Contraceptive effectiveness of two insertions of quinacrine: results from 10-year follow-up in Vietnam.

BACKGROUND: This study was conducted to evaluate the long-term effectiveness of two insertions of quinacrine pellets for nonsurgical sterilization among women in northern Vietnam. STUDY DESIGN: Observational cohort study of 1335 women who received two quinacrine insertions between 1989 and 1993. RESULTS: About 90% of the study population participated in the last round of interviews. Cumulative follow-up time for this cohort was 14,294 person-years. The 1-, 5- and 10-year cumulative pregnancy probabilities for quinacrine were 3.3% (95% CI, 2.4-4.3), 10.0% (95% CI, 8.4-11.6) and 12.1% (95% CI, 10.4-13.9), respectively. Pregnancy estimates with quinacrine in this cohort were higher than that reported from US-based research on surgical tubal sterilization and higher than results of quinacrine sterilization in Chile. Quinacrine effectiveness was better among older women. CONCLUSION: The effectiveness of quinacrine in Vietnam was lower than other forms of sterilization. Factors such as inconsistent training and use of various insertion techniques may have contributed to the relatively high failure rate.