“Our findings emphasize the need for better health care provider education and appropriate patient selection and counseling before selecting opioids for pain management. Although some opioid use may be unavoidable in endometriosis, medical management should be aggressively optimized, and multiple treatment modalities pursued (surgery and involvement of pain specialists) to minimize inappropriate or excessive use,” the researchers explain.
Georgine Lamvu, MD, MPH, from the Department of Obstetrics and Gynecology, the University of Central Florida College of Medicine, the Orlando VA Medical Center, and colleagues reported their findings in the June issue of Obstetrics and Gynecology.
The findings may not change clinical practice, but they do provide important information, Tatnai L. Burnett, MD, Mayo Clinic, Rochester, Minnesota, told Medscape Medical News. “We already know what the right thing to do is with these patients; [these] data just show us what we have been doing.”
The researchers conducted a retrospective analysis of data from the Clinformatics Datamart database, a large administrative claims database that includes more than 150,000 individuals residing in different areas in the United States. The study included 53,847 women aged 18 to 49 years who had endometriosis and 107,694 women who did not have endometriosis and who were matched for age, region, race, insurance payer, and plan type. Most of the women (68.1%) had point-of-service insurance coverage.
The mean age of the study participants was 38 years, 62.4% of the women were white, and 51.6% resided in the south.
Compared with women in the control group, those in the endometriosis group were more likely to fill a prescription for an opioid (79.3% vs 24.2%; adjusted relative risk [aRR] ratio, 2.91) and were more likely to fill prescriptions with a dose of at least 50 morphine milligram equivalents (MMEs) (45.6% vs 9.7%; aRR ratio, 4.07) or 100 MMEs or more (14.9% vs 3.3%; aRR ratio, 3.56).
“Even after excluding opioid prescriptions filled within 30 days after the first postindex period surgery, these analyses showed that endometriosis patients had higher rates of filling opioid prescriptions, for longer duration and concomitantly with benzodiazepines than did a matched cohort of women without endometriosis,” the authors write.
Women in the endometriosis group were also more likely to fill concomitant opioid and benzodiazepine prescriptions (10.1% vs 3.5%; aRR ratio, 1.95) and to have used these drugs concurrently for at least 30 days (3.0% vs 1.2%; aRR ratio, 1.43) or at least 90 days (1.6% vs 0.7%; aRR ratio, 1.2).
Similar results were obtained after excluding opioid prescriptions received during a 30-day postsurgery window.
Women in the endometriosis group and matched control patients were diagnosed most often with noncancer pain (49.7% vs 36.0%), arthritis or joint pain (36.8% vs 27.1%), or back or neck pain (28.6% vs 19.2%) during the preindex period. For each condition, rates were significantly higher among the women with endometriosis than among the control patients (for all, P < .001).
Mental health problems were also more common among women with endometriosis than among those without endometriosis. Rates of mental disorders (20.7% vs 14.6%), anxiety (13.4% vs 9.2%), and episodic mood disorders (12.9% vs 8.7%) were significantly higher in the endometriosis group compared with the control group (for all, P < .001).
“That said, the findings are not unexpected. We all know that a significant portion of chronic pain patients do end up using opioids, despite that not being in line with the majority of research on chronic pain and opioids, and I would expect that women with endometriosis — given that it’s a chronic pain condition — would have higher rates of opioid use than those without it,” Burnett continued.
Although the study “shines a flashlight on a corner of medical practice that previously we didn’t have the data for, it doesn’t change what we already know to be the case: number one, that women with chronic pain typically do not have improved function or improved quality of life by taking opioid medications, particularly those who do not have a cancer or terminal illness; and, number two, it actually doesn’t significantly improve pain. In most of the studies looking at patients with chronic, noncancer, nonterminal pain, when you look at patients while on opioids vs after they’ve been discontinued on opioids for some time, their pain levels are about the same,” he said.
Burnett said one of the study‘s biggest limitations is the fact that the researchers identified women with endometriosis by using billing codes. “That is very different from knowing that they actually have an accurate diagnosis of endometriosis,” he explained.
“Further work is also needed to explore whether opioid prescribing differs among endometriosis patients without medical insurance. Moreover, although we suspect that opioid use in patients with endometriosis may lead to similar negative consequences as in other chronic pain patients, this assumption has not yet been specifically confirmed,” the researchers conclude.
The study was funded by AbbVie, Inc. The authors’ relevant financial relationships are listed in the original article. Burnett has disclosed no relevant financial relationships.
Obstet Gynecol. Published online May 9, 2019. Full text