A logistic model for the prediction of endometriosis
Received 16 January 2007; received in revised form 14 November 2007; accepted 14 November 2007. published online 07 May 2008.
Objective
To develop a model that uses individual and lesion characteristics to help surgeons choose lesions that have a high probability of containing histologically confirmed endometriosis.
Design
Secondary analysis of prospectively collected information.
Setting
Government research hospital in the United States.
Patient(s)
Healthy women 18–45 years of age, with chronic pelvic pain and possible endometriosis, who were enrolled in a clinical trial.
Intervention(s)
All participants underwent laparoscopy, and information was collected on all visible lesions. Lesion data were randomly allocated to a training and test data set.
Main Outcome Measure(s)
Predictive logistic regression, with the outcome of interest being histologic diagnosis of endometriosis.
Result(s)
After validation, the model was applied to the complete data set, with a sensitivity of 88.4% and specificity of 24.6%. The positive predictive value was 69.2%, and the negative predictive value was 53.3%, equating to correct classification of a lesion of 66.5%. Mixed color; larger width; and location in the ovarian fossa, colon, or appendix were most strongly associated with the presence of endometriosis.
Conclusion(s)
This model identified characteristics that indicate high and low probabilities of biopsy-proven endometriosis. It is useful as a guide in choosing appropriate lesions for biopsy, but the improvement using the model is not great enough to replace histologic confirmation of endometriosis.
aReproductive Biology and Medicine Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
cBiostatistics and Clinical Epidemiology Service, Clinical Center, National Institutes of Health, Bethesda, Maryland
bDepartment of Epidemiology and Center for Women's Health Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
dDepartment of Obstetrics and Gynecology, Vanderbilt University Medical Center, Nashville, Tennessee
Reprint requests: Pamela Stratton, M.D., Reproductive Biology and Medicine Branch, National Institute of Child Health and Human Development, National Institutes of Health, Building 10, CRC, Room 1-3140, MSC 1109, 10 Center Drive, Bethesda, Maryland, 20892-1109 (FAX: 301-480-6703).
Supported, in part, by the intramural research program of the Reproductive Biology and Medicine Branch of the National Institute of Child Health and Human Development, National Institutes of Health (NIH; Bethesda, MD), by the NIH Clinical Center (Bethesda, MD), and by the NIH-sponsored Training in Epidemiology and Clinical Trials training grant (T32 HD40672) at the University of North Carolina, Chapel Hill, North Carolina.
Presented as a poster at the Society for Gynecologic Investigation Annual Meeting, Toronto, Ontario, Canada, March 21–25, 2006.