Objective To examine the long-term effectiveness and continuation of the Standard Days Method (SDM) ® , a fertility awarenessbased method of family planning that identifi es Days 8-19 (inclusive) of the cycle as the fertile window. On these days users avoid unprotected sexual intercourse to prevent pregnancy. The method works best for women with cycles that are usually in the range of 26-32 days, which is an important reason for method discontinuation in the fi rst year of use. The authors determine if this continues to be an issue in the second and third years of method use. Methods Participants in an earlier effi cacy study (478 women in three countries) and method introduction studies (1181 women in four countries) were followed for 2 years beyond the original 1-year study period, to determine their continued use of the method, intended and unintended pregnancies, and reasons for discontinuation. Life-tables were used to approximate typical use pregnancy rates. Results The method continues to be effective in the second and third years of use, and compares favourably to other user-directed family planning methods. Women with no more than two cycles outside the 26-32-day range within a year are likely to continue having cycles within this range. Conclusions Women who complete the fi rst year of SDM use are likely to continue to be able to use the method successfully and effectively. The method presents a viable longer-term option for women who prefer this approach to family planning.
IntroductionFor most family planning methods, studies of method effectiveness, acceptability and continuation focus on the first year of method use. The reason seems obvious. Women who use the method for a year clearly find the method acceptable. Side effects severe enough to cause discontinuation of method use usually occur in the first few months of use. Also, efficacy in the second and third year is likely to be better than in the first year because (1) women for whom the method is biologically less effective would tend to get pregnant earlier and (2) failure due to user error is more likely to occur in the first few months of method use while users learn to use the method correctly. These findings are confirmed in the studies that include efficacy or continuation figures for any family planning method beyond the first year of use, though these studies usually examine longer-acting methods, such as intrauterine devices and implants.
1-3The Standard Days Method (SDM) ® is a fertility awareness-based method of family planning. The method identifies Days 8-19 (inclusive) of the cycle as the fertile window for every user in every cycle. 4 To prevent pregnancy, users avoid unprotected sexual intercourse on these days. The method works best for women with cycles that usually range between 26 and 32 days. Users are advised that the method may not be effective for them if they have a second cycle out of this range in a year. A multisite clinical trial of the SDM that followed women for up to 13 cycles of method use showed it to ...