883). We expect results in 2017.Conflicts of interest None.