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Risk and Protective Factors for Adolescent Drug Use:
Findings from the 1999 National Household Survey on Drug Abuse

Chapter 2. Distributions of Risk and Protective Factors for Substance Use

2.1 Introduction

This chapter presents summary statistics for each of the risk and protective factors that were included in the 1999 National Household Survey on Drug Abuse (NHSDA). This chapter addresses the following issues:

The 1999 NHSDA included 24 risk and protective factors divided into 4 domains: community, family, peer/individual, and school. Some of these factors were measured using multiple-item scales; others were measured using single items.7 When more than one item was used to measure a factor, the responses from all the items were combined into a single score. These scores were computed by taking the mean of all the items used to measure a given construct. All scales were coded such that higher scale scores for risk factors indicated that a respondent was at higher risk for substance use. Higher scores for protective factors indicated that a respondent scored high on variables that had a lower risk for substance use.

Appendix A contains a complete list of the questions used to create the measures for each of the risk and protective factors (Tables A.1 to A.4); the distributions for each of these questions (Tables A.5 to A.8); and the correlations between the risk factors (Table A.9), the correlations between the protective factors (Table A.10), and the correlations between the risk factors and the protective factors (Table A.11). These correlations show the degree to which each factor is associated with the other factors. When two factors are highly correlated (i.e., greater than 0.50 or less than -0.50), the questions making up these factors may be measuring similar constructs. Tables 2.1 to 2.4 present the following summary statistics for each factor: (1) the number of items used to measure the factor; (2) the sample size (number of youths with scores for each factor); (3) the range of responses for continuous factors; (4) the mean scale score for continuous factors or percentage giving a certain response for dichotomous factors; (5) the standard deviation for continuous factors; (6) the quartiles for continuous factors; and (7) Cronbach's alpha reliability8 for factors with two or more items.

Most items specific to substance use were asked separately for marijuana, cigarettes, and alcohol. In Chapters 2 and 3 of this report, each of these factors is first presented as a "multiple substance" scale, which is a scale score derived by taking the mean of the responses for these three substances. Following this, scores for the separate substances are presented.

In this chapter, descriptive statistics for each of the risk and protective factors are first presented for the full national sample. For clarity of presentation, the distributions for some factors are presented in figures. Descriptive statistics then are presented separately for different racial/ethnic groups (whites, blacks, Hispanics, and "others"), genders, and age groups. Researchers may find the nationally representative scale scores by age, race/ethnicity, and gender helpful in providing a comparison to similar scores based on local analyses.

For about half of the factors, the distribution of responses was skewed, meaning that most youths gave the same or similar responses to the questions. Among the risk factors, most youths agreed that community adults and parents would strongly disapprove of their use of marijuana, that they themselves would disapprove of other youths using marijuana, and that the prevalence of marijuana use was low among community adults, their friends, and students in their grade at school. Among protective factors, most youths agreed that their parents provide encouragement and that their schools had strong sanctions against illegal drug and alcohol use.

2.2 Community Domain

Community domain risk and protective factors included community disorganization and crime, neighborhood cohesiveness, community attitudes toward substance use, community norms toward substance use, availability of illicit drugs, and exposure to prevention messages. The individual questions that were used to create these factors are presented in Table A.1, and the distributions of these individual items are presented in Table A.5 (see Appendix A). Summary statistics for each of these factors are presented in Table 2.1.

2.2.1 Community Disorganization and Crime

Community disorganization and crime constitute a risk factor that focuses on the physical environment and level of crime in neighborhoods. This factor was measured using six questions in which youths were asked how much they agreed or disagreed that there was a lot of crime, a lot of drug selling, a lot of street fights, many empty or abandoned buildings, a lot of graffiti, and many people moving in and out of their neighborhoods. Each question was answered using the following scale: 1 ("strongly disagree"), 2 ("somewhat disagree"), 3 ("somewhat agree"), and 4 ("strongly agree"). The mean score on these six questions was 1.65, which is between strongly disagree and somewhat disagree. Among the individual items, youths were more likely to somewhat or strongly agree that people often moved in and out of their neighborhoods (30.5 percent) and that there was a lot of drug selling in the neighborhood (25.7 percent) compared with other items (Figure 2.1). Fewer youths agreed that there were a lot of street fights (14.1 percent) or many empty/abandoned buildings in their neighborhoods (11.1 percent).

Figure 2.1 Percentages of Youths Aged 12 to 17 Reporting That They Somewhat or Strongly Agreed with Community Disorganization and Crime Items: 1999

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Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1999.

2.2.2 Neighborhood Cohesiveness

Neighborhood cohesiveness is a protective factor that was measured by asking youths how much they agreed or disagreed that people in the youths' neighborhood helped each other out and visited each other in their homes. The questions were answered using the same 1 ("strongly disagree") to 4 ("strongly agree") scale used for community disorganization and crime. The mean and median scores on these questions were around 3.00, indicating that on average youths "somewhat agreed" to these statements (Table 2.1). Among the individual items, approximately 78.5 percent of youths somewhat or strongly agreed that people in their neighborhood often help each other out, and 72.9 percent of youths somewhat or strongly agreed that people in their neighborhood often visit each other's homes (Table A.5).

2.2.3 Community Attitudes Toward Substance Use

Community attitudes toward substance use (specifically, lack of adult disapproval of youth substance use) constitute a risk factor that focuses on youths' perceptions of how adults in their neighborhood would feel about the youth using marijuana, cigarettes, or alcohol. Youths were asked whether they thought that most neighborhood adults would "strongly disapprove," "somewhat disapprove," or "neither approve nor disapprove" (scored 1, 2, and 3 respectively) if the respondent were to try marijuana or hashish once or twice, smoke one or two packs of cigarettes per day, or have one or more drinks of an alcoholic beverage nearly every day. The mean score across these three substances was 1.42, which falls between strongly disapprove and somewhat disapprove (Table 2.1). Among the different substances, 78.8 percent of youths reported that most neighborhood adults would strongly disapprove if they tried marijuana, 65.1 percent reported that most neighborhood adults would strongly disapprove if they smoked cigarettes daily, and 70.3 percent reported that most neighborhood adults would strongly disapprove if they drank alcohol daily (Table A.5).

2.2.4 Community Norms Toward Substance Use

Community norms toward substance use (specifically, knowing adults who are substance users) constitute a risk factor that focuses on youths' perceptions of substance use among adults they know personally. Youths were asked whether "none," "some," "most," or "all" (scored 1, 2, 3, and 4 respectively) of adults they know personally used marijuana/hashish, smoked cigarettes, drank alcoholic beverages, or got drunk at least once a week. The mean score across the four questions was 1.88, which falls between "none" and "some" on the scale (Table 2.1). Among the individual substances, youths were more likely to report that most or all of the adults they personally knew used alcohol (45.2 percent) or cigarettes (28.3 percent) compared with marijuana (3.8 percent) (Figure 2.2). However, more than one out of four youths (28.8 percent) reported that they knew at least some adults who used marijuana, and nearly half of youths (45.1 percent) reported that they personally knew at least some adults who got drunk once a week or more (Table A.5).

Figure 2.2 Percentages of Youths Aged 12 to 17 Reporting Substance Use by Adults Whom They Knew Personally: 1999

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Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1999.

2.2.5 Availability of Illicit Drugs

Availability of illicit drugs, a risk factor, was measured by asking youths how difficult or easy it would be for them to get marijuana, LSD, cocaine, crack, or heroin if they wanted some. The questions were answered using the following scale: 1 ("probably impossible"), 2 ("very difficult"), 3 ("somewhat difficult"), 4 ("somewhat easy"), or 5 ("very easy"). The mean response was 3.41, which falls between somewhat difficult and somewhat easy (Table 2.1). Among the different substances, youths were more likely to report that marijuana was fairly or very easy to obtain (56.5 percent) compared with other drugs (Figure 2.3). Approximately one out of four youths reported that it would be fairly or very easy for them to obtain LSD (24.9 percent), cocaine (27.5 percent), or crack (28.4 percent). Nearly one in five youths (18.1 percent) reported that heroin would be fairly or very easy to obtain.

Figure 2.3 Percentages of Youths Aged 12 to 17 Reporting That Drugs Would Be Fairly or Very Easy to Obtain: 1999

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Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1999.

2.2.6 Exposure to Prevention Messages in the Media

Exposure to prevention messages in the media, a protective factor, was measured by a single item asking youths whether they had seen or heard any alcohol or drug prevention messages from sources outside of school, such as posters, pamphlets, and radio or TV ads, in thepast 12 months. Among youths, 82.3 percent reported that they had seen or heard these types of prevention messages in the past 12 months (Table A.5).

2.2.7 Community Factors, by Race/Ethnicity, Gender, and Age

Summary statistics for the community factors are presented by racial/ethnic groups, gender, and age in Table 2.5.9 Among youths, whites reported less community disorganization and crime, and more neighborhood cohesiveness, compared with other racial/ethnic groups. The perceived availability of marijuana was approximately equal among whites, blacks, and Hispanics, but marijuana was perceived to be less available for youths in the "other" category. Exposure to prevention messages in the media was reported more often by whites (83.5 percent) and youths in the "other" category (86.2 percent) compared with blacks (78.3 percent) and Hispanics (78.7 percent). There were no notable differences between racial/ethnic groups in community attitudes or community norms toward substance use.

There were little or no differences between males and females on the community disorganization and crime, neighborhood cohesiveness, community attitudes toward substance use, community norms toward substance use, or availability of marijuana measures. Females were more likely than males to have reported exposure to prevention messages in the media (84.6 vs. 80.0 percent).

Differences between younger and older youths are expected, largely due to common adolescent growth factors. For example, youths aged 15 to 17 reported that marijuana would be easier for them to obtain than did youths aged 12 to 14. There were no notable differences between these age groups for community disorganization and crime, neighborhood cohesiveness, community attitudes and norms toward substance use, or exposure to prevention messages in the media. For more information about distributions of risk and protective factors in the community domain by gender and age, see Appendix C.

2.3 Family Domain

Family domain variables included parental monitoring, parental encouragement, parental attitudes toward substance use, parental communication about substance use, and parents as a source of social support. The individual questions used to create these factors are presented in Table A.2, and the distributions of these items are presented in Table A.6 (see Appendix A). Summary statistics for each of these factors are presented in Table 2.2.

2.3.1 Parental Monitoring

Parental monitoring (specifically, a lack of parental monitoring) is a risk factor that focuses on youths' perceptions of rules placed upon them by their parents and how closely parents monitor youths' activities. This was measured using a set of five questions in which youths were asked how often in the past 12 months their parents checked on whether the youths had done their homework, provided help with homework if needed, made youths do chores around the house, limited the amount of television that youths watch, and limited the amount of time that youths spend with friends on school nights. Available response options for these questions were 1 ("always"), 2 ("sometimes"), 3 ("seldom"), or 4 ("never"). The mean and median on the scale was 2.00, indicating that, on average, youths perceived that their parents sometimes engage in these activities (Table 2.1). As shown in Figure 2.4, among the individual items, youths were more likely to report that parents sometimes or always made them do work/chores around the house (88.0 percent) and provided help with homework if needed (81.0 percent) compared with other items. Only 39.2 percent of youths reported that their parents limited the amount of time they watch television.

Figure 2.4 Percentages of Youths Aged 12 to 17 Reporting Different Responses to Parental Monitoring Items: 1999

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Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1999.

2.3.2 Parental Encouragement

Parental encouragement is a protective factor measured using two items in which youths were asked how often in the past 12 months their parents let them know they had done a good job and let them know they were proud of them for something they had done. The response options were 1 ("never"), 2 ("seldom"), 3 ("sometimes"), or 4 ("always"). The mean score across these two items was 3.34, and the median was 3.50, which falls between "sometimes" and "always" on the scale (Table 2.2). As shown in Figure 2.5, most youths reported that their parents sometimes or always let them know they had done a good job (85.7 percent) and told youths they were proud of them for something they had done (85.3 percent).

Figure 2.5 Percentages of Youths Aged 12 to 17 Reporting Different Responses to Parental Encouragement Items: 1999

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Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1999.

2.3.3 Parental Attitudes Toward Substance Use

Another risk factor focused on youths' perceptions of how their parents would feel if the youths used marijuana, cigarettes, or alcohol. Youths were asked three questions about whether they thought their parents would "strongly disapprove," "somewhat disapprove," or "neither approve nor disapprove" (scored 1, 2, and 3 respectively) if the youth were to try marijuana or hashish once or twice, smoke one or two packs of cigarettes per day, or have one or more drinks of an alcoholic beverage almost every day. The mean score across the three substances was 1.16, and the median and quartiles for each individual substance was 1.00, indicating that most youths believed their parents would strongly disapprove if they used these substances (Table 2.2). As shown in Figure 2.6, approximately 9 out of 10 youths reported that their parents would strongly disapprove if they tried marijuana once or twice (90.7 percent), had one or more drinks of alcohol every day (89.5 percent), or smoked one or two packs of cigarettes a day (87.4 percent).

Figure 2.6 Percentages of Youths Aged 12 to 17 Reporting That Their Parents Strongly Disapproved of Substance Use: 1999

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Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1999.

2.3.4 Parental Communication about Substance Use

Parental communication about substance use, a protective factor, was measured using a single item in which youths were asked whether they had talked with at least one of their parents about the dangers of tobacco, alcohol, or drug use in the past 12 months. Among youths, 57.4 percent reported that they had spoken with at least one of their parents about the dangers of using these substances in the past 12 months (Table 2.2).

2.3.5 Parents as Source of Social Support

Parents as source of social support, a protective factor, focuses on whether youths would talk to their parents if they needed to discuss a serious problem. A single item asked youths to whom they would turn if they had to discuss a serious problem (see Table A.2 for list of response options). Among youths, 71.7 percent reported that they would turn to either their mother or father if they needed to discuss a serious problem (Table 2.2).

2.3.6 Family Factors, by Race/Ethnicity, Gender, and Age

Summary statistics for family factors are presented by racial/ethnic group, gender, and age in Table 2.6. Among youths, parental communication about the dangers of substance use was reported by more whites (59.9 percent) and Hispanics (57.9 percent) compared with blacks (47.3 percent) or youths in the "other" category (51.1 percent). Youths in the "other" category were less likely to identify their parents as a source of social support (64.3 percent) compared with youths in other racial/ethnic groups. Scores were approximately equal for parental monitoring, parental encouragement, and parental attitudes toward substance use between different racial/ethnic groups.

Among youths, more females than males reported that their parents had communicated with them about the dangers of drug use (60.0 vs. 55.0 percent). There were no notable differences between male and female youths regarding parental monitoring, parental encouragement, parental attitudes toward substance use, or parents as a source of social support.

Youths aged 15 to 17 were less likely to identify their parents as a source of social support (67.0 percent) compared with youths aged 12 to 14 (76.3 percent). Smaller differences were also found for other factors, indicating that youths aged 15 to 17 reported less parental monitoring, less parental encouragement, and less communication from parents about the dangers of drug use compared with youths aged 12 to 14. Perceptions of parental attitudes toward substance use were approximately equal between youths aged 15 to 17 and youths aged 12 to 14.10

2.4 Peer/Individual Domain

Peer/individual domain factors included in the 1999 NHSDA included antisocial behavior, individual attitudes toward substance use, friends' attitudes toward substance use, friends' substance use, perceived risk of marijuana use, risk-taking proclivity, participation in extracurricular activities, and religiosity. The individual questions used to create these factors are presented in Table A.3, and the distributions of these items are presented in Table A.7 (see Appendix A). Summary statistics for each of these factors are presented in Table 2.3.

2.4.1 Antisocial Behavior

Antisocial behavior is a risk factor that focuses on criminal and violent activity by youths. This factor was measured using six items in which youths were asked how many times in the past 12 months they had gotten into a serious fight at school or at work, taken part in a fight where a group of their friends fought against another group, carried a handgun, sold illegal drugs, stolen or tried to steal anything worth more than $50, or attacked someone with the intent to seriously hurt them. The response options for these questions were 1 ("0 times"), 2 ("1 or 2 times"), 3 ("3 to 5 times"), 4 ("6 to 9 times"), or 5 ("10 or more times"). The mean score across the six items was 1.15, and the median was 1.00 (Table 2.3). As seen in Figure 2.7, 21.9 percent of youths reported getting into a serious fight at school or work at least once in the past year, 17.1 percent had taken part in a group-on-group fight at least once in the past year, and 8.4 percent had attacked someone with the intent of seriously injuring them at least once in the past year. Fewer than 5 percent of youths had carried a handgun, sold illegal drugs, or stolen/tried to steal anything worth more than $50 in the past year.

Figure 2.7 Percentages of Youths Aged 12 to 17 Who Engaged in Various Antisocial Behaviors One or More Times in the Past Year: 1999

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Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1999.

2.4.2 Individual Attitudes Toward Substance Use

Individual positive attitudes toward substance use constitute a risk factor that focuses on how youths feel about someone their age using marijuana, cigarettes, or alcohol. Youths were asked whether they would "strongly disapprove," "somewhat disapprove," or "neither approve nor disapprove" (scored 1, 2, and 3, respectively) if someone their age tried marijuana or hashish once or twice, smoked one or two packs of cigarettes per day, or had one or two drinks of an alcoholic beverage nearly every day (Table A.3). The mean score across the three substances was 1.55, which is between strongly disapprove and somewhat disapprove on the scale (Table 2.3). Nearly two out of three youths reported that they would strongly disapprove of youth use of marijuana (63.5 percent), alcohol (63.4 percent), or cigarettes (63.7 percent) (Figure 2.8).

Figure 2.8 Percentages of Youths Aged 12 to 17 Who Would Strongly Disapprove of Substance Use by Same-Aged Peers, by Substance: 1999

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Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1999.

2.4.3 Friends' Attitudes Toward Substance Use

Friends' attitudes toward substance use constitute a risk factor that focuses on youths' perceptions of how their close friends would feel if the respondent were to use marijuana, cigarettes, or alcohol. Youths were asked if they thought their close friends would "strongly disapprove," "somewhat disapprove," or " neither approve nor disapprove" (scored 1, 2, and 3, respectively) if the respondent tried marijuana or hashish once or twice, smoked one or two packs of cigarettes per day, or had one or two drinks of an alcoholic beverage nearly every day (Table A.3). The mean score across the three substances was 1.61, which is between strongly disapprove and somewhat disapprove on the scale (Table 2.3). More youths reported that their friends would strongly disapprove of their trying marijuana once or twice (63.2 percent) compared with daily alcohol use (59.6 percent) or daily cigarette use (57.5 percent) (Figure 2.9).

Figure 2.9 Percentages of Youths Aged 12 to 17 Whose Friends Would Strongly Disapprove of Youth Substance Use, by Substance: 1999

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Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1999.

2.4.4 Friends' Substance Use

Friends' substance use, a risk factor, was measured by asking youths how many of their friends used marijuana or hashish, smoked cigarettes, drank alcohol, or got drunk at least once a week. The response options were 1 ("none of them"), 2 ("a few of them"), 3 ("most of them"), or 4 ("all of them") (Table A.3). The mean score across the four questions was 1.69, which falls between none of them and some of them on the scale (Table 2.3). Among youths, 42.0 percent reported that at least a few of their friends used marijuana, with 11.7 percent reporting that most or all of their friends were marijuana users (Figure 2.10). Nearly 1 out of 4 youths reported that most or all of their friends used alcohol (23.0 percent), nearly 1 out of 5 reported that most or all of their friends used cigarettes (18.7 percent), and nearly 1 out of 10 reported that most or all of their friends get drunk at least once a week (8.8 percent).

Figure 2.10 Percentages of Youths Aged 12 to 17 Reporting Substance Use by Friends, by Substance: 1999

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Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1999.

2.4.5 Perceived Risk of Substance Use

Perceived risk of substance use (specifically, low perceived risk), a risk factor, was measured by asking youths how much people risk harming themselves physically and in other ways when they smoke marijuana once a month, smoke marijuana once or twice a week, smoke one or more packs of cigarettes per day, have four or five drinks every day, or have five or more drinks once or twice a week (Table A.3). The response options were 1 ("great risk"), 1 ("moderate risk"), 2 ("slight risk"), or 3 ("no risk"). The mean score was 1.70, indicating that on average youths believed there was between a moderate risk and great risk from using these substances (Table 2.3). More youths reported great risks from drinking four or five drinks nearly every day (63.6 percent), smoking one or more packs of cigarettes a day (60.7 percent), and using marijuana once or twice a week (56.5 percent) compared with using marijuana once a month (37.2 percent) or having five or more drinks of alcohol once or twice a week (42.0 percent) (Figure 2.11).

Figure 2.11 Percentages of Youths Aged 12 to 17 Who Perceived Great Risk of Substance Use, by Substance: 1999

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Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1999.

2.4.6 Risk-Taking Proclivity

Risk-taking proclivity, a risk factor, focuses on youths' tendencies to engage in high-risk activities. Youths were asked how often they get a real kick out of doing things that are a little dangerous, how often they test themselves by doing something a little risky, and how often they wear a seat belt when riding in the front passenger seat of a car (Table A.3). The response options were 1 ("always"), 2 ("often"), 3 ("seldom"), or 4 ("never").11 The mean score across the three items was 1.95, and the median score was 2.00, which indicates that on average youths sometimes engage in these behaviors (Table 2.3). Among youths, 40.5 percent reported that they sometimes or always get a real kick out of doing things that are a little dangerous, 33.5 percent sometimes or always test themselves by doing something a little risky, and 14.2 percent seldom or never wear a seatbelt when riding in the front passenger seat of a car (Table A.7).

2.4.7 Participation in Extracurricular Activities

Participation in extracurricular activities, a protective factor, was measured by asking youths to select which extracurricular activities they had participated in during the past 12 months (see Table A.3 for the list of possible activities). Among youths, 69.1 percent reported that they had participated in two or more extracurricular activities in the past 12 months (Table A.7).

2.4.8 Religiosity

Religiosity, a protective factor, focuses on the importance of religious beliefs to the respondent. Youths were asked how many times they had attended religious services in the past 12 months ("0 to 5 times," "6 to 24 times," "25 to 52 times," or "more than 52 times," scored 1, 2, 3, and 4, respectively) (Table A.3). Youths were also asked how much they agreed or disagreed that their religious beliefs are a very important part of their life, their religious beliefs influence how they make decisions in their life, and it is important that their friends share their religious beliefs. The response options for these last three questions were 1 ("strongly disagree"), 2 ("somewhat disagree"), 3 ("somewhat agree"), or 4 ("strongly agree"). The mean score across the four items was 2.62, and the median was 2.50 on the scale from 1 (low religiosity) to 4 (high religiosity). Figure 2.12 shows that 40.8 percent of youths reported they had attended church 0 to 5 times in the past 12 months, and 41.9 percent had attended church 25 or more times in the past 12 months. Most youths somewhat or strongly agreed that their religious beliefs are a very important part of their life (80.3 percent) and that religious beliefs influence how they make decisions in their life (72.7 percent). In contrast, only 36.6 percent of youths somewhat or strongly agreed that it is important that their friends share their religious beliefs.

Figure 2.12 Percentages of Youths Aged 12 to 17 with Different Responses to Religiosity Items: 1999

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Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1999.

2.4.9 Peer/Individual Factors, by Race/Ethnicity, Gender, and Age

Summary statistics for peer/individual factors are presented by racial/ethnic group, gender, and age in Table 2.7.12 Among youths, whites were the most likely to report participating in two or more extracurricular activities (72.2 percent), followed by blacks (68.3 percent), the "other" category (67.5 percent), and Hispanics (55.2 percent). Scores were approximately equal between racial/ethnic groups on the antisocial behavior, individual attitudes toward substance use, friends' attitudes toward substance use, friends' substance use, perceived risk of substance use, risk-taking proclivity, and religiosity measures.

Compared with females, male youths reported that their friends had more positive attitudes toward substance use (mean = 1.70 for males and 1.52 for females), lower perceived risk of substance use (mean = 1.78 for males and 1.62 for females), and higher risk-taking proclivity (mean = 2.06 for males and 1.83 for females). Males were also less likely than females to have participated in two or more extracurricular activities (65.4 vs. 72.9 percent). No notable differences were found between males and females on other measures (i.e., antisocial behavior, individual attitudes toward substance use, friends' substance use, and religiosity).

Compared with youths aged 12 to 14, youths aged 15 to 17 reported more positive attitudes toward substance use, more positive attitudes toward substance use among their close friends, higher substance use among their friends, lower perceived risk of marijuana use, and less participation in extracurricular activities.

2.5 School Domain

School domain factors included in the 1999 NHSDA included commitment to school, sanctions against substance use at school, perceived prevalence of substance use at school, academic performance, and exposure to prevention messages at school.13 The individual questions used to create these factors are presented in Table A.4, and the distributions of these items are presented in Table A.8 (see Appendix A). Summary statistics for each of these factors are presented in Table 2.4.

2.5.1 Commitment to School

Commitment to school, a protective factor, focuses on youths' beliefs and feelings about attending school. Youths were asked how much they liked going to school in the past 12 months, how often they felt the schoolwork they had been assigned in the past 12 months was meaningful and important, how important they thought the things they had learned in school in the past 12 months were going to be to them later in life, and how interesting the courses they took during the past 12 months had been. (Table A.4) presents the response options for these questions; all responses were coded so that 1 represented the lowest level of commitment and 4 represented the highest level of commitment.) The mean score across the four items was 3.06 on the scale from 1 (low commitment) to 4 (high commitment), which indicates that youths felt a fairly high commitment to school (Table 2.4). Among youths, 80.2 percent reported that they liked or kind of liked going to school, 78.0 percent sometimes or always felt their schoolwork was meaningful and important, 86.2 reported that they felt the things they have learned in school will be somewhat or very important to them later in life, and 74.9 percent reported that most of their courses at school have been somewhat interesting or very interesting (Figure 2.13).

Figure 2.13 Percentages of Youths Aged 12 to 17 with Different Responses to Commitment to School Items: 1999

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Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1999.

2.5.2 Sanctions Against Substance Use

Sanctions against substance use constitute a protective factor focusing on punishment for substance use in a youth's school. Youths were asked how much trouble a student in their grade would be in if he or she was caught using an illegal drug, smoking a cigarette, or drinking an alcoholic beverage (Table A.4). Response options were 1 ("no trouble at all"), 2 ("a little trouble"), or 3 ("a lot of trouble"). The mean score across the three substances was 2.79, and the median was 3.00, indicating that youths believed the students in their grades would be in a lot of trouble if they were caught using these substances at school (Table 2.4). More youths indicated that they would be in a lot of trouble for using an illegal drug (95.1 percent) or drinking alcohol (85.7 percent) in school compared with smoking cigarettes (62.8 percent) (Figure 2.14).

Figure 2.14 Percentages of Youths Aged 12 to 17 Reporting That Youths Would Get in a Lot of Trouble for Substance Use in School, by Substance: 1999

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Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1999.

2.5.3 Perceived Prevalence of Substance Use

Perceived prevalence of substance use in school, a risk factor, was measured by asking youths how many students in their grade at school used marijuana or hashish, smoked cigarettes, drank alcohol, or got drunk at least once a week (Table A.4). The response options were 1 ("none of them"), 2 ("a few of them"), 3 ("most of them"), or 4 ("all of them"). The mean score across the four questions was 2.10, and the median score was 2.00, which represents "a few of them" on the scale (Table 2.4). More youths reported that most or all of the students in their grade at school used cigarettes (40.0 percent) or alcohol (41.2 percent) than used marijuana (23.4 percent) or got drunk at least once a week (17.3 percent) (Figure 2.15).

Figure 2.15 Percentages of Youths Aged 12 to 17 Reporting Substance Use by Students in Their Grade, by Substance: 1999

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Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1999.

2.5.4 Academic Performance

Poor academic performance, a risk factor, was measured by asking youths to report their grades in the last semester that they had completed (Table A.4). Approximately 29 percent of youths who attended schools that give letter grades reported receiving grades of "C" or below in the past semester (Table 2.4).14

2.5.5 Exposure to Prevention Messages in School

Exposure to substance abuse prevention messages in school, a protective factor, was measured by asking youths whether in the past 12 months they had received any of the following three types of prevention messages in school: a special class about drugs or alcohol; films, lectures, discussions, or printed information about drugs or alcohol in one of their regular classes, such as health or physical education; or films, lectures, discussions, or printed information about drugs or alcohol outside one of their regular classes, such as in special assemblies (Table A.4). Among youths, 77.4 percent reported that they had been exposed to at least one of these types of prevention messages in school (Table 2.4).

2.5.6 School Factors, by Race/Ethnicity, Gender, and Age

Summary statistics for school factors are presented by racial/ethnic group, gender, and age in Table 2.8.15 Among youths, whites reported lower commitment to school (mean = 2.99) compared with blacks (mean = 3.24), Hispanics (mean = 3.20), or youths in the "other" category (mean = 3.21). Among youths, 25.8 percent of whites and 21.7 percent of those in the "other" category received grades of "C" or below in their last completed semester compared with 37.0 percent of blacks and 36.9 percent of Hispanics. Black and Hispanic youths were also less likely to report exposure to prevention messages in school (73.5 and 74.6 percent, respectively) compared with whites (78.6 percent) and those in the "other" category (78.7 percent). Scores were not notably different between different racial/ethnic groups for sanctions against substance use or perceived prevalence of substance use.

Among youths, 34.0 percent of males had received grades of "C" or below in the past semester compared with 23.0 percent of females. Males were also less likely than females to report having been exposed to prevention messages at school (74.3 vs. 80.7 percent). Scores were not notably different between males and females on commitment to school, sanctions against substance use, or perceived prevalence of substance use.

Youths aged 15 to 17 reported less severe sanctions against substance use in school (mean = 2.70) compared with youths aged 12 to 14 (mean = 2.89). This difference was primarily found for sanctions related to smoking cigarettes. Older youths also reported higher prevalence of substance use among students in their grade, lower academic performance, and less exposure to prevention messages in school compared with youths aged 12 to 14.

Table 2.1 Means or Percentages, Standard Deviations, and Quartiles of Youths Aged 12 to 17 Reporting Community Domain Risk and Protective Factors: 1999

Community Domain1 Risk/
Protective
Factors
Number
of Items
Sample
Size
Scale
Range
Mean or
Percentage2
Standard
Deviation
Quartiles Cronbach's
Alpha
Reliability3
25% 50% 75%
Community Disorganization and Crime Risk 6 25,108 1–44 1.65 0.63 1.17 1.50 2.00 0.79
Neighborhood Cohesiveness Protective 2 25,021 1–44 2.99 0.76 2.50 3.00 3.50 0.55
Community Attitudes Toward Substance Use Risk                  
     Multiple substance scale5   3 24,508 1–36 1.42 0.62 1.00 1.00 1.67 0.84
     Marijuana (trying once or twice)   1 24,473 1–36 1.31 0.65 1.00 1.00 1.00
     Cigarettes (1 or more packs a day)   1 24,386 1–36 1.52 0.77 1.00 1.00 2.00
     Alcohol (1 or 2 drinks every day)   1 24,493 1–36 1.43 0.71 1.00 1.00 2.00
Community Norms Toward Substance Use Risk                  
     Multiple substance scale5   4 25,100 1–47 1.88 0.50 1.50 1.75 2.25 0.70
     Marijuana   1 24,667 1–47 1.33 0.58 1.00 1.00 2.00
     Cigarettes   1 25,104 1–47 2.20 0.66 2.00 2.00 3.00
     Alcohol   2 24,525 1–47 1.98 0.63 1.50 2.00 2.50 0.56
Availability of Illicit Drugs Risk                  
     Marijuana   1 24,405 1–58 3.41 1.47 2.00 4.00 5.00
     LSD   1 23,473 1–58 2.46 1.31 1.00 2.00 3.00
     Cocaine   1 23,829 1–58 2.55 1.35 1.00 2.00 4.00
     Crack   1 23,871 1–58 2.57 1.37 1.00 2.00 4.00
     Heroin   1 23,706 1–58 2.23 1.26 1.00 2.00 3.00
Exposed to Prevention Messages in the Media Protective 1 25,037 Yes=82.3% 0.32
1 Specific questions and distributions for community domain constructs are presented in Tables A.1 and A.5 (see Appendix A).
2 Means are given for continuous variables, and percentages are given for categorical variables (marked with a percent sign).
3 Cronbach's alpha is a measure of the internal consistency of the individual items used to create multiple-item scales and is a function of the average intercorrelation between the items as well as the number of items. Cronbach's alpha values range from 0 (no correlation between items) and 1 (perfect correlation between items).
4 Response options were 1 = Strongly disagree, 2 = Somewhat disagree, 3 = Somewhat agree, and 4 = Strongly agree.
5 Multiple substance scales take the mean of responses for marijuana, cigarette, and alcohol use.
6 Response options were 1 = Strongly disapprove, 2 = Somewhat disapprove, and 3 = Neither approve nor disapprove.
7 Response options were 1 = None, 2 = Some, 3 = Most, and 4 = All.
8 Response options were 1 = Probably impossible, 2 = Very difficult, 3 = Somewhat difficult, 4 = Somewhat easy, and 5 = Very easy.

Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1999.

Table 2.2 Means or Percentages, Standard Deviations, and Quartiles of Youths Aged 12 to 17 Reporting Family Domain Risk and Protective Factors: 1999

Family Domain1 Risk/Protective Factors Number of Items Sample Size Scale Range Mean or Percentage2 Standard Deviation Quartiles Cronbach's Alpha Reliability3
25% 50% 75%
Parental Monitoring Risk 5 19,262 1–44 2.00 0.60 1.60 2.00 2.40 0.62
Parental Encouragement Protective 2 25,163 1–45 3.34 0.77 3.00 3.50 4.00 0.86
Parental Attitudes Toward Substance Use Risk                  
     Multiple substance scale6   3 24,972 1–37 1.16 0.41 1.00 1.00 1.00 0.83
     Marijuana (try once or twice)   1 24,949 1–37 1.14 0.46 1.00 1.00 1.00
     Cigarettes (1 or more packs a day)   1 24,938 1–37 1.19 0.53 1.00 1.00 1.00
     Alcohol (1 or 2 drinks a day)   1 24,960 1–37 1.15 0.46 1.00 1.00 1.00
Parents Communicate About Substance Use Protective 1 24,994 Yes=57.4% 0.40
Parents Are Source of Social Support Protective Checklist 25,051 Yes=71.7% 0.35
1 Specific questions and distributions for family domain constructs are presented in Tables A.2 and A.6 (see Appendix A).
2 Means are given for continuous variables, and percentages are given for categorical variables (marked with a percent sign).
3 Cronbach's alpha is a measure of the internal consistency of the individual items used to create multiple-item scales and is a function of the average intercorrelation between the items as well as the number of items. Cronbach's alpha values range from 0 (no correlation between items) and 1 (perfect correlation between items).
4 Response options were 1 = Always, 2 = Sometimes, 3 = Seldom, and 4 = Never.
5 Response options were 1 = Never, 2 = Seldom, 3 = Sometimes, and 4 = Always.
6 Multiple substance scales take the mean of responses for marijuana, cigarette, and alcohol use.
7 Response options were 1 = Strongly disapprove, 2 = Somewhat disapprove, and 3 = Neither approve nor disapprove.

Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1999.

Table 2.3 Means or Percentages, Standard Deviations, and Quartiles of Youths Aged 12 to 17 Reporting Peer/Individual Domain Risk and Protective Factors: 1999

Peer/Individual Domain1 Risk/Protective Factors Number of Items Sample Size Scale Range Mean or Percentage2 Standard Deviation Quartiles Cronbach's Alpha Reliability3
25% 50% 75%
Antisocial Behavior Risk 6 25,170 1–54 1.15 0.33 1.00 1.00 1.17 0.74
Individual Attitudes Toward Substance Use Risk                  
     Multiple substance scale5   3 25,967 1–36 1.55 0.70 1.00 1.00 2.00 0.87
     Marijuana (try once or twice)   1 24,938 1–36 1.57 0.78 1.00 1.00 2.00
     Cigarettes (1 or more packs a day)   1 24,955 1–36 1.55 0.81 1.00 1.00 2.00
     Alcohol (1 or 2 drinks a day)   1 24,953 1–36 1.55 0.78 1.00 1.00 2.00
Friends' Attitudes Toward Substance Use Risk                  
     Multiple substance scale5   3 24,847 1–36 1.61 0.73 1.00 1.33 2.00 0.89
     Marijuana (try once or twice)   1 24,833 1–36 1.58 0.81 1.00 1.00 2.00
     Cigarettes (1 or more packs a day)   1 24,829 1–36 1.65 0.81 1.00 1.50 2.00
     Alcohol (1 or 2 drinks a day)   1 24,824 1–36 1.61 0.81 1.00 1.00 2.00
Friends' Substance Use Risk                  
     Multiple substance scale5   4 24,940 1–47 1.69 0.67 1.00 1.50 2.00 0.88
     Marijuana   1 24,798 1–47 1.56 0.75 1.00 1.00 2.00
     Cigarettes   1 24,953 1–47 1.84 0.79 1.00 2.00 2.00
     Alcohol   2 24,646 1–47 1.68 0.73 1.00 1.50 2.00 0.82
Perceived Risk of Substance Use Risk                  
     Multiple substance scale5   5 24,910 1–48 1.70 0.60 1.20 1.60 2.00 0.84
     Marijuana   2 24,547 1–48 1.83 0.85 1.00 1.50 2.50 0.84
     Cigarettes   1 24,780 1–48 1.51 0.73 1.00 1.00 2.00
     Alcohol   2 24,790 1–48 1.66 0.70 1.00 1.50 2.00 0.73
Risk-Taking Proclivity Risk 3 25,169 1–48 1.95 0.66 1.33 2.00 2.33 0.59
Participation in Two or More Extracurricular Activities Protective Checklist 25,216 Yes=69.1% 0.38
Religiosity Protective 4 25,117 1–49 2.63 0.73 2.00 2.50 3.25 0.77
1 Specific questions and distributions for peer/individual domain constructs are presented in Tables A.3 and A.7 (see Appendix A).
2 Means are given for continuous variables, and percentages are given for categorical variables (marked with a percent sign).
3 Cronbach's alpha is a measure of the internal consistency of the individual items used to create multiple-item scales and is a function of the average intercorrelation between the items as well as the number of items. Cronbach's alpha values range from 0 (no correlation between items) and 1 (perfect correlation between items).
4 Response options were 1 = 0 times, 2 = 1 or 2 times, 3 = 3 to 5 times, 4 = 6 to 9 times, and 5 = 10 or more times.
5 Multiple substance scales take the mean of responses for marijuana, cigarette, and alcohol use.
6 Response options were 1 = Strongly disapprove, 2 = Somewhat disapprove, and 3 = Neither approve nor disapprove.
7 Response options were 1 = None, 2 = Some, 3 = Most, and 4 = All.
8 Response options were 1 = Great risk, 2 = Moderate risk, 3 = Slight risk, and 4 = No risk.
9 Response options for number of times attending religious services in the past 12 months were 1 = 0 to 5 times, 2 = 6 to 24 times, 3 = 25 to 52 times, and 4 = More than 52 times. For other items, response options were 1 = Strongly disagree, 2 = Somewhat disagree, 3 = Somewhat agree, and 4 = Strongly agree.

Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1999.

Table 2.4 Means or Percentages, Standard Deviations, and Quartiles of Youths Aged 12 to 17 Reporting School Domain Risk and Protective Factors: 1999

School Domain1 Risk/Protective Factors Number of Items Sample Size Scale Range Mean or Percentage2 Standard Deviation Quartiles Cronbach's Alpha Reliability3
25% 50% 75%
Commitment to School Protective 4 19,290 1–44 3.06 0.62 2.75 3.00 3.50 0.78
Sanctions Against Substance Use at School Protective                  
     Multiple substance scale5   3 19,157 1–36 2.79 0.33 2.67 3.00 3.00 0.70
     Illegal drugs   1 19,173 1–36 2.94 0.28 3.00 3.00 3.00
     Cigarettes   1 19,125 1–36 2.58 0.57 2.00 3.00 3.00
     Alcohol   1 19,139 1–36 2.84 0.40 3.00 3.00 3.00
Perceived Prevalence of Substance Use Risk                  
     Multiple substance scale5   4 18,765 1–47 2.10 0.64 1.75 2.00 2.50 0.89
     Marijuana   1 18,488 1–47 1.99 0.73 1.00 2.00 2.00
     Cigarettes   1 18,888 1–47 2.29 0.71 2.00 2.00 3.00
     Alcohol   2 18,229 1–47 2.05 0.71 1.50 2.00 2.50 0.83
Academic Performance Risk 1 18,976  
     A+ / A / A-         28.5% 0.47        
     B+ / B / B-         41.5% 0.48        
     C+ / C / C-         22.2% 0.40        
     D / less than D average         5.9% 0.22        
     School does not give such grade          2.0% 0.14        
Exposed to Prevention Messages in School Protective 3 19,510 Yes=77.4% 0.38
1 Specific questions and distributions for school domain constructs are presented in Tables A.4 and A.8 (see Appendix A).
2 Means are given for continuous variables, and percentages are given for categorical variables (marked with a percent sign).
3 Cronbach's alpha is a measure of the internal consistency of the individual items used to create multiple-item scales and is a function of the average intercorrelation between the items as well as the number of items. Cronbach's alpha values range from 0 (no correlation between items) and 1 (perfect correlation between items).
4 Response options for overall feelings toward school were 1 = Hated going to school, 2 = Didn't like going to school, 3 = Kind of liked going to school, and 4 = Liked going to school. Response options for belief about the meaningfulness and importance of school work were 1 = Never, 2 = Seldom, 3 = Sometimes, and 4 = Always. Response options for importance of school work to later life were 1 = Very unimportant, 2 = Somewhat unimportant, 3 = Somewhat important, and 4 = Very important. Response options for interest in courses at school were 1 = Very boring, 2 = Somewhat boring, 3 = Somewhat interesting, and 4 = Very interesting.
5 Multiple substance scales take the mean of responses for marijuana, cigarette, and alcohol use.
6 Response options were 1 = Strongly disapprove, 2 = Somewhat disapprove, and 3 = Neither approve nor disapprove.
7 Response options were 1 = None, 2 = Some, 3 = Most, and 4 = All.

Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1999.

Table 2.5 Means or Percentages and Standard Deviations of Community Domain Risk and Protective Factors among Youths Aged 12 to 17, by Race/Ethnicity, Gender, and Age: 1999

Community Domain Race/Ethnicity Gender Age in Years
Mean or Percentage1
(Standard Deviation)
p value3 Mean or Percentage1
(Standard Deviation)
p value4 Mean or Percentage1
(Standard Deviation)
p value4
White Black Hispanic Other2 Males Females 12–14 15–17
Community Disorganization and Crime 1.55
(0.55)
1.97
(0.78)
1.83
(0.69)
1.67
(0.63)
<.0001 1.67
(0.64)
1.64
(0.61)
 .0006 1.65
(0.63)
1.66
(0.63)
 ..0782
Neighborhood Cohesiveness 3.07
(0.73)
2.85
(0.82)
2.80
(0.79)
2.90
(0.75)
<.0001 2.97
(0.76)
3.01
(0.76)
<.0001 3.05
(0.74)
2.93
(0.78)
<.0001
Community Attitudes Toward Substance Use                      
     Multiple substance scale5 1.37
(0.56)
1.50
(0.71)
1.57
(0.71)
1.42
(0.65)
<.0001 1.43
(0.62)
1.41
(0.61)
 .0057 1.30
(0.54)
1.54
(0.66)
<.0001
     Marijuana (trying once or twice) 1.26
(0.58)
1.43
(0.77)
1.46
(0.76)
1.31
(0.68)
<.0001 1.32
(0.65)
1.30
(0.64)
 .0224 1.22
(0.56)
1.40
(0.71)
<.0001
     Cigarettes (1+ pack per day) 1.47
(0.73)
1.60
(0.83)
1.65
(0.84)
1.53
(0.80)
<.0001 1.52
(0.76)
1.52
(0.77)
 .8837 1.35
(0.67)
1.68
(0.82)
<.0001
     Alcohol (1 or 2 drinks every day) 1.38
(0.66)
1.49
(0.78)
1.61
(0.80)
1.42
(0.73)
<.0001 1.45
(0.72)
1.40
(0.70)
<.0001 1.32
(0.63)
1.53
(0.76)
<.0001
Community Norms Toward Substance Use                      
     Multiple substance scale5 1.88
(0.48)
1.93
(0.57)
1.86
(0.53)
1.77
(0.52)
<.0001 1.88
(0.50)
1.88
(0.50)
 .6461 1.80
(0.47)
1.96
(0.52)
<.0001
     Marijuana 1.31
(0.55)
1.49
(0.70)
1.34
(0.60)
1.24
(0.55)
<.0001 1.33
(0.58)
1.33
(0.58)
 .8472 1.22
(0.50)
1.44
(0.63)
<.0001
     Cigarettes 2.22
(0.65)
2.26
(0.70)
2.08
(0.67)
2.10
(0.67)
<.0001 2.18
(0.65)
2.22
(0.66)
<.0001 2.16
(0.65)
2.24
(0.67)
<.0001
     Alcohol 1.99
(0.60)
1.98
(0.71)
1.99
(0.66)
1.86
(0.62)
<.0001 1.98
(0.63)
1.97
(0.62)
 .2483 1.89
(0.60)
2.06
(0.64)
<.0001
Availability of Illicit Drugs 3.45
(1.43)
3.41
(1.56)
3.34
(1.50)
3.05
(1.50)
<.0001 3.42
(1.48)
3.41
(1.45)
 .5653 2.82
(1.45)
3.99
(1.22)
<.0001
Exposed to Prevention Messages in the Media 83.5%
(0.35)
78.3%
(0.94)
78.7%
(0.91)
86.2%
(1.50)
<.0001 80.0%
(0.45)
84.6%
(0.42)
<.0001 82.3%
(0.44)
82.2%
(0.44)
 .8892
Note: Care should be taken in interpreting statistically significant differences in this table. With large sample sizes, very small differences between groups can reach statistical significance.
1 Means are given for continuous variables, and percentages are given for categorical variables (marked with a percent sign).
2 "Other" includes those other than whites, blacks, and Hispanics (i.e., Asians, American Indians or Alaska Natives, or Native Hawaiians or other Pacific Islanders).
3 p value derived from F-tests for continuous variables and chi-square tests (df = 3) for dichotomous variables.
4 p values derived from t-tests for continuous variables and chi-square tests (df = 1) for dichotomous variables.
5 Multiple substance scales take the mean of responses for marijuana, cigarette, and alcohol use.

Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1999.

Table 2.6 Means or Percentages and Standard Deviations of Family Domain Risk and Protective and Protective Factors among Youths Aged 12 to 17, by Race/Ethnicity, Gender, and Age: 1999

Family Domain Race/Ethnicity Gender Age in Years
Mean or Percentage1
(Standard Deviation)
p value3 Mean or Percentage1
(Standard Deviation)
p value4 Mean or Percentage1
(Standard Deviation)
p value4
White Black Hispanic Other2 Males Females 12–14 15–17
Parental Monitoring 2.02
(0.60)
1.94
(0.60)
2.01
(0.61)
2.00
(0.62)
<.0001 2.02
(0.60)
1.99
(0.60)
 .0077 1.85
(0.54)
2.14
(0.61)
<.0001
Parental Encouragement 3.37
(0.75)
3.31
(0.81)
3.27
(0.82)
3.20
(0.83)
<.0001 3.34
(0.77)
3.34
(0.78)
 .7953 3.43
(0.72)
3.25
(0.81)
<.0001
Parental Attitudes Toward Substance Use                      
     Multiple substance scale5 1.14
(0.38)
1.22
(0.52)
1.18
(0.46)
1.16
(0.47)
<.0001 1.17
(0.44)
1.14
(0.39)
<.0001 1.12
(0.38)
1.20
(0.45)
<.0001
     Marijuana (try once or twice) 1.12
(0.43)
1.20
(0.55)
1.15
(0.49)
1.14
(0.50)
<.0001 1.15
(0.48)
1.12
(0.44)
<.0001 1.10
(0.41)
1.17
(0.50)
<.0001
     Cigarettes (1 or more packs a day) 1.18
(0.51)
1.25
(0.61)
1.19
(0.55)
1.18
(0.56)
<.0001 1.20
(0.54)
1.18
(0.52)
 .0072 1.13
(0.46)
1.25
(0.59)
<.0001
     Alcohol (1 or 2 drinks a day) 1.13
(0.42)
1.19
(0.55)
1.19
(0.52)
1.15
(0.51)
<.0001 1.17
(0.48)
1.13
(0.43)
<.0001 1.12
(0.41)
1.18
(0.50)
<.0001
Parents Communicate About Substance Use 59.9%
(0.47)
47.3%
(1.15)
57.9%
(1.07)
51.1%
(2.01)
<.0001 55.0%
(0.55)
60.0%
(0.55)
<.0001 58.8%
(0.55)
55.9%
(0.56)
 .0168
Parents Are Source of Social Support 72.8%
(0.42)
71.5%
(1.00)
69.2%
(1.03)
64.3%
(1.99)
 .0018 72.5%
(0.50)
70.8%
(0.52)
 .1271 76.3%
(0.49)
67.0%
(0.54)
<.0001
Note: Care should be taken in interpreting statistically significant differences in this table. With large sample sizes, very small differences between groups can reach statistical significance.
1 Means are given for continuous variables, and percentages are given for categorical variables (marked with a percent sign).
2 "Other" includes those other than whites, blacks, and Hispanics (i.e., Asians, American Indians or Alaska Natives, or Native Hawaiians or other Pacific Islanders).
3 p value derived from F-tests for continuous variables and chi-square tests (df = 3) for dichotomous variables.
4 p values derived from t-tests for continuous variables and chi-square tests (df = 1) for dichotomous variables.
5 Multiple substance scales take the mean of responses for marijuana, cigarette, and alcohol use.

Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1999.

Table 2.7 Means or Percentages and Standard Deviations of Peer/Individual Domain Risk and Protective Factors among Youths Aged 12 to 17, by Race/Ethnicity, Gender, and Age: 1999

Peer/Individual Domain Race/Ethnicity Gender Age in Years
Mean or Percentage1
(Standard Deviation)
p value3 Mean or Percentage1
(Standard Deviation)
p value4 Mean or Percentage1
(Standard Deviation)
p value4
White Black Hispanic Other2 Males Females 12–14 15–17
Antisocial Behavior 1.14
(0.32)
1.17
(0.37)
1.17
(0.39)
1.11
(0.32)
<.0001 1.19
(0.40)
1.10
(0.24)
<.0001 1.13
(0.29)
1.16
(0.38)
<.0001
Individual Attitudes Toward Substance Use                      
     Multiple substance scale5 1.55
(0.70)
1.55
(0.73)
1.59
(0.72)
1.48
(0.71)
 .0047 1.61
(0.74)
1.50
(0.67)
<.0001 1.40
(0.63)
1.71
(0.74)
<.0001
     Marijuana (try once or twice) 1.57
(0.80)
1.57
(0.83)
1.59
(0.81)
1.50
(0.80)
 .0116 1.62
(0.82)
1.52
(0.79)
<.0001 1.37
(0.69)
1.77
(0.87)
<.0001
     Cigarettes (1 or more packs a day) 1.55
(0.78)
1.55
(0.80)
1.58
(0.80)
1.48
(0.77)
 .0010 1.59
(0.80)
1.50
(0.76)
<.0001 1.41
(0.71)
1.68
(0.83)
<.0001
     Alcohol (1 or 2 drinks a day) 1.55
(0.78)
1.54
(0.80)
1.60
(0.80)
1.47
(0.77)
<.0001 1.62
(0.81)
1.47
(0.75)
<.0001 1.41
(0.70)
1.69
(0.83)
<.0001
Friends' Attitudes Toward Substance Use                      
     Multiple substance scale5 1.62
(0.73)
1.62
(0.76)
1.61
(0.74)
1.51
(0.72)
 .1521 1.70
(0.76)
1.52
(0.69)
<.0001 1.43
(0.65)
1.79
(0.76)
<.0001
     Marijuana (try once or twice) 1.58
(0.81)
1.60
(0.83)
1.57
(0.81)
1.48
(0.80)
 .0002 1.65
(0.84)
1.50
(0.79)
<.0001 1.37
(0.69)
1.78
(0.87)
<.0001
     Cigarettes (1 or more packs a day) 1.65
(0.82)
1.66
(0.84)
1.63
(0.82)
1.53
(0.80)
<.0001 1.73
(0.84)
1.56
(0.79)
<.0001 1.48
(0.73)
1.81
(0.86)
<.0001
     Alcohol (1 or 2 drinks a day) 1.61
(0.80)
1.60
(0.81)
1.62
(0.81)
1.52
(0.80)
 .0003 1.71
(0.76)
1.50
(0.83)
<.0001 1.44
(0.72)
1.77
(0.85)
<.0001
Friends' Substance Use                      
     Multiple substance scale5 1.70
(0.67)
1.61
(0.64)
1.72
(0.69)
1.60
(0.68)
<.0001 1.68
(0.67)
1.69
(0.67)
 .3779 1.42
(0.54)
1.96
(0.68)
<.0001
     Marijuana 1.55
(0.74)
1.57
(0.79)
1.63
(0.78)
1.47
(0.75)
<.0001 1.57
(0.76)
1.54
(0.75)
 .0073 1.31
(0.59)
1.80
(0.81)
<.0001
     Cigarettes 1.87
(0.80)
1.74
(0.76)
1.81
(0.77)
1.74
(0.82)
<.0001 1.83
(0.78)
1.84
(0.81)
 .2940 1.59
(0.71)
2.08
(0.79)
<.0001
     Alcohol 1.70
(0.73)
1.56
(0.68)
1.71
(0.74)
1.58
(0.70)
<.0001 1.67
(0.73)
1.69
(0.72)
 .0173 1.39
(0.57)
1.97
(0.75)
<.0001
Perceived Risk of Substance Use                      
     Multiple substance scale5 1.69
(0.57)
1.70
(0.67)
1.74
(0.64)
1.69
(0.65)
 .0015 1.78
(0.63)
1.62
(0.56)
<.0001 1.64
(0.58)
1.76
(0.61)
<.0001
     Marijuana 1.81
(0.82)
1.91
(0.92)
1.89
(0.88)
1.83
(0.88)
<.0001 1.90
(0.90)
1.76
(0.80)
<.0001 1.68
(0.77)
1.98
(0.89)
<.0001
     Cigarettes 1.50
(0.68)
1.56
(0.86)
1.54
(0.78)
1.53
(0.76)
<.0001 1.57
(0.76)
1.45
(0.69)
<.0001 1.52
(0.74)
1.51
(0.72)
 .0336
     Alcohol 1.68
(0.68)
1.57
(0.75)
1.68
(0.73)
1.62
(0.74)
<.0001 1.76
(0.75)
1.56
(0.64)
<.0001 1.65
(0.70)
1.68
(0.71)
 .0009
Risk-Taking Proclivity 2.00
(0.66)
1.80
(0.65)
1.88
(0.67)
1.80
(0.65)
<.0001 2.06
(0.68)
1.83
(0.63)
<.0001 1.87
(0.65)
2.05
(0.67)
<.0001
Participated in Two or More Extracurricular Activities 72.2%
(0.45)
68.3%
(1.09)
55.2%
(1.08)
67.5%
(1.87)
<.0001 65.4%
(0.54)
72.9%
(0.50)
<.0001 72.4%
(0.50)
65.7%
(0.55)
<.0001
Religiosity 2.60
(0.75)
2.75
(0.69)
2.62
(0.66)
2.56
(0.70)
<.0001 2.57
(0.74)
2.69
(0.72)
<.0001 2.70
(0.71)
2.55
(0.75)
<.0001
Note: Care should be taken in interpreting statistically significant differences in this table. With large sample sizes, very small differences between groups can reach statistical significance.
1 Means are given for continuous variables, and percentages are given for categorical variables (marked with a percent sign).
2 "Other" includes those other than whites, blacks, and Hispanics (i.e., Asians, American Indians or Alaska Natives, or Native Hawaiians or other Pacific Islanders).
3 p value derived from F-tests for continuous variables and chi-square tests (df = 3) for dichotomous variables.
4 p values derived from t-tests for continuous variables and chi-square tests (df = 1) for dichotomous variables.
5 Multiple substance scales take the mean of responses for marijuana, cigarette, and alcohol use.

Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1999.

Table 2.8 Means or Percentages and Standard Deviations of School Domain Risk and Protective and Factors among Youths Aged 12 to 17, by Race/Ethnicity, Gender, and Age: 1999

School Domain Race/Ethnicity Gender Age in Years
Mean or Percentage1
(Standard Deviation)
p value3 Mean or Percentage1
(Standard Deviation)
p value4 Mean or Percentage1
(Standard Deviation)
p value4
White Black Hispanic Other2 Males Females 12–14 15–17
Commitment to School 2.99
(0.62)
3.24
(0.57)
3.20
(0.60)
3.21
(0.58)
<.0001 3.00
(0.64)
3.12
(0.59)
<.0001 3.12
(0.61)
3.00
(0.63)
 .0002
Sanctions Against Substance Use at School                      
     Multiple substance scale5 2.78
(0.33)
2.80
(0.35)
2.80
(0.36)
2.83
(0.33)
 .0012 2.79
(0.34)
2.79
(0.32)
 .6345 2.89
(0.27)
2.70
(0.36)
<.0001
     Illegal drugs 2.94
(0.27)
2.93
(0.30)
2.92
(0.33)
2.96
(0.27)
 .0008 2.93
(0.29)
2.95
(0.27)
 .0004 2.96
(0.23)
2.92
(0.32)
<.0001
     Cigarettes 2.57
(0.57)
2.63
(0.56)
2.62
(0.59)
2.65
(0.55)
<.0001 2.59
(0.58)
2.58
(0.57)
 .1510 2.80
(0.23)
2.40
(0.32)
<.0001
     Alcohol 2.84
(0.40)
2.84
(0.42)
2.84
(0.42)
2.87
(0.39)
 .1588 2.84
(0.41)
2.85
(0.39)
 .3846 2.90
(0.33)
2.80
(0.45)
<.0001
Perceived Prevalence of Substance Use                      
     Multiple substance scale5 2.11
(0.63)
2.08
(0.68)
2.08
(0.68)
1.98
(0.66)
<.0001 2.05
(0.64)
2.15
(0.64)
<.0001 1.75
(0.58)
2.39
(0.54)
<.0001
     Marijuana 1.98
(0.70)
2.07
(0.84)
2.03
(0.78)
1.89
(0.73)
<.0001 1.96
(0.73)
2.02
(0.74)
<.0001 1.65
(0.67)
2.27
(0.66)
<.0001
     Cigarettes 2.31
(0.70)
2.29
(0.76)
2.23
(0.74)
2.16
(0.72)
<.0001 2.23
(0.71)
2.34
(0.71)
<.0001 2.00
(0.70)
2.53
(0.62)
<.0001
     Alcohol 2.08
(0.69)
1.98
(0.74)
2.04
(0.74)
1.94
(0.73)
<.0001 2.00
(0.70)
2.11
(0.71)
<.0001 1.67
(0.62)
2.37
(0.61)
<.0001
Academic Performance                      
     A+ / A / A- 32.1%
(0.57)
16.4%
(1.02)
20.2%
(1.18)
40.5%
(2.56)
<.0001 23.9%
(0.61)
34.4%
(0.68)
<.0001 32.9%
(0.68)
25.7%
(0.59)
<.0001
     B+ / B / B- 42.1%
(0.55)
44.6%
(1.36)
42.9%
(1.44)
38.0%
(2.33)
42.1%
(0.64)
42.5%
(0.69)
41.5%
(0.70)
43.0%
(0.62)
     C+ / C / C- 20.1%
(0.45)
32.6%
(1.18)
28.8%
(1.27)
18.0%
(1.77)
26.3%
(0.60)
18.8%
(0.53)
20.1%
(0.56)
24.8%
(0.56)
     D / less than D average 5.7%
(0.25)
6.4%
(0.61)
8.1%
(0.71)
3.7%
(0.81)
7.7%
(0.35)
4.2%
(0.26)
5.4%
(0.32)
6.5%
(0.31)
Exposed to Prevention Messages in School 78.6%
(0.43)
73.5%
(1.13)
74.6%
(1.11)
78.7%
(1.85)
 .0067 74.3%
(0.54)
80.7%
(0.52)
<.0001 81.5%
(0.55)
73.8%
(0.52)
<.0001
Note: Care should be taken in interpreting statistically significant differences in this table. With large sample sizes, very small differences between groups can reach statistical significance.
1 Means are given for continuous variables, and percentages are given for categorical variables (marked with a percent sign).
2 "Other" includes those other than whites, blacks, and Hispanics (i.e., Asians, American Indians or Alaska Natives, or Native Hawaiians or other Pacific Islanders).
3 p value derived from F-tests for continuous variables and chi-square tests (df = 3) for dichotomous variables.
4 p values derived from t-tests for continuous variables and chi-square tests (df = 1) for dichotomous variables.
5 Multiple substance scales take the mean of responses for marijuana, cigarette, and alcohol use.

Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1999.

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This page was last updated on July 17, 2008.