Background: Endometriosis is one of the most common diseases with high socio- economic burden in women. The aim of this study was to investigate the factors influencing on endometriosis by logistic regression.

Materials and methods:  In this case- control study, data were collected from patients records in Hazrat Rasoole Akram Hospital in Tehran. The patients who suffered from endometriosis (250), and their disease was diagnosed by laparoscopy, were selected as case group, and 250 patients with gynecologic disorder, other than endometriosis, confirmed by laparoscopy were chosen as control group. Factors affecting endometriosis were evaluated by logistic regression using the software SPSS. P- value <0.05 was considered significant.

Results: Mean age (±standard deviations) of women in case group (34.84±0.62) was significantly higher than control group (33.75±0.55) (P=0.02). Single variable logistic regression for independent variables candidate age, irregular menses, the duration of menstrual cycle, the duration of bleeding, the number of pregnancies, the number of live births, infertility, speck before menstrual bleeding to enter into multi variable logistic regression at error level of 0.2. Variables of age, the number of live births, and premenstrual spotting were predicted as factors influencing endometriosis.

Conclusion: According to the result of present study, age, the number of live births, premenstrual spotting were predicted as effective factors for endometriosis. As we know, increasing awareness of women about factors influencing endometriosis may help timely diagnosis and treatment of this important disease.

Keywords: Endometriosis, Reproductive age, Logistic regression, Laparoscopy.