Mon, Sept 19 at noon:
Paradox of Unintended Pregnancy, Jennifer Barber
Potter, R.G., F. Kobrin, and R. Langsten. "Three Contraceptive Acceptance Strategies." Mathematical Biosciences, 43(March1979): 1-22.
3 main cases of contraceptive acceptance strategy may be distinguished: "fixed duration T" (women counseled to accept T months after childbirth); "postamenorrheic" (accept directly after the 1st postpartum menses); and "mixed T" (accept T months after childbirth or after 1st menses, whichever occurs sooner). Any 2 strategies may be compared by means of a probability model simulating the 1st passage times from childbirth to next pregnancy of 2 cohorts of mothers identical in their fecundity and in the effectiveness and continuation with which contraception is practiced, but contrasting in their acceptance regimes. Of particular interest is the class of mixed-T strategies, which have not previously been analyzed. The efficiency of the mixed-T rule at least equals, and for most T-values exceeds, that of the corresponding fixed-duration rule both in the short run (lower cumulative pregnancy rate during the 1st few months) and in the long run (greater mean interval to next conception). Conditions for the superiority of the mixed-T over the postamenorrheic are also given. Several results are illustrated with reference to a Bangladesh population.