TABLE 3.
Risk factors for endometriosis by cohort, ENDO Study, 2007 through 2009 (n = 600)
| Risk factor | Operative cohort (n = 473) | Population cohort (n = 127) | ||
|---|---|---|---|---|
| Unadjusted OR (95% CI) | Adjusteda OR (95% CI) | Unadjusted OR (95% CI) | Adjusteda OR (95% CI) | |
| Sociodemographic | ||||
| Age, y | 0.97 (0.94–0.99) | — | 1.02 (0.95–1.09) | — |
| Above poverty level (yes/no)b | 1.53 (0.83–2.80) | 1.88 (1.00–3.52) | 0.86 (0.17–4.24) | 0.87 (0.17–4.53) |
| College educated (yes/no) | 1.63 (1.00–2.64) | 1.83 (1.12–3.00) | 0.58 (0.11–2.98) | 0.58 (0.11–3.13) |
| Reproductive history | ||||
| Gravid (vs nulligravid) | 0.48 (0.33–0.71) | 0.49 (0.32–0.75) | 1.24 (0.39–3.93) | 1.02 (0.27–3.78) |
| Parous (vs nulliparous) | 0.47 (0.32–0.68) | 0.42 (0.28–0.64) | 1.31 (0.43–4.02) | 1.06 (0.28–3.96) |
| Infertility history (yes/no) | 2.49 (1.61–3.83) | 2.43 (1.57–3.76) | 7.13 (1.72–29.6) | 7.91 (1.69–37.2) |
| Age at first consenting sex, y | 1.05 (1.00–1.11) | 1.06 (1.01–1.12) | 1.07 (0.88–1.29) | 1.05 (0.87–1.28) |
| Surgical indication for laparoscopy (pelvic pain vs other) | 3.91 (2.65–5.76) | 3.67 (2.44–5.50) | — | — |
| Menstruation (past 12 mo) | ||||
| Age at menarche, y | 1.06 (0.95–1.18) | 1.05 (0.94–1.17) | 1.27 (0.87–1.87) | 1.25 (0.84–1.85) |
| Mean no. of periodsc | 0.99 (0.95–1.02) | 0.99 (0.96–1.02) | 0.99 (0.91–1.08) | 0.99 (0.91–1.07) |
| Mean cycle length, dc | 0.99 (0.98–1.00) | 0.99 (0.98–1.00) | 0.95 (0.85–1.06) | 0.95 (0.85–1.06) |
| Mean length shortest cycle, dc | 0.99 (0.98–1.00) | 0.99 (0.98–1.00) | 1.02 (0.98–1.06) | 1.02 (0.98–1.06) |
| Mean length longest cycle, dc | 0.99 (0.99–1.00) | 0.99 (0.99–1.00) | 1.01 (0.98–1.04) | 1.01 (0.99–1.04) |
| Dysmenorrhea (yes/no) | 2.78 (1.46–5.29) | 2.46 (1.28–4.72) | 1.37 (0.28–6.58) | 1.41 (0.28–7.14) |
| Pelvic pain (yes/no) | 0.95 (0.93–0.98) | 1.39 (0.95–2.04) | 1.01 (0.93–1.09) | 0.76 (0.09–6.54) |
| Body mass index, kg/m2 | 0.95 (0.93–0.98) | 0.95 (0.93–0.98) | 1.01 (0.93–1.09) | 1.01 (0.93–1.09) |
Excludes 22 women in operative cohort whose surgeries were cancelled and 4 women in population cohort with unreadable magnetic resonance images.
Cl, confidence interval; OR, odds ratio.
a
Adjusted for age (y) and site;
b
Based upon 2007 Health and Human Services Poverty Guidelines accounting for numbers of persons in household for 48 contiguous states and District of Columbia;
c
Among women with ≥1 menstrual cycles in past 12 mo.
Peterson. Risk factors associated with endometriosis. Am J Obstet Gynecol 2013.