CONTINUATION RATES WITH A LEVONORGESTREL-RELEASING CONTRACEPTIVE IMPLANT (NORPLANT(R)) - A PROSPECTIVE-STUDY IN BELGIUM

Contraceptive protection offered by a method depends on its duration o f use, which reflects costs, side effects, and relatives' opinions. Th is study investigated in Norplant((R)) implants users the continuation rates, some of their determinants, and the motives for removals. Sinc e 1988, 612 Norplant implants sets, designed to protect for 5 years, h ave been inserted. Observing 13,907 months of use, we determined over time the continuation rates and how age, parity, circumstances at inse rtion (postpartum, postabortum, others), and patronymic origins (surro gate for sociocultural factors) influenced them. Statistics included K aplan-Meier's method and log rank tests, and uni-and multivariate Cox models. Continuation increased with age and depended on sociocultural factors. Parity exerted influence only in younger women. Median durati on of use was 3 years 11 months. Removals before 5 years related almos t equally to irregular bleeding, other side effects, and pregnancy wis h. The cumulative 5-year failure rate was 1.5%. Unsatisfied users retu rned earlier, distorting the first results. A literature search showed that implants yield, in the mean, slightly better continuation figure s than do intrauterine devices, and clearly higher than those obtained with pills and injectables. To optimize costs and counseling, warning s about the risk of short duration of use in young nullipara, especial ly if negative sociocultural influences prevail, are recommended. In n o category are the implants absolutely to be avoided. Individual and p rogrammatic contraceptive choice should take into account the expected continuation of use. (C) 1997 Elsevier Science Inc. All rights reserv ed.