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CHAPTER 3 CONTRACEPTIVE DECI SION-MAKING AMONG ADOLESCENTS Sandra L. Hofferth Unlike many other activities which require a conscious effort, con- ception is highly likely (given sexual activity) unless some action is taken to prevent it. One writer suggested that if it were the reverse, civilization would have long since died out. There is a certain cost to making a decision to act--it requires motivation, time, resources, and knowledge. It requires a change in behavior--overcoming inertia, as it were. This takes time and energy. Thus it is really no surprise that the risk of pregnancy is highest during the first months of sexual activity {Zabin et al., 1979~. However, it appears that that risk is also higher the younger the girl. Although contraception may be problemmatic for older women as well (Tanfer and Horn, 1984), it may be especially problemmatic for teenagers. This is because effective use of contraception is linked to the process of defining oneself as sexually active, becoming aware of pregnancy risk and its consequences, developing motivation to prevent pregnancy and taking active steps to prevent an unwanted pregnancy The major question that will be addressed in this chapter is, given sexual activity, what determines whether a teenager takes active steps to prevent pregnancy? The chapter is organized as follows. Background is first provided on contraceptive use among teens compared to adults. Second, a framework is provided to organize the review. Third is a discussion of some methodological issues, in particular, different ways to measure contraceptive use and their implications. The research that bears on the issue of contraceptive use versus non-use is pre- sented, following the model presented earlier. Finally, the f indings are summarized, conclusions drawn and implications for further research presented. BACKGROUND Table 2.7 displays the number of women age 15-44 exposed to the risk of unintended pregnancy who are currently practicing contracep- tion. Women exposed to the risk of unintended pregnancy includes those practicing contraception, and those not practicing contraception who had sexual intercourse in the last three months and were not pregnant, 56

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57 postpartum, seeking pregnancy, or noncontraceptively sterile. Never- married women of all ages are less likely than married women to prac- tice contraception; of these, teens are the least likely to practice contraception (Bachrach, 1984~. The proportion contracepting is very high: 9 of ten women at risk of unintended pregnancy. Never-married women are less likely than married women to practice contraception, and, of these, teens are the least likely to contracept: 69 percent of never-married teens 15-19 were practicing contraception. Thus 30 percent of never-married teens 15-19 at risk of an unwanted pregnancy were not contracepting. There are substantial black-white differences, with black teen- agers less likely than white teenagers to be contracepting {Table 2.8~. However, since blacks who are exposed to the risk of pregnancy are likely to be younger and less economically well-off, and since the young and the poor are less likely to use contraception, this differ- ence may merely reflect socioeconomic differences between the two groups. This will be explored further in a later section. Table 2.9 shows contraceptive use by Hispanic teenagers compared with non-Hispanic black and white teenagers. Hispanic teenagers are less likely than white but more likely than black teenagers to be cur- rently contracepting. This table includes teenagers of all marital statuses. More Hispanic teenagers are married, which may explain the rather small differences among the three groups. A comparison of sexually active never-married teenagers of Hispanic and non-Hispanic descent would be more appropriate but the data are not currently available. One problem with statistics is deciding what the appropriate com- parison group is for teenagers. Is it women 20-44 of all marital statuses? A much larger proportion of older women than teenagers will be married, and marriage improves contraceptive practice. A better choice might be never-married women 20-44. The only problem is that there are few women above 30 who have never been married. Those who haven't may be unusual and therefore, not constitute an appropriate comparison group. A good choice, therefore, for a comparison group appears to be never-married women 20-24 (and perhaps 25-291. They are similar in marital status and, given the increasing proportion in their twenties who have never married, probably not exceedingly different from their married peers in other respects. Fortunately, several sources contain information on contraceptive use among never-married women in their twenties, making possible comparisons with teenagers. It is clear that contraceptive use does improve with age. Table 2.7 showed that 81 percent of never-married women 20-24 practiced contra- ception compared with 69 percent of those 15-19 in 1982. A second study found that 85 percent of never-married sexually active women 20-24 were currently using contraception (Tanfer and Horn, 1984~. Table 2.8 shows the methods currently used by never-married users 15-19 and 20-24 in 1982. Teens are more likely than 20-24 year aids

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58 to use the pill and the condom; they are less likely to use the IUD, diaphragm or other methods. Teens are unlikely to be sterilized for contraceptive purposes. The probability of sterilization is higher for 20 to 24 year olds, and surprisingly high given their age. (Of course, many of these young women may have children, though unmarried and their partners may also have had children and had vasectomies). Although there are differences between the two age groups, the dif- ferences are not that striking. The largest difference appears to be in condom use. Almost 4 times as many teens say that it is their current method, compared with 20-24 year olds. Table 2.9 shows the current method used by Hispanic and non- Hispanic teenage contraceptive users in 1982. Two thirds of Hispanic teenagers use the pill and 9 percent use the IUD or are sterilized, which results in a very high level of use of effective methods (pill, IUD, sterilization), a level as high as that of blacks, among whom three quarters use the most effective methods. Again, this table includes teenage women of all marital statuses. The high level of effective contraceptive use among Hispanic teenage women is probably due to the higher proportion of married teenagers among Hispanics. One important issue is that of trends over time. According to data from the National Survey of Family Growth, among 15 to 24 year old currently married users, pill and IUD use declined substantially between 1973 and 1982, while use of sterilization and barrier methods such as the condom and diaphragm increased (Bachrach, 1984: Tables 7 and 8~. Trends among teenagers are somewhat different. According to data on never-married teenagers 15 to 19, between 1971 and 1976 pill use increased. Then, between 1976 and 1979, pill and JUD use dropped while diaphragm and condom use increased. Data from the 1982 NSFG survey suggest that the use of both pill and diaphragm among teenagers increased since 1979 (Table 2.81. Since the measures are not identical the size of the increase cannot be taken as definitive. However, the data certainly show that the decline in pill use since the late 1970s has been reversed. Sterilization showed major increases among young women as well as older women, though levels are still very low among young unmarried women. The model used here for contraception was developed by Delameter (1983~. It assumes that individuals determine and evaluate the potential consequences of their actions and, after weighing these consequences, act so as to maximize their benefits or minimize their costs. This calculation need not be made consciously or even care- fully. These basic assumptions are common to several theoretical models in use today: The Health Belief model (Nathanson and Becker, 1983), the Fishbein model (Fishbein, 1972; Fishbein and Jaccard, 1973), the economic utility model (Bauman and Udry, 1981; Becker, 1960; Willis, 1973; Nambocdiri, 1972),j, and the Luker model (Luker, 1975; Philliber et al., 1983~. hi.

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59 In this model, the proximal factors affecting contraceptive be- havior are the perceived probability of pregnancy, given intercourse, and its frequency, and the cognitive assessment of pregnancy, as well as positive and negative experience with contraceptives. The psycho- social factors in the model of sexual intercourse presented in Chapter 1 determine whether and how often intercourse takes place. In addi- tion, these same factors {society, family, peers) also affect the individual's perceived probability of pregnancy and cognitive assess- ment of pregnancy and well as attitudes toward contraception and some portion of experience with contraceptives. METHODOLOGICAL ISSUES A variety of measures have been used to study contraceptive use. One of the first issues to address is at what point should contracep- tive use be measured: first intercourse, last intercourse, in last month, currently? There appears to be no apparent rationale for using one or the other measure. One distinction does appear to be important. That is the distinction between use of contraception at first inter- course and continuing use of contraception. Contraceptive use at first intercourse {Table 2.2) is poorer than current use (Table 2.8~; this is the case for those whose first intercourse occurred when they were under 18 as well as those whose first intercourse occurred when they were 18 and older (Table 3.3; Figure 3.1~. Nonuse at initial intercourse and during the first months of sexual activity appears to be problemmatic: the risk of pregnancy is highest in those months (Zabin et al., 19801. The decision to first use contraception appears to be an important one. And the factors associated with initiating contraception may differ from those associated with continuing contra- ceptive use, once initiated. Thus the second major concern will be a discussion of the factors associated with continued contraceptive use including the difficulties associated with using it, change from one method to another, and the effectiveness and consistency of use. A second important issue is which of the variety of measures of current use that have been utilized by researchers are most appro- priate. Measures include whether ever used contraception, frequency or regularity of use, use at last intercourse, use during last month. Since these measures are all relevant to one concept, continuing use, the results of the research will be discussed together. One study (Herold, 1980} comparing these various measures will be discussed. Another issue is how to measure the type of contraception used and its effectiveness. Questions involve not only the time point at which use is measured (first, last intercourse, current use) but also whether and how methods are grouped: e.g., medical (pill, IUD) vs. non-medical methods, prescription (pill, IUD, diaphragm) vs. non-prescription methods; more effective vs. less effective methods; rank ordering of effectiveness; scale score based on use effectiveness.

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60 One of the major problems with the research in contraception appears to be its static nature. Contraceptive use at one point in time may not be a good proxy for use over the period of a year or more. Panel data that bears on this issue will be described. Another important issue is that of comparability with a sample of similar older women. Where possible this chapter compares the results for teenagers with those for older women to see if and where the findings differ. Finally, most of the analytic work so far has been based on data collected by Kantner and Zelnik (cf. Zelnik et al., 1981) in 1971, 1976 and 1979. Although the National Survey of Family Growth con- ducted in 1982 was released in 1984, so far no analytic studies of the type that would show factors associated with contraceptive decision- making have been completed. There is no reason to believe that the factors associated with contraceptive initiation and continuation have changed over time. Therefore, it makes sense to discuss the results obtained from that earlier survey as a baseline for understanding. Unfortunately, neither the National Survey of Young Women nor the National Survey of Family Growth provides the kind of information about potential rewards and costs of pregnancy and the perceived probability of pregnancy that could shed light on details of the theoretical model. Thus most of the studies discussed here are reduced form models with no intervening variables. This is not problemmatic as long as it is recognized that background factors are not expected to have substantial direct effects on contraceptive initiation and continuation. To fill in the detail on intervening factors this review focuses on a few small scale studies that have collected such information. Although these studies are generally conducted on highly selective samples, the information they provide is useful in evaluating the model. RESEARCH Frequency of Sexual Intercourse There is only one study so far to explore factors associated with the frequency of sexual intercourse among never-married teenagers. Zeloik et al. (1981) found that white teen women who reported that they had marriage plans, who used a medical contraceptive method at last intercourse, and who had had 4 or more partners had a higher frequency of intercourse than their peers. For black teen women, having had a greater number of partners and having used a medical method at last intercourse were associated with a greater frequency of sexual intercourse.

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61 Probability/Risk of Pregnancy What is the n best" way to measure contraceptive use depends on the purpose of the study. If researchers wish to measure how adequately individuals protect themselves from an unwanted or unplanned pregnancy, they would first need to adequately measure motivation to avoid pregnancy. Some individuals, for example, may be trying to get pregnant. Others may be infertile for a variety of non-contraceptive reasons. Finally, others may not care if they become pregnant or not. Some individuals may be knowledgeable about their menstrual cycle and may contracept actively only during the high risk parts of the cycle. In this case it would be helpful to know how accurate the individual's knowledge is about the menstrual cycle and at what time of the cycle the questions are asked. Table 2.10 shows perception of risk of pregnancy to be poor among teenage women, even among those sexually experienced. In 1976 only two out of five could name the time of month of greatest pregnancy risk. On the other hand, a number of contraceptive methods do not require any knowledge of time of greatest risk, and some studies sug- gest that users of such methods are least knowledgeable about timing of pregnancy risk (Presser, 19777. Thus it may not be critical to know exactly when pregnancy is most likely to occur to use contracep- tion effectively, only that the risk is relatively high. The associa- tion between knowledge about pregnancy risk and use of contraception is not very strong, though it has been found in a few studies (Philliber et al., 1983; Cvetkovich and Grote, 1980~. The relationship between knowledge of methods and contraceptive use is also not very strong (Flaherty and Marecek, 1982; Poppen, 1979~. This appears to be because most teens can name several methods. What kind of knowlege leads to earlier and more consistent use of contraception is an issue that needs additional exploration Cognitive Assessment of Pregnancy How do teenagers feel about pregnancy and childbearing? Do they want to become pregnant? Do they not care? Do they not want to avoid it strongly enough to contracept adequately? What information do we have about this issue? There is, of course, an important distinction between childbearing intention and wantedness of a child. In particular, most young child- less women eventually do want children. Thus many teenage pregnancies are timing failures; this does not imply that children are not wanted ever. A child may be wanted, but not at that time. Three categories of child-bearing intentions at the time of conception are commonly distinguished: 1) Timing success - a child is wanted at that time; 2) Timing failure - a child is wanted, but not at that time; 3) Unwanted - a child is not wanted at that time or ever.

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62 Of those young women who become pregnant as teenagers, about 45 percent have abortions (excluding miscarriages from the total) (see Pregnancy Resolution). Presumably abortions represented unwanted pregnancies. Early studies showed that of those teens who experienced a first birth as a teenager, only about half (45 percent) could be considered intended or timing successes, that is, both wanted ever and wanted at that time (Trussell and Menken, 1978~. The majority (55 percent) of first births to teenagers, represented either timing failures or unintended or unwanted births. Thus, of the total pregnancies to teenagers, only about 25 percent were intended, that is, wanted at that time. This study was conducted at a time when a large proportion of teenagers married. The proportion of pregnancies that could be considered intended has probably draped, but no recent research was available to address this question. Initiating Contraceptive Use What proportion of youth used a contraceptive method at first intercourse? Among those who did not use contraception at first intercourse, when did they begin using contraception? What methods were used at first intercourse among users? What methods did later initiators first use? Table 2.1 shows that in 1979 almost half of all teen women reported that they used a contraceptive method at first intercourse. The per- centage of teen women in 1982 who used a method at first intercourse is identical to that in 1979. There appears to have been no major shift between 1979 and 1982 in use at first intercourse. This repre- sents a substantial improvement over 1976, when 40 percent of teen women said that they contracepted at first intercourse (Zelnik and Kantner, 1978~. The pattern of contraceptive use at first intercourse varies sub- stantially by age at that time {(unpublished tabulations from the NSFG; Zelnik and Shah, 19831. Under a third of women and men who first had intercourse at under 15, half of those who first had intercourse at 15 to 17 and three-fifths of those who first had intercourse at age 18 or older used a contraceptive method at first intercourse. There is very little sex difference. The race difference is sharper; blacks are less likely than whites to have used a method at first intercourse. However, in an analysis of the 1976 National Survey of Young Women, Zeloik and colleagues (1981) found that after adjusting for other differences between young women, in particular the age at first sex, current age, SES and family stability the race difference was not statistically significant. The difference in use of a contraceptive method at first sex by age at the time remained highly significant; women who were older at first intercourse were much more likely than women who were younger to have used a method at that time.

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63 Mosher and Bachrach (1986) conducted a multivariate analysis on data from the 1982 National Survey of Family Growth. They found that, for women 15-44 in 1982, there was a substantial race difference in use of contraception at first intercourse--whites were much more likely than blacks to use a contraceptive method at that time. When they controlled for differences between blacks and whites in education of mother, year of first intercourse, ethnicity/religion, age at first intercourse and whether ever discussed menstrual cycle with a parent, that race difference declined slightly but did not disappear. This analysis differs from that of Zelnik et al. in that 1) it was not re- stricted to teenagers, and 2) it did not control for family stability or religiosity, which were included in the previous analysis. Thus we cannot draw any conclusions as to whether a change has occurred such that there is now a true race difference in contraceptive use at first intercourse net of other differences, where there was not one in 1976. An analysis comparable to that of Zelnik et al. (1981) should be conducted on the 1982 NSFG or other recent data. Zelnik et al. (1981) focused primarily on the influence of back- ground factors on use of contraception at first intercourse. A few relationships were significant, but overall the relationships were not very strong. Young women with better educated parents and in intact families were more likely to have contracepted at first intercourse. Surprisingly, women younger at the time of the survey were also more likely to have contracepted at first intercourse. Given that age at first intercourse is also controlled, this suggests that more recent cohorts of young women, particularly blacks, are more likely than early cohorts to use contraception at first intercourse. What proportion of those who used a method at first intercourse used a prescription method--the pill, IUD or diaphragm? Use of such methods requires planning and a doctor or clinic visit. According to data from the 1979 National Survey of Young Women black teenagers are much more likely than white teenagers to report having used a prescrip- tion method at first intercourse: 41 percent compared to 15 percent of whites (Zelnik and Shah, 1983~. Even when other factors are con- trolled, using the data from a similar 1976 survey, Zelnik et al. (1981) found the black-white differences to be large and statistically significant. Age at first intercourse continues to be important, with those older at first intercourse more likely to have used a medical method at that time. Again, only a few variables were associated with use of a prescription method, and the total proportion of variation in contraceptive use explained by these variables was very small. This analysis of medical methods points out some of the pitfalls of relying on one analysis of contraceptive use. For example, the condom, which is not a medical method and was therefore not included in the analysis discussed above, is effective if used properly. Is an analysis, therefore, adequately measuring contraceptive use at first intercourse if condom use is ignored? Table 2.3 shows the distribution of contraception used at first intercourse among all sexually ex

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64 perienced respondents and among users only. Comparing black and white female users in 1979 (Table 2.3) we see that white women users relied heavily {three quarters to four-fifths) on a male method (condom and withdrawal); in contrast, half of black female users reported using female and half reported using male methods, with most of the female methods being prescription methods. The reports of white male users are very similar to those of white female users, with 7 out of 10 reporting use of a male method at first intercourse. However, the reports of black male users are very different from those of black female users. Of the former, 6 or 7 out of 10 say that they used a male method at first intercourse. Of course, there is no reason these figures have to be the same. In fact, the data suggest that the first partner is older and, therefore, probably already experienced. Data are similar for 1982 (Table 2.4), except that among users the use of female prescription methods at first intercourse appears to have de- clined among black female teens and the use of the condom has in- creased. Sample differences make this conclusion tenuous, however. The planning status of first intercourse does appear to be related to use of contraception (Table 2.31. Young women who planned their first intercourse were more likely to have used contraceptive methods than those who didn't plan it, but the differences are small. Young men who planned their first intercourse were more likely to have used a male method. Table 2.5 shows reasons respondents gave for not using a method at first intercourse. Under 5 percent said they wanted a pregnancy or didn't care; another small proportion thought pregnancy impossible. Almost 20 percent said they didn't know about contraception. The majority said it was unavailable, didn't think about it, or didn't want to use it. Contraceptive Use in the First Six Months After Sexual Debut Half of all initial premarital pregnancies occur in the first six months of sexual activity (Zabin et al., 1979), and more than one-fifth in the first month. Yet data show that teenagers delay coming to a clinic--the average delay is about 1 year after initiation of sexual activity. What is the pattern of contraception during the period? Research on the sequence of contraceptive use from first inter- course is greatly needed. Table 2.1 shows the percentage distribution of premaritally sexually active women age 15-19 by contraceptive use status and race in 1982, 1979 and 1976. About one-third of the young women in 1979 reported using contraception at first intercourse and using it consistently thereafter. Fifteen percent contracepted at first intercourse, but not always, 25 percent did not use a method at first intercourse but did at some time afterwards, and 27 percent claim to have never used contraception. Since 1979 there has been an apparent decline in the proportion of teen women who never used con

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65 traception and an increase in the proportion who used it at sometime, although not at first intercourse. Of course, Table 2.1 does not show us how long after first inter- course it takes to adopt contraception. Table 2.6 shows, for those who did not use a method at first intercourse, but who had ever used a method by the interview date in 1982, the length of time between first intercourse and first contraceptive use. It is clear that the older the age at first intercourse, the quicker a young woman adopts contra- ception. Twenty-two percent of those under 15 compared to 53 percent of those 18-19 at first intercourse adopted contraception within one month; 42 percent of the former and only IS percent of the latter de- layed more than one year. Among those who do not use contraception at first intercourse, blacks were consistently slower to adopt contracep- tion than whites. This difference is smallest among the earliest initiators, and is surprisingly large among later initiators {although sample sizes are small). Since blacks were also less likely than whites to have used contraception at first intercourse, blacks appear to be at much higher risk than whites of a pregnancy at or soon after first intercourse. In 1976, on average those 15-17 year olds who did not use contraception at first intercourse did so within about 6 months (excluding those who did not use contraception by the time of the sur- vey or prior to pregnancy or marriage). Among those teenagers visiting clinics, the average delay in 1980 was more than a year (Kicker, 1984' This figure understates the average delay since many (41.7 percent of all 15-19 year olds) used no contraception between first intercourse and either a pregnancy, marriage or the survey date. The most imp portent reason young women gave for delaying a family planning visit to a clinic was that they simply didn't get around to it. Two other major reasons cited were n fear of family discovery" and n relationship with partner not close enough. What factors would be expected to be related to contraceptive use at first intercourse? 1) correct perception of pregnancy risk and time in the month of greatest risk, 2) motivation to avoid pregnancy. So far there has been little attempt to measure these concepts and test their association with contraceptive use at first intercourse or rela- tionship to contraceptive adoption soon after. Table 2.10 shows that sexually inexperienced women are less likely than experienced women to correctly perceive the time of greatest pregnancy risk in the menstrual cycle. There is very little work on adoption of contraception after first intercourse--either the process or the types of methods used. Very little research has even categorized young women by length of time since f irst intercourse. Research to sort out this process, preferably using a life table methodology, is needed.

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66 Contraceptive Continuation For this review three aspects of contraceptive continuation are important: 1) whether currently using, 2) regularity of use and 3) effectiveness of method. Current Contraceptive Use Probably the most common measures are 1) whether used a contracep- tive method at last intercourse, and 2) whether currently using a con- traceptive method. The reference point for the second measure is usually specified as during the last month or last 4 weeks preceding the survey and is specified as among those sexually active. Some analysts, in addition, eliminate those who cannot become pregnant and those who are trying to become pregnant. Some studies utilize the first and others utilize the second measure. Comparisons of the results obtained (for example, Tanfer and Horn, 1985) show that the distributions are very similar. So it makes sense to consider these two together. There was substantial improvement in current contraceptive use between 1971 and 1982. Slightly under half of all women 15-19 used a method at last intercourse in 1971; close to 2/3 of all teens used a method at last intercourse in 1976 {Zelnik and Kantner, 1977~. 1982 data show that 71 percent of teens exposed to the risk of an unwanted pregnancy are currently practicing contraception (Bachrach, 1984~. In 1971 black teenagers appeared to be similar to whites in contraceptive practice. When other factors were controlled, such as differences in socioeconomic status and in family structure, no significant difference between blacks and whites in use at last intercourse remained {Zelnik et al., 19811. One of the most important factors associated with currently using contraception are current age and length of time sexually active. Zelnik et al. (1981) controlled simultaneously for current age and for age at first intercourse. Thus age at first intercourse really rep- resents length of time since first intercourse. Of two young women with similar ages, the one who became sexually active earlier has been active longer. Zeloik et al. {1981) found that women who were older at first intercourse (and therefore had been sexually active less time) were more likely to contracept at last intercourse. Using the same data set, Devaney and Hubley (1981) found current age but not age at first intercourse to be associated with contraceptive use. That is, older teens were more likely to be contracepting at last intercourse than younger teens. The Devaney and Hubley study included a larger set of control variables, which may explain the difference in findings. Studies using the National Survey of Young Women found frequency of intercourse (Devaney and Hubley, 1981) and number of partners (Zelnik et al., 1981) to be associated with use of contraception at

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67 last intercourse. A women who was engaged to be married (Devaney and Hubley, 1981) and one who had been pregnant {Zelnik et al., 1981) were likely to be contracepting. A history of past use was associated with current use. Teens who contracepted at first intercourse (Zelnik et al., 1981) and those who had few unprotected months after first method use (Philliber et al., 1983) were more likely to be contracepting at last intercourse. Family background and interpersonal factors contribute to use of birth control. Young women with better educated parents were more likely to be contracepting (Zelnik et al., 1981~. A young woman in a family receiving welfare was less likely to have contracepted at last intercourse than a young women not in a family receiving welfare (Philliber et al., 1983~. Living in group quarters was associated with greater use of contraception at last intercourse (Devaney and Hubley, 1981~. Finally, Philliber et al. (1983) found that the more persons who knew about the teenager's birth control use the more likely she was to be contracepting at last intercourse. One factor strongly associated with use of contraception at last intercourse is educational expectations. The higher the educational expectations, the more likely a young woman is to have used contra- ception at last intercourse (Devaney and Hubley, 1981), a relationship that holds for whites and blacks alike. This variable may be a proxy for motivation to prevent pregnancy. Philliber et al. (1983) tested the Luker formulation of a decision- making model on youth attending a New York City youth center. In- cluded in the model were a series of socioeconomic background charac- teristics as well as a series of variables measuring perceived advan- tages and disadvantages of pregnancy and perceived pregnancy risk. She found that using effective contraception at last intercourse was associated with a high score on the subjective probability of preg- nancy, a low score on perceived advantages, a high score on perceived disadvantages of pregnancy, a low estimate of the probability of using abortion if pregnancy occurs, and a low rating of disadvantages of birth control. Those with a high level of ego development were also more likely to use effective contraception. Few background factors added significantly to the model. This research provides strong support for the value of a decision-making model. Further research should address the issue of the factors affecting individual percep- tions of consequences and the ways these affect behavior that is, the mechanisms whereby background factors lead to differential contracep- tive use. Regularity of Contraceptive Use Regularity of contraceptive use has been measured in a variety of ways. Flaherty and Marecek (1982) divided their sample into contracep- tors versus non-contraceptors. The former reported use of contracep

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68 Lion either always or usually, the latter reported rarely using con- traception, and were using nothing at the time of interview. Poppen (1979) and Cvetkovich and Grote (1980) used two measures: 1) ever versus never had unprotected intercourse and 2) frequency of con- traceptive use in the last three months {always, almost always, usually, sometimes, never), including all methods, even rhythm. Nathanson and Becker's definition of contraceptive use was the pro- portion of time subsequent to the baseline interview that a respondent at risk of pregnancy (sexually active and not pregnant) was using a medical method of contraception (mostly oral contraceptives) (Nathanson and Becker, 1985~. Ager (1982) defined contraceptive non-use as 1) program discontinuance or 2) method discontinuance. The former refers to whether still in program or not; the latter refers to those not continuously practicing contraception, compared to those who were either continuously practicing effective contraception or were not at risk over the interval. Zelnik et al. (1981) divided women into two groups: ever and never users of contraception. Unfortunately, except for Zelnik et al. (1981), none of these studies controlled for length of time since first intercourse, and only a few controlled for current age. Since these respondents are at all stages of sexual experience the results should be taken with cau- tion. Zelnik et al. (1980) showed that both age at first intercourse and current age are related to frequency of contraceptive use. Net of current age, age at first intercourse measures length of time or dura- tion since first intercourse. Results of their study show that the older the current age and the longer the time since first intercourse, the less likely a teenager is to have always contracepted. The former represents a cohort effect: older teens were born before younger teens; more recent cohorts appear to use contraception sooner than earlier cohorts. The latter represents pure length of exposure effect. The longer the period in which to have contracepted, the less likely the respondent is to have always contracepted. In another study which controlled for background factors as well as characteristics of the respondent and current relationship and which used a different data set, Furstenberg (1983) did not find either duration of exposure to pregnancy risk or current age to be associated with contraceptive continuation (continuous contraceptive use over 15 months as measured by two different measures). This suggests that factors included by Furstenberg and not by Zelnik et al. (1981), such as parental employment, n steadiness" of the relationship, academic performance, school/employment status, and convenience of method, may explain the impact of current age and length of time since first intercourse on contraceptive continuation. However, this is purely speculation, since the research to test such an hypothesis has not been conducted. None of the studies cited showed significant black-white differ- ences in frequency of contraceptive use. Although one study suggested that sexually active blacks may be slightly more likely to have ever

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69 contracepted (Devaney and Hubley, 1981), the evidence certainly is not sufficient to reject the conclusion that contraceptive regularity differs little by race. Cvetkovich and Grote (1980) found that black males whose mothers have a high education use contraception more regularly; Zelnik et al. (1981) found a similar effect of parental education on the contracep- tive use of black females. Flaherty and Maracek (1982) found that girls who talked with their mothers and cited the mother as a source of birth control information used contraception more regularly; how- ever, she did not control for other differences between young women. Fox (1980) found a similar effect of maternal communication on daughters' contraceptive use, but it disappeared with controls for other factors such as socioeconomic background and family structure. Flaherty and Marecek (1982) found type of maternal discipline associa- ted with frequency of contraceptive use. In particular, daughters who had experienced parental rules and punishments for violations and for whom restrictions of privileges were favored over corporal punishment for misbehavior were more likely to use contraception. Again, however, these researchers did not control for potentially confounding factors. Thus these results should be taken as suggestive, not definitive. One important hypothesis is that young women who don't perceive opportunities other than motherhood open to them will be less motivated to prevent pregnancy than women who perceive better opportunities for jobs and careers. Nathanson and Becker (1983) found that black girls who perceived better opportunities for non-reproductive roles were more likely to be regular contraceptors than those who didn't. However, the association was weak for black teens and there was no association for white teens. They did find that the older the preferred marriage age, the greater the continuity of contraception among white and black teen- agers (Nathanson and Becker, 19831. Religion doesn't appear to be related to frequency of contraceptive use. Flaherty and Marecek (1982) showed a positive effect of religios- ity in general. Devaney and Hubley (1981) found that blacks who said that religion was important to them were more likely to have ever-used contraception than others. In contrast, whites who said they attend church regularly were less likely to have ever-used contraception. Their particular religious affiliation was not associated with ever having used contraception. However, using the same data, Zelnik et al. (1981) did not find either religiosity or religion to be associa- ted with ever having used contraception, net of other factors. One study based on samples from two urban areas and one small town found that knowledge about sex and contraception were associated with greater frequency of contraceptive use among white males {Cvetkovich and Grote, 19801. Fear of side effects of contraception and perception of harmful effects of contraception were associated with less frequent use (Popper, 1979; Cvetkovich and Grote, 1980~. Self-esteem was asso- ciated with more frequent contraceptive use for both whites and blacks (Cvetkovich and Grote, 1980~.

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70 For a discussion of the effects of the clinics themselves on con- traceptive use, see Programs and Policies, Chapter 9. Contraceptive Effectiveness The final measure of contraceptive continuation to be discussed is contraceptive effectiveness, that is, the level of effectiveness of the contraceptive method the women/couple used at last intercourse or is currently using. Effectiveness is measured by the failure rate. It is the proportion of women exposed to the risk of unintended pregnancy who would become pregnant if they used a given method and no other for one year. Measuring effectiveness therefore, requires a knowledge of method used and an estimation of its associated failure rate. There are several potential ways of measuring failure rate. The theoretical or biological failure rate is impossible to measure but is often ap- proximated by the lowest failure rate measured among different popula- tion groups. The actual use effectiveness rate, in contrast, is the average failure rate for the group to which the individual belongs, which will be higher than that of the theoretical rate. Table 2.11 shows use failure rates for unmarried women over the period 1979 to 1982, from the National Survey of Family Growth (Grady et al., 19861. Failure rates vary substantially by age, contraception method, duration of exposure, poverty ratio income, race, parity and contraceptive intention of the woman. In general failure rates are higher the younger the woman. Among those who intend to delay a birth, failure rates are highest for those 18-19 years old, not for those under 18. This is probably due to the fact that 18-19 year old single women have the highest frequency of intercourse (see Chapter 1~. There was not enough information in the NSFG to control for frequency of intercourse. Among those who seek to prevent a birth entirely, failure rates are highest among those under age 18, and decline gradually to their lowest level among women 30-44. Surprisingly, failure rates are higher up to age 29 among women who seek to prevent an additional birth rather than those who seek to delay a birth. Grady et al. ( 1986) speculate that either 1) young women redef ine their intentions at the time of conception after the fact, or 2) young single women who are preventing a pregnancy are doing so because they have already had one or more unwanted births. Those who intend to prevent at a young age may be ineffective users and high risk nonusers, while the older age groups would include many post married women who had successfully regulated their fertility. Black women have no higher risk of un- intended pregnancy than women of other racial groups; the similarities are probably exaggerated since abortions are underreported more by black than white women. Women who have had children have higher failure rates than those who don't. Such women may be more fecund. Finally, failure rates are higher among women with lower incomes; those below the poverty level have the highest failure rate.

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71 Grady et al. (1985) found that the failure rates for single women were somewhat lower than those for married women. They hypothesized that this difference was due to the fact that abortions were under- reported more by single than by married women. When they adjusted the use-failure rates to take into consideration this reporting difference, the use-failure rates for single and married women were more similar. Comparing single with married women, failure rates for the former are higher for the pill, lower for the condom and use of no methods. It is likely that the differential frequency of intercourse among married women explains their greater failure rates for the condom and no method, while greater inconsistency of pill use explains the greater failure rates of pill use among unmarried compared with married women. The lowest possible failure rates measured among different population groups are presented in Grady et al. (1986~. Although other factors, such as interpersonal relationships and contraceptive attitudes may also affect use effectiveness, no research has been conducted using such factors to distinguish effectiveness. In practice, almost no one has simply taken these theoretical or use effectiveness scores and used them as a dependent variable. Contraceptives are generally rank ordered by effectiveness and then grouped into categories such as medical and non-medical or effective and non-effective. An example is that of Zelnik et al. (1981) who distinguished medical (prescription) from non-medical (non-prescrip- tion) methods. An example of research using effectiveness ratings as a dependent variable is that of Polit et al. (1981~. The dependent variable n at risk to pregnancy" combines four types of information: a) the percentage of time that the couple used a method of birth control, b) the theoretical effectiveness of the methods used, c) the use-effectiveness of the methods used and d) assessments of how effec- tively this couple used their contraception. The final score ranged from 3 to 90, with 3 representing low risk (e.g., consistent users of the pill) and 90 representing highest risk of pregnancy (e.g., no birth control at all). Current age and age at first intercourse predict use of effective contraception. Older teens are more likely to have used a medical method at last intercourse (Zelnik et al., 1981~. The longer the duration of exposure to sexual activity (the younger the age at first intercourse) the more likely to have used a medical method. Young black women with better educated parents are more likely to have used a medical method at last intercourse (Zelnik et al., 1981~. Net of other factors, blacks are more likely than whites to have used a medi- cal method at last intercourse (Zelnik et al., 1981~. Not listing a religion and not being religious are associated with a higher probabil- ity of using a medical method at last intercourse (Zelaik et al., 1981). These authors also found that young women who have been pregnant are more likely to use a medical method at last intercourse (Zelnik et

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72 al., 1981~. In contrast, Polit et al. (1981) found that couples in which the female had been pregnant were less effective contraceptors. Characteristics of the relationship are important predictors of effectiveness of contraception. The greater the number of partners, the more committed the relationship with the partner, and the more frequently intercourse occurs, the more effective the contraception (Thompson and Spanier, 1978; Herold, 1980; Zelaik et al., 1981~. The greater the likelihood of couple continuity (boy's report) and the higher the communication rating, the more effective the contraception (Polit et al., 19811. Attitudes toward sex and contraception have been found to affect the effectiveness of the contraception couples use. Herold (1980) found that teen females who have favorable attitudes toward contracep- tion, a low level of embarrassment about contraception, and a low level of premarital sex guilt are more likely to use effective contra- ception. Beliefs about who should have responsibility for birth control have also been found to be associated with more effective contracep- tion. Polit et al., (1981) found that teen women who believe that the female should take responsibility for birth control tend to be more effective contraceptors. Although the same authors (Polit et al., 1981) hypothesized that males and females who were rated high on decision-making skills would be better contraceptors, in fact, she found no difference among females and that couples in which the male had good decision-making skills were less effective contraceptors. She concluded that, contrary to her hypotheses, contraception is more suc- cessful when one person, particularly the female, takes responsibility for it. Some Methodological Issues Presumably the reason that we are interested in measuring contra- ceptive use is that we want to know the risk of unwanted or unintended pregnancy that women incur. Thus it would seem important to validate these measures. To what extent do they measure what they purport to measure that is, pregnancy risk. Herold (1980) attempted to validate the different measures of contraceptive use by looking at their inter- correlation and by looking at the association of each variable with other potential determinants. He concluded that the weakest measure, that is, the one with fewest associations with other measures of contraceptive use and apparently with the most random variance, is whether a young women ever used any method at all. The strongest measures are those of effectiveness. Unfortunately, Herold did not explore which of these measures best predicts avoidance of pregnancy. Two studies have explored the relationship between these measures and eventual pregnancy {Koenig and Zelnik, 1982; and Furstenberg et

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73 al., 1983~. Both studies show that women who claim to be using con- traception consistently, that is, who always use a contraceptive method at intercourse, have a much lower likelihood of pregnancy than women who are not consistently using a contraceptive method, than women who are currently using a contraceptive method, and than women who have never used a contraceptive method. Distinguishing between medical and non-medical methods helped discriminate levels of pregnancy risk only slightly. Unfortunately, however, Furstenberg (1982) also discovered considerable inconsistency in respondents' reports of con- traceptive use. Using a measure of consistency of use based on retro- spective accounts 15 months after the initial survey, 73 percent of clinic patients surveyed were consistent users. However, there were substantial inconsistencies in reporting of use between the 6 month and the 15 month interviews. If those whose reports at the two time points are inconsistent are not included with consistent users, then the percent who are consistent users drops to 43 percent. The authors concluded that "Retrospective measures contain a large element of error because of the respondents' inability or unwillingness to recall past use accurately. Without more frequent interviews and a good deal of probing regarding inconsistent reponses, investigators are likely to exaggerate rates of contraceptive continuation" (Furstenberg et al., 1983:217~. Prediction of pregnancy was strongly affected by the measure of contraceptive continuation used (Furstenberg et al., 1983~. The most refined measure, the measure that included prospective as well as retrospective reports of contraceptive use over a 15 month period, was the best predictor of pregnancy and was also best explained by a number of characteristics of adolescents; random error appeared to be mini- mized. The authors concluded that better measures of contraceptive use are needed before factors affecting that use can be identified and addressed. Males Very little contraceptive research has included males. Few national surveys have collected information on male contraceptive use among adults, let alone among teenagers. The only survey that included young men, the 1979 Zelnik-Kantner National Survey of Young Men, 17-21, has not been fully analyzed. The research there is suggests that know- ledge about and attitudes toward birth control, as well as self-esteem, are very important to contraceptive use as reported by males (Cvet- kovich and Grate, 1980~. Unfortunately, knowledge is poor. In one study of teen males (Finkel and Finkel, 1975), fewer than one-half could correctly identify the time during the menstrual cycle when conception is likeliest to occur. Attitudes and knowledge of males toward contraception are also less than favorable. In her study of contraceptive decision-making in adolescent couples, Polit et al. (1981) found that, in general, men were less knowledgeable about specific contraceptives and had less favorable attitudes toward con

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~4 7 traceptive use than women. In particular, more males than females thought oral contraceptives were dangerous. In spite of these findings, males do appear to use effective (male) methods at first intercourse (Table 2.5~. They also appear to use male methods cur- rently or at last/most recent intercourse, as reported by their part- ners (Table 2.8~. No data are yet available on current use or use at last/most recent intercourse as reported by males. Partners .. Among adults, both partners have been found to have an independent contribution to the contraceptive decision; however, the important decision-maker is still the woman. In studies primarily of college students, Thompson and Spanier (1978) and Herold (1980) found partner influence very important in contraceptive use. Very little research, however, has been conducted using teenage couples. Polit (1983) found that the couples best protected against unwanted pregnancy were those in which one person, (usually the female) took charge. Luker (1975) found male partners to be perceived by women as frustrated and feeling relatively powerless in preventing pregnancy (p. 133J: Men are socially cast into the role of passive spectators to contraceptive decision making by the same social and technological changes that structure the way in which women take risks. If both reponsibility and accountability are defied as exclusively female, men have neither the social means nor the personal motivation to take more active interest. However, her sample was comprised of women seeking abortion; the feelings and perception of male frustration and powerlessness are likely to be heightened in this sample. Polit et al. (1981) found that the agreement between partners' responses to questions about contraceptive practice ranged from 60 to 90 percent, the correlations between responses ranged from .18 to .90. These results suggest substantial variation between teen part- ners' reports of contraceptive use. Experience with Contraceptives It could be expected that individuals' experience with contracep- tion would affect subsequent behavior. It has been hypothesized, for example, that perceived/experienced side effects of the pill (as well as adverse publicity) resulted in the apparent decline in pill use between 1976 and 1979 among teenagers (see Table 2.8), and its re- surgence between 1979 and 1982 may be due to more recent reports that show very low risks for teenagers and some positive effects, such as protection from some cancers. As important as side effects are, only one project has studied reported side effects and contraceptive use

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75 (Mindick and Oskamp, 19803. This study could not adequately test the association because the authors did not statistically correlate the reported side effects with reports of actual contraceptive use, but, rather, the likelihood that a relationship between side effects and unwanted pregnancy or clinic discontinuation existed was rated by project personnel based on clinic records, and these ratings were then used as a dependent variable for analysis. SUMMARY AND CONCLUSIONS This review has been organized around a rational decision-making model of contraception, in which the proximate determinants are fre- quency of intercourse, perceived probability of pregnancy, willingness to use abortion as backup if pregnancy occurs, positive advantages and disadvantages of pregnancy and contraception, and positive and nega- tive experience with contraception. Although research is still rela- tively scarce in this area, what there is supports the importance of such factors in distinguishing degree of contraceptive use. The family appears to have little influence on contraceptive use; few studies have examined peer influence. Societal influence may operate through accessibility and availability. A recent study suggests that broader societal attitudes and values re sex and contraception may also affect contraceptive use (Jones et al., 1985~; no other research was identified on this issue. In this review contraceptive use was divided into two major areas of substantive interest: initiating use and continuing use. There is very little research on contraceptive use at first intercourse; only two studies deal with the process of initiating contraceptive use after first intercourse (Koenig and Zeloik, 1982; Zabin et al., 1979~. Initiating contracepive use is heavily influenced by the age of the young woman at the time. The younger the woman the less likely to have used contraception at first intercourse and the longer the delay before initiating use. In addition, recent birth cohorts of women appear to be more likely to use contraception at first intercourse than early cohorts. There are no race differences in contraception at first intercourse, once other factors such as socioeconomic status are controlled. Background factors had only weak influences on the initiation of contraception. Young women with better educated parents and in intact families were more likely to have contracepted at first intercourse. Black women are more likely to have reported using a medical method at first intercourse. Women who planned their first intercourse were more likely to have used a contraceptive method than those who didn't plan it. There is substantially more work looking at contraceptive continua- tion, current use of contraception, regularity of use, and effective- ness of use. There is some evidence that those who become sexually

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76 active at a young age are less likely to be currently contracepting, less likely to have always contracepted, but more likely to be using a medical method currently. Frequency of intercourse and being engaged to be married are associated with a higher likelihood of contracepting at last intercourse and with more effective contraception. Women who perceived a greater probability of pregnancy, more dis- advantages and fewer advantages of pregnancy, more advantages of birth control and who were less likely to say that they would resort to abor- tion if they became pregnant were more likely to report having used contraception at last intercourse and to report having used effective methods. One small scale study found knowledge about sex and contraception to be associated with greater frequency of contraceptive use among males and females. The relationship between previous pregnancy and contraceptive use is not clear as one study found such young women to be more likely to use a medical method and the other found such young women less effective contraceptors. One of the most important problems in studying contraception is the appropriate measurement of contraceptive use. First, very little research has attempted to validate the various measures of contracep- tive use standardly used. Second, the validation studies that have been conducted have found substantial inconsistencies in reports of contraceptive use. This is especially crucial for looking at consis- tency of use over time. The results of such studies suggest that one of the reasons reseachers have had so much trouble identifying factors associated with good or the contraceptive practice may be the poor reliability of the measures of contraceptive use. This is especially important for determining use effectiveness, which, at the present time, is based solely on individual reports of contraceptive use. In conclusion, birth control use is largely a function of current age and age at first intercourse, relationship with partner, perceived risk of pregnancy, acceptance of abortion, attitudes toward contracep- tion, desirability of pregnancy, and experience with contraception. It is only weakly related to knowledge about contraception. The family plays a relatively small part. Society may affect the availa- bility and accessibility of contraception, which may affect contracep- tive practice. The part peers play is not well known. Why some youth are effective contraceptors and others are not is still a little researched issue. Research suggests that women of all ages have trouble with contraception in actual use; teenagers differ only slightly from their 20-24 year old unmarried peers~in practice. How- ever, since their pregnancy rates also appear to be higher, how good our understanding is of actual contraceptive practice is in question. Nor do we know the full extent of differences in pregnancy or contra- ceptive failure rates by age.

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77 This paper concludes with a list of important issues: 1. What is the process of becoming a user and a regular user? This issue has not been explored although it is extremely important. 2. How should contraceptive use be measured? More studies are needed to better measure actual contraceptive use. 3. What is the contribution of male partners to effective contra- ception? This is an important question but one that only a few in- vestigators (Finkel and Finkel, 1975; Polit et al., 1981; Shea and Freeman, 1983; Shea et al., 1983; Cvetkovich and Grote, 1980) have explored. 4. Are there race/ethnic group differences in contraceptive practice? Although Zelnik et al. (1980) show distinct black-white differences in contraception at first intercourse, ever used con- traception, and contraception at last intercourse, these differences disappear when background factors are controlled. There is no differ- ence between blacks and whites in use at first or last intercourse or ever use, net of other factors. However, one difference does hold up. Black users are more likely to use a medical method at first and at last intercourse, probably due to greater clinic access for blacks. Blacks and whites do differ in types of methods used, with blacks more likely to use medical methods. Recent data suggest differential use effectiveness. Differences by ethnicity (e.g., Hispanic background) are small probably due to the fact that Hispanic teenagers are more likely than other teenagers to be married. 5. Is having been pregnant associated with better or poorer con- traception? Zelnik et al. (1980J found that, net of other factors, a previously pregnant woman was more likely to use a method at last intercourse, and to use a medical method. Polit et al. (1981) in contrast, found that, net of other factors, a previously pregnant woman was a less effective contraceptor, measured in terms of effectiveness of current contraception. 6. Do actual or perceived opportunities and alternatives affect contraceptive use? It is commonly hypothesized that they do; however, very little research has been conducted on this issue. The research that has been conducted shows little support for the hypothesis.