Risk factors for pelvic inflammatory disease. A case control study

Pelvic inflammatory disease (PID) is associated with major medical and economic consequences for women of reproductive age. Identification of the risk factors associated with PID is crucial to efforts for prevention of these consequences.

To identify risk factors and markers for symptomatic PID.

A case-control study of 234 women with PID treated at San Francisco General Hospital between October 1986 and August 1989 and 122 controls attending the Women's Clinic at the same institution. The two groups were comparable in sociodemographic, reproductive, sexual, and medical history.

Risk factors and markers identified by univariate analysis were < 12 years education, gravidity > 0, parity > 0, spontaneous abortion > 0, lack of a birth control method, > 1 male sexual partner in the previous 30 days, younger than 18 years at age of first sex, history of gonorrhea, sex during the previous menses, douching, exposure to nongonococcal urethritis in the previous 30 days, and history of crack cocaine use. With multivariate analysis to control for confounders the risks still identified were parity > 0, (odds ratio [OR] 4.44; 95% confidence interval [CI] 2.34 to 8.42), > 1 sexual partner in the previous 30 days (OR 11.08; 95% CI 4.31 to 28.5), sex during the previous menses (OR 5.22; 95% CI 1.88 to 14.48), and a lack of contraception (OR 7.6; 95% CI 4.10 to 14.09).

Findings indicated that certain reproductive behaviors could be targeted for public health attention and risk reduction interventions to reduce the incidence of PID. These include limiting numbers of sexual partners and encouraging the use of barrier methods of contraception for sexually transmitted disease prevention. Another finding was that it is probably best to avoid sexual intercourse during the menses. The question of douching as a risk factor for PID could not be answered by this study.