Perils and promise in big data The study by Kawwass et al. (1) in the current issue of Fertility and Sterility reports the outcomes of in vitro fertilization cycles from 2000 to 2011 as self-reported per mandate to the National Assisted Reproductive Technology (ART) Surveillance System (CDC-NASS) database. The authors analyzed all ART cycles in which endometriosis had been identified as a diagnosis using cycles with male factor infertility as a control. Those with both endometriosis and male factor infertility were excluded, but the selection allowed for cycles with other concomitant diagnoses. Table 1 notes that the concomitant diagnoses included ovulatory dysfunction, tubal factor infertility, and diminished ovarian reserve—all potential confounders in the setting of endometriosis. Tubal factor infertility was more common for patients with endometriosis whereas other concomitant diagnoses were more common in the setting of male factor infertility. After controlling for concomitant infertility diagnoses as well as other factors in the regression analysis, the authors found that endometriosis-associated cycles were statistically significantly more likely to result in fewer oocytes retrieved, less hyperstimulation, and an increased risk of cycle cancellation. The clear strength of this study lies in the sheer number of cycles included. However, the perils of analysis in the setting of ‘‘big data’’ are apparent in the lack of clinically relevant conclusions available. As gynecologists and surgeons who are dedicated to the treatment of all aspects of endometriosis, we are painfully aware that the ideal treatment of this disease, whether in the context of fertility, pain, or organ dysfunction, has yet to elucidated (2, 3). Work has been done (4, 5), but basic questions remain about the optimal diagnosis and the role of surgical treatment in suspected or known endometriosis for enhancing fertility. Looking at the data presented, we feel there is little here to inform our practice. The method of diagnosis of endometriosis, the prior surgical treatment, the timing thereof, and the level or stage of disease are not known for the cycles reported. The data are self-reported, and as diagnostic procedures likely vary greatly between clinics, the categorizations also likely vary. As the authors note, even the simple finding of a decreasing trend in endometriosis-associated cycles may reflect multiple confounding factors, including a potential downward trend in the gold standard of laparoscopically diagnosed disease. Examination of large data sets such as these seems akin to looking at a landscape at 30,000 feet and trying to understand

1424

the nuance of traffic patterns. Certainly, trends are apparent even from a distance. However, a true understanding of how to address specific bottlenecks would require much more robust information from the ground. That said, there is much promise in the collection and analysis of large national and international databases. We commend the authors for their attempt to answer questions surrounding endometriosis with the data available. What this article ultimately brought to light for us as gynecologic surgeons is the need for further study of endometriosisrelated infertility. Perhaps it can serve as a call to action to create a registry specific to endometriosis or to expand on the currently available data-collection systems. Louise P. King, M.D., J.D. Camran Nezhat, M.D. Center for Special Minimally Invasive and Robotic Surgery, Palo Alto, California http://dx.doi.org/10.1016/j.fertnstert.2015.03.033 You can discuss this article with its authors and with other ASRM members at http://fertstertforum.com/kingl-perils-promise-big-data/ Use your smartphone to scan this QR code and connect to the discussion forum for this article now.* * Download a free QR code scanner by searching for “QR scanner” in your smartphone’s app store or app marketplace.

REFERENCES 1.

2.

3.

4.

5.

Kawwass JF, Crawford S, Session DR, Kissin DM, Jamieson JD. Endometriosis and assisted reproductive technology: United States trends and outcomes 2000–2011. Fertil Steril 2015;103:1537–43. Benschop L, Farquhar C, van der Poel N, Heineman MJ. Interventions for women with endometrioma prior to assisted reproductive technology. Cochrane Database Syst Rev 2010:CD008571. Jacobson TZ, Duffy JM, Barlow D, Farquhar C, Koninckx PR, Olive D. Laparoscopic surgery for subfertility associated with endometriosis. Cochrane Database Syst Rev 2010:CD001398. Littman E, Giudice L, Lathi R, Berker B, Milki A, Nezhat C. Role of laparoscopic treatment of endometriosis in patients with failed in vitro fertilization cycles. Fertil Steril 2005;84:1574–8. Veeraswamy A, Lewis M, Mann A, Kotikela S, Hajhosseini B, Nezhat C. Extragenital endometriosis. Clin Obstet Gynecol 2010;53:449–66.

VOL. 103 NO. 6 / JUNE 2015