Sequence of events following adoption of contraception: an exploratory analysis of 1973 fertility history data.

Abstract

This paper describes and tests a model for constructing data-based estimates of probabilities of pregnancy following initial acceptance of a contraceptive method. The report outlines the basic features of the model, describes the sampling framework of the 1973 U.S. National Survey of Family Growth (NSFG) against whose data the model is tested, and explains estimation procedures. The model summarizes the behavior of a cohort of continuously married couples from acceptance of a contraceptive method, including nonuse, pill, other methods, or IUD, until the 1st subsequent pregnancy, marital dissolution, or sterility. Estimated probabilities of these outcomes are presented and compared to 1-step transition probabilities and directly observed NSFG data on pregnancy, marital dissolution, or contraceptive sterilization in order to assess the validity of the model and the biases resulting from its use. The model was found to be more successful for transitions to marital dissolution or contraceptive sterilization than for transitions to pregnancy. Possible reasons for this include small sample size in some categories and inappropriateness of some assumptions underlying the model.