What Do Different Measures of Pain Tell Us? A Comparison in Sexually Active Women With Provoked Vestibulodynia

Abstract

Introduction: Studies of pain measurement in women with provoked vestibulodynia (PVD) use various methods of capturing pain intensity. The degree to which these different measures of pain correspond with one another is not known.

Aim: To compare 3 different measures of pain intensity in sexually active women with PVD participating in a clinical treatment study.

Methods: A total of 64 women (mean age 30.9 years) provided baseline measures of pain intensity using (i) a numeric rating scale that provided a self-report of pain during recalled vaginal penetration; (ii) the pain subscale of the female sexual function index; and (iii) pain elicited with a vulvalgesiometer, an objective method of eliciting pain.

Main outcome measure: Correlations among these 3 measures of pain were moderate in size (range r = 0.39-0.61). Moreover, the numeric rating scale of pain was more likely to be associated with self-reported measures of pain catastrophizing and pain hypervigilance than were scores on the pain subscale of the female sexual function index or scores from the vulvalgesiometer.

Clinical implications: Overall, there was a moderate level of correlation between different often-used measures of pain in women with PVD. These findings suggest that, in addition to measuring a common dimension, these different measures tap into different aspects of women's experiences with vulvovaginal pain, and researchers should consider how the chosen measure addresses their primary research question when selecting pain measures in future PVD research.

Strengths & limitations: A strength of this study was the large sample size (n = 64 sexually active women) who had received confirmed clinical diagnoses of PVD. 1 limitation of the findings is that our self-report outcome measures are based on retrospective ratings of pain over 4 weeks, and it is possible that other variables, such as mood, could have impacted scores on these measures.

Conclusion: This study showed statistically significant and moderate correlations among 3 different pain measures widely used in PVD research and treatment. In addition, only 1 pain measure showed a significant independent association with emotion function measures. These findings provide a rationale for including multiple measures of pain and emotional function in treatment outcome studies of PVD. Wammen Rathenborg FL, Zdaniuk B, Brotto LA. What Do Different Measures of Pain Tell Us? A Comparison in Sexually Active Women With Provoked Vestibulodynia. J Sex Med 2019;16:278-288.

Keywords: Dyspareunia; Genital Pain; Numeric Rating Scale; Pain Measurement; Provoked Vestibulodynia; Vulvalgesiometer.