Field Effectiveness of the Oral and the Intrauterine Methods of Contraception: The Baltimore Public Program, 1964-1966

Abstract

All the women--more than 12000--who had received either oral or intrauterine contraception through public services in Baltimore Health Departmemt hospital clinics and Planned Parenthood clinics by May 1966 were studied. A great majority of all patients at all the family planning services received 1 ot these 2 methods. Oral and IUD users differed sociodemographically but not consistently from clinic to clinic. Generally pill users had fewer children were younger more often married and at a lower socioeconomic level than IUD users. The data indicate that the IUD is a significantly more effective method of contraception than the pill. Effectiveness of a method was measured by the probability of continuance. The age-adjusted continuation rate for 1 year was 10% higher for both white and black women using IUDs than for those on pills. The difference in continuation rate cannot be attributed to differences in the users. It is likely that women on pills tend to continue less because of the need to return frequently for supplies and the ease of discontinuing. Continuation rates from this study are consistent with results from other similar studies.