Use-effectiveness of oral and intrauterine contraception

The use-effectiveness of oral contraception and intrauterine contraception was studied in 3 family planning centers in the United States: Grady Memorial Hospital in Atlanta, Georgia; State University of New York, Downstate Medical Center, in Brooklyn; and the Planned Parenthood Center in Buffalo, New York. In each locality 1000 women were selected for the study. 2900 women accepted intrauterine devices (IUDs) or oral contraceptives (OCs) as their first method of contraception. In Brooklyn 3 out of 4 women chose OCs; in Atlanta and Buffalo roughly equal numbers selected each method. The mean age of admission was 25.7 years in Buffalo, 24 years in Brooklyn, and 23.8 years in Atlanta. IUD acceptors were older than those choosing OCs. The difference was greatest in Buffalo (3.3 years) and smallest in Atlanta (.8 years). A special one-page, self-coding questionnaire was designed to collect the information required. In all 3 clinics contraceptive termination rates were markedly lower for the IUDs than for OCs. At 1 year of use for the first method only about one-fourth the women who chose the IUD had discontinued its use. Women on OCs terminated at rates from 10-20% higher. Termination rates for all contraception, both first-method and substitution, were lower than for first-method alone and lower for IUDs than for OCs. The highest continuation rate for all contraception was 92.5% for IUD users in Brooklyn while OC users in Atlanta were at the lowest level at 60.5%. Pregnancy rate studies demonstrated higher failure rates with OCs than with IUDs in all 3 clinics. Statistics by age showed that termination rates for both IUD and OC users declined with age. Women who selected IUDs as their method of contraception were more persistent users of contraception. Even after discontinuing IUD use, they were more likely to adopt another contraceptive method.