The prevalence and severity of endometriosis today

The true frequency of undiagnosed endometriosis and its proportion among all women with endometriosis is still unknown.

Key Points

Highlights:

• A systematic review of the prevalence of endometriosis worldwide over the past 30 years finds no time trend, but highly heterogeneous data influenced by population sampling.

 Importance:

• It is necessary to give priority to improved and unbiased quantification of endometriosis prevalence and incidence.

What’s done here?

• Researchers reviewed the papers on the prevalence, incidence, and stage of endometriosis worldwide reported over the past 30 years.

Key Points:

• Prevalence estimates of endometriosis reported from general population studies ranged from 0.7% to 8.6%, while among single clinic or hospital-based studies ranged from 0.2% to 71.4%.
• Endometriosis prevalence ranged from 15.4% to 71.4% among women with chronic pelvic pain, 9.0% to 68.0% among women presenting with infertility, and 3.7% to 43.3% among women undergoing tubal sterilization.
• There was no trend across time among the ‘general population in country/region’ studies’ single hospital or clinic’ studies.
• A decrease over time was observed among general population studies abstracted from health system/insurance systems.

 Limitations:

• We need studies with large numbers of diverse girls and women that collect data about demographic characteristics and gynecologic and other medical symptoms and experiences.

Lay Summary

Ghiasi M. et al., a group of researchers from the USA, presented a comprehensive review of the prevalence, incidence, and stage of endometriosis worldwide as reported over the past 30 years.

Researchers performed a search in four databases, including PubMed, Web of Science, EMBASE, and CINAHL for relevant manuscripts.  Search terminologies were “endometriosis” AND “prevalence” or “incidence” or “epidemiology”, or “frequency”, or “occurrence”, or “statistics.”

A total of 69 cross-sectional and cohort studies were included for the qualitative synthesis between 1989 and 2019. Among 69 studies, 16 reported the incidence of endometriosis, 62 reported the prevalence. Twenty-six studies had a sampling frame from the general population, the remaining 43 were conducted in a single hospital or clinic setting. The largest proportion of studies was from Europe (38%) and the smallest from Australia (3%). Fourteen studies reported a population sample size >=10,000 women. Large studies typically reported a prevalence of less than 5%. Only 27 studies reported histologic verification.

The risk of bias within and among the 69 studies was found to be moderate. There was no clear time-trend for endometriosis prevalence across the past 30 years. Among the 69 studies, 16 studies provided incidence estimates. Considerable heterogeneity among studies was seen by geographic region and sample population, including age ranges, mean ages at the time of staging, the case definition for endometriosis, and indication for surgery.

There is a large variation in prevalence estimates among studies - driven by heterogeneity in study populations, sampling scheme, endometriosis case definition, and indications for evaluation for the presence of endometriosis. The true frequency of undiagnosed endometriosis and its proportion among all women with endometriosis is unknown. General population studies yield an underestimate of the true prevalence of endometriosis due to diagnostics bias, while single hospital/clinic populations yield an overestimate due to selection bias.

Briefly, we need studies with large numbers of diverse girls and women that collect data about demographic characteristics and gynecologic and other medical symptoms and experiences. The change over time in exposure frequency and distribution of environmental and sociologic risk factors could drive true changes in endometriosis incidence, as well as changes in symptom and phenotypic presentation.

This study has recently been published in the journal named The Jornal of Minimally Invasive Gynecology.

Research Source: https://www.ncbi.nlm.nih.gov/pubmed/31816389