(003) Taking a Step Back for a (Future) Step Forward: Latent Class Analyses of Vulvo-Vaginal Pain Symptoms
Authors: Bittoni C , Kiesner J 
Published: March 2024

Abstract

Introduction
Persistent genital pain represents a significant health issue among females, with prevalence ranging from 18.5% for lower genital tract discomfort [2], 20% for chronic dyspareunia [3], and 8.3%-27.9% for vulvodynia [6, 7]. Latent class analyses (LCA) allow the identification of groups of individuals who share common symptom profiles and have been used to subgroup vulvodynia patients based on psychological distress and pain sensitivity [1], spontaneous vs provoked pain and pain comorbidities [8] and based only on comorbid pain conditions [5]. Nonetheless, to our knowledge no study has been conducted investigating clusters of symptom-types commonly reported for persistent genital pain.

Objective
Test for latent classes (clusters) of individuals based on symptom-types profiles among women with vulvar and/or vaginal pain.

Methods
Self-reports on sexual and genital health were collected from 2199 women through online questionnaires, as part of a larger study. Efforts were made to recruit a heterogenous sample, with an oversampling of females with genito-pelvic pain. Participants were asked about the presence of specific vulvo-vaginal symptoms. Specifically, eight types of vulvar pain (itching, burning, irritation, needles, cut, electric-shock, bladder weight and urinary urgency) and nine types of vaginal pain (dryness, itching, burning, pulsating, needles, cut, electric shocks, spontaneous spasms and spasms at penetration) were measured. LCA were conducted to identify clusters of individuals sharing similar symptom profiles. Analyses were first done including all women with genital pain, then separately for women experiencing only vaginal and only vulvar pain.

Results
Of the 2199 participants, 1116 (51%) reported experiencing some type of genital pain, with 52% experiencing vulvar and vaginal pain, 17% only vaginal pain and 31% only vulvar pain. Results from LCA analyses suggest that women experiencing vulvo-vaginal pain could best be grouped into 5 clusters, based on the presence of vulvar and vaginal symptoms (Figure 1). Women with only vaginal pain were grouped into 3 clusters based on vaginal symptoms (Figure 2) and women with only vulvar pain were grouped into 3 clusters based on vulvar symptoms (Figure 3). Across all sets of analyses, clusters were clearly differentiated by specific symptoms.

Conclusions
Although rates of genital pain are high among females, classification of genito-pelvic pain conditions have been, and still are, a matter of debate. While in the DSM-5 vaginismus and dyspareunia were combined into one diagnostic entity, many clinicians continue referring to them as two distinct conditions, creating incoherence in terminology. In addition, chronic vulvar pain (or Vulvodynia) remains often undiagnosed [7], with women waiting an average of a 6-years before receiving a diagnosis [4]. Our data, obtained from a large sample, allowed us to identify profiles based on an empirical/data driven strategy, and provides an innovative approach to defining genital pain conditions. These results offer a starting point to re-think and discuss how diagnoses currently used to categorize female vulvo-vaginal pain can be improved. Longitudinal studies should be conducted to test whether the current strategy of grouping women with vulvo-vaginal pain provides improved diagnoses, more accurate prognoses, or improves our ability to identify patients who will or will not respond to specific treatments.

Disclosure
No.