Ethnic differences in adolescent smoking behaviors, sources of tobacco, knowledge and attitudes toward restriction policies

Addictive Behaviors 28 (2003) 249–268

Ethnic differences in adolescent smoking behaviors, sources of tobacco, knowledge and attitudes toward restriction policies Grace X. Maa,*, Steve Shiveb,1, Patricia Legosc, Yin Tand a

Department of Health Studies, 304A Vivacqua Hall, Temple University, P.O. Box 2843, Philadelphia, PA 19122-0843, USA b California State University, Chico, Chico, CA 95926-0505, USA c Department of Health Studies, 304 Vivacqua Hall, Temple University, P.O. Box 2843, Philadelphia, PA 19122-0843, USA d Department of Health Studies, 301K Vivacqua Hall, Temple University, P.O. Box 2843, Philadelphia, PA 19122-0843, USA

Abstract The purpose of this study was to examine racial/ethnic differences in adolescent smoking behavior, sources of tobacco, knowledge of and attitudes toward youth tobacco restriction policies, and perceptions of tobacco availability by adolescents. The study is important as it will add to the growing body of literature regarding tobacco use by minors, and will help policymakers and public health professionals develop efficacious policies and interventions to prevent and reduce tobacco use among adolescents. Minors obtain tobacco from social and commercial sources. Previous studies have emphasized rural homogeneous populations and so the present study addresses the need to determine these sources of tobacco to youth in a large urban, heterogeneous population, such as Philadelphia. A stratified multistage purposive sampling procedure was used to ensure an ethnically/ racially sample. A 68-item questionnaire was administered to 645 students in Grades 8–10 in five public and nonpublic funded schools in a culturally diverse part of Philadelphia. Correlations between selected independent variables and smoking behavior were determined. Results from this study indicate that rates of smoking are high among students, with 50% of students ever having smoked, 19% within the last month, 17% weekly, and 15% smoke daily. Further, there were

* Corresponding author. Tel.: +1-215-204-5108; fax: +1-215-204-1854. E-mail addresses: [email protected] (G.X. Ma); [email protected] (S. Shive). 1 Tel.: + 1-530-898-6018; fax: + 1-530-898-5107. 0306-4603/02/$ – see front matter D 2002 Elsevier Science Ltd. All rights reserved. PII: S 0 3 0 6 - 4 6 0 3 ( 0 1 ) 0 0 2 2 5 - 8

250

G.X. Ma et al. / Addictive Behaviors 28 (2003) 249–268

differences in rates of smoking between ethnic/racial groups. Social sources were the most common sources of tobacco reported, with friends being the most frequent source. There were differences in social and commercial ever sources of cigarettes between ethnic/racial groups and in perceived school and parental sanctions for tobacco use. The results of this study suggest that more financial and educational resources should be committed to prevent and reduce smoking behaviors among adolescents. Educational prevention programs, especially parenting programs should be employed to reduce smoking. D 2002 Elsevier Science Ltd. All rights reserved.

1. Introduction The most preventable cause of disease and premature death in the US is tobacco use (McGinnis & Foege, 1993). It is estimated that 20% (431,000) of the preventable deaths in the US each year are attributed to tobacco use (Centers for Disease Control and Prevention, 1999a). Cigarettes account for approximately 95% of all tobacco use in the US (Inaba, Cohen, & Holstein, 1997), with an estimated 21% (48 million) of adults smoking everyday (American Cancer Society, 1999). Surveys find that from 25.2% to 42.8% of high school students smoke cigarettes and that use varies by ethnicity, race, and gender (Centers for Disease Control and Prevention, 1999b, 2000a, 2000b; Faulkner, Escobedo, Zhu, Chrismon, & Merritt, 1996; Faulkner & Merrit, 1998; Maddahian, Newcomb, & Bentler, 1986; National Center for Health Statistics, 1995; Wang, Fitzhugh, Green, Eddy, & Westerfield, 1994; Wiecha, 1996). Researchers have investigated various correlates of adolescent tobacco use onset. These variables have included social pressure or influences, family members who smoke, peer pressure, social image, development, and parental and institutional sanctions. Parents and older siblings who smoke are important in the initiation of smoking (Chassin, Presson, Sherman, Corty, & Olshavsky, 1984; Jackson, Bee-Gates, & Henriksen, 1994). Older students have significantly more positive attitudes toward smoking than younger students, independent of having friends who smoke (Botvin, Botvin, & Baker, 1983). Peer influences have consistently been associated with tobacco use onset (Conrad, Flay, & Hill, 1992; Wang, Fitzhugh, Eddy, Fu, & Turner, 1997; Wang, Fitzhugh, Turner, & Fu, 1997). Tobacco users report lower perceived parental and school sanctions or consequences than nonusers (Boyle, Claxton, & Forster, 1997). While it had been determined that social influences were good predictors of adolescent tobacco use onset, and that there were ethnic/racial differences in tobacco use, it was uncertain as to the source of tobacco product supply to minors. It was uncertain how access to availability was related to tobacco use onset and behavior. Adolescents have indicated that tobacco products are readily available. Primary commercial sources of cigarettes include gas stations, convenience stores, vending machines, grocery stores, and drug stores (Centers for Disease Control and Prevention, 2000a; Forster, Knut-Inge, & Jeffery, 1989; Forster, Wolfson, Murray, Wagenaar, & Claxton, 1997). Commercial sources were targeted as the primary source of cigarettes to minors and led to subsequent enforcement of youth access

G.X. Ma et al. / Addictive Behaviors 28 (2003) 249–268

251

restriction policies. While efforts to reduce commercial access to tobacco products have met with some success, youth can obtain tobacco from social sources. These social sources include parents, older siblings, other adults, peer friends, and through theft (Centers for Disease Control and Prevention, 2000a; Forster et al., 1989, 1997). Various categories of variables are related to differences in tobacco use among racial/ethnic groups such as sociodemographic, environmental, historical, behavioral, personal, and psychological. Despite the recent studies which have attempted to determine why there are differences between racial/ethnic groups in tobacco use, the specific risk factors and the predictive power of these categories of variables are still uncertain because few studies have been done (Centers for Disease Control and Prevention, 1999b). Previous studies, which have investigated the relationship between tobacco use and the various psychosocial factors, may not be applicable with other ethnic/racial populations. Many of the recent studies pertaining to commercial and social availability, and examination of predictor variables for adolescent provision of tobacco to other adolescents need further investigation among these populations (Wolfson, Forster, Claxton, & Murray, 1997). The primary purpose of this study is to examine the racial/ethnic differences in adolescent smoking behavior, sources of tobacco, knowledge of and attitudes toward youth tobacco restriction policies, and perceptions of tobacco availability by adolescents. A secondary purpose is to report the reliability and validity of the tobacco survey utilized in the study. This study addressed the following research questions: 1. 2. 3. 4. 5.

What is the perceived availability of tobacco? What are the smoking behaviors among racial/ethnic adolescents in Philadelphia? What are the primary sources of tobacco to adolescents in Philadelphia? What are the perceived consequences of tobacco use behavior by racial/ethnic adolescents? What are the knowledge of and attitudes toward youth restriction policy by adolescent racial/ethnic groups? 6. Which of the following independent variables are correlated with tobacco use among ethnic/racial adolescents: demographics, social influences, perceived consequences, perceived availability, sources of cigarettes, smoking behavior.

2. Methods 2.1. Sample A cross-sectional, self-report survey design was used in this study. A 68-item survey was developed. Data were collected February–March of 2000 from 645 eighth, ninth, and tenth grade students, according to a geographically stratified, multistage purposive sampling plan of the South Philadelphia School District Cluster (Babbie, 1992). The cases (n = 8) which indicated the racial/ethnic categories of American Indian and other were excluded from the analysis due to insufficient sample size. Eighth, ninth, and tenth graders from public

252

G.X. Ma et al. / Addictive Behaviors 28 (2003) 249–268

(n = 290) and nonpublic (n = 355) funded schools were chosen as the sample for the survey because, at 15 or 16 years of age they would be old enough to have started to smoke in large numbers and yet too young to be sold cigarettes legally. The South Philadelphia area was chosen to conduct the study due to the heterogeneity provided by its culturally diverse population within the city. Also, it was estimated by a health service agency that the sales rate of tobacco products to minors by merchants is the highest in Philadelphia. Klepp et al. (1996) suggested that a student population be chosen for conducting a study in which tobacco use was a salient issue. Students from public and nonpublic funded schools located in South Philadelphia were selected in the sample to be more inclusive and representative of the neighborhood population. A current listing (1997–1998) of all public and nonpublic funded middle and high schools in the South Philadelphia cluster was obtained from the School District of Philadelphia and the Pennsylvania Department of Education. The primary sampling unit was comprised of students in five schools in South Philadelphia, a public funded middle and high school, and two nonpublic funded elementary schools and one high school. Seven schools were approached and two did not want to participate. The first stage was to select schools that were ethnically and racially diverse and were considered neighborhood schools. Schools were considered neighborhood schools if they showed very few nonresident student enrollment. Once the schools were chosen, the second stage involved selecting classrooms in the schools. In the high schools, subjects were chosen in which there was very little overlap of students and the courses were required for all students in that grade. These courses included Health, Physical Education, English, and Social Studies. The survey was administered in the classrooms by the investigator and by teachers. The survey included questions about demographics; smoking behavior; commercial, social, and perceived availability of tobacco; perceived consequences of tobacco use; knowledge of and attitudes toward policy restrictions of youth access to tobacco. Participation in the survey was voluntary and anonymous. If students did not wish to participate, they remained in the class and turned in the questionnaire without completing it. 2.2. Instrument Many of the survey questions were adapted from an existing instrument (Klepp et al., 1996) and some were developed by the investigators (Table 1). Smoking behaviors included the variables of age of initiation, whether students ever used a cigarette, frequency of use (monthly, weekly, daily), rate of use, students’ perceptions of their ability to quit, and quitting attempts. Certainty in ability to quit was measured by a seven-point Likert scale, 1 (I am sure I could not quit) to 7 (I am sure I could quit). To measure the commercial and social sources of tobacco, questions were included which asked students from whom they typically get their cigarettes, both their first, most recent, and where they ever obtained a cigarette. Answers included social sources such as friends and family. Family was further specified with other questions that included such responses as father, mother, brother, sister, uncle, aunt, or grandfather, grandmother, and cousin.

G.X. Ma et al. / Addictive Behaviors 28 (2003) 249–268

253

Table 1 Description of the study variables Variable

Description

Source

Survey item

Cigarette use

Age of initiation, ever used a cigarette, frequency of use, perceived ability to quit, and quit attempts Commercial/social sources, types of sources, personally purchase cigarettes, purchase attempts OTC/VM, and results of the last purchase attempt Perceived availability of tobacco products from sources Perceived sanctions of parents, school, and police for use Knowledge of legal minimum age to purchase cigarettes and posting of signs in stores Respondent is asked to respond to a statement that there should be youth restriction laws. (Likert scale of agreement) Gender, racial/ethnic group self-description, educational status of father and mother, disposable weekly income Smoking status of father, mother, older siblings, best friend, number of friends who smoke, and guess of percentage of students in grade who smoke Public or nonpublic funded school attendance

Forster et al., 1997; Pechacek et al., 1984

38–40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 59

Cismoski & Sheridan, 1993; Forster et al., 1989, 1997; Rigotti et al., 1997

24–26, 27, 28, 34, 35, 50, 51, 52, 53, 54, 55, 56, 57, 58

Forster et al., 1997

19, 20, 21, 22, 23

Wolfson et al., 1997

11, 12, 14, 15, 16, 17 13, 29

Sources of tobacco

Perceived availability Perceived consequences of tobacco use Knowledge of policy restrictions Attitudes toward policy restriction

Demographics

Social influences

Type of school

Jacobson, Wasserman, & Anderson, 1997

18

DiFranza, Savageau, & Aisquith, 1996; Wolfson et al., 1997

1, 2, 3, 4, 62, 63, 64, 65, 66, 67, 68

Boyle et al., 1997; Males, 1995; Wang, Fitzhugh, Eddy, et al., 1997; Wang, Fitzhugh, Turner, et al., 1997; Wolfson et al., 1997

5, 6, 7, 8, 9, 10

OTC = over-the-counter; VM = vending machine.

Commercial sources included answers such as vending machines and convenience stores. Stores were further specified into types, such as: convenience stores, gas stations, bars and taverns, drug stores and restaurants. Perceived availability was measured by the participant’s response to five questions pertaining to the difficulty of obtaining tobacco products from various social and commercial sources, such as family, friends, vending machines, salespersons, and theft from stores. Responses were based on a seven-point Likert scale, 1 (very difficult) to 7 (not at all difficult). Perceived consequences of tobacco included a student’s perception of school, parental, and police sanctions if he or she was caught smoking. One question asked the respondent to check

254

G.X. Ma et al. / Addictive Behaviors 28 (2003) 249–268

what are the school’s rules, ranging from, ‘‘students are not allowed to smoke on school property’’ to they are ‘‘allowed to smoke on school property but in certain designated areas.’’ ‘‘I don’t know’’ was also included as a response. Two items measured school and parental sanctions by asking students what school personnel or a parent would do if caught smoking. Youth attitudes toward youth policy restrictions were measured with a forced-choice Likert scale of agreement, 1 (strongly disagree) to 4 (strongly agree). 2.3. Reliability and validity To determine reliability and validity of the instrument and to verify the methodology, the questionnaire was pilot tested with 52 eighth grade students from two schools which did not participate in the main study. In addition to taking the survey, students were asked to comment on the length, level of difficulty, whether the directions and language used were clear, and whether the title and purpose of the survey were clearly understood, to determine validity and improve the questionnaire for the main study. The two types of validity that were measured were face and content validity (Babbie, 1992). The validity was evaluated by selecting a panel of six health professionals, which included university faculty and health service agency staff in the field of Health Education and Public Health. The feedback from the health professional panel and the students were incorporated into the final version of the survey. Reliability was estimated by the internal consistency (coefficient a) and the test–retest methods (Murphy & Davidshofer, 1998). There were 2 weeks between the test administrations. The test–retest reliability was measured by k statistics for all dichotomous and polychotomous variables and by Pearson’s correlation coefficients for continuous variables. Values of k greater than 0.75 indicate excellent agreement beyond chance, between 0.40 and 0.75 are fair to good, and less than 0.40 indicate poor agreement (SPSS Base 10.0 Applications Guide, 1999, p. 82). The pilot study consisted of 52 students that were not a part of the main study. The ‘‘perceived access to tobacco’’ (a =.55) and the ‘‘likelihood of being caught using tobacco’’ (a =.61) had acceptable internal consistency (Table 2). Both of these scales had a test–retest correlation of .63 and .72, respectively. Reported parents’ educational levels had a test–retest correlation of .73–.83. Items measuring social and commercial sources of tobacco, the most recent sources, and use of tobacco had good levels of test– retest reliability. The item measuring purchase attempt (.41) in the last month had a fair correlation. Items assessing provision to a minor and purchase refusal had poor test–retest correlations. 2.4. Data analysis Data were analyzed with SPSS version 10.0. The statistical tests used in the analysis of the data in this study included descriptive statistics, the phi, contingency, and point biserial correlations, one-way analysis of variance, and chi-square. Descriptive statistics were reported for the demographic variables. Chi-square analyses were conducted for commercial

G.X. Ma et al. / Addictive Behaviors 28 (2003) 249–268

255

Table 2 Consistency of distribution of demographic characteristics and reported tobacco use and perceived access to tobacco across two administrations in Philadelphia Eighth grade

Sex: % female Race: % White African American Age: mean years (S.D.) Father’s education: %  High school > High school Don’t know Mother’s education: %  High school >High school Don’t know Reported tobacco use: % Never smoked tobacco Regular smokers (weekly) How most recent cigarette was obtained: % Never smoked From friend From family member From vending machine From salesperson at a business Stole it from a business Have ever obtained cigarettes: % Never smoked From friend From family member From vending machine From salesperson at a business Stole it from a business Tried to buy tobacco in last month: % Refused purchasing tobacco: % Ever given tobacco to someone < 18: % Perceived access to tobacco (1–7)a,b Likelihood of being caught if using tobacco (1–7)a,b a b

Time 1 (n = 52)

Time 2 (n = 52)

Test–retest reliability (n = 52)

53.8

56.0

1.00

33.3 64.7 13.1 (0.52)

34.0 62.0 13.1 (0.48)

1.00

36.5 40.4 23.1

36.7 38.8 24.5

.73

28.8 59.6 11.5

32.7 57.1 10.2

.83

67.3 5.7

72.0 6.0

.87 .88

75.0 17.3 5.8 0 1.9 0

80.0 10.0 4.0 0 2.0 2.0

.59

35.3 8.6 3.4 1.7 3.4 0 3.8 5.8 5.8 4.5 (2.0) 3.7 (2.1)

33.6 8.6 1.7 1.7 1.7 0 7.7 5.8 4.0 4.3 (2.0) 3.7 (2.1)

.79

.94 .80 .79 1.00 .65 .79 .41 .39 .37 .63 .72

The test–retest reliability is measured by Pearson’s correlation coefficients for these continuous variables. Mean values ± standard deviation are presented for these items.

and social sources of tobacco, perceived school sanctions, perceived parental sanctions, knowledge of the legal minimum purchase age, and school rules related to tobacco use. A one-way analysis of variance was conducted for the following independent variables:

256

G.X. Ma et al. / Addictive Behaviors 28 (2003) 249–268

perceived availability, smoking behaviors, likelihood of parents and police catching adolescents smoking, and attitudes toward youth restriction policies. The dependent variable was racial/ethnic group. Correlations were also reported. The dependent variable is adolescent tobacco use. The contingency coefficient was reported for nominal and dichotomous variables with more than two categories. The phi correlation was reported where there are two dichotomous variables. The point biserial correlation was reported for variables where there is one dichotomous variable and one interval or ratio variable.

3. Results 3.1. Characteristics of respondents The sample consisted of 72.7% males and 27.3% females (Table 3). The ethnic/racial male composition within each group was 69.2% Asian, 60.6% Black, 75% Hispanic, and 82.2% White males. The female composition was 30.8% Asian, 39.4% Black, 25% Hispanic, and 17.8% White. Tenth graders composed 48.1% of the sample, followed by almost equal

Table 3 Characteristics of respondents by race Demographics

Asian (n = 78, %)

Gender Male 69.2 Female 30.8 Grade Eight 15.4 Ninth 25.6 Tenth 59.0 Educational status of mother  High school 29.7 >High school 13.3 Don’t know 55.3 Educational status of father  High school 27.6 >High school 17.0 Don’t know 53.9 Amount of disposable weekly income  US$10 46.0 US$11–25 22.4 >US$25 31.6 Type of school Public 71.8 Nonpublic 28.2

Black (n = 221, %)

Hispanic (n = 24, %)

White (n = 314, %)

Total (n = 645, %)

60.6 39.4

75.0 25.0

82.2 17.8

72.7 27.3

12.1 7.8 14.7

50.0 33.3 41.7

16.6 33.4 50.0

23.4 28.5 48.1

31.9 49.3 17.8

52.1 26.0 21.7

64.8 35.2 12.6

48.2 32.3 20.2

39.0 32.4 27.7

34.8 30.4 34.8

61.5 23.2 15.3

48.1 26.0 25.5

20.9 22.4 62.7

28.5 14.3 57.1

21.7 23.7 54.7

24.6 22.8 52.6

62.4 37.6

79.2 20.8

24.2 75.8

45.0 55.0

G.X. Ma et al. / Addictive Behaviors 28 (2003) 249–268

257

Table 4 Perceived availability of tobacco by race Perceived availability a: mean (S.D.)

Asian (n = 77)

Black (n = 218)

Hispanic (n = 24)

White (n = 313)

F

Total (n = 640)

Weekly smokers (n = 103)

Friend Family Vending machine Over-the-counter Steal from store

5.7 2.9 5.2 4.1 3.0

5.8 2.8 5.3 4.4 3.2

6.0 3.6 4.5 4.3 3.0

6.1 3.1 5.5 4.7 3.0

2.2 1.5 2.2 2.4 0.6

6.0 3.0 5.3 4.5 3.1

6.2 3.8 5.5 5.1 2.9

Smokers: mean (S.D.)

n = 67

F

n = 539

Cigarettes smoked past 24 h Cigarettes smoked past week Age of initiation Certain in ability to quitb Quit attempts

(1.7) (2.0) (1.9) (1.8) (1.8)

(1.9) (2.2) (2.0) (2.2) (2.3)

n = 201

(1.9) (2.3) (2.2) (2.1) (2.0)

n = 14

(1.5) (2.1) (1.8) (1.8) (2.0)

n = 257

(1.7) (2.1) (1.9) (2.0) (2.1)

2.4 (4.6)

0.7 (2.1)

3.7 (5.8)

2.8 (6.3)

3.7*

2.2 (5.3)

15.5 (23.2)

3.8 (11.1)

19.6 (28.5)

19.2 (41.3)

4.4*

14.4 (33.6)

12.0 (1.5) 4.6 (2.0)

12.0 (2.4) 5.7 (2.2)

11.9 (2.8) 5.2 (2.5)

11.7 (2.0) 5.3 (1.9)

0.4 1.3

11.8 (2.1) 5.3 (2.0)

4.0 (8.3)

1.9 (4.9)

3.3 (6.8)

1.4 (2.1)

1.6

1.9 (4.2)

(1.6) (2.2) (2.0) (1.8) (2.0)

a

Mean responses are on a seven-point scale: 1 (very difficult) to 7 (not at all difficult). b Mean responses are on a seven-point scale: 1 (I am sure I could not quit) to 7 (I am sure I could quit). * P < .01.

portions of ninth (28.5%), and eighth (23.4%). Asian students were more likely to report that they did not know their parents’ highest level of education compared to White, Black, and Hispanic students. Within ethnic/racial groups, Asian students had the lowest reported weekly disposable income than the other three groups and Blacks had the highest. Fifty-five percent attended

Fig. 1. Cigarette use by race/ethnic group.

258

Black Hispanic White c2 (n = 89) (n = 18) (n = 176)

Total Weekly (n = 314) smokers (n = 103, %)

16.4

66.6 16.9 1.0 2.9 1.0 1.9

67.0 22.3 1.0 2.9 1.9 1.9

43.7 7.8 2.9 39.8 1.0 1.0

89.2 66.7 44.1 69.6 7.8

Source of first cigarette Friend Family Vending machine Over-the-counter purchase Stolen from business Other

69.0 10.3 0 3.4 0 0

60.7 20.2 1.1 3.4 2.2 2.2

66.7 11.1 5.6 0 5.6 5.6

69.9 17.0 0.6 2.8 0 1.7

Source of most recent cigarette Friend Family Vending machine Over-the-counter purchase Stolen from business Other

37.9 10.3 3.4 24.1 0 3.4

52.8 7.9 0 10.1 1.1 0

50.0 11.1 0 22.2 5.6 0

59.4 6.3 1.1 17.7 0 0.6

21.0

54.6 7.3 1.0 16.3 0.6 0.6

Ever obtained cigarettes Friend Family Vending machine Over-the-counter Stolen from business

69.0 34.5 31.0 31.0 3.4

64.8 19.3 4.5 15.9 1.1

83.3 50.0 33.3 44.4 5.6

79.5 37.7 21.7 38.3 5.1

7.9* 11.6** 18.3*** 15.0** 2.7

74.1 32.7 18.3 31.4 3.9

G.X. Ma et al. / Addictive Behaviors 28 (2003) 249–268

Table 5 Primary social and commercial sources of tobacco products to adolescent smokers by race

n = 64

8.3 16.7 13.9 22.2 27.8 0 5.6 2.8 2.8

14.1

7.8 14.1 12.5 17.2 32.8 0 4.7 7.8 3.1

n = 18

n = 175

c2

n = 138

16.7 27.8 22.2 5.6 0 0 5.6 5.6

8.0 24.0 15.4 9.1 7.4 3.4 5.7 13.7

4.2 14.3** 0.9 3.2 6.2 3.7 1.7 22.0***

7.1 17.9 15.1 7.4 4.8 2.2 5.1 11.2

n = 29

n=4

n = 36

Father Mother Brother Sister Cousin (blood relative) Grandfather Grandmother Aunt Uncle

0 0 0 25.0 75.0 0 0 0 0

10.0 15.0 10.0 10.0 35.0 0 0 15.0 5.0

0 0 25.0 0 25.0 0 25.0 25.0 0

Type of business ever a source

n = 29 n = 88

Restaurant Gas station/convenience store Grocery store Pharmacy Bar, tavern, pub, liquor store Hotel/motel Discount store Recreational/sports center

3.4 3.4 13.8 0 3.4 3.4 0 31.0

* P < .05. ** P < .01. *** P < .001.

4.5 9.1 13.6 6.8 1.1 0 5.7 1.1

1.9 4.9 3.9 7.8 7.8 0 1.9 1.9 0

16.7 39.2 32.4 15.7 12.7 6.9 13.7 27.5

G.X. Ma et al. / Addictive Behaviors 28 (2003) 249–268

c2

If family is first source of cigarette n = 4

259

260

G.X. Ma et al. / Addictive Behaviors 28 (2003) 249–268

nonpublic schools and 45% attended public schools. Whites were more likely to attend nonpublic schools than Asians, Blacks, and Hispanics. 3.2. Perceived availability of tobacco All racial/ethnic groups perceived that friends were the least difficult to get tobacco from and that family was the most difficult (Table 4). The means of students who reported perceived availability from commercial and social sources were compared using a one-way ANOVA. No significant difference ( P > .05) was found for friends, family, vending machines, over-the-counter purchases, and theft. Overall, students thought that it was fairly easy to get tobacco from stores, vending machines, and friends. 3.3. Initiation and frequency of tobacco use Overall, 49.5% of students tried tobacco by the tenth grade, followed by 19.3% past month, 16.9% weekly, and 15.2% daily (Fig. 1). A one-way ANOVA was computed which compared the number of daily and weekly cigarettes smoked across ethnic/racial groups. A significant difference was found among the groups for daily [ F(3,307) = 3.69, P < .01] and weekly [ F(3,307) = 4.40, P < .01] cigarette use. Tukey’s HSD was used to determine the differences between the groups. This analysis revealed that Whites (M = 2.81, S.D. = 6.3) used more cigarettes daily than African Americans (M = 0.68, S.D. = 2.1). Whites (M = 19.2, S.D. = 41.3) used more cigarettes weekly than African Americans (M = 3.8, S.D. = 11.1) (Table 4). The means of the age of initiation, certainty in ability to quit, and quit attempts were compared using a one-way ANOVA. No significant difference was found between racial/ethnic groups in the age of initiation, certainty in ability to quit, and in the number of quit attempts. 3.4. Sources of tobacco products to adolescent smokers Social sources were the highest reported first, most recent, and ever source of cigarettes for smokers, especially friends (Table 5). Commercial sources were higher for most recent sources of cigarettes and for weekly smokers. A chi-square test of independence was calculated comparing the sources of cigarettes for racial/ethnic groups. A significant interaction was found for friends [c2(7.9,3) = P < .05], family [c2(11.6,3) = P < .01], vending machines [c2(18.3,3) = P < .001], and over-the-counter purchases [c2(15.0,3) = P < .01]. Hispanics (83.3%) and Whites (79.5%) were more likely to get cigarettes from friends than Asians (69.0%) or Blacks (64.8%). Whites were more likely to get cigarettes from family and through over-the-counter purchases than Asians or Blacks. If family was a first source of cigarettes for smokers, cousins were the most likely family members from which to obtain them across all racial/ethnic groups, followed by siblings. No significant relationship was found between racial/ethnic groups and family as first source of cigarettes [c2(14.1,12) = P >.05].

G.X. Ma et al. / Addictive Behaviors 28 (2003) 249–268

261

For all racial/ethnic groups, gas stations/convenience stores (17.9%) were the most likely commercial source, followed by grocery stores (15.1%), recreational/sports centers (11.2%), restaurants (7.1%), pharmacies (7.4%), discount stores (5.1%), and bars (12.7%) (Table 5). A chi-square test of independence was calculated comparing type of commercial source of cigarettes with racial/ethnic groups. A significant interaction was found for gas stations [c2(14.3,3) = P < .05], and recreational/sports centers [c2(22.0,3) = P < .001]. Hispanics (27.8%) and Whites (24.0%) were more likely to get cigarettes from gas stations/convenience stores than Blacks (9.1%) and Asians (3.4%). Asians (31.0%) were more likely than the other three racial/ethnic groups to get cigarettes at a recreational or sports center. 3.5. Perceived consequences of tobacco use As shown in Table 6, 11.7% of students thought that there would be no school sanctions for smoking and 16.4% thought that they would be warned. Overall, 30.2% reported that they would be sent to the office, 31.8% believed parents would be notified, 14.2% said they would be suspended from sports, 19.9% reported in-school suspension, 13.4% said they would be expelled from school, and 20.1% did not know the school sanctions. A chi-square test of independence was calculated comparing perceived school and parental sanctions for racial/ethnic groups. A significant interaction was found for the categories of nothing [c2(32.6,3) = P < .001], sent to the office [c2(16.1,3) = P < .001], in-school suspension [c2(21.9,3) = P < .001], and being expelled from school [c2(39.4,3) = P < .001]. Blacks were more likely to report that nothing would happen and that they would be expelled from school if caught smoking compared to Asians and Whites. More Whites thought they would be sent to the office and obtain an in-school suspension than the other three ethnic groups. For parental sanctions, 42.5% of students thought they would be grounded, 36% reported their parents would take away some privileges, 38.8% indicated that their parents would tell them not to use it, and 11.5% thought their parents would do nothing. A significant interaction was found for the categories of nothing [c2(17.8,3) = P < .001] and being grounded [c2(31.1,3) = P < .001]. Whites were significantly more likely to report that they would be grounded than the other three groups. Overall, students did not think that it was likely that the police would catch them smoking (M = 2.3) or do anything about it if they were caught (M = 2.3). They also did not think that their parents would catch them (M = 3.8). A one-way ANOVA comparing the means of the likelihood of parents and the police catching them smoking and the likelihood that police would do something if they were caught with ethnic/racial group was calculated. There were significant differences found among groups in perceptions of the likelihood of the police catching them smoking [ F(3,308) = 3.6, P < .01] and in doing anything about it if they did catch them [ F(3,309) = 3.6, P < .01]. Tukey’s HSD was used to determine the differences between racial/ethnic groups. This analysis revealed that Whites (M = 2.1, S.D. = 1.5) were less likely to think that the police would catch them if they smoked than Asians (M = 2.7, S.D. = 1.6). Whites (M = 2.0, S.D. = 1.4) were less likely

262

G.X. Ma et al. / Addictive Behaviors 28 (2003) 249–268

Table 6 Perceived consequences of tobacco use by race Race Asian (n = 78)

Black (n = 220)

Hispanic (n = 23)

White (n = 313)

c2

Total (n = 634)

Perceived school sanctions (%) Nothing Warned Sent to the office Stay after school Parents notified Required to go to a special class Suspended from sports/activities In-school suspension Arrested Expelled from school I don’t know

14.1 17.9 23.1 12.8 30.8 7.7 10.3 17.9 0 1.3 26.9

15.9 18.6 24.5 9.5 33.2 5.9 16.4 12.3 4.1 24.1 16.8

39.1 8.7 13.0 0 26.1 0 4.3 4.3 0 0 17.4

5.8 15.0 37.4 7.0 31.3 8.3 14.1 27.2 2.2 9.6 21.1

32.6** 2.4 16.1** 5.3 0.6 3.0 3.7 22.0** 4.9 39.4** 4.0

11.7 16.4 30.3 8.4 31.8 7.2 14.2 19.9 2.5 13.4 20.1

Perceived parental sanctions (%) Nothing Tell me not to use it Take away some privileges Ground me Other

9.0 47.4 42.3 25.6 12.8

11.4 38.2 35.0 37.7 19.5

39.1 26.1 13.0 13.0 21.7

10.5 37.7 36.7 52.1 14.1

17.8** 4.2 6.8 31.0** 4.0

11.7 38.8 36.0 42.5 16.4

School’s rules (%) No smoking on school property Can smoke outside Can smoke only in designated areas Can smoke anywhere in school Don’t know

59.0 9.0 3.8 0 28.2

58.4 14.2 3.7 3.7 19.6

43.5 21.7 13.0 4.3 17.4

71.9 12.1 2.2 1.0 12.8

64.9 12.6 3.3 1.9 33.6** 17.2

Knowledge of legal minimum age (%) 15–17 18 19–21 No minimum legal age

7.8 55.8 31.2 5.2

4.1 58.3 34.3 3.2

8.7 56.5 26.0 8.7

5.7 74.4 17.3 2.6

5.6 65.9 25.2 28.2** 3.3

Likelihood of parents catching thema (S.D.) Likelihood of police catching them if they purchased cigarettesa (S.D.) Likelihood of police doing something if catching thema (S.D.) Attitudes toward tobacco restriction policiesb (S.D.) a

4.2 (2.3) 2.7 (1.6)

3.7 (2.4) 2.4 (2.1)

3.4 (2.3) 2.1 (2.0)

3.9 (2.1) 2.1 (1.5)

1.6 3.6*

3.8 (2.2) 2.3 (1.7)

2.6 (1.8)

2.7 (1.7)

2.4 (1.8)

2.0 (1.4)

7.8**

2.3 (1.6)

2.1 (0.91)

2.0 (0.97)

1.5 (1.2)

1.8 (1.1)

4.4*

1.9 (1.0)

Mean responses are on a seven-point scale: 1 (not at all likely) to 7 (very likely). Mean responses are on a four-point Likert scale: 0 (strongly disagree) to 3 (strongly agree). * P < .01. ** P < .001. b

G.X. Ma et al. / Addictive Behaviors 28 (2003) 249–268

263

than Asians (M = 2.6, S.D. = 1.8) and Blacks (M = 2.7, S.D. = 1.7) to think that the police would do anything if they caught them smoking.

Table 7 Correlation of independent variables with adolescent tobacco use Independent variables

Adolescent tobacco use (n = 634)

Demographics Racea Father’s educationa Mother’s educationa Genderb Gradea Disposable incomea

.18*** .05 .07 .09* .04 .06

Social influences Father smokesb Mother smokesb Sibling smokesb Best friend smokesb Number of friends who smokea Perceived percentage in grade who smokea

.14** .18*** .12* .38*** .38*** .14*

Perceived sanctions Low school sanctionsb Medium school sanctionsb High school sanctionsb Parental sanctionsb

.06 .04 .01 .12**

Perceived availability Difficulty of getting cigarettes Difficulty of getting cigarettes Difficulty of getting cigarettes Difficulty of getting cigarettes Difficulty of getting cigarettes

from from from from from

frienda familya vending machinea salespersona stealinga

Source of most recent cigaretteb Type of school attended Certainty in ability to quit Likelihood of parents catching them Likelihood of police catching them Knowledge of legal minimum age Attitudes toward youth tobacco restriction policies a

Contingency coefficient. Phi correlation. c Point biserial correlation. * P < .05. ** P < .01. *** P < .001. b

.21*** .18*** .09 .17** .07 .07 .04 .32*** .14* .14 .17** .31***

264

G.X. Ma et al. / Addictive Behaviors 28 (2003) 249–268

3.6. Tobacco restriction policy knowledge and attitudes Overall, 65.9% knew the correct minimum age to purchase cigarettes (Table 6). A chisquare test of independence was calculated comparing knowledge of the legal minimum age with racial/ethnic groups. A significant interaction was found [c2(28.2,9) = P < .001]. Whites (74.4%) were more likely to know the correct age, than Blacks (58.3%), Hispanics (56.5%), and Asians (55.8%). Overall, students agreed with youth tobacco restriction policy (M = 2.0). A one-way ANOVA comparing the attitudes toward youth restriction policy with the groups was calculated. A significant difference was found among the groups [ F(3,625) = 4.39, P < .01]. Tukey’s HSD was used to determine the differences between the groups. Blacks (M = 2.0, S.D. = 0.97) were more likely to agree than Whites (M = 1.8, S.D. = 1.1). Overall, 64.9% indicated that there was no smoking on school property, 12.6% reported that smoking could occur outside the building, and 17.2% did not know the school rules (Table 6). A chi-square test of independence was calculated comparing reported knowledge of school rules with racial/ethnic groups. A significant interaction was found [c2(33.6,12) = P < .001]. Whites (71.9%) were the most likely to report that there was no smoking on school property. Hispanics were the most likely to report that students can smoke outside the school building, only in designated areas, and anywhere in school. Overall, 17.2% said that they did not know the school rules about smoking. Asian students (28.2%) were the most likely to report that they did not know the school rules. 3.7. Independent variables correlated with adolescent tobacco use The following independent variables were found to be significantly correlated with adolescent tobacco use: race, gender, father smokes, mother smokes, sibling smokes, best friend smokes, number of friends who smoke, perceived norms among peers for smoking, parental sanctions, perceived difficulty in getting from a friend, family, and salesperson, certainty in ability to quit, the likelihood of parents catching them, knowledge of the legal minimum age, and attitudes toward youth tobacco restriction policies (Table 7). Medium perceived sanctions were negatively correlated with adolescent tobacco use, but this correlation was not statistically significant. Parental sanctions were also significantly negatively correlated with adolescent tobacco use (r = .12, P < .01).

4. Discussion The larger percentage of males than females in the sample was primarily due to the unisex nature of one nonpublic funded school. African Americans reported the highest level of weekly disposable income and yet they had the lowest rates of smoking. Disposable income is a prerequisite to enabling the purchase, but not a determining factor. In general, across all ethnic/racial groups, students perceived that it was easy to get cigarettes from social sources, especially friends. They perceived it slightly more difficult to

G.X. Ma et al. / Addictive Behaviors 28 (2003) 249–268

265

get cigarettes from commercial sources. It was more difficult to get cigarettes from family, especially for Asian American students. These findings are consistent with previous studies which examined a predominantly White group of students (Forster et al., 1997). The perception of difficulty in obtaining cigarettes between the groups was not statistically significant. One study found that that Black and Latino minors were more able to purchase than Whites, even in minority neighborhoods (Klonoff, Landrine, & Alcaraz, 1997; Landrine & Klonoff, 1997). The perceptions of difficulty of obtaining tobacco from family and friends were also significantly correlated with tobacco use behavior. Consistent with previous studies, this study also found that close to 50% of students have tried tobacco before the tenth grade (Johnston, O’Malley, & Bachman, 1996) and that Blacks smoked the least among ethnic/racial groups (Wills & Cleary, 1997). Being certain in ability to quit was significantly positively correlated with tobacco use. While there was no significant differences between the groups in smokers’ perceptions of ability to quit, Blacks were more likely to be less certain in their ability to quit if they smoked. Blacks may perceive that they are more susceptible to nicotine addiction, or they perceive a greater threat from tobacco use. These findings suggest and support educational efforts to change students’ perceptions and positive attitudes toward cigarette smoking. Tobacco must be made to appear distasteful so that adolescents will be less interested in obtaining it. There were significant differences in social sources of ever smokers between racial/ethnic groups. Student perception that it is easy to get cigarettes from friends is consistent with their behaviors. Across all ethnic/racial groups, social sources were the highest source of first cigarettes, especially friends. Commercial sources seem to be more important as a most recent source and for weekly smokers. This finding is consistent with other studies that show that adolescents gravitate toward commercial sources as personal consumption increases (Hinds, 1992). Students obtained their first cigarettes from friends and family members such as cousins. These findings suggest that since students initiate smoking from sources such as friends and even family, targeting commercial sources alone may not substantially reduce smoking behaviors. Educational programs, which are aimed at both parents and peer students, will need to be implemented simultaneously with law enforcement efforts. Efforts to reduce sales to minors should be maintained and supported, as evidenced by the perception of the ease to acquire tobacco from commercial sources and high percentage of purchases from various types of stores. The findings of this study are consistent with previous studies which found that sales of cigarettes are common among certain types of commercial sources such as gas stations/convenience stores, grocery stores, recreational/sports centers, and restaurants (Forster et al., 1989, 1997). In general, 20.1% of all students did not know their school’s sanctions and 11.7% thought that nothing would be done if they were caught smoking. About 32% thought that their parents would be notified, but close to 12% indicated that their parents would do nothing and 38.8% reported that their parents would tell them not to use it. Less than 45% indicated that their parents would ground them or take away some privileges. Further, students did not feel that it was likely that their parents or the police would catch them, and if they did, very little would happen as a consequence. These findings indicate that more consideration should be given to determining proper sanctions for tobacco use among adolescents. Students also need to see the

266

G.X. Ma et al. / Addictive Behaviors 28 (2003) 249–268

sanctions implemented. A greater emphasis on changing students’ attitudes so that they perceive that greater school and parental sanctions will be imposed if caught may lead to a reduction in smoking behavior. Studies have shown that male tobacco users reported lower perceived parental and school sanctions than nonusers (Boyle et al., 1997). The findings of the present study are consistent with Boyle’s study because there was a negative correlation with smoking behavior medium school and parental sanctions. While the medium school sanctions were not statistically significant, there appears to be an inverse relationship between perceived sanctions and smoking behavior. More investigation should be done as to the role that school and parental sanctions, perceived and real, have on tobacco use behavior among adolescents. Thirty-five percent of students did not know the correct minimum age to purchase cigarettes and there were significant differences between racial/ethnic groups in knowledge of the minimum age. More efforts should be directed at educating students about the laws and local ordinances in purchasing tobacco. The findings of this study indicate that knowledge does not suffice in reducing age of initiation of tobacco use. Whites were more likely to know the correct minimum age, yet had the youngest age of initiation and one of the highest smoking rates. In addition, while knowledge and attitudes were significantly correlated with tobacco use, they were not negatively correlated with use. Knowledge of the law may not in itself reduce tobacco use. The results of this study indicated that students agreed that there should be youth tobacco restriction laws. This may also indicate that they would be receptive to educational programs which could lead to a reduction in tobacco use. Social influences are very important in determining whether or not an adolescent smokes. Across ethnic/racial groups, father, mother, siblings, and best friends who smoke and the perceived numbers of peers who smoke are significantly positively correlated with adolescent smoking. These findings support previous research conducted among White adolescents (Kandel & Wu, 1995). Race is also correlated with tobacco use. This suggests that there are differences in tobacco use among ethnic/racial groups given protective factors among certain ethnic/racial groups. While not being statistically significant, there was a negative correlation between tobacco use and type of school attended. There was less smoking in the nonpublic schools. There may be some differences between perceived consequences of tobacco use between public and nonpublic schools, different cultural factors, or different parental attitudes. While smoking occurs in both types of schools, the various psychosocial factors associated with tobacco use may be different in the two types of schools which may warrant further investigation. This study has some limitations related to generalization and research design. First, since the study utilized a self-report cross-sectional survey design, the study is limited in that the survey relies on a respondent’s recall and veracity in reporting. In addition, cross-sectional data cannot be used to establish cause and effect relationships between the variables since the observations were made at one point in time. Second, generalization to Hispanics is limited due to the relatively small subsample size. Third, generalizations made from the study are based on results from an ethnically/racial heterogeneous sample from a large urban area and may not be applicable to populations that do not share the study’s sample characteristics. Throughout this study, the results were compared with the studies which used predominantly White adolescent student populations. Many of the underlying

G.X. Ma et al. / Addictive Behaviors 28 (2003) 249–268

267

psychosocial factors, which contribute to tobacco use behavior, cut across ethnic/racial groups but each group may not cope with these factors in the same way. Therefore, tobacco prevention programs need to target the psychosocial and cultural factors that are relevant to the particular ethnic/racial group.

Acknowledgments This study was funded by the Barra Foundation, The authors also wish to express their gratitude to the members of the American Heart Association, American Cancer Society, American Lung Association, and the Health Promotion Council of Southeastern Pennsylvania, for their encouragement to conduct the study and for their continued efforts at health promotion.

References American Cancer Society (1999). Cancer facts and figures — 1999 (Atlanta, GA). Babbie, E. (1992). The practice of social research (6th ed.). Belmont, CA: Wadsworth Publishing. Botvin, E. M., Botvin, G. J., & Baker, E. (1983). Developmental changes in attitudes toward cigarette smokers during early adolescence. Psychological Reports, 53, 547–553. Boyle, R. G., Claxton, A. J., & Forster, J. L. (1997). The role of social influences and tobacco availability on adolescent smokeless tobacco use. Journal of Adolescent Health, 20, 279–285. Centers for Disease Control and Prevention (1999a). Smoking-attributable mortality and years of potential life lost — United States, 1984. Morbidity and Mortality Weekly Report, 48( LMRK), 131–138. Centers for Disease Control and Prevention (1999b). Tobacco use among middle and high school students — Florida, 1998 and 1999. Mortality and Morbidity Weekly Report, 48(12), 248–253. Centers for Disease Control and Prevention (2000a). CDC surveillance summaries. Morbidity and Mortality Weekly Report, 49(SS-10), 1–94. Centers for Disease Control and Prevention (2000b). CDC surveillance summaries. Morbidity and Mortality Weekly Report, 49(SS-5), 1–96. Chassin, L., Presson, C. C., Sherman, S. J., Corty, E., & Olshavsky (1984). Predicting the onset of cigarette smoking in adolescents: a longitudinal study. Journal of Applied Social Psychology, 14(3), 224–243. Cismoski, J., & Sheridan, M. (1993). Availability of cigarettes to under-age youth in Fond du Lac, Wisconsin. Wisconsin Medical Journal, 92(11), 626–630. Conrad, K. M., Flay, B. R., & Hill, D. (1992). Why children start smoking cigarettes: predictors of onset. British Journal of Addiction, 87, 1711–1724. DiFranza, J. R., Savageau, J. A., & Aisquith, B. F. (1996). Youth access to tobacco: the effects of age, gender, vending machine locks, and ‘‘it’s the law’’ programs. American Journal of Public Health, 86, 221–224. Faulkner, D. L., Escobedo, L. G., Zhu, B., Chrismon, J. H., & Merritt, R. K. (1996). Race and the incidence of cigarette smoking among adolescents in the United States. Journal of the National Cancer Institute, 88(16), 1158–1160. Faulkner, D. L., & Merrit, R. K. (1998). Race and cigarette smoking among United States adolescents: the role of lifestyle behaviors and demographic factors. Pediatrics, 101(2), 300–304. Forster, J. L., Knut-Inge, K., & Jeffery, R. W. (1989). Sources of cigarettes for tenth graders in two Minnesota cities. Health Education Research, 4(1), 45–50. Forster, J. L., Wolfson, M., Murray, D. M., Wagenaar, A. C., & Claxton, A. J. (1997). Perceived and measured availability of tobacco to youths in 14 Minnesota communities: the TPOP study. American Journal of Preventive Medicine, 13(3), 167–174.

268

G.X. Ma et al. / Addictive Behaviors 28 (2003) 249–268

Hinds, M. W. (1992). Impact of a local ordinance banning tobacco sales to minors. Public Health Reports, 107, 355–358. Inaba, D. S., Cohen, W. E., & Holstein, M. E. (1997). Uppers, downers, all arounders: physical and mental effects of psychoactive drugs (3rd ed.). Ashland, OR: CNS Publications. Jackson, C., Bee-Gates, D. J., & Henriksen, L. (1994). Authoritative parenting, child competencies, and initiation of cigarette smoking. Health Education Quarterly, 21(1), 103–116. Jacobson, P. D., Wasserman, J., & Anderson, J. R. (1997). Historical overview of tobacco legislation and regulation. Journal of Social Issues, 53(1), 75–95. Johnston, L. D., O’Malley, P. M., & Bachman, J. G. (1996). National survey results on drug use from the monitoring the future study, 1975–1995. Washington, DC: U.S. Government Printing Office (DHHS Publication No. NIDA 96-4139). Kandel, D. B., & Wu, P. (1995). The contributions of mothers and fathers to the intergenerational transmission of cigarette smoking in adolescence. Journal of Research on Adolescence, 5(2), 225–252. Klepp, K., Jones-Webb, R., Wagenaar, A. C., Short, B., Murray, D. M., & Forster, J. L. (1996). Measurement of alcohol and tobacco availability to underage students. Addictive Behaviors, 21(5), 585–595. Klonoff, E. A., Landrine, H., & Alcaraz, A. (1997). An experimental analysis of sociocultural variables in sales of cigarettes to minors. American Journal of Public Health, 87(5), 823–826. Landrine, H., & Klonoff, E. A. (1997). Racial discrimination in minors’ access to tobacco. Journal of Black Psychology, 23(2), 135–147. Maddahian, E., Newcomb, M. D., & Bentler, P. M. (1986). Adolescents’ substance use: impact of ethnicity, income, and availability. Advances in Alcohol and Substance Abuse, 5(3), 63–78. Males, M. (1995). The influence of parental smoking on youth smoking: is the recent down playing justified? Journal of School Health, 65(6), 228–230. McGinnis, J. M., & Foege, W. H. (1993). Actual causes of death in the United States. Journal of the American Medical Association, 270, 2207–2212. Murphy, K. R., & Davidshofer, C. O. (1998). Psychological testing: principals and applications (4th ed.). Upper Saddle River, NJ: Prentice-Hall. National Center for Health Statistics (1995). Health, United States, 1994. Washington, DC: U.S. Government Printing Office. Pechacek, T. F., Murray, D. M., Luepker, R. V., Mittelmark, M. B., Johnson, C. A., & Shutz, J. M. (1984). Measurement of adolescent smoking behavior: rationale and methods. Journal of Behavioral Medicine, 7(1), 123–140. Rigotti, N. A., Difranza, J. R., Change, Y., Tisdale, T., Kemp, B., & Singer, D. E. (1997). The effect of enforcing tobacco-sales laws on adolescents’ access to tobacco and smoking behavior. New England Journal of Medicine, 337(15), 1044–1051. SPSS Base 10.0 Applications Guide. Chicago, IL: SPSS. Wang, M. Q., Fitzhugh, E. C., Eddy, J. M., Fu, Q., & Turner, L. (1997). Social influences on adolescents’ smoking progress: a longitudinal analysis. American Journal of Health Behavior, 21(2), 111–117. Wang, M. Q., Fitzhugh, E. C., Green, L., Eddy, J. M., & Westerfield, R. C. (1994). Tobacco use among American adolescents: geographic and demographic variations. Southern Medical Journal, 87(6), 607–610. Wang, M. Q., Fitzhugh, E. C., Turner, L., & Fu, Q. (1997). Social influence on southern adolescents’ transition: a retrospective study. Southern Journal of Medicine, 90(2), 218–222. Wiecha, J. M. (1996). Differences in patterns of tobacco use in Vietnamese, African-American, Hispanic, and Caucasian adolescents in Worcester, Massachusetts. American Journal of Preventive Medicine, 12(1), 29–37. Wills, T. A., & Cleary, S. D. (1997). The validity of self-reports of smoking: analyses by race/ethnicity in a school sample of urban adolescents. American Journal of Public Health, 87, 56–61. Wolfson, M., Forster, J. L., Claxton, A. J., & Murray, D. M. (1997). Adolescent smokers’ provision of tobacco to other adolescents. American Journal of Public Health, 87, 649–651.