Health Education & Behavior http://heb.sagepub.com/
Attitudes, Norms, and Self-Efficacy: A Model of Adolescents' HIV-Related Sexual Risk Behavior Karen Basen-Engquist and Guy S. Parcel Health Educ Behav 1992 19: 263 DOI: 10.1177/109019819201900209 The online version of this article can be found at: http://heb.sagepub.com/content/19/2/263
Published by: http://www.sagepublications.com
On behalf of:
Society for Public Health Education
Additional services and information for Health Education & Behavior can be found at: Email Alerts: http://heb.sagepub.com/cgi/alerts Subscriptions: http://heb.sagepub.com/subscriptions Reprints: http://www.sagepub.com/journalsReprints.nav Permissions: http://www.sagepub.com/journalsPermissions.nav Citations: http://heb.sagepub.com/content/19/2/263.refs.html
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Attitudes, Norms, and Self-Efficacy: A Model of Adolescents’ HIV-Related Sexual Risk Behavior
Basen-Engquist, PhD Guy S. Parcel, PhD
Karen
Using data from a cross-sectional, statewide survey of 1,720 Texas ninth graders in 13 school districts, a model of psychosocial predictors of human immunodeficiency virus (HIV)-related sexual risk behavior was tested. Predictor variables in the model, based on variables from the Theory of Reasoned Action and Social Learning Theory, were attitudes, norms, self-efficacy, and behavioral intentions. Attitudes, norms, and selfefficacy predicted 36.4% of the variance in the intention to limit the number of sexual partners and the same variables plus intention predicted 24.6% of the variance in number of sexual partners in the past year. Attitudes, norms, and self-efficacy regarding condom use predicted 17.0% of the variance in condom use intentions; these variables plus intentions predicted 19.0% of the variance in condom use frequency. Attitudes, norms, and intentions were directly related to the number of sexual partners, while self-efficacy ad condom use intentions were directly related to frequency of condom use. INTRODUCTION Effective programs to prevent the spread of human immunodeficiency virus in adolescent populations are a high priority for many concerned with the health of adolescents. At this time relatively few adolescents have been diagnosed with acquired immunodeficiency virus (AIDS), but there are indications that it may be a larger problem than it appears. Of the 139,765 cases of AIDS reported in the United States as of June 1990, only 541 have been among adolescents. These figures underestimate the potential AIDS problem in the adolescent population, however. A large number of AIDS cases, 5,932 have been reported in the 20-24 year old age group.’ Given the length of time it can
(HIV)
Supported by grant #5T32 CA09542 from the National Cancer Institute Agency.
and
a
contract
from the
Texas Education
Both authors are with the Center for Health Promotion Research and Development, School of Public Health, The University of Texas Health Science Center at Houston. Address reprint requests to Karen Basen-Engquist, PhD, Center for Health Promotion Research and Development, School of Public Health, UTHSC-H, P.O. Box 20186, Houston, TX 77225. Health Education Quarterly, Vol. 19(2): 263-277 (Summer © 1992 by SOPHE. Published by John Wiley & Sons, Inc.
1992) CCC 0195-8402/92/020263-15$04.00
Downloaded from heb.sagepub.com at UNIV OF SOUTHERN CALIFORNIA on April 7, 2014
264
take the HIV infection to develop into AIDS, it is likely that many of these 2024 year olds were infected with HIV during their adolescent years. Sexual behaviors that put one at risk for HIV infection are common among adolescents. By the time they are 17 years old, 57% have had sexual intercourse. Only one-third of sexually active adolescents use contraception consistently; 27% never use any form of contraception.2 Condom use is still relatively rare; 20.8% of women aged 15-24 who use contraception report that they use condoms.’ Because the behaviors practiced by adolescents can put them at risk for contracting HIV, research on factors associated with risk behaviors that can assist us in altering these behaviors is crucial. Several studies have surveyed adolescents’ knowledge about AIDS and HIV infection. Although early studies on adolescents’ knowledge about AIDS showed deficits in certain crucial areas4 their knowledge appears to be improving over time.5 Despite the fairly high level of knowledge among adolescents, they continue to practice sexual behavior that puts them at risk for HIV infection. A random sample, cross-sectional survey of Massachusetts adolescents found no difference in knowledge between those who used condoms and those who did not.Surveys of small convenience samples of adolescents (all from clinics) showed mixed results on the knowledge-behavior association, with two studies showing such 8 an association 6,7 and one showing no association. Other psychosocial variables have been found to be associated with behavior. The Massachusetts survey, using variables from the Health Belief Model, found that barriers to condom use were inversely related to condom use, and perceived effectiveness of condoms and worry about getting AIDS were directly associated with condom use.’ Worry about getting AIDS, or perceived risk, was found to be associated with behavior changes in two studies of adolescent, minority women, 6&dquo; but was not associated with behavior changes in a study of male and female adolescents from a family planning clinic.’7 Despite these surveys on adolescents’ knowledge and beliefs about AIDS, relatively little research has been done to apply behavioral theory to the problem of educating youth to reduce their AIDS/HIV-related risk behavior. In order to know how to best educate young people about avoiding HIV infection, we must apply existing theory and knowledge about health risk behavior to the
problem. Ajzen and
Fishbein’s Theory of Reasoned Action&dquo;’ postulates that intention is an immediate determinate of behavior. Attitudes, conceptualized as beliefs about the consequences of the actions combined with the evaluation of the consequences, and subjective norms, which are composed of the opinions of others and a person’s motivation to comply with those individuals, are the predictors of behavioral intention. The Theory of Reasoned Action has been applied successfully to health behaviors as varied as driving under the influence of alcohol,&dquo; patient compliance in taking medication,’2 adolescents’ use of smokeless tobacco, 11,14 vaccination behavior,&dquo; family planning,’~ and breast feeding.&dquo; A recent study has added the Social Learning Theory construct of self-efficacy to the theory, resulting in the ability to predict a greater proportion of the variance in adolescent smoking behavior.’~ Self-efficacy, which refers to one’s expectations about the ability to carry out a specific behavior, 1920 has been found
Downloaded from heb.sagepub.com at UNIV OF SOUTHERN CALIFORNIA on April 7, 2014
265
be related to a number of health behaviors and is hypothesized to be related behaviors to prevent HIV transmission as well. Its demonstrated relationship to contraceptive behavior2’ is especially germane to this study, as practicing safer sex involves some of the same behaviors and communication issues as contraceptive behavior. To apply these concepts to the problem of AIDS/HIV risk behavior, a model is hypothesized based on the study by de Vries et al.’~ to predict smoking behavior. Two domains of sexual behavior are studied: the decision to have or abstain from sexual intercourse and the frequency of condom use. Subjects’ personal evaluations of the behaviors (attitudes), their perceptions of their friend’s evaluations of the behaviors (norms), and their expectations about skills and abilities relevant to the behaviors (self-efficacy) are used to predict the intention to perform the behaviors. Attitudes, norms, self-efficacy, and intentions were tested to determine their association with the behaviors. In addition, a secondary purpose of this study is to determine whether self-efficacy makes a unique contribution to understanding condom use and choices about having or abstaining from sexual intercourse. to to
METHODS
Sample A multistage sample design was used to select respondents for the survey. The first stage consisted of selecting 30 school districts using a probability proportional to size sampling technique. At the next stage, up to three school campuses at each district were selected, again using probability proportional to size sampling. At the final stage, up to five sections of a ninth grade social studies class were randomly selected to participate in the survey. The superintendent of each school district in the sample was contacted by the Texas Education Agency (TEA) to determine whether he or she was willing to participate in the survey. Of the 30 districts that were selected, 13 participated in the survey. After the superintendent agreed to having students participate in the survey, the sample of appropriate classrooms was randomly selected by the TEA representative making the telephone contact with the district. A total of 1,720 ninth graders participated in the survey.
Procedures
and survey materials were mailed to the school campuses. Surveys administered in the classroom by school district personnel, and then returned by mail for scoring and analysis. To increase honest disclosure of information, students’ responses to the survey were anonymous and protected from disclosure by allowing each student to return the survey in a sealed envelope.
Surveys
were
Downloaded from heb.sagepub.com at UNIV OF SOUTHERN CALIFORNIA on April 7, 2014
266
Measures A written questionnaire, using items adapted from preexisting instruments, used to assess demographic information and the following constructs. Sample items from each of the scales are displayed in Table 1. was
Attitudes In
items taken from the National Adolescent Student Health students were asked how they felt about people their age having sexual Survey,22 intercourse (high scores indicating more conservative attitudes) and using condoms (a high score indicating a positive attitude towards condoms). The internal
Likert-type
Table 1.
Sample
Items From Each Scale
Downloaded from heb.sagepub.com at UNIV OF SOUTHERN CALIFORNIA on April 7, 2014
267
for the measure of attitudes towards having sexual intermeasured by a standardized Cronbach’s alpha, was .70. Because it was measured with only one item, no reliability coefficient could be calculated for attitudes about condoms.
consistency reliability course,
as
Norms These items also
taken from the National Adolescent Student Health the attitude items, asking students how their friends Survey. They paralleled feel about people their age having sexual intercourse and using condoms. Friends were used as a reference group because they are an important source of both positive and negative social pressure for adolescents. The measure of norms about having sexual intercourse had an internal consistency reliability of .67 (standardized Cronbach’s alpha). The norms regarding condom use were measured using one item. were
Self Efficacy The
self-efficacy scales were adapted from an instrument developed by Longoria.~ Each of the scales, self-efficacy about making the decision to have or abstain from intercourse and self-efficacy about condom use, consists of five Likert-type items that ask the respondent to rate his/her confidence that he/ she can implement particular HIV-preventive behaviors. The measure of selfefficacy about the decision to have/abstain from sexual intercourse had an internal consistency reliability of .77. The standardized Cronbach’s alpha for the measure of condom use self-efficacy was .70.
Behavioral Intentions The intention to limit the number of sexual partners and the intention to use condom in the next year were assessed by two Likert-type items each. These items were developed by the investigator for use in the survey. The standardized Cronbach’s alpha was .58 for the intention to limit the number of sexual partners and .78 for condom use intentions. a
Behaviors of the decision to have or abstain from sexual inoperationalized as the number of sexual partners an individual she had the year prior to the survey. This item, along with another he or reported on the reported frequency of condom use, was taken from a questionnaire developed by the Centers for Disease Control. The behavioral
measure
tercourse was
Downloaded from heb.sagepub.com at UNIV OF SOUTHERN CALIFORNIA on April 7, 2014
268
Data
Analysis
Before analysis, 123 cases (7.2%) had to be dropped because of missing or inconsistent data. These cases were slightly different demographically from the cases that were retained for the analysis. The dropped cases were more likely to have been male and to have reported a slightly lower average grade in English, and to have reported &dquo;other&dquo; for their racial/ethnic group. There were no significant differences between dropped and retained cases in age or the proportion of students eligible for reduced school lunch. The students’ responses were weighted to reflect their probability of selection and a post-stratification adjustment was made to adjust the ethnic distribution of the sample, which was not comparable to that of the state. The weights were calculated by dividing the number of ninth graders who completed the survey by the number of ninth graders in the district, multiplying this figure by the district’s selection probability, and dividing the resulting weight by the average weight for the entire sample. Multiple regression in SPSS-PC was used to test the hypothesis that the variables are related to sexual risk behavior in high school students. After the equation was calculated a multiple regression was run using the program PCCARP.24 This program is able to take the sampling design into account when computing the error variance by which significance levels are determined.
RESULTS
Descriptive
Statistics
Table 2 presents the demographic characteristics of the sample, both before the weighting and post-stratification adjustment (for sex and race/ethnicity) and after. The remainder of the statistics and tests use only the data that have been weighted and adjusted. Table 3 displays the means and standard deviations for the independent variables. When analyzing the variables related to the decision to have sexual intercourse, data from all subjects are used. When anlayzing the variables related to condom use, only the data from those subjects who have had sexual intercourse are used. Table 4 presents the descriptive statistics for the dependent variables by gender.
Univariate
Analysis
Tables 5 and 6 present the Pearson correlation coefficients among all the variables. For variables related to having/abstaining from sexual intercourse, the intercorrelations among the independent variables are all statistically significant and range from .23 (norms-self efficacy) to .64 (attitudes-norms). These variables are all significantly related to number of partners. The correlations between the independent variables and number of partners are negative because high scores on the independent variables indicate a negative attitude towards adolescents having sexual intercourse.
Downloaded from heb.sagepub.com at UNIV OF SOUTHERN CALIFORNIA on April 7, 2014
269
Table 2.
Weighted,
Demographic Characteristics and Adjusted Percentages
of
Table 3. Means and Standard Deviations of
Sample: Unweighted, Unadjusted
Independent
and
Dependent
Downloaded from heb.sagepub.com at UNIV OF SOUTHERN CALIFORNIA on April 7, 2014
and
Variables
270
Table 4. Distribution of
Dependent
Variables
by
Gender
For variables related to condom use, the intercorrelations among the independent variables are significant, ranging from .19 (attitudes-self efficacy) to .42 (attitudes-norms). The correlation coefficients between the independent variables and frequency of condom use are significant and in the expected positive direction (.22 to .34). The correlation between condom use and number of
partners (among those having
at
least
partner)
one
was
not
significant (r =
-.02). Multivariate
Analysis
To test the significance of the contribution of self-efficacy to the prediction of intention and behavior, a hierarchical multiple regression strategy was used. The original Theory of Reasoned Action variables were first entered into the model and then self-efficacy was added to the equation to determine whether it added significantly to the proportion of variance predicted. In predicting intention to limit the number of partners, attitudes and norms account for 34.4% of our variance. Adding self-efficacy to the equation adds 2% to the percentage of variance accounted for in intention. In the equation to
Table 5. Pearson Correlations Coefficients-Decision To Have Variables (N 1,595)d
or
=
a
All correlations
are
statistically significant, p
Attitudes, Norms, and Self-Efficacy: A Model of Adolescents' HIV-Related Sexual Risk Behavior Karen Basen-Engquist and Guy S. Parcel Health Educ Behav 1992 19: 263 DOI: 10.1177/109019819201900209 The online version of this article can be found at: http://heb.sagepub.com/content/19/2/263
Published by: http://www.sagepublications.com
On behalf of:
Society for Public Health Education
Additional services and information for Health Education & Behavior can be found at: Email Alerts: http://heb.sagepub.com/cgi/alerts Subscriptions: http://heb.sagepub.com/subscriptions Reprints: http://www.sagepub.com/journalsReprints.nav Permissions: http://www.sagepub.com/journalsPermissions.nav Citations: http://heb.sagepub.com/content/19/2/263.refs.html
Downloaded from heb.sagepub.com at UNIV OF SOUTHERN CALIFORNIA on April 7, 2014
Attitudes, Norms, and Self-Efficacy: A Model of Adolescents’ HIV-Related Sexual Risk Behavior
Basen-Engquist, PhD Guy S. Parcel, PhD
Karen
Using data from a cross-sectional, statewide survey of 1,720 Texas ninth graders in 13 school districts, a model of psychosocial predictors of human immunodeficiency virus (HIV)-related sexual risk behavior was tested. Predictor variables in the model, based on variables from the Theory of Reasoned Action and Social Learning Theory, were attitudes, norms, self-efficacy, and behavioral intentions. Attitudes, norms, and selfefficacy predicted 36.4% of the variance in the intention to limit the number of sexual partners and the same variables plus intention predicted 24.6% of the variance in number of sexual partners in the past year. Attitudes, norms, and self-efficacy regarding condom use predicted 17.0% of the variance in condom use intentions; these variables plus intentions predicted 19.0% of the variance in condom use frequency. Attitudes, norms, and intentions were directly related to the number of sexual partners, while self-efficacy ad condom use intentions were directly related to frequency of condom use. INTRODUCTION Effective programs to prevent the spread of human immunodeficiency virus in adolescent populations are a high priority for many concerned with the health of adolescents. At this time relatively few adolescents have been diagnosed with acquired immunodeficiency virus (AIDS), but there are indications that it may be a larger problem than it appears. Of the 139,765 cases of AIDS reported in the United States as of June 1990, only 541 have been among adolescents. These figures underestimate the potential AIDS problem in the adolescent population, however. A large number of AIDS cases, 5,932 have been reported in the 20-24 year old age group.’ Given the length of time it can
(HIV)
Supported by grant #5T32 CA09542 from the National Cancer Institute Agency.
and
a
contract
from the
Texas Education
Both authors are with the Center for Health Promotion Research and Development, School of Public Health, The University of Texas Health Science Center at Houston. Address reprint requests to Karen Basen-Engquist, PhD, Center for Health Promotion Research and Development, School of Public Health, UTHSC-H, P.O. Box 20186, Houston, TX 77225. Health Education Quarterly, Vol. 19(2): 263-277 (Summer © 1992 by SOPHE. Published by John Wiley & Sons, Inc.
1992) CCC 0195-8402/92/020263-15$04.00
Downloaded from heb.sagepub.com at UNIV OF SOUTHERN CALIFORNIA on April 7, 2014
264
take the HIV infection to develop into AIDS, it is likely that many of these 2024 year olds were infected with HIV during their adolescent years. Sexual behaviors that put one at risk for HIV infection are common among adolescents. By the time they are 17 years old, 57% have had sexual intercourse. Only one-third of sexually active adolescents use contraception consistently; 27% never use any form of contraception.2 Condom use is still relatively rare; 20.8% of women aged 15-24 who use contraception report that they use condoms.’ Because the behaviors practiced by adolescents can put them at risk for contracting HIV, research on factors associated with risk behaviors that can assist us in altering these behaviors is crucial. Several studies have surveyed adolescents’ knowledge about AIDS and HIV infection. Although early studies on adolescents’ knowledge about AIDS showed deficits in certain crucial areas4 their knowledge appears to be improving over time.5 Despite the fairly high level of knowledge among adolescents, they continue to practice sexual behavior that puts them at risk for HIV infection. A random sample, cross-sectional survey of Massachusetts adolescents found no difference in knowledge between those who used condoms and those who did not.Surveys of small convenience samples of adolescents (all from clinics) showed mixed results on the knowledge-behavior association, with two studies showing such 8 an association 6,7 and one showing no association. Other psychosocial variables have been found to be associated with behavior. The Massachusetts survey, using variables from the Health Belief Model, found that barriers to condom use were inversely related to condom use, and perceived effectiveness of condoms and worry about getting AIDS were directly associated with condom use.’ Worry about getting AIDS, or perceived risk, was found to be associated with behavior changes in two studies of adolescent, minority women, 6&dquo; but was not associated with behavior changes in a study of male and female adolescents from a family planning clinic.’7 Despite these surveys on adolescents’ knowledge and beliefs about AIDS, relatively little research has been done to apply behavioral theory to the problem of educating youth to reduce their AIDS/HIV-related risk behavior. In order to know how to best educate young people about avoiding HIV infection, we must apply existing theory and knowledge about health risk behavior to the
problem. Ajzen and
Fishbein’s Theory of Reasoned Action&dquo;’ postulates that intention is an immediate determinate of behavior. Attitudes, conceptualized as beliefs about the consequences of the actions combined with the evaluation of the consequences, and subjective norms, which are composed of the opinions of others and a person’s motivation to comply with those individuals, are the predictors of behavioral intention. The Theory of Reasoned Action has been applied successfully to health behaviors as varied as driving under the influence of alcohol,&dquo; patient compliance in taking medication,’2 adolescents’ use of smokeless tobacco, 11,14 vaccination behavior,&dquo; family planning,’~ and breast feeding.&dquo; A recent study has added the Social Learning Theory construct of self-efficacy to the theory, resulting in the ability to predict a greater proportion of the variance in adolescent smoking behavior.’~ Self-efficacy, which refers to one’s expectations about the ability to carry out a specific behavior, 1920 has been found
Downloaded from heb.sagepub.com at UNIV OF SOUTHERN CALIFORNIA on April 7, 2014
265
be related to a number of health behaviors and is hypothesized to be related behaviors to prevent HIV transmission as well. Its demonstrated relationship to contraceptive behavior2’ is especially germane to this study, as practicing safer sex involves some of the same behaviors and communication issues as contraceptive behavior. To apply these concepts to the problem of AIDS/HIV risk behavior, a model is hypothesized based on the study by de Vries et al.’~ to predict smoking behavior. Two domains of sexual behavior are studied: the decision to have or abstain from sexual intercourse and the frequency of condom use. Subjects’ personal evaluations of the behaviors (attitudes), their perceptions of their friend’s evaluations of the behaviors (norms), and their expectations about skills and abilities relevant to the behaviors (self-efficacy) are used to predict the intention to perform the behaviors. Attitudes, norms, self-efficacy, and intentions were tested to determine their association with the behaviors. In addition, a secondary purpose of this study is to determine whether self-efficacy makes a unique contribution to understanding condom use and choices about having or abstaining from sexual intercourse. to to
METHODS
Sample A multistage sample design was used to select respondents for the survey. The first stage consisted of selecting 30 school districts using a probability proportional to size sampling technique. At the next stage, up to three school campuses at each district were selected, again using probability proportional to size sampling. At the final stage, up to five sections of a ninth grade social studies class were randomly selected to participate in the survey. The superintendent of each school district in the sample was contacted by the Texas Education Agency (TEA) to determine whether he or she was willing to participate in the survey. Of the 30 districts that were selected, 13 participated in the survey. After the superintendent agreed to having students participate in the survey, the sample of appropriate classrooms was randomly selected by the TEA representative making the telephone contact with the district. A total of 1,720 ninth graders participated in the survey.
Procedures
and survey materials were mailed to the school campuses. Surveys administered in the classroom by school district personnel, and then returned by mail for scoring and analysis. To increase honest disclosure of information, students’ responses to the survey were anonymous and protected from disclosure by allowing each student to return the survey in a sealed envelope.
Surveys
were
Downloaded from heb.sagepub.com at UNIV OF SOUTHERN CALIFORNIA on April 7, 2014
266
Measures A written questionnaire, using items adapted from preexisting instruments, used to assess demographic information and the following constructs. Sample items from each of the scales are displayed in Table 1. was
Attitudes In
items taken from the National Adolescent Student Health students were asked how they felt about people their age having sexual Survey,22 intercourse (high scores indicating more conservative attitudes) and using condoms (a high score indicating a positive attitude towards condoms). The internal
Likert-type
Table 1.
Sample
Items From Each Scale
Downloaded from heb.sagepub.com at UNIV OF SOUTHERN CALIFORNIA on April 7, 2014
267
for the measure of attitudes towards having sexual intermeasured by a standardized Cronbach’s alpha, was .70. Because it was measured with only one item, no reliability coefficient could be calculated for attitudes about condoms.
consistency reliability course,
as
Norms These items also
taken from the National Adolescent Student Health the attitude items, asking students how their friends Survey. They paralleled feel about people their age having sexual intercourse and using condoms. Friends were used as a reference group because they are an important source of both positive and negative social pressure for adolescents. The measure of norms about having sexual intercourse had an internal consistency reliability of .67 (standardized Cronbach’s alpha). The norms regarding condom use were measured using one item. were
Self Efficacy The
self-efficacy scales were adapted from an instrument developed by Longoria.~ Each of the scales, self-efficacy about making the decision to have or abstain from intercourse and self-efficacy about condom use, consists of five Likert-type items that ask the respondent to rate his/her confidence that he/ she can implement particular HIV-preventive behaviors. The measure of selfefficacy about the decision to have/abstain from sexual intercourse had an internal consistency reliability of .77. The standardized Cronbach’s alpha for the measure of condom use self-efficacy was .70.
Behavioral Intentions The intention to limit the number of sexual partners and the intention to use condom in the next year were assessed by two Likert-type items each. These items were developed by the investigator for use in the survey. The standardized Cronbach’s alpha was .58 for the intention to limit the number of sexual partners and .78 for condom use intentions. a
Behaviors of the decision to have or abstain from sexual inoperationalized as the number of sexual partners an individual she had the year prior to the survey. This item, along with another he or reported on the reported frequency of condom use, was taken from a questionnaire developed by the Centers for Disease Control. The behavioral
measure
tercourse was
Downloaded from heb.sagepub.com at UNIV OF SOUTHERN CALIFORNIA on April 7, 2014
268
Data
Analysis
Before analysis, 123 cases (7.2%) had to be dropped because of missing or inconsistent data. These cases were slightly different demographically from the cases that were retained for the analysis. The dropped cases were more likely to have been male and to have reported a slightly lower average grade in English, and to have reported &dquo;other&dquo; for their racial/ethnic group. There were no significant differences between dropped and retained cases in age or the proportion of students eligible for reduced school lunch. The students’ responses were weighted to reflect their probability of selection and a post-stratification adjustment was made to adjust the ethnic distribution of the sample, which was not comparable to that of the state. The weights were calculated by dividing the number of ninth graders who completed the survey by the number of ninth graders in the district, multiplying this figure by the district’s selection probability, and dividing the resulting weight by the average weight for the entire sample. Multiple regression in SPSS-PC was used to test the hypothesis that the variables are related to sexual risk behavior in high school students. After the equation was calculated a multiple regression was run using the program PCCARP.24 This program is able to take the sampling design into account when computing the error variance by which significance levels are determined.
RESULTS
Descriptive
Statistics
Table 2 presents the demographic characteristics of the sample, both before the weighting and post-stratification adjustment (for sex and race/ethnicity) and after. The remainder of the statistics and tests use only the data that have been weighted and adjusted. Table 3 displays the means and standard deviations for the independent variables. When analyzing the variables related to the decision to have sexual intercourse, data from all subjects are used. When anlayzing the variables related to condom use, only the data from those subjects who have had sexual intercourse are used. Table 4 presents the descriptive statistics for the dependent variables by gender.
Univariate
Analysis
Tables 5 and 6 present the Pearson correlation coefficients among all the variables. For variables related to having/abstaining from sexual intercourse, the intercorrelations among the independent variables are all statistically significant and range from .23 (norms-self efficacy) to .64 (attitudes-norms). These variables are all significantly related to number of partners. The correlations between the independent variables and number of partners are negative because high scores on the independent variables indicate a negative attitude towards adolescents having sexual intercourse.
Downloaded from heb.sagepub.com at UNIV OF SOUTHERN CALIFORNIA on April 7, 2014
269
Table 2.
Weighted,
Demographic Characteristics and Adjusted Percentages
of
Table 3. Means and Standard Deviations of
Sample: Unweighted, Unadjusted
Independent
and
Dependent
Downloaded from heb.sagepub.com at UNIV OF SOUTHERN CALIFORNIA on April 7, 2014
and
Variables
270
Table 4. Distribution of
Dependent
Variables
by
Gender
For variables related to condom use, the intercorrelations among the independent variables are significant, ranging from .19 (attitudes-self efficacy) to .42 (attitudes-norms). The correlation coefficients between the independent variables and frequency of condom use are significant and in the expected positive direction (.22 to .34). The correlation between condom use and number of
partners (among those having
at
least
partner)
one
was
not
significant (r =
-.02). Multivariate
Analysis
To test the significance of the contribution of self-efficacy to the prediction of intention and behavior, a hierarchical multiple regression strategy was used. The original Theory of Reasoned Action variables were first entered into the model and then self-efficacy was added to the equation to determine whether it added significantly to the proportion of variance predicted. In predicting intention to limit the number of partners, attitudes and norms account for 34.4% of our variance. Adding self-efficacy to the equation adds 2% to the percentage of variance accounted for in intention. In the equation to
Table 5. Pearson Correlations Coefficients-Decision To Have Variables (N 1,595)d
or
=
a
All correlations
are
statistically significant, p
