Optimizing pelvic organ prolapse research.

For many years, researchers on this field have suffered from the lack of an efficient method for describing pelvic organ prolapse. Struggling to solve this problem, the International Continence Society has proposed a pelvic organ prolapse quantification (POP-Q) system [Bump RC, Mattiasson A, Bo K, Brubaker LP, DeLancey JO, Klarskov P, Shull B, Smith ARB, Am J Obstet Gynecol, 175(1):1956-1962, 1996], which was validated as a precise and reproducible technique for describing pelvic organ position. However, even though very precise at describing pelvic organ position, our critic to this system is its limited ability to quantify the prolapse itself, since it still classifies prolapse into four grades, almost the same way as Baden and Walker did in 1972. As a result, the same grade can include a wide prolapse intensity range. The objective of this paper is to propose a method that makes POP research more efficient by directly measuring prolapse as a continuous variable that requires lesser number of subjects in order to achieve statistical significance.