Race and Cigarette Smoking Among United States Adolescents: The Role of Lifestyle Behaviors and Demographic Factors

Study Population and Data Collection

The 1992 NHIS was conducted among a representative sample of the civilian noninstitutionalized US population, using a multistage cluster-area probability design of approximately 128 000 persons representing approximately 49 000 households. The YRBS was conducted as a supplement to the 1992 NHIS among a representative sample of US adolescents and young adults drawn from sampled households.⁵ Based on information collected at the time of the basic NHIS interview, a roster was prepared listing all youths aged 12 to 21 years and their school status. From this roster, one in-school youth and up to two out-of-school youths from each family were randomly selected to the NHIS-YRBS. Participation was voluntary. For adolescents aged 12 to 17 years, the consent of a parent or another responsible adult was required.^5,6

Interviews took place approximately 2 months after the basic household interview, from April 1992 through March 1993. Using headsets, respondents listened to a tape recording of the questionnaire and recorded their responses on a standardized answer sheet. A weighting factor was applied to each record to adjust for nonresponse and the oversampling of out-of-school youths.^5,6

The NHIS-YRBS interviews were completed for 10 645 youths aged 12 to 21 years, representing an overall response rate of 73.9%.⁵For this analysis, the eligible population consisted of African-American and white adolescents from 12 to 17 years of age (n = 6242). Six hundred seventy-three respondents (10.8%) were excluded because of missing data on at least one study variable. Thus, the final study population consisted of 5569 adolescents for whom information was complete.

Study Variables

In this study, race was the exposure variable; and current smoking was the outcome variable. Based on a question about main racial background and ethnic origin, respondents to the NHIS-YRBS described themselves as non-Hispanic white or non-Hispanic African-American. To determine smoking status, respondents were asked, “During the past 30 days, on how many days did you smoke cigarettes?” Respondents who had not smoked in the last month were considered nonsmokers, and those who had smoked on 1 or more days were classified as current smokers.

Various demographic and behavioral correlates of cigarette smoking among adolescents⁷ were selected as control variables for this study. The demographic factors included: gender (female, male); age (12 to 13 years, 14 to 15 years, 16 to 17 years), and parental education (<12 years, 12 years, 13 to 15 years, 16 or more years).

Behavioral factors were classified as health-compromising, intentional injury, or drug use behaviors. The health-compromising behaviors included nonuse of seat belts and physical inactivity. Respondents to the NHIS-YRBS were asked, “How often do you wear a seat belt when riding in a car driven by someone else?” Response options were: “always,” “most of the time/sometimes,” and “rarely/never.” Physical activity was assessed by asking respondents, “On how many of the past 7 days did you exercise or participate in sports activities that made you sweat and breathe hard, such as basketball, jogging, fast dancing, swimming laps, tennis, fast bicycling, or similar aerobic activities?” Responses options were: “3 or more days,” “1 to 2 days”, and “0 days.”

The intentional injury behaviors included weapon carrying and physical fighting. The NHIS-YRBS assessed weapon carrying by asking respondents, “During the past 30 days, on how many days did you carry a weapon such as a gun, knife, or club?” Response options were “0 days,” “1 to 5 days,” and “6 or more days.” Physical fighting was measured by asking respondents, “During the past 12 months, how many times were you in a physical fight?” Response options were: “0 times,” “1 to 3 times,” and “4 or more times.”

The drug use behaviors included binge drinking, use of marijuana, and use of other illegal drugs. Binge drinking was assessed by asking respondents, “During the past 30 days, on how many days did you have 5 or more drinks of alcohol in a row, that is, within a couple of hours?” Response options were: “not during life,” “0 days,” 1 to 2 days,“ and ”3 or more days.“ Marijuana use was measured by asking respondents, ”During the past 30 days, how many times did you use marijuana?“ Response options were: ”not during life,“ ”0 times,“ and ”1 or more times.“

Other illegal drug use was determined by respondents' answers to two questions: “During your life, how many times have you used any form of cocaine, including powder, crack, or freebase?” and “During your life, how many times have you used any other type of illegal drug such as LSD, PCP, ecstasy, mushrooms, speed, ice, heroin, or pills without a doctor's prescription?” Those who answered “0 times” to both questions were considered never users; all others were considered ever users.

Statistical Analysis

First, weighted percentages were used to estimate the prevalence of current smoking among the two groups of adolescents. Then, logistic regression analysis⁸ was used to estimate the PORs of current smoking for white adolescents versus African-American adolescents before and after simultaneous adjustment for lifestyle behaviors and demographic factors. For the multivariate model, correlations among control variables were moderate and did not present problems of multicolinearity.^8,9 SUDAAN,¹⁰ a procedure for analyzing complex sample survey data, was used to calculate weighted percentages and their corresponding 95% confidence intervals and to estimate the PORs and their corresponding 95% confidence intervals.