TABLE 1

Sample Characteristics Among All Baseline Respondents, Baseline Respondents With Follow-up, and Baseline Respondents Without Follow-up

VariableNAll Baseline Respondents (N = 13 651)Baseline Respondents With Follow-up (N = 11 996)Baseline Respondents Without Follow-up (N = 1655)P
Prevalence, % (95% CI)Prevalence, % (95% CI)Prevalence, % (95% CI)
Age group, y
 12–14699750.4 (49.6–51.3)51.0 (50.0–51.9)46.7 (44.2–49.3).001
 15–17665349.6 (48.7–50.4)49.0 (48.1–50.0)53.3 (50.7–55.8).001
Sex
 Female665748.7 (47.8–49.6)48.7 (47.8––49.7)48.4 (45.8–51.0).80
 Male699351.3 (50.4–52.2)51.3 (50.3–52.2)51.6 (49.0–54.2).80
Race and/or ethnicity
 Non-Hispanic white661454.5 (53.7–55.4)54.6 (53.7–55.5)54.2 (51.7–56.8).78
 Hispanic392022.3 (21.6–22.9)22.4 (21.7–23.1)21.4 (19.5–23.2).33
 Non-Hispanic African American185913.9 (13.3–14.5)13.9 (13.2–14.5)14.0 (12.2–15.8).86
 Non-Hispanic other12579.3 (8.7–9.8)9.1 (8.6–9.7)10.4 (8.6–12.1).12
Parental education
 At least some college814763.9 (63.0–64.7)64.4 (63.5–65.3)60.4 (57.9–62.9).002
 High school graduate257018.1 (17.4–18.8)17.8 (17.0–18.5)20.5 (18.5–22.6).009
 Less than high school283418.0 (17.4–18.7)17.9 (17.2–18.6)19.1 (17.1–21.0).26
Weekly income
 None or <$1493137.0 (36.1–37.8)37.2 (36.3–38.1)35.3 (32.9–37.8).14
 $1–$20569641.6 (40.7–42.5)42.0 (41.1–42.9)39.1 (36.6–41.7).03
 $21–$50140610.5 (9.9–11.0)10.3 (9.7–10.9)11.8 (10.1–13.4).08
 $51+142910.9 (10.4–11.5)10.5 (9.9–11.1)13.8 (12.0–15.5)<.001
School performance
 Mostly As335926.5 (25.7–27.3)27.1 (26.2–27.9)22.6 (20.4–24.8)<.001
 As and Bs464133.8 (33.0–34.7)33.8 (32.9–34.7)34.3 (31.8–36.7).69
 Mostly Bs11868.8 (8.3–9.3)8.7 (8.2–9.3)9.0 (7.5–10.5).71
 Bs and Cs259618.3 (17.6–19.0)18.1 (17.3–18.8)19.8 (17.8–21.9).09
 Mostly Cs to mostly Fs172112.0 (11.4–12.5)11.8 (11.2–12.4)13.4 (11.7–15.1).07
 School ungraded800.6 (0.5–0.8)0.6 (0.4–0.7)1.0 (0.4–1.5).14
Internet access
 Several times a day832462.2 (61.3–63.0)62.2 (61.3–63.2)61.7 (59.2–64.2).68
 Approximately once a d200515.0 (14.3–15.6)15.1 (14.4–15.8)14.0 (12.2–15.8).23
 3–5 d a wk13089.3 (8.8–9.8)9.4 (8.8–9.9)8.9 (7.5–10.3).53
 1–2 d a wk5513.9 (3.6–4.3)3.9 (3.5–4.2)4.2 (3.2–5.2).58
 Less than once a wk14159.6 (9.1–10.1)9.4 (8.9–9.9)11.2 (9.6–12.8).03
Social networking account use
 Several times a day445234.6 (33.8–35.5)34.4 (33.5––35.3)36.3 (33.7–38.8).15
 Daily372528.6 (27.7–29.4)28.8 (27.9–29.7)26.9 (24.6–29.3).12
 Weekly159312.2 (11.6–12.8)12.4 (11.7–13.0)11.1 (9.4–12.8).13
 Monthly or less319324.6 (23.8–25.4)24.4 (23.6–25.3)25.7 (23.4–28.1).27
Use smartphone
 No414430.2 (29.3–31.0)30.7 (29.8–31.5)26.6 (24.3–28.9)<.001
 Yes947069.8 (69.0–70.7)69.3 (68.5–70.2)73.4 (71.1–75.7)<.001
Sensation seeking
 Low456333.3 (32.5–34.2)33.2 (32.3–34.1)34.5 (32.1–37.0).28
 Moderate522838.4 (37.5–39.3)38.3 (37.4––39.2)39.1 (36.6–41.6).54
 High384428.2 (27.4–29.0)28.5 (27.6–29.4)26.4 (24.1–28.6).07
Internalizing problems
 Low506837.1 (36.3–38.0)36.6 (35.7–37.6)40.5 (37.9–43.0).003
 Moderate409229.9 (29.1–30.8)30.0 (29.1–30.8)29.8 (27.4–32.1).87
 High449132.9 (32.1–33.8)33.4 (32.5–34.3)29.8 (27.4–32.1).003
Externalizing problems
 Low367226.5 (25.7–27.3)25.9 (25.1–26.7)30.6 (28.3–33.0)<.001
 Moderate373127.4 (26.6–28.2)27.2 (26.3–28.0)28.9 (26.5–31.2).16
 High624846.1 (45.2–47.0)46.9 (46.0–47.9)40.5 (38.0–43.0)<.001
Currently lives with a tobacco user
 No870965.4 (64.6–66.3)65.7 (64.8–66.6)63.5 (61.0–66.0).08
 Yes482734.6 (33.7–35.4)34.3 (33.4–35.2)36.5 (34.0–39.0).08
Exposure to tobacco coupons by mail
 No13 07995.9 (95.6–96.3)95.8 (95.4–96.1)97.1 (96.2–97.9).004
 Yes5724.1 (3.7–4.4)4.2 (3.9–4.6)2.9 (2.1–3.8).004
Exposure to other tobacco information by mail
 No13 48898.8 (98.7–99.0)98.9 (98.7–99.1)98.7 (98.1–99.3).52
 Yes1631.2 (1.0–1.3)1.1 (0.9–1.3)1.3 (0.7–1.9).52
Other substance use
 011 49684.2 (83.6–84.8)84.2 (83.6–84.9)83.9 (82.0–85.8).72
 1170812.5 (11.9–13.1)12.3 (11.7–13.0)13.7 (12.0–15.5).13
 2+4473.3 (3.0–3.6)3.4 (3.1–3.8)2.4 (1.7–3.1).01
Online engagement
 No12 02488.2 (87.6–88.7)88.0 (87.4–88.7)89.0 (87.4–90.6).24
 Yes162711.8 (11.3–12.4)12.0 (11.3–12.6)11.0 (9.4–12.6).24
Tobacco use status
 Tobacco never-users10 24678.2 (77.4–78.9)78.6 (77.8–79.4)75.3 (73.1–77.6).005
 Tobacco ever-users286821.8 (21.1–22.6)21.4 (20.6–22.2)24.7 (22.4–26.9).005
 Past-y single product users9366.9 (6.5–7.4)6.7 (6.3–7.2)8.0 (6.6–9.4).07
 Past-y tobacco users217516.1 (15.4–16.7)15.7 (15.0–16.4)18.3 (16.4–20.3).01