Incidence of menstrual symptoms suggestive of possible endometriosis in adolescents: and variance in these by ethnicity and socio-economic status

BACKGROUND: Dysmenorrhoea affects up to 94% of adolescents who menstruate; approximately one third miss school and activities. Dysmenorrhoea can occur without identified pelvic pathology (primary dysmenorrhoea) or in association with other conditions (secondary dysmenorrhoea). In adolescence, the commonest cause of secondary dysmenorrhoea is endometriosis. The incidence of symptoms in adolescence suggesting possible endometriosis has not been previously documented in GP records. AIM: To document incidence of adolescent endometriosis and symptoms associated with endometriosis in English GP records. METHOD: Data from the QResearch primary care database were used for adolescent females aged 10- 19 years between 1 January 2011 and 30 June 2021, reported using descriptive statistics. RESULTS: The population cohort included 2 843 347 female adolescents; 98 887 participants had coded dysmenorrhoea (3.48%) and 1994 (0.07%) had documented endometriosis. The cumulative incidence for the cohort who turned 10 years old in 2011 was 7.2% for dysmenorrhoea and 0.12% for endometriosis. The period prevalence of coded symptoms during adolescence potentially associated with dysmenorrhoea and endometriosis includes: heavy menstrual bleeding (3.73%), irregular menstrual bleeding (2.21%), pelvic pain (0.63%), dyspareunia (0.40%), premenstrual syndrome (PMS)/premenstrual dysphoric disorder (PMDD) (0.22%), cystitis (8.45%), and irritable bowel syndrome (IBS) (1.00%). Disparities in coding were observed for these variables by ethnicity and socioeconomic status. Incidence of prescribed hormonal medication, with and without coded dysmenorrhoea, varied by ethnicity. This was less apparent for non-steroidal anti-inflammatory medications. CONCLUSION: Prevalence of coded dysmenorrhoea in GP records is significantly lower than community surveys suggest; however, adolescent menstrual symptoms are commonly encountered in primary care, and deserve specific guidance and resources. There are demographic patterns, likely structural, that warrant further exploration.