Title: Comorbid Bladder Pain Syndrome and Vulvodynia - A Cross-Sectional Analysis of the
UNICORN-4 Study
Version: 0 Date: 20 Oct 2024
Reviewer's report:
The study investigates the comorbidity of Bladder Pain Syndrome/Interstitial Cystitis (BPS/IC)
and vulvodynia, analysing distinct patient subgroups based on symptom profiles, psychological
characteristics, and sexual function. Using unsupervised clustering methods, the study identified
three distinct clusters within the patient cohort, emphasising the need for personalised treatment
approaches. The study presents a compelling argument for the integration of psychological and
sexual function assessments into the management of BPS/IC and vulvodynia patients.
Strengths
The study addresses an under-researched area—the coexistence of BPS/IC and vulvodynia—
highlighting the complexity and heterogeneity of the condition.
The hierarchical and k-means clustering methods, supported by multiple validated
questionnaires (PHQ-9, GAD-7, FSFI, FSDS-R), provide a robust framework for identifying
distinct patient phenotypes.
The study's identification of subgroups suggests personalised management strategies for BPS/
IC and vulvodynia patients, which could potentially improve patient outcomes and quality of
life. The recognition of severe sexual dysfunction across all clusters further underscores the need
for targeted interventions.
Weaknesses and Suggestions for Improvement
Generalisability of the data:
All participants were recruited from a single clinic in Japan, which may reduce the
generalisability of the findings to other populations. The authors should acknowledge this
limitation more explicitly and suggest ways to validate the findings in a larger, more diverse
cohort.
Cross-Sectional Design:
The author already acknowledged that as a cross-sectional study, it cannot establish causal
relationships between psychological distress, sexual dysfunction, and BPS/IC.
Assessment of Sexual Function:
The study highlights the limitations of current sexual function questionnaires in capturing the
full extent of sexual distress experienced by BPS/IC and vulvodynia patients. However, the
study stops short of offering recommendations for improving these tools. It would strengthen
the manuscript if the authors provided suggestions for developing or adapting assessment tools
tailored to this specific patient population.
Missing Data Clarification:
There is a lack of clarity in the handling of missing data, particularly with regard to patients who
were excluded or dropped out. It is not clear why patients with Hunner's lesions were excluded
while it is characteristic of BPS/IC.
Providing a detailed explanation of how missing data were handled (if applicable) would
enhance the study’s transparency.
Recommendations for the author:
Address Sample Size Limitations:
Provide a more explicit discussion on how the limited sample size and single-center recruitment
may affect the generalisability of your findings.
Clarify Handling of Missing Data:
Include details on how missing data were handled and consider providing a flowchart of patient
inclusion and exclusion criteria.
Recommendations for Sexual Function Tools:
Expand on the limitations of current sexual function questionnaires and offer suggestions for
improving these tools for patients with comorbid BPS/IC and vulvodynia.