Neisseria gonorrhea and chlamydia trachomatis screening at intrauterine device insertion and pelvic inflammatory disease

OBJECTIVE: To evaluate the relationship between Neisseria gonorrhea and Chlamydia trachomatis screening strategies and risk of pelvic inflammatory disease (PID) after intrauterine device (IUD) insertion. METHODS: We conducted a retrospective cohort study of all IUD insertions at Kaiser Permanente Northern California from January 2005 to August 2009. The PID incidence within 90 days after insertion was compared among women who were and were not screened for N gonorrhea and C trachomatis. The study was powered for equivalence with a PID risk difference of -0.006 to 0.006 between two groups considered to be clinically insignificant. Risk difference was calculated by subtracting the proportion of females with PID in one screening group from the proportion of females with PID in the comparison screening group. RESULTS: Of 57,728 IUD insertions, 47% were unscreened within 1 year of insertion; of screened women, 19% were screened on the same day. The overall risk of PID was 0.54% (95% confidence interval [CI] 0.48-0.60%). Nonscreening had an equivalent risk of PID as any screening (risk difference -0.0034, 95% CI -0.0045 to -0.0022), and same-day screening was equivalent to prescreening (risk difference -0.0031, 95% CI -0.0049 to -0.0008). The equivalence persisted when adjusted for age and race and when stratified by age younger than 26 years and older than 26 years. CONCLUSION: The risk of PID in women receiving IUDs was low. These results support IUD insertion protocols in which clinicians test women for N gonorrhea and C trachomatis based on risk factors and perform the test on the day of insertion. These findings have potential to reduce barriers to IUD use for women seeking highly effective, long-term, reversible contraception.