TABLE 3

Rates of Self-Reported Alcohol and Cannabis Use, Initiation, and Cessation at Baseline and 3- and 12-mo Follow-up Visits

Any Past-90-Day Use at 3-Month Follow-up
New EnglandPrague, Czech Republic
NTAU n (%) (n = 755)cSBA n (%) (n = 761)aRRRa,c (95% CI)NTAU n (%) (n = 245)cSBA n (%) (n = 271)aRRRa,c (95% CI)
Alcohol
 Baseline1516155 (20.5)122 (16.0)0.77 (0.56–1.05)516113 (46.1)129 (47.6)1.00 (0.80–1.25)
 3 Months1515d173 (22.9)118 (15.5)0.54 (0.38–0.77)e516127 (51.8)126 (46.5)0.82 (0.63–1.06)
   Initiationb106630 (5.9)17 (3.1)0.64 (0.32–1.28)19810 (11.4)13 (11.8)0.96 (0.42–2.21)
   Cessationb450101 (41.4)104 (50.7)1.49 (1.17–1.91)e31840 (25.5)48 (29.8)1.54 (0.99–2.38)
Cannabisa
 Baseline151662 (8.2)62 (8.1)1.25 (0.79–1.95)51616 (6.5)14 (5.2)0.74 (0.35–1.54)
 3 Months1515d72 (9.5)56 (7.4)0.68 (0.40–1.15)51624 (9.8)15 (5.5)0.37 (0.17–0.77)e
   Initiationb130915 (2.3)8 (1.2)0.45 (0.18–1.11)4428 (3.8)2 (0.9)0.22 (0.05–1.04)
   Cessationb20650 (46.7)51 (51.5)1.00 (0.72–1.40)7416 (50.0)29 (69.0)1.50 (0.97–2.32)
Any Past-12-Month Use at 12-Month Follow-up
New EnglandPrague, Czech Republic
NTAU n (%) (n = 758)cSBA n (%) (n = 765)aRRRa,c (95% CI)NTAU n (%) (n = 266)cSBA n (%) (n = 264)aRRRa,c (95% CI)
Alcohol
 Baseline1523240 (31.7)194 (25.4)0.82 (0.64–1.06)530163 (61.3)153 (58.0)0.89 (0.76–1.03)
 12 Months1523284 (37.5)224 (29.3)0.73 (0.57–0.92)e530199 (74.8)185 (70.1)0.96 (0.86–1.04)
   Initiationb108992 (17.8)68 (11.9)0.66 (0.47–0.93)e21635 (43.7)37 (33.3)0.76 (0.53–1.08)
   Cessationb43448 (20.0)38 (19.6)1.50 (0.93–2.42)3169 (5.5)5 (3.3)1.18 (0.37–3.73)
Cannabis
 Baseline1522f101 (13.3)95 (12.4)0.77 (0.56–1.05)529f36 (13.6)38 (14.4)1.02 (0.63–1.64)
 12 Months1522f133 (17.5)119 (15.6)0.85 (0.61–1.19)529f76 (28.7)45 (17.0)0.47 (0.32–0.71)e
   Initiationb132658 (8.8)52 (7.8)0.81 (0.54–1.21)45847 (20.5)22 (9.7)0.47 (0.29–0.76)e
   Cessationb19627 (26.7)28 (29.5)1.01 (0.57–1.78)747 (19.4)15 (39.5)2.53 (1.06–6.05)e
  • a New England logistic models for both 3- and 12-month outcomes adjusted for the multisite sampling design; baseline past-12-month substance use; age; gender; parent education level; type of visit (well visit or other); perceived parent, sibling, and peer substance use; provider gender; and connectedness to provider. Prague models adjusted for the multisite sampling design, baseline past-12-month substance use, age, and gender.

  • b “Initiation” models analyzed only participants reporting no past-12-month use at baseline, whereas “cessation” models included only those reporting any past-12-month use at baseline. New England and Prague models adjusted for the same variables listed in footnote a, excluding baseline substance use, which is already accounted for by the stratified analyses.

  • c aRRRs with TAU as the reference group.

  • d There were missing data for 1 respondent each in 3-month New England alcohol use (cSBA) and cannabis use (TAU).

  • e P < .05.

  • f There were missing data for 1 respondent each in 12-month marijuana use for New England and Prague TAU groups.