Pelvic endometriosis diagnosed in an entire nation over 20 years.

The annual incidence of pelvic endometriosis among women aged 15-49 years and up to age 69 years was ascertained for the Icelandic population between 1981 and 2000 by using Iceland's extensive record linkage systems. Comprehensive, state-financed health care and unique personal identification numbers enabled care to be tracked from first diagnosis. To identify cases, a centralized discharge-code registry was searched, as well as all hospital databases and, for individual patients, all hospital records. Each case of visually diagnosed and histologically verified endometriosis was cross-checked against the nationwide pathology registry. The revised American Society for Reproductive Medicine classification system was used for staging. Recorded was type of operation at diagnosis and presence of disease at 5 sites: deep pelvis, appendages, central pelvis, vesicouterine pouch, and ovaries. A total of 1,383 women were diagnosed surgically, with histologic verification of 811 (58.6%). All but 6 cases could be staged; 297 (36.9%) had minimal/mild and 508 (63.1%) had moderate/severe disease. The estimates of crude annual incidence were 0.1% for visually confirmed and 0.06% for histologically verified endometriosis, and respective age-standardized annual incidence was 0.1% and 0.05% for women aged 15-49 years. The most common site was the ovary, followed by deep pelvis, central pelvis, appendages, and vesicouterine pouch.