Estimating the effects of contraceptive use on fertility: techniques and findings from the 1974 Philippine National Acceptor Survey

Abstract

Survey data on contraceptive use-effectiveness and on the fertility of family planning acceptors can provide a useful basis for estimating the fertility effects of a family planning program. The 1974 Philippine National Acceptor Survey (NAS), a sample survey of nearly 3,000 family planning acceptors reported by clinics in 1970--72 and interviewed in 1974, provided data for such an evaluation of the Philippine family planning program. The program's effects on the fertility of acceptors were estimated utilizing a series of analytical techniques, which are described in this article. Data from the NAS on continuation, pregnancy, and fertility following acceptance, as well as estimates of fertility decline associated with acceptance and continuing use of contraception, are analyzed. Findings are presented for acceptors of the four major program methods--pills, and the IUD, rhythm, and condoms. An appendix presents special procedures employed in estimating fertility effects.