Symptoms-Based Phenotypes Among Women With Dysmenorrhea: A Latent Class Analysis.

Dysmenorrhea is highly prevalent and may increase women's risk for developing other chronic pain conditions. Although it is highly variable, symptom-based dysmenorrhea phenotypes have not been identified. The aims of the study were to identify symptom-based dysmenorrhea phenotypes and examine their relationships with demographic and clinical characteristics. In a cross-sectional study, 762 women with dysmenorrhea rated severity of 14 dysmenorrhea-related symptoms. Using latent class analysis, we identified three distinctive phenotypes. Women in the "mild localized pain" phenotype ( n = 202, 26.51%) had mild abdominal cramps and dull abdominal pain/discomfort. Women in the "severe localized pain" phenotype ( n = 412, 54.07%) had severe abdominal cramps. Women in the "multiple severe symptoms" phenotype ( n = 148, 19.42%) had severe pain at multiple locations and multiple gastrointestinal symptoms. Race, ethnicity, age, and comorbid chronic pain conditions were significantly associated with phenotypes. Identification of these symptom-based phenotypes provides a foundation for research examining genotype-phenotype associations, etiologic mechanisms, and/or variability in treatment responses.