journal
of substance
Abuse,
$2
1 g-234
(I 992)
Parent Educational
Attainment
and Adolescent Cigarette Smoking Laurie Chassin Clark C. Presson Arizona
State University
Steven j. Sherman Indiana
University
Debra A. Edwards Arizona
State University
In a longitudinal design, this study examined psychosocial mediators of the effects of parental educational attainment on adolescent smoking acquisition and also examined whether smoking transition had different antecedents among adolescents from families of varying educational backgrounds. Parents’ low educational attainment acted as a moderate to strong risk factor for the initial onset of smoking among middle school girls. Some of this effect was mediated by the higher smoking prevalence among both parents and friends of these adolescent girls, as well as by their lowered expectations for academic success. However, these variables only partially mediated the effect of parent education. There were few indications of differential antecedents of smoking acquisition among adolescents from less and more highly educated families. Implications for public health antismoking campaigns are discussed.
Because of its negative health impact, there is considerable interest in studying the processes underlying risk for cigarette smoking. Among sociodemographic risk factors, lowered educational attainment is currently the most powerful predictor of smoking behavior in the United States (U.S. Surgeon General, 1989). Individuals with the lowest levels of educational attainment show the highest smoking prevalence, the highest rates of smoking initiation, and the lowest rates of cessation, and the magnitude of these effects have been increasing since the 1964 Surgeon General’s Report (U.S. Surgeon General, 1989). Because less educated individuals have been less successfully influenced by national antismoking campaigns, it has become particularly important to understand the processes that place less educated individuals at risk to smoke.
This research was supported by Grant HDl.3449 Institute of Child Health and Human Development. Correspondence and requests for reprints should ment, Arizona State University, Tempe, AZ 85287-l
to the first
three
be sent to Laurie 104.
authors Chassin,
from
the
Rychology
National Depart-
219
220
1. Chassin,
C.C.
Presson,
S.J. Sherman,
and
D.A.
Edwards
Not only is one’s own level of educational attainment important as a risk factor, but the educational level of one’s parents also is important. This is especially true for adolescent smoking. Previous research has consistently found smoking to be most common among adolescents from less educated families (Horn, Courts, Taylor, & Solomon, 1959; Salber & MacMahon, 1961). Some early studies (before 1979) also found gender differences in risk such that lower socioeconomic status (correlated with parent education) was a stronger risk factor for boys than girls (cf. Flay, d’Avernas, Best, Kersell, & Ryan, 1983, for a review). However, more recent data have produced conflicting findings concerning gender differences. Waldron and Lye (1990) found no gender differences in the magnitude of risk associated with low parental education, and Mittelmark et al. (1987) found that parents’ education predicted smoking onset for girls but not for boys. Thus, having less educated parents is a risk factor for adolescent smoking, although it is unclear if the magnitude of that risk varies for boys and girls. Although the association between parental education and adolescent smoking has actuarial, predictive value, thus far it has had little explanatory value. Saying that adolescents from less educated families are overrepresented among adolescent smokers does not help us to understand the processes that underlie smoking behavior among this group. Therefore, our first goal was to examine some potential mediating mechanisms that place adolescents from less educated families at risk to become smokers. First, these adolescents may be at risk because of their family environments. Low parent educational attainment is associated with greater parental smoking. Thus, adolescents from less educated families should be exposed more frequently to parental modeling of cigarette smoking. Perhaps it is parent smoking that places adolescents from less educated families at risk to start smoking. Previous studies have noted the correlation between parent education and parent smoking, and have produced some data consistent with partial mediation of parent education effects by parent smoking status (McNeil1 et al., 1988; Oechsli & Seltzer, 1984; Salber 8c MacMahon, 1961). However, explicit tests of parent smoking as a mediator (with appropriate statistical analyses) have not been performed. Moreover, given that less educated parents are themselves more likely to smoke, they also may be relatively tolerant of their adolescents’ smoking. This greater parental tolerance might mediate the relation between parent education and adolescent smoking. There also may be broader aspects of the family environment that place these adolescents at risk. According to Jessor and Jessor’s (1977) problem behavior theory, family environment that are low in parental controls and supports are less effective in socializing adolescents into conventional behavior, and thus place adolescents at risk for “problem behaviors” such as cigarette smoking. Thus, not only may less educated parents be less likely to set smoking abstinence as a goal for their adolescents, but even if they have this goal, their family environments may make it less likely that they will achieve it. Thus, parental control and support might mediate the relation between parent education and adolescent smoking.
Parent
Education
and Teen
Smoking
221
A similar argument can be made for peer factors. Adolescents from less educated homes may have friends who are from similar demographic backgrounds, and thus, their peer networks may have relatively high rates of cigarette smoking and tolerance for cigarette smoking. Peer modeling and peer tolerance of smoking thus may account for the relation between low parent education and adolescent smoking. Similarly, peer support and control variables in the Jessor and Jessor (1977) model (analogous to those described before for parents) may be potential mediators. Adolescents with less educated parents may have friends who are lower in personal controls and in supportiveness and who thus do not serve as socializing agents for conventional behavior. A third class of explanatory variables are found in Jessor and Jessor’s (1977) “personality” system. Adolescents who are at risk for problem behaviors have higher attitudinal tolerance for deviant behavior, lower aspirations for academic achievement, and lower expectations for attaining academic success. In a crosssectional study, Waldron and Lye (1990) found that educational aspirations mediated the relation between parental education and adolescent smoking. They suggested that adolescents with lower educational aspirations may find positive benefits in smoking that can compensate for their lack of academic success, and that (compared to college-bound students) these adolescents also may be less dependent on adults for their future plans, and thus, less willing to accept conventional adult values and authority. Thus, adolescents with less educated families may have less socially conventional attitudes and values, and these may mediate the relation between parent education and adolescent smoking. Finally, we investigated adolescents’ smoking-related beliefs as mediators of parent education effects. Adolescents form beliefs about the effects of using substances even before having actual personal experience with the substance itself (Goldman, Brown, & Christiansen, 1987). Moreover, adolescents’ beliefs about smoking are prospective predictors of smoking initiation (Chassin, Presson, Sherman, Corty, & Olshavsky, 1984). Perhaps adolescents from less educated family backgrounds are selectively exposed to more positive beliefs about smoking, or are more skeptical of antismoking information in public health campaigns. If so, then their relatively less negative beliefs about smoking could mediate the effects of parent education. In short, our first goal was to examine mediators of the relation between parent education and adolescent smoking initiation including family and peer environment variables, adolescents’ attitudes about conventional behaviors, and their smoking related beliefs. The only prior study to address this question (Waldron & Lye, 1990) found that peer disapproval of smoking, adolescents’ attitudes toward smoking, school grades and attendance, and the adoption of behaviors associated with adult status were significant mediators. However, because that study was cross-sectional, the directionality of the relation between the presumed mediators and smoking behavior was unclear. Moreover, subjects in the Waldron and Lye study were all high school seniors. This is a disadvantage not only for sample representativeness (because of the exclusion of high school drop-outs) but also because the processes of smoking maintenance among the 12th graders may be quite different from processes of initiation or escalation
222
1. Chassin,
C.C.
Presson,
S.J. Sheman,
and
D.A.
Edwards
among younger adolescents. Accordingly, we used a longitudinal design to examine smoking onset and smoking escalation separately for younger and older adolescents. Our second goal was to examine whether parent education moderated the relation between psychosocial predictors and smoking transitions. The preceding mediational issues address the question of why there might be more smoking initiation among adolescents from less educated families. However, questions of mediation do not imply that there are different antecedents of smoking behavior for adolescents from less educated and more educated families. The mediators hypothesized before may predict smoking behavior among all adolescents, but because they are presumed to be correlated with parent education, these mediationai processes may explain why there is elevated smoking prevalence among adolescents from less educated families. Moderator questions, on the other hand, ask whether predictors of smoking onset significantly differ for adolescents from more and less educated families. Not only may adolescents from less and more educated families be at different levels of risk to smoke, but adolescents from more and less educated families may smoke for different reasons (see Baron & Kenny, 1986, for a fuller explanation of the mediator-moderator distinction). These moderator questions have both theoretical and practical significance. For example, Bauman, Koch, and Lentz (1989) found that fathers’ smokeless tobacco use was a weaker predictor of adolescents’ use in families with lower levels of education. This raises a broader theoretical question about whether less educated parents serve as less powerful behavioral models for their children than do highly educated parents. Moderators of parent-education effects also may have practical importance for the design of antismoking campaigns. Campaigns targeted at less educated segments of the population should be constructed to counteract the predictors of smoking that are most powerful for that group. However, to date, it is unknown whether the predictors of smoking initiation vary for adolescents from families of different educational backgrounds. METHOD Subjects
Subjects were drawn from participants in an ongoing longitudinal study of cigarette smoking (cf. Chassin et al., 1984). In the larger study, at Times 1 and 2 of measurement (1980 and 1981), subjects were all 6th-12th graders in a midwestern county school system who were present in school on the day of testing. The rate of retention between Time 1 and Time 2 was 72.3%. Parent education was not measured in the study until our most recent follow-up (1987-1988). Thus, the current analyses were restricted to those who were present at Times 1, 2, and the long-term follow-up. Of those present at Times 1 and 2, 83.3% were reassessed at long-term follow-up. The current analyses focus on subjects who were either abstainers from cigarettes at Time 1 or were experimental smokers only (see the following for operational definitions). These subjects were predominantly white (96.9%), evenly
Parent
Education
and Teen
Smoking
223
divided between boys and girls (52.3% female), and had an average age of 13.9 years in 1980. Subjects were divided into initial middle school subjects (Grades 6-8 in 1980) and initial high school subjects (Grades 9-l 1 in 1980). Attrition
Bias
Although retention rates in this study have consistently been over 70%, analyses were undertaken to assess differences between those who remained and those who were lost to the study. A detailed report of these analyses can be found in Chassin et al. (1984, for the year-to-year adolescent studies) and in Chassin, Presson, Sherman, and Edwards (1990, for the long-term follow-up). In general, these analyses show that those lost to the study were somewhat more “deviance prone” in Jessor and Jessor’s (1977) sense of the term, in being more likely to smoke, having more smoking in their environments, and showing more unconventionality in attitudes and social environments. Although the magnitude of the bias has been small, some caution is warranted in generalization. As in any study requiring multiple measurement, more deviance-prone individuals are likely to be underrepresented in the sample.’ Procedure Data were collected using group-administered questionnaires in classrooms. Questionnaires were administered by members of the research team who were unconnected to the school system. Subjects were assured of confidentiality. Data on all study variables except for parent education were derived from these school surveys administered at Times 1 and 2 of measurement (1980 and 1981). Parent education data were obtained from our most recent follow-up (19871988). For subjects whose cohorts were still in high school at the time of measurement, data were collected in classroom groups using the same procedures described before. For older subjects and those who were not present in school, mail-in questionnaires were used. A more detailed account of these procedures is provided in Chassin et al. (1990). Only parent education data were used from the long-term follow-up. Measures There were 19 variables that were examined as potential mediators and moderators of the effects of parent education. These variables were all assessed at the first time of measurement (1980). t To assess whether sample attrition could affect the current mediational analyses, we examined the correlations between our predictor variables and smoking status cross-sectionally at Time 1. We examined the pattern of correlations that was produced when all Time 1 subjects were analyzed with the pattern that was produced when the sample was restricted only to subjects who were present at Times 1 and 2 and the long-term follow-up (i.e., when we used the current sampling restrictions). There were no differences in the correlations between the predictor variables and smoking status in the two samples. Thus, it is unlikely that sample attrition affected the mediational relations examined here.
224
1. Chassin,
C.C.
Presson,
S.J. Sherman,
and D.A.
Edwards
Perceived Parent and Peer Smoking and Tolerance of the Adolescent’s Smoking (4 variables) Subjects reported the number of their five best friends who smoked and the smoking of their fathers and mothers. Parent smoking was dichotomized (no smoking in either parent vs. at least one parent who smoked). Subjects also reported on their parents’ and peers’ approval of their smoking (one item each, e.g., “My friends think that I should smoke cigarettes.“). Perceived Family and Peer Support and Control (9 variables) These were assessed using variables from Jessor and Jessor’s (1977) problembehavior theory. Subjects’ perceptions of their parents’ (and peers’) supportiveness, strictness, expectations for the adolescents’ attaining academic success, agreement between parents, agreement between the adolescent and his or her friends, and agreement between the adolescents’ friends and parents in their values all were measured with items taken from Schlegel and DiTecco’s (1978) empirically shortened version of the Jessor and Jessor questionnaire with 5-point response scales. Internal consistencies (indexed by coefficient alpha) were generally acceptable and ranged from .64 to .72. Internal consistencies for the strictness of parents and friends were somewhat lower (.38 for friends and .49 for parents), although these variables were assessed with only two items each. Socially Conventional Attitudes (3 variables) Socially conventional attitudes were measured with three variables from the Jessor and Jessor (1977) personality system. These were value on attaining academic success, expectations for actually attaining academic success, and attitudinal intolerance of deviant behavior. These scales were measured with items from Schlegel and DiTecco’s (1978) empirically shortened version of the Jessor and Jessor questionnaire. Internal consistencies (indexed by coefficient alpha) ranged from .73 to .88. Beliefs About Smoking (3 variables) Subjects’ beliefs about the health consequences of smoking were assessed with six items concerning whether smoking would result in a long life, a healthy life, lung cancer, heart disease, coughs, and nicotine addiction (coefficient a = .76). Subjects’ beliefs about the social consequences of smoking were assessed with two items concerning whether smoking would result in being left out of the group and losing friends (coefficient OL= .57). Subjects’ beliefs about the psychological consequences of smoking were assessed with three items concerning whether smoking would produce relaxation, an escape from problems, and a feeling of adult status (coefficient (Y= .7 1). All items were worded to be personally relevant (e.g., “If I smoke, I will be able to relax.“). Smoking Behavior Smoking status was assessed with a single six-level item: never smoked, not even a single $n@ (abstainers, 44.0% of the entire Time 1 sample); smoked once or twice, “just to try,” but has not smoRed in the past month (triers, 36.5% of the entire
Parent
Education
and Teen
Smoking
225
Time 1 sample); smokes regularly, but not more than once a month (1.5% of the entire Time 1 sample); smokes regularly but not more than once a week (1.3% of the entire Time 1 sample); smokesmore than once a week (10.5% of the entire Time 1 sample); and wed to smoke regularly, but no longer smokes (exsmokers, 6.2% of the entire Time 1 sample). The current analyses focus on subjects who were assessed in 1980, 1981, and 1987-1988 and who were initial abstainers from cigarettes (820 middle schoolers and 433 high schoolers) or who were initial triers of cigarettes (370 middle schoolers and 455 high school students). Starting with these initially homogeneous groups at Time 1, we predicted their smoking outcomes at Time 2. For never smokers, we predicted whether they remained abstainers or showed any use of cigarettes by Time 2 (i.e., self-reported as triers, exsmokers, or smokers). For triers, we predicted whether or not they showed any escalation to regular smoking by Time 2 (i.e., self-reported as exregular smokers or regular smokers at Time 2). To increase the validity of self-reported smoking, we instituted a bogus pipeline procedure (Evans, Hansen, & Mittelmark, 1977) at Time 2 of measurement. A substudy comparing smoking prevalences obtained with and without the bogus pipeline procedure showed that it had no detectable effects (cf. Chassin et al., 1981, for details), suggesting that these subjects were not deliberately distorting their self-reports of cigarette use. Parent Education At the long-term follow-up, subjects reported the highest level of education attained by each of their parents. Because the attainment of college education significantly decreases risk for smoking initiation (U.S. Surgeon General, 1989), parent educational attainment was treated as a dichotomous predictor (both parents have a high school education or less, 35.2% of the sample vs. at least one parent has some education beyond high school, 64.8% of the sample). RESULTS The Effect of Parent Education
on Smoking
Initiation
Before examining mediators of parent education effects, it was necessary to establish that parent education was significantly related to transition in smoking status. Logistic regression analyses were used to predict smoking transition (four analyses, separately among initial middle school and high school abstainers and triers of cigarettes). Predictor variables were parent education, gender, and the interaction of parent education and gender. Parent education showed a significant effect, in an interaction of parent education with gender, only among initial middle school abstainers, Wald x2( 1, N = 765) = 5.04, p < .03. For the other groups there were no significant main effects or interactions involving parent education. To describe further the pattern and magnitudes of the effects of parent edu-
226
1. Chassin,
C.C.
Presson,
S.J. Sherman,
and
D.A.
Edwards
cation on smoking transition, a series of chi-square comparisons were performed. First, four separate chi-square analyses were conducted (for middle school and high school subjects; separately for initial abstainers and initial triers of cigarettes). The percentages of adolescents with high and low levels of parent education who increased their smoking over the l-year study period are presented in Table 1. As found previously for the logistic regression, there was a significant relation between parent education and smoking transition among middle school abstainers, x2 (1, N = 765) = 15.05, p < .OOl, with Yates’ correction. The relative risk index (Breslow 8c Day, 1980) showed the effect to be of moderate magnitude (relative risk = 2.10). Although parent education was not significantly related to smoking transition among any other group (see Table l), the direction of effect was consistent across all groups. In all cases, adolescents from less educated families were more likely to adopt cigarette smoking, but the effect was large enough to be statistically reliable only among middle school abstainers. Because the logistic regressions showed a significant interaction between parent education and gender for the middle school abstainers, chi-square analyses relating parent education to smoking transition were performed separately by gender in this group. Although the direction of effect was the same for both boys and girls, there was no significant relation between parent education and smoking transition for boys [transition rates of 25.8% and 20.8% for subjects with low and high parent education, x2( 1, N = 324) = 0.70, n.s.1. For girls, those with low parent education were significantly more likely to initiate smoking initiation rates of 29.6% and 11.8% for girls with low and high parent education, x2( 1, N=441)=19.73, p < .OOOl, relative risk = 3.161. This magnitude of risk would be considered moderate to strong by epidemiological standards (Ibrahim, 1985).* 2 The effect of parent education on smoking transition among initial middle school abstaining girls was of substantial magnitude. It is also of interest to consider whether this effect is detectable in the long-term smoking outcomes for this group. A chi-square comparison was performed for the initial middle school abstaining girls in which parent education was related to long-term smoking outcome assessed 7-8 years later (abstinence or less than monthly smoking versus weekly smoking or more; exsmokers and monthly smokers were eliminated). Results showed that there was a marginally significant relation between parent education and long-term smoking outcomes. Of those with less educated parents, 24.6% were adult regular smokers at follow-up, whereas, of those with more highly educated parents, only 18.0% were regular smokers at adult follow-up, x2( I, N = 470) = 2.35, p < .13, after Yates’ correction. This prospective analysis may underestimate the long-term importance of parent education because it does not allow for the cumulative effects of smoking transitions that occurred either before the period of study or after the period of study. A better estimate of the long-term impact of parent education can be made by examining the cross-sectional relation between parent education and smoking at the adult follow-up. Chi-square comparisons were performed relating parent education to young adult current smoking (a dichotomous variable, never smoked or only tried vs. at least weekly smoking; exsmokers and monthly smokers were eliminated). These comparisons showed significant relations between parent education and young adult current smoking for all four subgroups; x2 (I, N = 472) = 4.36, p < .03, for older girls, x2 (I, N = 52 I) = 6.06, p < .02. for younger boys, and x2 (1, N = 584) = 6.52, p < .02. for younger girls. For older boys, the relation was in the same direction but not significant, x2 (1, N = 43 I) = 2.3 I, p < .I3. The magnitudes of the effect of parent education were similar across subgroups (cp = .08-. I 1).
Parent
Table
Education
1.
and Teen
Effects
Smoking
of Parent
227
Education
on the Transition
to Cigarette
Smoking
96 of Subjects Increasing Their Smoking Status frum Time 1 k Time 4 Subjects
N
X2
Low Parent Education
Middle school abstainers Middle school triers High school abstainers High school triers
765 334 407 431
15.05* 2.53 0.96 1.26
28.1 17.6 24.8 15.8
High Parent Education 15.6 10.8 19.7 11.5
*p < .Ol.
It would be inappropriate, however, to conclude that parent education is important for smoking only among young females. First, as noted before, the prospective effect of parent education showed the same pattern for all groups, even though the effect was large enough to be statistically reliable only for young girls. Second, recall that previous research using cross-sectional analyses has demonstrated the effects of parent education for both boys and girls (e.g., Waldron & Lye, 1990). Accordingly, we performed cross-sectional analyses using chi-square comparisons to relate parent education to smoking status at Time 1 of measurement. Smoking status was defined as a dichotomous variable, comparing abstainers with those who had at least tried cigarettes, and eliminating exsmokers. For middle school subjects this relation was significant for both boys and girls (x2 = 8.36 and 11.46, p < .Ol, respectively). Moreover, in contrast to the preceding longitudinal analyses, this magnitude of effect was similar for both sexes (+ = .13 and .14 for boys and girls). For high school subjects, the relation between parent education and smoking status at Time 1 of measurement was significant for both boys and girls (x * = 8.61 and 6.48, respectively). For these older subjects, the magnitude of the effect also was similar for boys and girls (+ = .14 and .12, respectively). Thus, cross-sectional analyses showed statistically significant relations between parent education and smoking status for both boys and girls, and both older and younger subjects, with similar magnitudes of effect. Potential
Mediators
of the Effects of Parent Education
As described before, a necessary precondition for mediational analyses is a significant relation between parent education and smoking outcomes. However, cross-sectional versus longitudinal analyses of this relation produced somewhat different findings. It is the longitudinal analyses that are critical for our mediator questions because the cross-sectional analyses leave open the direction of causal influence between smoking and the potential psychosocial mediators. Accordingly, we performed mediational analyses only for initial middle school abstaining girls, the only group to show a significant longitudinal effect of parent education on smoking transition.
1. Chassin,
228
C.C.
Presson,
S.J. Sherman,
and D.A.
Edwards
In order to qualify as a potential mediator between parent education and smoking transition, a predictor variable must be significantly related to both parent education and smoking transition (Baron & Kenny, 1986). Accordingly, Pearson correlations were calculated between each of the 19 predictor variables and both parent education and smoking transition. Of the 19 predictor variables, 7 were significantly correlated with both parent education and smoking transition at p < .05 or less. These variables were: parents’ smoking, parental supportiveness, agreement between parents, friends’ smoking, friends’ strictness, agreement in values between the subject and her friends, and expectations for attaining academic success. Tests of Potential
Mediators
To assess whether these variables mediated the relation between parent education and smoking initiation, a series of logistic regression analyses were performed (again, only for the middle school girls who were abstainers at Time 1). When the effect of parent education on smoking initiation was considered alone, parent education (as shown previously) had a significant effect, Wald x2(1, N = 420) = 17.92, p < .OOl. If these 7 psychosocial variables mediate the effect of parent education on smoking initiation, there should be a significant drop in the chi square associated with the parent education effect when these variables are entered into the regression. When all 7 variables were entered into the regression, the chi square associated with parent education dropped to 7.45, p < .Ol. The drop in chi square (10.47, df = 1) was significant at p < .O 1. This shows significant mediation (although not complete mediation because the effect of parent education was still significant after all mediating variables had been entered). To identify which of the individual variables were significant mediators, a series of 7 logistic regressions were run in which parent education was entered in combination with each mediator separately. The chi squares associated with parent education in these regressions were compared to the chi square obtained when parent education was entered alone. A significant drop in the chi square associated with parent education was considered to indicate a mediational effect. By this criterion, the significant individual mediators of the effects of parent education were parental smoking (x2 drop of 4.58, p < .05), friends’ smoking (~2 drop of 4.75, p C .05), and expectations for attaining academic success (x2 drop of 3.40, p < .07). Parent Education
as a Moderator
of the Psychosocial
Predictors
Our second question was whether parent education moderated the effects of the psychosocial variables on smoking transition. To address this question, we ran logistic regressions predicting smoking transition from parent education, gender, each of the 19 psychosocial predictors separately, all two-way interac-
Parent
Education
and Teen
Table 2. Significant in Predicting Smoking
Parent
Interaction Education
Smoking
229
Interactions Transitions
Between (Wald
of With
Middle School Abstainers Tolerance for deviance Friends’ strictness Middle School Triers Parent agreement Psychological beliefs about Note. For high *p < .05. **p
school .Ol.
of substance
Abuse,
$2
1 g-234
(I 992)
Parent Educational
Attainment
and Adolescent Cigarette Smoking Laurie Chassin Clark C. Presson Arizona
State University
Steven j. Sherman Indiana
University
Debra A. Edwards Arizona
State University
In a longitudinal design, this study examined psychosocial mediators of the effects of parental educational attainment on adolescent smoking acquisition and also examined whether smoking transition had different antecedents among adolescents from families of varying educational backgrounds. Parents’ low educational attainment acted as a moderate to strong risk factor for the initial onset of smoking among middle school girls. Some of this effect was mediated by the higher smoking prevalence among both parents and friends of these adolescent girls, as well as by their lowered expectations for academic success. However, these variables only partially mediated the effect of parent education. There were few indications of differential antecedents of smoking acquisition among adolescents from less and more highly educated families. Implications for public health antismoking campaigns are discussed.
Because of its negative health impact, there is considerable interest in studying the processes underlying risk for cigarette smoking. Among sociodemographic risk factors, lowered educational attainment is currently the most powerful predictor of smoking behavior in the United States (U.S. Surgeon General, 1989). Individuals with the lowest levels of educational attainment show the highest smoking prevalence, the highest rates of smoking initiation, and the lowest rates of cessation, and the magnitude of these effects have been increasing since the 1964 Surgeon General’s Report (U.S. Surgeon General, 1989). Because less educated individuals have been less successfully influenced by national antismoking campaigns, it has become particularly important to understand the processes that place less educated individuals at risk to smoke.
This research was supported by Grant HDl.3449 Institute of Child Health and Human Development. Correspondence and requests for reprints should ment, Arizona State University, Tempe, AZ 85287-l
to the first
three
be sent to Laurie 104.
authors Chassin,
from
the
Rychology
National Depart-
219
220
1. Chassin,
C.C.
Presson,
S.J. Sherman,
and
D.A.
Edwards
Not only is one’s own level of educational attainment important as a risk factor, but the educational level of one’s parents also is important. This is especially true for adolescent smoking. Previous research has consistently found smoking to be most common among adolescents from less educated families (Horn, Courts, Taylor, & Solomon, 1959; Salber & MacMahon, 1961). Some early studies (before 1979) also found gender differences in risk such that lower socioeconomic status (correlated with parent education) was a stronger risk factor for boys than girls (cf. Flay, d’Avernas, Best, Kersell, & Ryan, 1983, for a review). However, more recent data have produced conflicting findings concerning gender differences. Waldron and Lye (1990) found no gender differences in the magnitude of risk associated with low parental education, and Mittelmark et al. (1987) found that parents’ education predicted smoking onset for girls but not for boys. Thus, having less educated parents is a risk factor for adolescent smoking, although it is unclear if the magnitude of that risk varies for boys and girls. Although the association between parental education and adolescent smoking has actuarial, predictive value, thus far it has had little explanatory value. Saying that adolescents from less educated families are overrepresented among adolescent smokers does not help us to understand the processes that underlie smoking behavior among this group. Therefore, our first goal was to examine some potential mediating mechanisms that place adolescents from less educated families at risk to become smokers. First, these adolescents may be at risk because of their family environments. Low parent educational attainment is associated with greater parental smoking. Thus, adolescents from less educated families should be exposed more frequently to parental modeling of cigarette smoking. Perhaps it is parent smoking that places adolescents from less educated families at risk to start smoking. Previous studies have noted the correlation between parent education and parent smoking, and have produced some data consistent with partial mediation of parent education effects by parent smoking status (McNeil1 et al., 1988; Oechsli & Seltzer, 1984; Salber 8c MacMahon, 1961). However, explicit tests of parent smoking as a mediator (with appropriate statistical analyses) have not been performed. Moreover, given that less educated parents are themselves more likely to smoke, they also may be relatively tolerant of their adolescents’ smoking. This greater parental tolerance might mediate the relation between parent education and adolescent smoking. There also may be broader aspects of the family environment that place these adolescents at risk. According to Jessor and Jessor’s (1977) problem behavior theory, family environment that are low in parental controls and supports are less effective in socializing adolescents into conventional behavior, and thus place adolescents at risk for “problem behaviors” such as cigarette smoking. Thus, not only may less educated parents be less likely to set smoking abstinence as a goal for their adolescents, but even if they have this goal, their family environments may make it less likely that they will achieve it. Thus, parental control and support might mediate the relation between parent education and adolescent smoking.
Parent
Education
and Teen
Smoking
221
A similar argument can be made for peer factors. Adolescents from less educated homes may have friends who are from similar demographic backgrounds, and thus, their peer networks may have relatively high rates of cigarette smoking and tolerance for cigarette smoking. Peer modeling and peer tolerance of smoking thus may account for the relation between low parent education and adolescent smoking. Similarly, peer support and control variables in the Jessor and Jessor (1977) model (analogous to those described before for parents) may be potential mediators. Adolescents with less educated parents may have friends who are lower in personal controls and in supportiveness and who thus do not serve as socializing agents for conventional behavior. A third class of explanatory variables are found in Jessor and Jessor’s (1977) “personality” system. Adolescents who are at risk for problem behaviors have higher attitudinal tolerance for deviant behavior, lower aspirations for academic achievement, and lower expectations for attaining academic success. In a crosssectional study, Waldron and Lye (1990) found that educational aspirations mediated the relation between parental education and adolescent smoking. They suggested that adolescents with lower educational aspirations may find positive benefits in smoking that can compensate for their lack of academic success, and that (compared to college-bound students) these adolescents also may be less dependent on adults for their future plans, and thus, less willing to accept conventional adult values and authority. Thus, adolescents with less educated families may have less socially conventional attitudes and values, and these may mediate the relation between parent education and adolescent smoking. Finally, we investigated adolescents’ smoking-related beliefs as mediators of parent education effects. Adolescents form beliefs about the effects of using substances even before having actual personal experience with the substance itself (Goldman, Brown, & Christiansen, 1987). Moreover, adolescents’ beliefs about smoking are prospective predictors of smoking initiation (Chassin, Presson, Sherman, Corty, & Olshavsky, 1984). Perhaps adolescents from less educated family backgrounds are selectively exposed to more positive beliefs about smoking, or are more skeptical of antismoking information in public health campaigns. If so, then their relatively less negative beliefs about smoking could mediate the effects of parent education. In short, our first goal was to examine mediators of the relation between parent education and adolescent smoking initiation including family and peer environment variables, adolescents’ attitudes about conventional behaviors, and their smoking related beliefs. The only prior study to address this question (Waldron & Lye, 1990) found that peer disapproval of smoking, adolescents’ attitudes toward smoking, school grades and attendance, and the adoption of behaviors associated with adult status were significant mediators. However, because that study was cross-sectional, the directionality of the relation between the presumed mediators and smoking behavior was unclear. Moreover, subjects in the Waldron and Lye study were all high school seniors. This is a disadvantage not only for sample representativeness (because of the exclusion of high school drop-outs) but also because the processes of smoking maintenance among the 12th graders may be quite different from processes of initiation or escalation
222
1. Chassin,
C.C.
Presson,
S.J. Sheman,
and
D.A.
Edwards
among younger adolescents. Accordingly, we used a longitudinal design to examine smoking onset and smoking escalation separately for younger and older adolescents. Our second goal was to examine whether parent education moderated the relation between psychosocial predictors and smoking transitions. The preceding mediational issues address the question of why there might be more smoking initiation among adolescents from less educated families. However, questions of mediation do not imply that there are different antecedents of smoking behavior for adolescents from less educated and more educated families. The mediators hypothesized before may predict smoking behavior among all adolescents, but because they are presumed to be correlated with parent education, these mediationai processes may explain why there is elevated smoking prevalence among adolescents from less educated families. Moderator questions, on the other hand, ask whether predictors of smoking onset significantly differ for adolescents from more and less educated families. Not only may adolescents from less and more educated families be at different levels of risk to smoke, but adolescents from more and less educated families may smoke for different reasons (see Baron & Kenny, 1986, for a fuller explanation of the mediator-moderator distinction). These moderator questions have both theoretical and practical significance. For example, Bauman, Koch, and Lentz (1989) found that fathers’ smokeless tobacco use was a weaker predictor of adolescents’ use in families with lower levels of education. This raises a broader theoretical question about whether less educated parents serve as less powerful behavioral models for their children than do highly educated parents. Moderators of parent-education effects also may have practical importance for the design of antismoking campaigns. Campaigns targeted at less educated segments of the population should be constructed to counteract the predictors of smoking that are most powerful for that group. However, to date, it is unknown whether the predictors of smoking initiation vary for adolescents from families of different educational backgrounds. METHOD Subjects
Subjects were drawn from participants in an ongoing longitudinal study of cigarette smoking (cf. Chassin et al., 1984). In the larger study, at Times 1 and 2 of measurement (1980 and 1981), subjects were all 6th-12th graders in a midwestern county school system who were present in school on the day of testing. The rate of retention between Time 1 and Time 2 was 72.3%. Parent education was not measured in the study until our most recent follow-up (1987-1988). Thus, the current analyses were restricted to those who were present at Times 1, 2, and the long-term follow-up. Of those present at Times 1 and 2, 83.3% were reassessed at long-term follow-up. The current analyses focus on subjects who were either abstainers from cigarettes at Time 1 or were experimental smokers only (see the following for operational definitions). These subjects were predominantly white (96.9%), evenly
Parent
Education
and Teen
Smoking
223
divided between boys and girls (52.3% female), and had an average age of 13.9 years in 1980. Subjects were divided into initial middle school subjects (Grades 6-8 in 1980) and initial high school subjects (Grades 9-l 1 in 1980). Attrition
Bias
Although retention rates in this study have consistently been over 70%, analyses were undertaken to assess differences between those who remained and those who were lost to the study. A detailed report of these analyses can be found in Chassin et al. (1984, for the year-to-year adolescent studies) and in Chassin, Presson, Sherman, and Edwards (1990, for the long-term follow-up). In general, these analyses show that those lost to the study were somewhat more “deviance prone” in Jessor and Jessor’s (1977) sense of the term, in being more likely to smoke, having more smoking in their environments, and showing more unconventionality in attitudes and social environments. Although the magnitude of the bias has been small, some caution is warranted in generalization. As in any study requiring multiple measurement, more deviance-prone individuals are likely to be underrepresented in the sample.’ Procedure Data were collected using group-administered questionnaires in classrooms. Questionnaires were administered by members of the research team who were unconnected to the school system. Subjects were assured of confidentiality. Data on all study variables except for parent education were derived from these school surveys administered at Times 1 and 2 of measurement (1980 and 1981). Parent education data were obtained from our most recent follow-up (19871988). For subjects whose cohorts were still in high school at the time of measurement, data were collected in classroom groups using the same procedures described before. For older subjects and those who were not present in school, mail-in questionnaires were used. A more detailed account of these procedures is provided in Chassin et al. (1990). Only parent education data were used from the long-term follow-up. Measures There were 19 variables that were examined as potential mediators and moderators of the effects of parent education. These variables were all assessed at the first time of measurement (1980). t To assess whether sample attrition could affect the current mediational analyses, we examined the correlations between our predictor variables and smoking status cross-sectionally at Time 1. We examined the pattern of correlations that was produced when all Time 1 subjects were analyzed with the pattern that was produced when the sample was restricted only to subjects who were present at Times 1 and 2 and the long-term follow-up (i.e., when we used the current sampling restrictions). There were no differences in the correlations between the predictor variables and smoking status in the two samples. Thus, it is unlikely that sample attrition affected the mediational relations examined here.
224
1. Chassin,
C.C.
Presson,
S.J. Sherman,
and D.A.
Edwards
Perceived Parent and Peer Smoking and Tolerance of the Adolescent’s Smoking (4 variables) Subjects reported the number of their five best friends who smoked and the smoking of their fathers and mothers. Parent smoking was dichotomized (no smoking in either parent vs. at least one parent who smoked). Subjects also reported on their parents’ and peers’ approval of their smoking (one item each, e.g., “My friends think that I should smoke cigarettes.“). Perceived Family and Peer Support and Control (9 variables) These were assessed using variables from Jessor and Jessor’s (1977) problembehavior theory. Subjects’ perceptions of their parents’ (and peers’) supportiveness, strictness, expectations for the adolescents’ attaining academic success, agreement between parents, agreement between the adolescent and his or her friends, and agreement between the adolescents’ friends and parents in their values all were measured with items taken from Schlegel and DiTecco’s (1978) empirically shortened version of the Jessor and Jessor questionnaire with 5-point response scales. Internal consistencies (indexed by coefficient alpha) were generally acceptable and ranged from .64 to .72. Internal consistencies for the strictness of parents and friends were somewhat lower (.38 for friends and .49 for parents), although these variables were assessed with only two items each. Socially Conventional Attitudes (3 variables) Socially conventional attitudes were measured with three variables from the Jessor and Jessor (1977) personality system. These were value on attaining academic success, expectations for actually attaining academic success, and attitudinal intolerance of deviant behavior. These scales were measured with items from Schlegel and DiTecco’s (1978) empirically shortened version of the Jessor and Jessor questionnaire. Internal consistencies (indexed by coefficient alpha) ranged from .73 to .88. Beliefs About Smoking (3 variables) Subjects’ beliefs about the health consequences of smoking were assessed with six items concerning whether smoking would result in a long life, a healthy life, lung cancer, heart disease, coughs, and nicotine addiction (coefficient a = .76). Subjects’ beliefs about the social consequences of smoking were assessed with two items concerning whether smoking would result in being left out of the group and losing friends (coefficient OL= .57). Subjects’ beliefs about the psychological consequences of smoking were assessed with three items concerning whether smoking would produce relaxation, an escape from problems, and a feeling of adult status (coefficient (Y= .7 1). All items were worded to be personally relevant (e.g., “If I smoke, I will be able to relax.“). Smoking Behavior Smoking status was assessed with a single six-level item: never smoked, not even a single $n@ (abstainers, 44.0% of the entire Time 1 sample); smoked once or twice, “just to try,” but has not smoRed in the past month (triers, 36.5% of the entire
Parent
Education
and Teen
Smoking
225
Time 1 sample); smokes regularly, but not more than once a month (1.5% of the entire Time 1 sample); smokes regularly but not more than once a week (1.3% of the entire Time 1 sample); smokesmore than once a week (10.5% of the entire Time 1 sample); and wed to smoke regularly, but no longer smokes (exsmokers, 6.2% of the entire Time 1 sample). The current analyses focus on subjects who were assessed in 1980, 1981, and 1987-1988 and who were initial abstainers from cigarettes (820 middle schoolers and 433 high schoolers) or who were initial triers of cigarettes (370 middle schoolers and 455 high school students). Starting with these initially homogeneous groups at Time 1, we predicted their smoking outcomes at Time 2. For never smokers, we predicted whether they remained abstainers or showed any use of cigarettes by Time 2 (i.e., self-reported as triers, exsmokers, or smokers). For triers, we predicted whether or not they showed any escalation to regular smoking by Time 2 (i.e., self-reported as exregular smokers or regular smokers at Time 2). To increase the validity of self-reported smoking, we instituted a bogus pipeline procedure (Evans, Hansen, & Mittelmark, 1977) at Time 2 of measurement. A substudy comparing smoking prevalences obtained with and without the bogus pipeline procedure showed that it had no detectable effects (cf. Chassin et al., 1981, for details), suggesting that these subjects were not deliberately distorting their self-reports of cigarette use. Parent Education At the long-term follow-up, subjects reported the highest level of education attained by each of their parents. Because the attainment of college education significantly decreases risk for smoking initiation (U.S. Surgeon General, 1989), parent educational attainment was treated as a dichotomous predictor (both parents have a high school education or less, 35.2% of the sample vs. at least one parent has some education beyond high school, 64.8% of the sample). RESULTS The Effect of Parent Education
on Smoking
Initiation
Before examining mediators of parent education effects, it was necessary to establish that parent education was significantly related to transition in smoking status. Logistic regression analyses were used to predict smoking transition (four analyses, separately among initial middle school and high school abstainers and triers of cigarettes). Predictor variables were parent education, gender, and the interaction of parent education and gender. Parent education showed a significant effect, in an interaction of parent education with gender, only among initial middle school abstainers, Wald x2( 1, N = 765) = 5.04, p < .03. For the other groups there were no significant main effects or interactions involving parent education. To describe further the pattern and magnitudes of the effects of parent edu-
226
1. Chassin,
C.C.
Presson,
S.J. Sherman,
and
D.A.
Edwards
cation on smoking transition, a series of chi-square comparisons were performed. First, four separate chi-square analyses were conducted (for middle school and high school subjects; separately for initial abstainers and initial triers of cigarettes). The percentages of adolescents with high and low levels of parent education who increased their smoking over the l-year study period are presented in Table 1. As found previously for the logistic regression, there was a significant relation between parent education and smoking transition among middle school abstainers, x2 (1, N = 765) = 15.05, p < .OOl, with Yates’ correction. The relative risk index (Breslow 8c Day, 1980) showed the effect to be of moderate magnitude (relative risk = 2.10). Although parent education was not significantly related to smoking transition among any other group (see Table l), the direction of effect was consistent across all groups. In all cases, adolescents from less educated families were more likely to adopt cigarette smoking, but the effect was large enough to be statistically reliable only among middle school abstainers. Because the logistic regressions showed a significant interaction between parent education and gender for the middle school abstainers, chi-square analyses relating parent education to smoking transition were performed separately by gender in this group. Although the direction of effect was the same for both boys and girls, there was no significant relation between parent education and smoking transition for boys [transition rates of 25.8% and 20.8% for subjects with low and high parent education, x2( 1, N = 324) = 0.70, n.s.1. For girls, those with low parent education were significantly more likely to initiate smoking initiation rates of 29.6% and 11.8% for girls with low and high parent education, x2( 1, N=441)=19.73, p < .OOOl, relative risk = 3.161. This magnitude of risk would be considered moderate to strong by epidemiological standards (Ibrahim, 1985).* 2 The effect of parent education on smoking transition among initial middle school abstaining girls was of substantial magnitude. It is also of interest to consider whether this effect is detectable in the long-term smoking outcomes for this group. A chi-square comparison was performed for the initial middle school abstaining girls in which parent education was related to long-term smoking outcome assessed 7-8 years later (abstinence or less than monthly smoking versus weekly smoking or more; exsmokers and monthly smokers were eliminated). Results showed that there was a marginally significant relation between parent education and long-term smoking outcomes. Of those with less educated parents, 24.6% were adult regular smokers at follow-up, whereas, of those with more highly educated parents, only 18.0% were regular smokers at adult follow-up, x2( I, N = 470) = 2.35, p < .13, after Yates’ correction. This prospective analysis may underestimate the long-term importance of parent education because it does not allow for the cumulative effects of smoking transitions that occurred either before the period of study or after the period of study. A better estimate of the long-term impact of parent education can be made by examining the cross-sectional relation between parent education and smoking at the adult follow-up. Chi-square comparisons were performed relating parent education to young adult current smoking (a dichotomous variable, never smoked or only tried vs. at least weekly smoking; exsmokers and monthly smokers were eliminated). These comparisons showed significant relations between parent education and young adult current smoking for all four subgroups; x2 (I, N = 472) = 4.36, p < .03, for older girls, x2 (I, N = 52 I) = 6.06, p < .02. for younger boys, and x2 (1, N = 584) = 6.52, p < .02. for younger girls. For older boys, the relation was in the same direction but not significant, x2 (1, N = 43 I) = 2.3 I, p < .I3. The magnitudes of the effect of parent education were similar across subgroups (cp = .08-. I 1).
Parent
Table
Education
1.
and Teen
Effects
Smoking
of Parent
227
Education
on the Transition
to Cigarette
Smoking
96 of Subjects Increasing Their Smoking Status frum Time 1 k Time 4 Subjects
N
X2
Low Parent Education
Middle school abstainers Middle school triers High school abstainers High school triers
765 334 407 431
15.05* 2.53 0.96 1.26
28.1 17.6 24.8 15.8
High Parent Education 15.6 10.8 19.7 11.5
*p < .Ol.
It would be inappropriate, however, to conclude that parent education is important for smoking only among young females. First, as noted before, the prospective effect of parent education showed the same pattern for all groups, even though the effect was large enough to be statistically reliable only for young girls. Second, recall that previous research using cross-sectional analyses has demonstrated the effects of parent education for both boys and girls (e.g., Waldron & Lye, 1990). Accordingly, we performed cross-sectional analyses using chi-square comparisons to relate parent education to smoking status at Time 1 of measurement. Smoking status was defined as a dichotomous variable, comparing abstainers with those who had at least tried cigarettes, and eliminating exsmokers. For middle school subjects this relation was significant for both boys and girls (x2 = 8.36 and 11.46, p < .Ol, respectively). Moreover, in contrast to the preceding longitudinal analyses, this magnitude of effect was similar for both sexes (+ = .13 and .14 for boys and girls). For high school subjects, the relation between parent education and smoking status at Time 1 of measurement was significant for both boys and girls (x * = 8.61 and 6.48, respectively). For these older subjects, the magnitude of the effect also was similar for boys and girls (+ = .14 and .12, respectively). Thus, cross-sectional analyses showed statistically significant relations between parent education and smoking status for both boys and girls, and both older and younger subjects, with similar magnitudes of effect. Potential
Mediators
of the Effects of Parent Education
As described before, a necessary precondition for mediational analyses is a significant relation between parent education and smoking outcomes. However, cross-sectional versus longitudinal analyses of this relation produced somewhat different findings. It is the longitudinal analyses that are critical for our mediator questions because the cross-sectional analyses leave open the direction of causal influence between smoking and the potential psychosocial mediators. Accordingly, we performed mediational analyses only for initial middle school abstaining girls, the only group to show a significant longitudinal effect of parent education on smoking transition.
1. Chassin,
228
C.C.
Presson,
S.J. Sherman,
and D.A.
Edwards
In order to qualify as a potential mediator between parent education and smoking transition, a predictor variable must be significantly related to both parent education and smoking transition (Baron & Kenny, 1986). Accordingly, Pearson correlations were calculated between each of the 19 predictor variables and both parent education and smoking transition. Of the 19 predictor variables, 7 were significantly correlated with both parent education and smoking transition at p < .05 or less. These variables were: parents’ smoking, parental supportiveness, agreement between parents, friends’ smoking, friends’ strictness, agreement in values between the subject and her friends, and expectations for attaining academic success. Tests of Potential
Mediators
To assess whether these variables mediated the relation between parent education and smoking initiation, a series of logistic regression analyses were performed (again, only for the middle school girls who were abstainers at Time 1). When the effect of parent education on smoking initiation was considered alone, parent education (as shown previously) had a significant effect, Wald x2(1, N = 420) = 17.92, p < .OOl. If these 7 psychosocial variables mediate the effect of parent education on smoking initiation, there should be a significant drop in the chi square associated with the parent education effect when these variables are entered into the regression. When all 7 variables were entered into the regression, the chi square associated with parent education dropped to 7.45, p < .Ol. The drop in chi square (10.47, df = 1) was significant at p < .O 1. This shows significant mediation (although not complete mediation because the effect of parent education was still significant after all mediating variables had been entered). To identify which of the individual variables were significant mediators, a series of 7 logistic regressions were run in which parent education was entered in combination with each mediator separately. The chi squares associated with parent education in these regressions were compared to the chi square obtained when parent education was entered alone. A significant drop in the chi square associated with parent education was considered to indicate a mediational effect. By this criterion, the significant individual mediators of the effects of parent education were parental smoking (x2 drop of 4.58, p < .05), friends’ smoking (~2 drop of 4.75, p C .05), and expectations for attaining academic success (x2 drop of 3.40, p < .07). Parent Education
as a Moderator
of the Psychosocial
Predictors
Our second question was whether parent education moderated the effects of the psychosocial variables on smoking transition. To address this question, we ran logistic regressions predicting smoking transition from parent education, gender, each of the 19 psychosocial predictors separately, all two-way interac-
Parent
Education
and Teen
Table 2. Significant in Predicting Smoking
Parent
Interaction Education
Smoking
229
Interactions Transitions
Between (Wald
of With
Middle School Abstainers Tolerance for deviance Friends’ strictness Middle School Triers Parent agreement Psychological beliefs about Note. For high *p < .05. **p
school .Ol.
