Factors associated with vulvodynia incidence.

OBJECTIVE: To assess incidence rates of and risk factors for vulvodynia.
METHODS: We conducted a longitudinal population-based study of women in southeast Michigan (Woman-to-Woman Health Study) using a validated survey-based screening test for vulvodynia that was repeated at 6-month intervals over 30 months. Unadjusted incidence rates were determined using Poisson models. Demographic and symptom-related risk factors for incidence were assessed using discrete time survival analysis.
RESULTS: Women who screened negative for vulvodynia at baseline and were followed through at least one additional survey (n=1,786) were assessed for onset of vulvodynia. The incidence rate was 4.2 cases per 100 person-years, and rates per 100 person-years were greater in women who were younger (7.6 cases per 100 person-years at age 20 years, compared with 3.3 cases per 100 person-years at age 60 years), Hispanic (9.5 cases per 100 person-years), married, or living as married (4.9 cases per 100 person-years); had reported symptoms of vulvar pain but did not meet vulvodynia criteria on the initial survey (11.5 cases per 100 person-years); or had reported past symptoms suggesting a history of vulvodynia (7.5 cases per 100 person-years). Increased risk of new-onset vulvodynia also included baseline sleep disturbance, chronic pain in general, specific comorbid pain disorders, and specific comorbid psychological disorders.
CONCLUSIONS: The incidence rates of vulvodynia differ by age, ethnicity, and marital status. Onset is more likely among women with previous symptoms of vulvodynia or those with intermediate symptoms not meeting criteria for vulvodynia and among those with pre-existing sleep, psychological, and comorbid pain disorders. This suggests vulvodynia is an episodic condition with a potentially identifiable prodromal phase. LEVEL OF EVIDENCE: II.