WASHINGTON — The constellation of symptoms characterizing endometriosis may be more specific than currently thought, Karen D. Ballard, Ph.D., said at the annual meeting of the AAGL.
There is often a long delay in the diagnosis of endometriosis, in large part because the symptoms—primarily pelvic pain and dysmenorrhea—are nonspecific and can overlap with other conditions. But now, a case-control study from a primary care database in the United Kingdom suggests that women with a combination of gynecologic, urologic, and bowel symptoms are likely to have the condition.
“Specific, unremitting symptoms should raise a high suspicion of endometriosis,” said Dr. Ballard of the University of Surrey, Guildford, England.
Data were collected from the General Practice Research Database, the largest computerized database in the world containing longitudinal medical records from primary care. It currently comprises more than 3 million active patients from about 450 primary care practices, the setting in which all nonemergency patients in the United Kingdom are first seen.
During 1992–2002, 5,540 cases of endometriosis were identified from a total of 1,276,100 women aged 15–55 years. The average age at diagnosis was 35 years. The incidence of diagnosed endometriosis was 0.97 per 1,000 women-years, and the prevalence—calculated from the incidence rate and the average disease duration—was 1.5%. This proportion is lower than what has been reported in the literature, probably because it comes from general medical practice rather than a gynecology-based setting, Dr. Ballard noted.
There were 21,239 matched controls. The women with endometriosis were significantly thinner, with 49.3% having a body mass index less than 25 kg/m
As expected, the women with endometriosis had high rates of pelvic pain (15.6%) and dysmenorrhea (24.6%). But somewhat surprising was how low those rates were in the controls—1.5% and 3.4%, respectively—suggesting that “these symptoms are actually more specific than previously acknowledged,” Dr. Ballard said.
Other menstrual/pain symptoms reported significantly more often by the endometriosis patients than the controls were dyspareunia (9% vs. 1%, respectively), abdominal pain (45% vs. 13%), menorrhagia (23% vs. 6%), and menstrual problems (27% vs. 13%).
Gastrointestinal symptoms were also more common in the endometriosis group than in the control group, including constipation (9.2% vs. 4.4%) and rectal bleeding (2.0% vs. 1.1%), as were the urologic symptoms cystitis (8.8% vs. 5.3%) and dysuria (6.1% vs. 2.7%). Postcoital bleeding was reported by 2.9% vs. 0.7% and backache by 16.4% vs. 11.0%. All of these differences were statistically significant.
Women with endometriosis were also significantly more likely than were controls to have been diagnosed with subfertility (9.6% vs. 1.8%). But less expected was an association with the diagnosis of irritable bowel syndrome: 10.6% vs. 3.3%. Other diagnoses reported significantly more often among the women with endometriosis were urinary tract infection (18.5% vs. 9.8%), pelvic inflammatory disease (10.3% vs. 1.8%), and ovarian cysts (6.8% vs. 0.6%).
Stepwise regression analysis showed that the five “key symptoms” most strongly associated with endometriosis were infertility or subfertility (adjusted odds ratio 8.2), dysmenorrhea (8.1), symptoms associated with sexual intercourse (6.8), abdominopelvic pain (5.2), and menorrhagia (4.0).
In all, 84% of those with endometriosis had at least one of those symptoms, compared with 23% of those without, Dr. Ballard said.
The data also suggest there is opportunity for intervention: Nearly all (98%) of the women who were ultimately diagnosed with endometriosis had made at least one visit to a physician in the year before the diagnosis, compared with 81% of the controls.
In fact, 62% had visited the physician at least six times in that year, compared with 27% of those not diagnosed with endometriosis, she reported.
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