Hypothesis / aims of study
A recent study suggested that by age 40, 8% of women will experience vulvar pain on contact for a period of at least 3 months that limits or prevents sexual intercourse. When clinically confirmed, it is defined as debilitating vulvar discomfort due to burning pain or pain on contact that occurs in the absence of clinically visible pathological findings or identifiable disorders. We and others have shown that women who suffer from vulvodynia are more likely than others to experience co-morbid interstitial cystitis and urinary tract infections. However, no studies to our knowledge have assessed whether women with vulvodynia suffer from other lower urinary tract symptoms (LUTS) in the absence of Interstitial Cystitis and urinary tract infection (UTI) history. We sought to determine whether women with and without vulvodynia differed in their self-reported history of daytime and nighttime urination frequency, urgency after urination, and severity and bother associated with urgency experiences. This data comes from a community-based case-control study of women with clinically confirmed vulvodynia and community matched controls conducted in the metropolitan area of Minneapolis and Saint Paul, Minnesota.
Study design, materials and methods
Women 18-40 years of age who were part of the administrative database of a large health care network that represents approximately 27% of the population in the Minneapolis/St. Paul metropolitan area, were initially recruited through self-administered surveys to examine the prevalence of vulvar pain. Women seen for any reason in one of over 40 community health clinics within a two-year window between March, 2010, and October, 2013 were assessed for eligibility. Women likely to meet the International Society for the Study of Vulvovaginal Diseases (ISSVD) criteria for vulvodynia based on their initial survey responses were invited to participate in a clinical visit to confirm the diagnosis. Of the 1,398 women invited, 350 completed their examination and 234 were clinically confirmed as meeting the diagnostic criteria for vulvodynia. Women from this same pool of screened women with no history of vulvar discomfort were randomly selected and invited to serve as controls. Of 2,287 women invited, 251 agreed and 234 were clinically confirmed as having no ongoing or past history of vulvar pain. All cases and controls completed a background and medical history questionnaire by telephone that covered demographic characteristics, sexual and reproductive history, and personal hygiene practices. We specifically asked women to estimate how many times per day and per night they go to the bathroom, whether they have urgency after going to the bathroom, and if so, the severity and bother associated with that urgency. With a sample size of 234 cases and 234 controls, our study had 80% power to detect odds ratios ranging from1.72 to 2.13 for prevalence of urinary symptoms with 10 and 30 percent prevalence using two-sided tests and an α-level of 0.05. As shown in the Table below, the prevalence of any urgency after urination among controls was 18% and any bothersome nocturnal voiding was 32%.
Results
Women with any history of interstitial cystitis were excluded from this analysis. We observed no major difference in the frequency of urination during the day among women with and without vulvodynia. However, women with vulvodynia were 70% more likely to urinate 2 or more times at night compared to controls, after adjustment for age, use of sleeping medications, smoking history, anxiety, and history of urinary tract infections (95%CI 0.9-3.3). Among those who reported getting up at night to urinate, women with vulvodynia were 3.5 times more likely to report bother associated with nighttime voiding compared to controls (95%CI 1.7-7.2) after the same multivariate adjustments. Women with vulvodynia, compared to controls, were also 5 times more likely to report having any urgency after going to the bathroom (95%CI 1.4-17.4) and were 19 times more likely to report moderate to severe urgency after urination compared to controls (95%CI 5.5-64.1), again after adjustment for the same covariates listed above.
Interpretation of results
Our findings suggest that even after accounting for interstitial cystitis and history of urinary tract infections, women with vulvodynia were significantly more likely to experience urgency after urination that was bothersome and considered moderate to severe.