Study to Compare the Efficacy of Cognitive-behavioral Couple Therapy and Lidocaine for Provoked Vestibulodynia

A Comparison of Cognitive-behavioral Couple Therapy and Lidocaine in the Treatment of Provoked Vestibulodynia: A Randomized Clinical Trial

Chronic pain problems involving the female reproductive system are major health concerns for all women. Poorly understood, they entail great personal and financial cost. One such condition is vulvodynia, or chronic unexplained vulvar pain, which has a prevalence of 16%. Despite its negative impact on psychosexual and relationship satisfaction, there is little research examining empirically-tested treatments for afflicted couples. The proposed research builds on findings from our work focusing on the impact of relational factors on vulvodynia, and our previous research evaluating the efficacy of group cognitive-behavioral therapy for this problem. This two-centre randomized clinical trial aims to assess the efficacy of a novel, 12-week targeted couple therapy (CBCT) for women with vulvodynia in comparison to one of the most commonly prescribed first line medical interventions, topical lidocaine. Primary research question: Is there a significant difference between the two treatments on women's pain during intercourse post-treatment? Secondary research questions will assess for significant differences between the two treatments post-treatment and at 6-month follow-up on multidimensional aspects of pain using the McGill Pain Questionnaire, women and partners' sexuality (sexual function and satisfaction), psychological adjustment (anxiety, depression, catastrophizing, self-efficacy, attributions, and quality of life), relationship factors (partner responses, couple satisfaction, attachment, and communication styles), and self-reported improvement and treatment satisfaction. Results of this study will improve the health and quality of life of patients with vulvodynia by rigorously testing the efficacy of a novel couples treatment.

Background: Chronic pain problems involving the female reproductive system are major health concerns in women of all ages. As conditions which are poorly understood and often misdiagnosed or ignored, they entail a great personal cost to patients and a significant financial cost to society. One such condition is vulvodynia, or chronic unexplained vulvar pain. A recent population-based study suggests that the lifetime cumulative incidence of vulvodynia is 16%, indicating that approximately 2.5 million Canadian women may experience idiopathic vulvar pain during their lifetimes. Provoked vestibulodynia (PVD) - an acute recurrent pain localized within the vulvar vestibule and experienced primarily during sexual intercourse - is suspected to be the most frequent cause of vulvodynia in premenopausal women, with prevalence estimates of 12% in community samples. Despite its high prevalence and negative impact on psychosexual functioning, there has been a paucity of controlled research to provide empirically validated treatments for afflicted couples. The present proposal draws on our previous cross-sectional and prospective CIHR funded research on the dyadic determinants of pain and psychosexual impairment in women with PVD and their partners, as well as on our past randomized trials evaluating the efficacy of group cognitive-behavioral therapy for this condition. Specifically, the goal of our study is to evaluate the efficacy of a targeted cognitive-behavioral couple therapy (CBCT) intervention that we developed for the treatment of PVD.

Objectives: The proposed two-centre randomized clinical trial aims to evaluate the efficacy of a novel 12-week targeted couple therapy intervention (CBCT) for women with PVD in comparison to one of the most frequently prescribed first line medical interventions, topical lidocaine, shown to be effective and safe in the management of PVD. The primary research question focuses on whether there is a significant difference between the two treatments on women's pain during intercourse post-treatment. Secondary research questions focus on whether there are significant differences between the two treatments post-treatment and at 6-month follow-up on (a) the multidimensional aspects of women's pain on the McGill Pain Questionnaire and (b) women and partners' sexuality (sexual function and satisfaction, frequency of intercourse), psychological adjustment (anxiety, depression, catastrophizing, self-efficacy, pain attributions, quality of life, acceptance of pain, compassionate love for partner, self-compassion, emotion regulation and thoughts and feelings related to pain experience), relationship factors (partner responses, dyadic adjustment, attachment, and communication) and self-reported improvement and treatment satisfaction. We will also examine whether childhood trauma and co-morbid pain conditions moderate treatment response. Finally, a third research question is to evaluate the role of hormonal contraceptive use and the risk of PVD.

Research plan/methodology: The proposed research is a 3.5-year, two-centre parallel randomized controlled trial for PVD using an intent-to-treat analysis strategy, with pain during intercourse as the primary outcome. The main research questions will be addressed by: 1) recruiting 224 premenopausal women and their partners with medically diagnosed PVD; 2) performing comprehensive gynecological and psychosexual pre-treatment evaluations focusing on our outcome measures; 3) randomly assigning women to one of the two 12-week treatment arms: CBCT or lidocaine, and 4) evaluating pain during intercourse, as well as sexual, psychological and relationship outcomes, in addition to self-reported improvement and treatment satisfaction, post-treatment and at 6-month follow-up. These procedures will take place in two different university centers: Université de Montréal in Montréal, Québec, and Dalhousie University in Halifax, Nova Scotia, and their affiliated hospitals. Both university centres will store data securely, adhering to the protocols outlined by the ethics review boards at each site.

Statistical Analyses: Analyses will be conducted based on intention to treat. Descriptive statistics will be used to define and compare the participants in both intervention groups. More specifically, we will calculate means, medians, deviations and interquartile ranges and T-tests will be used to determine the differences between groups for socio-demographic variables. Chi-square tests and observed differences between groups will be used for categorical variables. If differences are observed between groups, these variables will be controlled for in subsequent analyses. We will verify that variables are normally distributed. If variables are not normally distributed, non-parametric tests will be employed. A repeated measures analysis of variance will permit the assessment of efficacy of the two treatments at post-treatment and at 6-month follow-up. The analyses will focus on the changes in pain experienced during intercourse from pre-treatment assessment to post-treatment and 6-months follow-up. To do this, time will be the intra-subject variable, and the experimental condition will be the inter-subject variable.

For secondary analysis, multiple analyses will be conducted in multiple steps, with multivariate analyses being conducted first for repeated measures (MANOVA). Correlated measures will be grouped based on conceptual domain (e.g., pain, dyadic adjustment, catastrophizing). Univariate analyses will be conducted if the multivariate results are significant (ANOVA). This will be followed by orthogonal contrasts to examine changes between different measurements. Moreover, we will use exploratory analyses for participants who completed the experimental protocol to determine the effect protocol adherence has on treatment efficacy. Multiple regression analyses will be used to examine the link between socio-demographic variables, pre-treatment dependent variables and pain at post-treatment and 6-months follow-up to identify factors associated with therapeutic success. These latter analyses will be conducted for each treatment group separately. Bonferroni corrections will be used during analyses for multiple comparison adjustments. In the case of missing data, we will explore the effects of withdrawal on sensitivity analyses, replace the missing data with data from the most recent assessment or with averaged or aggregate values.

Significance of study: Results of the proposed research may improve the health and quality of life of Canadians afflicted with a highly prevalent and neglected women's health problem - vulvodynia - by providing a rigorous test of the efficacy of a novel targeted couple therapy intervention.

Inclusion Criteria:

• pain during intercourse which a) is subjectively distressing, b) occurs on 80% of intercourse attempts, and c) has lasted for at least six months;
• pain limited to intercourse and other activities involving pressure to the vestibule;
• ability to undergo the gynecological examination to completion;
• significant pain in one or more locations of the vestibule during the gynecological exam, which is operationalized as a minimum patient pain rating of 4 on a scale of 0 to 10;
• having engaged in vaginal intercourse as a couple once per month for the last three month;
• partnered in a committed, monogamous relationship for at least 6 months; and
• has had at least four in-person contacts per week with their partner for at least six months.
• Partners will be recruited conditional upon the patient meeting study selection criteria.
• Both women and partners must be able to read, speak, and understand English or French (in Montreal), and English (in Halifax) to participate.

Exclusion Criteria:

• vulvar pain not clearly linked to intercourse or pressure applied to the vestibule;
• presence of one of the following: a) major medical and/or psychiatric illness, b) active infection, c) dermatologic lesion, d) pregnancy or planning a pregnancy;
• age less than 18 for couples or greater than 45 for women with pain;
• major medical and/or psychiatric illness for partners;
• severe relational distress or conflict as determined by baseline measures and interview;
• current participation in another couple therapy, or therapy/treatment related to PVD.