MODELED ESTIMATES OF MYOCARDIAL-INFARCTION AND VENOUS THROMBOEMBOLIC-DISEASE IN USERS OF 2ND-GENERATION AND 3RD-GENERATION ORAL-CONTRACEPTIVES

Consistent reports from several recent studies suggest that users of t hird generation oral contraceptives (OCs) containing gestodene and des ogestrel may be at increased risk of Venous thromboembolic disease (VT E). Paradoxically, other reports indicate that these users may be at d ecreased risk of acute myocardial infarction (MI) compared with users of second generation OCs. To determine whether the potentially increas ed risk of VTE would outweigh the potentially reduced risk of MI in us ers of third generation OCs, we conducted an analysis to quantify the trade-offs providers and users may be faced to make between these form ulations. The baseline rates of VTE and MI among non-users were calcul ated using US data on incidence and mortality of these conditions and estimates of the proportion of women exposed to these formulations in the US. These were multiplied by relative risks published in recent st udies on third generation progestins to produce age- and formulation-s pecific risks. Results indicate that there would be small differences in disease burden between users of second and third generation OCs und er the model assumptions at younger ages. However, among women 35-44 y ears of age, modeling results indicate that the potentially decreased incidence of MI among users of third generation OCs more than offsets the potentially increased risk of VTE at this age. (C) 1997 Elsevier S cience Inc.