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Reproductive Health |
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The morning session included three presentations providing background information pertinent to discussing barrier methods and emergency contraception. Effectiveness of Available Barrier Methods Effectiveness of Available Barrier Methods-- Dr. James Trussell, Princeton University Four pieces of information about contraceptive effectiveness would help couples to make an informed decision when choosing a contraceptive method:
The difference between failure rates during imperfect use and failure rates during perfect use reveals how forgiving of imperfect use a method is. The difference between failure rates during typical use and failure rates during perfect use reveals the consequences of imperfect use. This difference depends both on how unforgiving of imperfect use a method is and on how hard it is to use that method perfectly. Many investigators have recognized the importance of distinguishing between contraceptive failure associated with user error and failure attributable to the inherent inadequacy of the method itself. By convention, all failures that occur during a month (or menstrual cycle) in which a barrier method is either not used at every act of intercourse or used improperly are labeled user failures. Only those pregnancies that occur during a month (cycle) during which a method is used perfectly are classified as method failures; perfect use does not imply that the method did not fail, only that the method was used consistently and correctly according to a well-specified set of rules. The standard procedure is to compute separate method and user failure rates (pregnancies divided by exposure). In this procedure, all exposure from both perfect and imperfect use is included in the denominator of both method and user failure rates. Under this convention, method and user failures are treated as two of many possible causes of method discontinuation. The sum of all cause-specific discontinuation rates is the overall or total discontinuation rate, and the sum of method and user failure rates is the overall or total failure rate. The common misinterpretation is that the resulting method rate yields information about the inherent efficacy of the method. That this interpretation is incorrect is obvious when one realizes that inherent method efficacy can be measured only when the numerator (method failures) is assessed in relation to the proper risk set (exposure only when the method is used perfectly). Method failure rates computed by the standard procedure confound inherent method efficacy with the proportion of exposure that is characterized by perfect use. There are two primary measures of contraceptive failure: the Pearl index pregnancy rate and life-table probabilities of pregnancy. The Pearl index is the ratio of the number of pregnancies observed in a study divided by the total number of years that all study participants have been exposed to the risk of pregnancy. A shortcoming of the Pearl rates is that they decline as the length of a study increases because participants likely to become pregnant tend to do so early, leaving in the study a pool increasingly comprised of more consistent and correct users or less fecund couples. With life table approaches, separate pregnancy rates are calculated for each month and then combined to yield the cumulative proportion of women becoming pregnant within specific time durations (e.g., 6 or 12 months). Summaries of the best available estimates of the probability of becoming pregnant within the first year of typical use and of perfect use of each method can be found in Table 31-1 in Contraceptive Technology (Hatcher et al.). Tables 31-2 through 31-16 in the same publication summarize research results published separately for each method. Uniform Contraceptive Labeling -- An FDA Update-- Colin Pollard, Chief, OB-GYN Devices Branch, U.S. Food and Drug Administration (FDA) Following approval of the female condom in 1992, the FDA initiated an effort to make labeling for all contraceptive products, both devices and drugs, use uniform language to convey information about protection from sexually transmitted diseases (STDs), as well as protection from pregnancy. In 1993, the FDA issued letters to manufacturers of all contraceptive products about how to label those products for STD protection: STD Protection
Equivocal/Difficult-to-Convey Message Several contraceptive products require special labeling statements to address and position the product with respect to STD protection:
No Protection
Between 1994 and 1996, the FDA also conducted a series of focus studies to develop a table that gives the effectiveness of all contraceptive products and methods, including devices and drugs, in a form that is easy for the consumer to read and understand. This table is based on one that is published periodically in Contraceptive Technology. The industry has been asked to incorporate this table into their consumer labeling for their respective products. Health providers and educators are also encouraged to use this table when discussing contraceptive options. The FDA will continue to update this table and its recommendations as new information becomes available. The influence of emergency contraception may affect contraceptive labeling at some point in the future. The FDA looks to researchers and others for ideas on how to keep these recommendations up-to-date and as meaningful to the consumer as possible. Guidance on the FDA's uniform contraceptive labeling initiative was issued in July 1998 and can be accessed via the FDA's Web site. Comments and suggestions about the FDA's uniform contraceptive labeling initiative may be submitted to Mr. Pollard (see the conference participants list for contact information). Also, information on labeling issues can be obtained through the Center for Devices and Radiological Health's (CDRH) "Facts-on-Demand," at 1-800-899-0381 (specify #1251 when prompted for the document shelf number). Availability and Utilization of Emergency Contraception-- Dr. Felicia Stewart, Henry J. Kaiser Family Foundation Currently, there are a limited number of products available for emergency contraception (EC), although the number is growing. The newest product is Preven (Gynetics), which the FDA approved for use in the United States in 1998. Other products include PC 4 (Schering), available in Europe since 1984; Postinor (Gedeon Richter), available in Eastern Europe since 1980, and, more recently Postinor 2 (Gedeon Richter); nine pill products not packaged specifically for EC; and the copper IUD. Preven includes an instruction book, a pregnancy test and emergency contraceptive pills (ECPs). Currently, substantial use of EC occurs only in two western European countries: 2.3 percent of reproductive age women in Finland, and 6 percent in the United Kingdom. Also, millions of women use Postinor in some 36 countries, but the instructions and regimen for Postinor are not the same as for ECPs. A recent study by Glasier and Baird compared results when routinely providing ECPs and when providing only information before ECPs are needed. With routine provision, use of ECPs increased and more unintended pregnancies were prevented. Of the 549 women given an ECP pack in advance, 47 percent used ECPs at least once in a year and there were 18 unintended pregnancies; among the 522 women receiving only information on ECPs, 27 percent used it and 25 unintended pregnancies occurred. The Washington State Pharmacy Project, which made ECPs readily available through a broad public education campaign, estimated that from 4 percent to 8 percent of U.S. women would use ECPs if good pharmacy access and public education existed. Currently, there are no good data on ECP use in the United States; some estimate its use at 1 percent. The 1997 Kaiser Family Foundation Survey found that virtually all obstetricians-gynecologists, nurse practitioners, and family planning providers in the United States knew about ECPs, and a substantial proportion provided ECPs at least once during the year. More than half of these providers discussed EC in an emergency situation, but only about 10 percent routinely discussed EC. The number of providers registered with the national hotline increased from 1,200 in 1997 to 2,700 in 1998. Use is increasing along a continuum. At first, only those who were raped were offered EC. Then providers began to include women who asked and had been exposed on high-risk days, and then to all women who ask. Now, some routine education about EC exists, with easier access by phone or through pharmacies in select locations. Eventually, some locations may routinely provide advance provision. User knowledge is also increasing. Currently, about 10 percent of women in the United States know ECPs are available and know the time frame for their use. Another 55 percent have heard of ECPs but don't know the time frame for use or that they are available in the United States. The media can increase knowledge of ECPs. The television show, "ER," included a brief scene that involved EC use. A telephone survey by Princeton Survey Research Associates found that knowledge of ECPs increased sharply the week after the show, although the pre-show level returned 10 weeks after the show. Similarly, a 30-second news spot on MTV resulted in 4,200 calls to the national hotline in two days, compared to 133 calls a day on the average. It is hard to tell how much more use of EC there will be, but the curve is clearly going up. The growing availability of EC also has wider and more fundamental implications. For example, integrating an initial EC dose into routine protocols for beginning other contraceptive options, such as oral contraception, injectable contraception, or vaginal barrier method use, could be explored to allow method start any time in the menstrual cycle. Similarly, couples today no longer select simply a contraceptive method. Rather, they select a strategy. The strategy often involves more than one method, such as condom use backed up by EC, or oral contraceptives with condom use to reduce STD risk in all or some sexual encounters. The era of contraception as a single method has come to an end.
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