Table 1

Baseline characteristics of included studies

Study name	Alternative name (if applicable)	Study design	Average age (years)	Gender % female	Curriculum intensity (sessions)	Curriculum duration (months, unless otherwise stated)	Curriculum deliverer	Control group type	Ethnicity (dominant)	Country
Armstrong et al (peer)10		C-RCT	12	49	5	6	Peers	No curriculum	NS	Australia
Armstrong et al (teacher)10		C-RCT	12	49	5	6	Teachers	No curriculum	NS	Australia
Ausems et al (in school)11		C-RCT	13	52	3×50 min	NS	Teachers	NS	NS	The Netherlands
Ausems et al (out school)11		C-RCT	13	52	NS	NS	Teachers	NS	NS	The Netherlands
Aveyard et al199912		C-RCT	13.5	50	6×1 h	12	Teachers	Usual practice	86% White	UK
Botvin and Eng 198013		C-RCT	13.5	NS	10	3	Outside specialists	No curriculum	White	USA
Botvin and Eng 198214		C-RCT	12.5	NS	12×1 h	3	Peers	No curriculum	90%+ White	USA
Botvin et al (LST intensive)15		C-RCT	12.5	NS	15	1	Teachers	Usual practice	91% White	USA
Botvin et al (LST)15		C-RCT	12.5	NS	15	3.5	Teachers	Usual practice	91% White	USA
Botvin et al16		C-RCT	11.5	100	15+ 10 boosters	NS	Teachers	10 sessions of information only, plus 3 boosters	60% African-American	USA
Brown et al17		C-RCT	13.5	50	NS	NS	Students and teachers	Usual practice	NS	Canada
Buller et al (Australia)18	Consider This	C-RCT	11 to 14	52	6×1 h	6	Web-based	Usual practice	73% Australian/European	Australia
Buller et al (USA)18	Consider This	C-RCT	11 to 13	52	6×1 h	6	Web-based	Usual practice	56% White	USA
Chou et al19		C-RCT	12.5	48	13×45 min	3	Health educators (USA)	Usual practice	NS	China
Coe et al20		C-RCT	12.5	NS	8	NS	Medical students	No curriculum	88%+ White	USA
Connell et al21	Adolescent Transitions Programme	C-RCT	11	47	6	2	Parent consultants	NS	42% White	USA
Conner and Higgins (I)22		C-RCT	11.5	50	NS	24	NS	Information and homework intentions	NS	UK
Crone et al23		C-RCT	10 to 12	53	6×1 h	24	Teachers	Usual practice	NS	The Netherlands
De Vries et al (High)24		C-RCT	12.5	NS	5×45 min	NS	Peers and teachers	NS	NS	The Netherlands
De Vries et al (Denmark)25	European Smoking Prevention Framework Approach	C-RCT	13	50	6×1 h	NS	Teachers	Usual practice	European	Denmark
De Vries et al (Finland)25	European Smoking Prevention Framework Approach	C-RCT	13	50	5×45 min	NS	Teachers	Usual practice	European	Finland
De Vries et al (Portugal)25	European Smoking Prevention Framework Approach	C-RCT	13	50	6	NS	Teachers	Usual practice	European	Portugal
De Vries et al (UK)25	European Smoking Prevention Framework Approach	C-RCT	13	50	50×30 min	NS	Teachers	Usual practice	European	UK
Denson and Stretch26		C-RCT	12 to 14	NS	3	24	Researcher	No curriculum	NS	Canada
Elder et al 199627	CATCH	C-RCT	10.5	51	4×50 min	NS	Teachers	No curriculum	71% White	USA
Ellickson and Bell (HealthEd)28	ALERT	C-RCT	13.5	48	8+3 booster	2	Community adults	No curriculum or usual practice	67% White	USA
Ellickson and Bell 1990 (Teen)28	ALERT	C-RCT	13.5	48	8+3 booster	2	Students	No curriculum or usual practice	67% White	USA
Ellickson et al29	ALERT	C-RCT	12.5	50	7+3	NS	Teachers	Usual practice	NS	USA
Ennett et al30	DARE	C-RCT	10.5	49	17×1 h	4	Uniformed police officer	NS	54% White	USA
Faggiano et al31	Unplugged	C-RCT	12 to 14	48	12×1 h	3	Teachers	Usual practice	NS	Austria, Belgium, Germany, Greece, Italy, Spain, Sweden
Figa-Talamanca and Modolo32		C-RCT	15 to 17	47	3	3 (days)	Health educators	No curriculum	NS	Italy
Gabrhelik et al33	Unplugged	C-RCT	11	50	12×45 min	12	Teachers	Usual practice	Czech	Czech Republic
Garcia et al 200534	ALERT	C-RCT	13	47	8×1 h	NS	Teachers	Usual practice	NS	Spain
Hort et al35		C-RCT	13	38	4×1–2 h + 15×1 h	24	Physicians and teachers	Physician talk on smoking if requested	NS	Germany
Howard et al36		C-RCT	10	46	5×40 min	NS	Teachers	NS	NS	USA
Johnson et al37	Acadiana Coalition of Teens against Tobacco	C-RCT	15	51	NS	30	Teachers	NS	61% White	USA
Kellam and Anthony (GBG)38	Good Behaviour Game	C-RCT	5.5	50	3× per week×10 min	24	Teachers	Usual practice	70% African-American	USA
La Torre et al (adolescents)39		C-RCT	14	52	NS	NS	Teachers	NS	NS	Italy
Luna-Adame et al40		C-RCT	11	51	21×1 h in year 1, 12×1 h in second year	24	Psychology students	Usual practice	NS	Spain
Nutbeam et al (FSE)41		C-RCT	11.5	43	3	NS	Teachers	No curriculum	NS	UK
Peterson et al 200042	Hutchinson Smoking Prevention Project	C-RCT	7 to 9	49	65	NS	Teachers	Usual practice	90% Caucasian	USA
Piper et al (HFL Age)43	Healthy for Life Project	C-RCT	14.5	52	58 (in 3×4-week periods)	36	Community adults	Usual practice	92%+ White	USA
Piper et al (HFL)43	Healthy for Life Project	C-RCT	14.5	52	54	12	Community adults	Usual practice	92%+ White	USA
Prokhorov et al44	A Smoking Prevention Interactive Experience	C-RCT	16	59	5×30 min+2 boosters	NS	Computer	Usual practice	51% Hispanic	USA
Resnicow et al (Harm Min)45	Keep Left	C-RCT	14	50	8	24	Teachers	Usual practice	60% Black	South Africa
Resnicow et al (LST)45	Life Skills Training	C-RCT	14	50	8	24	Teachers	Usual practice	60% Black	South Africa
Ringwalt et al46	ALERT	C-RCT	11	52	11×45 min+3 boosters	24	Teachers	No curriculum	53% White	USA
Schulze et al47	Be smart—don’t start	C-RCT	12	50	NS	NS	Teachers	No curriculum	NS	Germany
Seal48		C-RCT	15.5	11	10×1 h	NS	NS	Usual practice	Thai	Thailand
Simons-Morton et al49	Going Places	C-RCT	11	57	18	36	Teachers	NS	72% White	USA
Spoth et al (ISFP)50	Iowa Strengthening Families Program	C-RCT	11	55	7	1 (day)	Project staff	4 mailed booklets on changes in adolescents	NS	USA
Spoth et al (PDFY)50	Preparing for the Drug Free Years Program	C-RCT	11	55	5	NS	Project staff	4 mailed booklets on changes in adolescents	NS	USA
Spoth et al (LST + SFP)51	SFP 10	C-RCT	12.5	45	7×1 h + 4 boosters	1 (day) + boosters 1 yr later	Project staff and teachers	NS	95%+ White	USA
Spoth et al (LST)51	SFP 10	C-RCT	12.5	45	15×45 min	NS	Project staff and teachers	NS	95%+ White	USA
Storr et al52		C-RCT	5.7	47	NS	NS	Teachers	Usual practice	86% African-American	USA
Telch et al (no peers)53		C-RCT	12	47	5	0.75	Teachers	No curriculum	24% White	USA
Telch 1990 (peers)53		C-RCT	12	47	5	0.75	Peers	No curriculum	24% White	USA
Unger et al (CHIPS)54	Choosing Healthy Influences for a Positive Self	C-RCT	11	54	NS	NS	Health educators	Usual practice	61% Hispanic	USA
Unger et al (FLAVOR)54	Fun Learning About Vitality, Origins and Respect	C-RCT	11	54	NS	NS	Health educators	Usual practice	58% Hispanic	USA
Valente et al55	Project Towards No Drug Abuse	C-RCT	16	38	12	3–4-weeks	Peers	Usual practice	72% Hispanic/Latino	USA
Van Lier et al56	Good Behaviour Game	C-RCT	7	48	3× per week×10 min	NS	Teachers	No curriculum	69% Dutch descent	The Netherlands
Walter et al57	Know your Body	C-RCT	9	47	2 per week	12	Teachers	Information	84% White	USA
Weichold et al (peer)58	Life Skills Training	C-RCT	11	44	10×90 min, 5× 45 min+boosters	NS	Peers	Produced student newspaper	German	Germany
Weichold et al (teacher)58	Life Skills Training	C-RCT	11	44	10×90 min 5×45 min + boosters	NS	Teachers	Produced student newspaper	German	Germany
Wen et al59		C-RCT	13	46	NS	18	School nurses and health educators	Usual practice	NS	China

C-RCT, cluster randomised controlled trial; NS, not stated.