Evidence-based medicine: an analysis of prophylactic bilateral oophorectomy at time of hysterectomy for benign conditions

Sackett et al. 1 defined evidence-based medicine as “the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients.” Prospective randomized clinical trials, through a double-blind process using treatment and control groups, are the optimal method for determining best evidence on interventions used to address a specific medical problem. However, because of economic and ethical issues, it is often not feasible to conduct those types of studies. Short and long-term health outcomes data from diagnostic and treatment protocols applied in actual patients serve as the best substitute. The management of noncancerous uterine fibroids is central to this research because the standard treatment for abnormal uterine bleeding associated with uterine fibroids is hysterectomy. More than 600,000 hysterectomies are performed annually in the United States as a direct result of symptomatology associated with uterine fibroids. Of that group, 55% will undergo a prophylactic bilateral oophorectomy at the time of hysterectomy, although fewer than 5% of the patients meet the high-risk criteria for developing ovarian or breast cancer for which the procedure is indicated. Prophylactic interventions, according to Hodges et al. 2, are intended to provide a net benefit to the patient with minimal risk to the patient’s health, in a patient at high risk for developing the disease in the absence of the procedure. Three hundred thousand women without risk factors for developing ovarian or breast cancer undergo this surgical procedure each year, which raises the question of its medical necessity. Further, if the procedure is performed in the absence of medical necessity, it raises the question of health risks precipitated with its use—the focal point of this dissertation. Adverse health outcomes experienced after undergoing a hysterectomy and prophylactic bilateral oophorectomy for treatment of noncancerous uterine fibroids was the impetus for this research. The onset of high blood pressure, high cholesterol, pre-diabetes, and weight gain postoperatively, raised questions regarding health risks associated with this prophylactic procedure and whether similar postoperative health outcomes may have been reported by clinicians and researchers conducting outcomes research. Culiner 3 first raised questions about the use of incidental bilateral oophorectomy at the time of hysterectomy for benign conditions a half-century ago, citing “an endocrine imbalance that cannot be corrected artificially, cardiovascular effects and osteoporosis.” Since the mid-1950s, epidemiologists, public health experts, and gynecologists have made additions to this initial risk profile of an increasingly severe and debilitating nature: Colditz et al. 4 reported a higher incidence of coronary vascular disease. Shoupe 5 reported a higher incidence of dementia, depressive, and mood disorders; a higher incidence of coronary vascular disease; and a higher incidence of sexual dysfunction. Parker et al. 6 reported a higher incidence of heart disease, cancer, stroke, all-cause mortality, and premature death. Rocca et al. 7–11 reported a higher incidence of cognitive decline, dementia, and Parkinson disease, and a higher incidence of anxiety, depressive, and psychiatric disorders. Schuster et al. 12 reported a higher incidence of all-cause mortality and a higher incidence of premature death. Rather than the adverse health outcomes experienced postoperatively being an “N of 1,” the foregoing dissertation research findings indicate that these outcomes, may in fact, be a prototype for many women who undergo this surgical procedure. “Why have rates of incidental bilateral oophorectomy in women without risk factors remained at 50% since the late 1980s, in spite of the growing body of scientific evidence that documents severe and debilitating health consequences, up to and including premature death, reported with its use?” was the research question that drove this dissertation. In academic health centers across the United States, 35 obstetrician–gynecologists were interviewed in this qualitative research study—10 in phase i and 25 in phase iv—to more fully understand clinical decision-making and evidence-based support for the use of incidental bilateral oophorectomy in women without risk factors. The Centers for Disease Control and Prevention and the American College of Obstetricians and Gynecologists (acog) were both included to be interviewed in the original research design, but declined to participate. Issues of critical importance in this dissertation research include when incidental bilateral oophorectomy in women without risk factors was first introduced. the scientific basis for the procedure’s use in women without risk factors. why and how its use in women without risk factors became widespread. when adverse health consequences associated with this procedure first appeared in the literature. the severity of adverse health consequences reported in the literature over time. the response of specialists to these scientific publications. the role of acog practice guidelines in the use of this procedure in women without risk factors. De-identification protocols were used for subjects and institutions interviewed, with one exception: William Parker md, who requested to remain public. De-identification protocols with Parker were particularly difficult, in large part because of the release of his study results, which were publicized on the CBS Evening News with Katie Couric, WebMD (www.webmd.com/), and The New York Times during the final phase of research. Although subjects in the Parker et al. study 14 had a decreased risk for breast or ovarian cancer, their risk for all-cause mortality, for both fatal and nonfatal coronary artery disease, and lung cancer increased. These dissertation research findings indicate that, for more than 35 years, prophylactic bilateral oophorectomy in women without risk factors, widely assumed to be life-enhancing, has for many women been inducing a wide variety of chronic disabling conditions and causing premature death. These results have occurred unbeknownst to many of the specialists performing the procedure and to many of the patients who consented to it. The dissertation provides an explanation for this phenomenon and for the institutional and behavioural factors that have contributed to the persistence of this surgical procedure’s use in women without risk factors. It is considered to be the first scientific analysis of this surgical procedure conducted by a former patient.