The Research Committee (RC) of the European Society for Pediatric Urology was established to advance pediatric urological health by promoting medical research through education and mentoring. More recently, it moved toward fostering collaborative studies both across Europe and internationally. In this spirit, the RC initiated a prospective multinational collaborative study which had 2 main objectives: addressing a clinically relevant question and demonstrating the feasibility of conducting such a study on a large scale. The study was designed to be collaborative, multinational, and multicentric while emphasizing simplicity, affordability, and regulatory feasibility to encourage broad participation.

It was decided to focus the research question on antibiotic prophylaxis during pediatric cystoscopy. This subject was chosen for several reasons. The first is that cystoscopic evaluation and treatment of the bladder constitute a significant portion of pediatric urology procedures. The second is that fear of postoperative UTI has led to the routine use of antibiotic prophylaxis.¹ However, the increasing prevalence of antimicrobial resistance raises concerns about the widespread and sometimes indiscriminate use of prophylactic antibiotics.^2,3 The third reason is that postoperative febrile UTI is a reasonably easy-to-define outcome. The Cy-Phy study sought to capture real-world antibiotic prophylaxis practices during pediatric cystoscopy globally, generating data that would help inform safer and more rational antibiotic use in this patient population.

The primary objective of the study was therefore to identify current antibiotic prophylaxis practices during pediatric cystoscopy on an international scale. Secondary objectives included estimating the incidence of postcystoscopy febrile UTIs and identifying risk factors associated with these infections.

This study was open to all European Society for Pediatric Urology members. Data were collected via an ENNOV Clinical database, and collective authorship was offered to acknowledge all contributors. Other than addressing an important clinical question while ensuring ease of implementation, key criteria for the study included maintaining a low financial burden, avoiding complex ethical approval processes, and being supported by a recognized institution. We therefore collaborated with the Reunion Island Academic Hospital to manage regulatory compliance, including proper study registration, intercenter agreements covering data protection and transfer (data transfer agreements), and secure data storage in accordance with privacy standards.

Data collected included patient demographics, details of antibiotic prophylaxis (drug, dose, timing), urine dipstick and culture results when routinely performed, indications and type of cystoscopy, and presence of culture-proven postoperative febrile UTI occurrence within 7 days after the procedure. No changes were made to standard care pathways. Data entry was anonymized to ensure patient confidentiality. Participating centers had access only to their own data, while overall analysis was conducted by the principal investigators.

The study aimed to recruit at least 50 centers, each contributing data on a minimum of 10 patients, targeting a total sample size between 500 and 2000 patients. Data collection was planned over approximately 8 to 10 weeks, leveraging the routine nature of pediatric cystoscopy. This was a low-risk observational study using anonymized, routinely collected data, and requirements for ethic approval varied between countries. Need for informed consent, for instance, differed between countries. Hospital leads were required to secure appropriate local approvals. The study complied with the Declaration of Helsinki and applicable data protection legislation.

In total the study ran from October 1, 2024, until February 28, 2025. Initially, we did not know how many centers would actually participate, and we were quite amazed by the enthusiasm the trial generated. Around 115 centers contacted us to participate in the study. As expected, the main difficulty was getting local ethics approval. Some of these processes were swift and required only signing data transfer agreements between the participating center and the Reunion Island Hospital, but in other cases formal Institutional Review Board approval was locally required and some centers did not manage to get it in time to participate. A few centers demanded changes in the protocol, but these were systematically refused even if it led to the centers not participating. There were also occasions when we looked at the participating centers’ national ethical guidelines in order to assist them in securing approval. In practice, during the study period there was daily communication with one participating center or another to answer various queries.

Ultimately, the trial recruited 90 centers from 40 countries ranging over 6 continents, and a total of 3337 patients were included with full data. Statistical analysis including descriptive statistics for prophylaxis protocols and infection rates and nonparametric tests for differences across institutions, geographic regions, and prophylaxis regimens is still currently taking place. Risk factors for febrile UTIs are being explored using multivariate analyses. The full results will be published within the coming months, but it can already be stated that the study, because of the number of patients included and weight of available data, is a success. The study illustrates the feasibility and potential power of multicentric international collaborative research. Having a snapshot of current practices worldwide is unique. Having such a large contemporary dataset in pediatric urology or even pediatric surgery is unique and allows us to draw solid conclusions. To build on the momentum of the Cy-Phy study, the RC is preparing a second study on the use of antibiotic prophylaxis for hypospadias repair, which will be named Hy-Phy. We expect that having already created links with participating centers and shared data transfer agreements will expedite the process for centers that have already participated. Certainly, the enthusiasm shared by the success of the Cy-Phy study has convinced many more centers to participate in Hy-Phy.